From thoyer1 at verizon.net Mon Jan 1 10:59:21 2018 From: thoyer1 at verizon.net (thoyer) Date: Mon, 1 Jan 2018 10:59:21 -0500 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto Message-ID: <85F741CC6AD349C6B042800E2FEFFD62@TomHP> I'm getting ready to start working on an R-274 that I picked up this past fall. A quick survey of the internals shows that many of the capacitors show evidence of decay (cracking) and the resistors I did a quick measurements on are out of tolerance. First order of business will be a complete disassembly and cleaning (it is pretty dirty and smelly.....). Then replace any out of spec parts, reassemble and see how it plays. It is mostly original from what I can tell with the exception of a replacement 455kc crystal. Looking for advice from those who have "been there, done that" with one of these radios before. What should I look out for - what parts are typical troublemakers, etc....... Just finished an overhaul on an R-390A that came out well and have been tinkering with these boat anchors for many years so I have some experience and a bunch of test equipment. Never been inside one if these so looking for advice. Regards, Tom W3TA From joeconnor53 at yahoo.com Mon Jan 1 11:06:34 2018 From: joeconnor53 at yahoo.com (Joe Connor) Date: Mon, 1 Jan 2018 16:06:34 +0000 (UTC) Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: <85F741CC6AD349C6B042800E2FEFFD62@TomHP> References: <85F741CC6AD349C6B042800E2FEFFD62@TomHP> Message-ID: <1324716311.7114924.1514822794759@mail.yahoo.com> Tom, here's a pretty good write-up from the Radio Boulevard site: http://www.radioblvd.com/R-274%20Receiver.htm ????????Joe Connor On Monday, January 1, 2018 11:00 AM, thoyer wrote: I'm getting ready to start working on an R-274 that I picked up this past fall. A quick survey of the internals shows that many of the capacitors show evidence of decay (cracking) and the resistors I did a quick measurements on are out of tolerance. First order of business will be a complete disassembly and cleaning (it is pretty dirty and smelly.....). Then replace any out of spec parts, reassemble and see how it plays. It is mostly original from what I can tell with the exception of a replacement 455kc crystal. Looking for advice from those who have "been there, done that" with one of these radios before. What should I look out for - what parts are typical troublemakers, etc....... Just finished an overhaul on an R-390A that came out well and have been tinkering with these boat anchors for many years so I have some experience and a bunch of test equipment. Never been inside one if these so looking for advice. Regards, Tom W3TA ______________________________________________________________ Hallicrafters mailing list Home: http://mailman.qth.net/mailman/listinfo/hallicrafters Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Hallicrafters at mailman.qth.net List Administrator: Duane Fischer, W8DBF ** For Assistance: dfischer at usol.com ** This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html | | Virus-free. www.avast.com | From pincon at erols.com Mon Jan 1 11:42:10 2018 From: pincon at erols.com (Charlie T) Date: Mon, 1 Jan 2018 11:42:10 -0500 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: <85F741CC6AD349C6B042800E2FEFFD62@TomHP> References: <85F741CC6AD349C6B042800E2FEFFD62@TomHP> Message-ID: <006901d3831f$7b68d8d0$723a8a70$@erols.com> Along with the usual capacitor suspects, carefully check all those low value resistors in the IF strip. Basically, the tuned circuit bandwidth of the IF is around 2 - 3 kHz which is fine for SSB. Various broadening low ? shunt resistors and/or coupling coils are used to widen the bandwidth in steps. I just did two of these radios and ALL of those resistors were WAY off in value, some measuring 3 X their nominal value. With those higher than spec resistors in place, the bandwidth is never widened as far as it was designed to be. Also, the S-meter & AGC circuit must have been designed by a team of Boris Karloff & Bela Lugosi. I never could get it all to work right after screwing with it for many hours. I used a beautiful circuit * board from TREE-TOP circuits in Canada (Where they have STRONGER Beer) to drive the AGC & S-Meter as well as provide great sounding SSB AND AM detection. Another minor suggestion is to change out the audio output transformer for one that allows direct connection of a 4 or 8? speaker, but this isn't all that necessary, just a slight convenience. I am in the process of writing a restoration article describing all that I did. I will be selling one of these radios and will keep the other. They both are in about the same condition. 73, Charlie k3ICH *A TREE-TOP CIRCUITS "SB-75" was used with a few slight mods to the board for the SX-73. This circuit board is designed to almost be a plug & play mod for the Collins 75A-2 & 3. I have used it for the Collins and it works great, so after many conversations with Bob at Tree-Top, I decided to give it a try for the Hallicrafters. I am very happy with how it turned out AND Bob's advice was priceless too. A very nicely done board AND a clever design. -----Original Message----- From: hallicrafters-bounces at mailman.qth.net [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of thoyer Sent: Monday, January 01, 2018 10:59 AM To: hallicrafters at mailman.qth.net Subject: [Hallicrafters] SX-73 / R-274 Starting Resto I'm getting ready to start working on an R-274 that I picked up this past fall. A quick survey of the internals shows that many of the capacitors show evidence of decay (cracking) and the resistors I did a quick measurements on are out of tolerance. First order of business will be a complete disassembly and cleaning (it is pretty dirty and smelly.....). Then replace any out of spec parts, reassemble and see how it plays. It is mostly original from what I can tell with the exception of a replacement 455kc crystal. Looking for advice from those who have "been there, done that" with one of these radios before. What should I look out for - what parts are typical troublemakers, etc....... Just finished an overhaul on an R-390A that came out well and have been tinkering with these boat anchors for many years so I have some experience and a bunch of test equipment. Never been inside one if these so looking for advice. Regards, Tom W3TA ______________________________________________________________ Hallicrafters mailing list Home: http://mailman.qth.net/mailman/listinfo/hallicrafters Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Hallicrafters at mailman.qth.net List Administrator: Duane Fischer, W8DBF ** For Assistance: dfischer at usol.com ** This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html From thoyer1 at verizon.net Mon Jan 1 14:46:11 2018 From: thoyer1 at verizon.net (thoyer) Date: Mon, 1 Jan 2018 14:46:11 -0500 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: <006901d3831f$7b68d8d0$723a8a70$@erols.com> References: <85F741CC6AD349C6B042800E2FEFFD62@TomHP> <006901d3831f$7b68d8d0$723a8a70$@erols.com> Message-ID: <602200306CDF42E1855CBDE930E59129@TomHP> Hi Charlie, Well you helped me with my 51S-1's and now the R-274 - one stop shop for advice! Thanks. I'd be interested in the write up you are doing from your overhaul experiences. I have a couple other radios waiting in the wings for some attention that may be easier then the R-274 (RCA CR-88A and a very early SP-600) but I'm drawn to the R-274 right now. Both of these had been gon over before by previous owners but I'm always leary of others work and will walk through each to bring them up to snuff. This R-274 appears to be all original. Looking through the parts list I see that a lot of the pF capacitors are shown as being ceramic dielectric, I'm surprised they are not mica. Will there be any issue replacing them with mylar or mica if needed? I will look into the Tree Top Circuits board - but that is probably at least a month away - lots to do first. If anyone has interest, I'll be uploading some pictures to my website later today www.thdesignsinc.com/r-274.html Tom W3TA -----Original Message----- From: hallicrafters-bounces at mailman.qth.net [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of Charlie T Sent: Monday, January 01, 2018 11:42 AM To: hallicrafters at mailman.qth.net Subject: Re: [Hallicrafters] SX-73 / R-274 Starting Resto Along with the usual capacitor suspects, carefully check all those low value resistors in the IF strip. Basically, the tuned circuit bandwidth of the IF is around 2 - 3 kHz which is fine for SSB. Various broadening low ? shunt resistors and/or coupling coils are used to widen the bandwidth in steps. I just did two of these radios and ALL of those resistors were WAY off in value, some measuring 3 X their nominal value. With those higher than spec resistors in place, the bandwidth is never widened as far as it was designed to be. Also, the S-meter & AGC circuit must have been designed by a team of Boris Karloff & Bela Lugosi. I never could get it all to work right after screwing with it for many hours. I used a beautiful circuit * board from TREE-TOP circuits in Canada (Where they have STRONGER Beer) to drive the AGC & S-Meter as well as provide great sounding SSB AND AM detection. Another minor suggestion is to change out the audio output transformer for one that allows direct connection of a 4 or 8? speaker, but this isn't all that necessary, just a slight convenience. I am in the process of writing a restoration article describing all that I did. I will be selling one of these radios and will keep the other. They both are in about the same condition. 73, Charlie k3ICH *A TREE-TOP CIRCUITS "SB-75" was used with a few slight mods to the board for the SX-73. This circuit board is designed to almost be a plug & play mod for the Collins 75A-2 & 3. I have used it for the Collins and it works great, so after many conversations with Bob at Tree-Top, I decided to give it a try for the Hallicrafters. I am very happy with how it turned out AND Bob's advice was priceless too. A very nicely done board AND a clever design. -----Original Message----- From: hallicrafters-bounces at mailman.qth.net [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of thoyer Sent: Monday, January 01, 2018 10:59 AM To: hallicrafters at mailman.qth.net Subject: [Hallicrafters] SX-73 / R-274 Starting Resto I'm getting ready to start working on an R-274 that I picked up this past fall. A quick survey of the internals shows that many of the capacitors show evidence of decay (cracking) and the resistors I did a quick measurements on are out of tolerance. First order of business will be a complete disassembly and cleaning (it is pretty dirty and smelly.....). Then replace any out of spec parts, reassemble and see how it plays. It is mostly original from what I can tell with the exception of a replacement 455kc crystal. Looking for advice from those who have "been there, done that" with one of these radios before. What should I look out for - what parts are typical troublemakers, etc....... Just finished an overhaul on an R-390A that came out well and have been tinkering with these boat anchors for many years so I have some experience and a bunch of test equipment. Never been inside one if these so looking for advice. Regards, Tom W3TA ______________________________________________________________ Hallicrafters mailing list Home: http://mailman.qth.net/mailman/listinfo/hallicrafters Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Hallicrafters at mailman.qth.net List Administrator: Duane Fischer, W8DBF ** For Assistance: dfischer at usol.com ** This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Hallicrafters mailing list Home: http://mailman.qth.net/mailman/listinfo/hallicrafters Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Hallicrafters at mailman.qth.net List Administrator: Duane Fischer, W8DBF ** For Assistance: dfischer at usol.com ** This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html From thoyer1 at verizon.net Mon Jan 1 14:58:01 2018 From: thoyer1 at verizon.net (thoyer) Date: Mon, 1 Jan 2018 14:58:01 -0500 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: <602200306CDF42E1855CBDE930E59129@TomHP> References: <85F741CC6AD349C6B042800E2FEFFD62@TomHP><006901d3831f$7b68d8d0$723a8a70$@erols.com> <602200306CDF42E1855CBDE930E59129@TomHP> Message-ID: <914BFAD7D6CC4C3D8441525D399E9696@TomHP> Corrected the link - sorry http://www.thdesignsinc.com/R-274.html -----Original Message----- From: hallicrafters-bounces at mailman.qth.net [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of thoyer Sent: Monday, January 01, 2018 2:46 PM To: 'Charlie T'; hallicrafters at mailman.qth.net Subject: Re: [Hallicrafters] SX-73 / R-274 Starting Resto Hi Charlie, Well you helped me with my 51S-1's and now the R-274 - one stop shop for advice! Thanks. I'd be interested in the write up you are doing from your overhaul experiences. I have a couple other radios waiting in the wings for some attention that may be easier then the R-274 (RCA CR-88A and a very early SP-600) but I'm drawn to the R-274 right now. Both of these had been gon over before by previous owners but I'm always leary of others work and will walk through each to bring them up to snuff. This R-274 appears to be all original. Looking through the parts list I see that a lot of the pF capacitors are shown as being ceramic dielectric, I'm surprised they are not mica. Will there be any issue replacing them with mylar or mica if needed? I will look into the Tree Top Circuits board - but that is probably at least a month away - lots to do first. If anyone has interest, I'll be uploading some pictures to my website later today www.thdesignsinc.com/r-274.html Tom W3TA -----Original Message----- From: hallicrafters-bounces at mailman.qth.net [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of Charlie T Sent: Monday, January 01, 2018 11:42 AM To: hallicrafters at mailman.qth.net Subject: Re: [Hallicrafters] SX-73 / R-274 Starting Resto Along with the usual capacitor suspects, carefully check all those low value resistors in the IF strip. Basically, the tuned circuit bandwidth of the IF is around 2 - 3 kHz which is fine for SSB. Various broadening low ? shunt resistors and/or coupling coils are used to widen the bandwidth in steps. I just did two of these radios and ALL of those resistors were WAY off in value, some measuring 3 X their nominal value. With those higher than spec resistors in place, the bandwidth is never widened as far as it was designed to be. Also, the S-meter & AGC circuit must have been designed by a team of Boris Karloff & Bela Lugosi. I never could get it all to work right after screwing with it for many hours. I used a beautiful circuit * board from TREE-TOP circuits in Canada (Where they have STRONGER Beer) to drive the AGC & S-Meter as well as provide great sounding SSB AND AM detection. Another minor suggestion is to change out the audio output transformer for one that allows direct connection of a 4 or 8? speaker, but this isn't all that necessary, just a slight convenience. I am in the process of writing a restoration article describing all that I did. I will be selling one of these radios and will keep the other. They both are in about the same condition. 73, Charlie k3ICH *A TREE-TOP CIRCUITS "SB-75" was used with a few slight mods to the board for the SX-73. This circuit board is designed to almost be a plug & play mod for the Collins 75A-2 & 3. I have used it for the Collins and it works great, so after many conversations with Bob at Tree-Top, I decided to give it a try for the Hallicrafters. I am very happy with how it turned out AND Bob's advice was priceless too. A very nicely done board AND a clever design. -----Original Message----- From: hallicrafters-bounces at mailman.qth.net [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of thoyer Sent: Monday, January 01, 2018 10:59 AM To: hallicrafters at mailman.qth.net Subject: [Hallicrafters] SX-73 / R-274 Starting Resto I'm getting ready to start working on an R-274 that I picked up this past fall. A quick survey of the internals shows that many of the capacitors show evidence of decay (cracking) and the resistors I did a quick measurements on are out of tolerance. First order of business will be a complete disassembly and cleaning (it is pretty dirty and smelly.....). Then replace any out of spec parts, reassemble and see how it plays. It is mostly original from what I can tell with the exception of a replacement 455kc crystal. Looking for advice from those who have "been there, done that" with one of these radios before. What should I look out for - what parts are typical troublemakers, etc....... Just finished an overhaul on an R-390A that came out well and have been tinkering with these boat anchors for many years so I have some experience and a bunch of test equipment. Never been inside one if these so looking for advice. Regards, Tom W3TA ______________________________________________________________ Hallicrafters mailing list Home: http://mailman.qth.net/mailman/listinfo/hallicrafters Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Hallicrafters at mailman.qth.net List Administrator: Duane Fischer, W8DBF ** For Assistance: dfischer at usol.com ** This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Hallicrafters mailing list Home: http://mailman.qth.net/mailman/listinfo/hallicrafters Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Hallicrafters at mailman.qth.net List Administrator: Duane Fischer, W8DBF ** For Assistance: dfischer at usol.com ** This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Hallicrafters mailing list Home: http://mailman.qth.net/mailman/listinfo/hallicrafters Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Hallicrafters at mailman.qth.net List Administrator: Duane Fischer, W8DBF ** For Assistance: dfischer at usol.com ** This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html From wf2u at ws19ops.com Mon Jan 1 15:43:04 2018 From: wf2u at ws19ops.com (WF2U) Date: Mon, 01 Jan 2018 15:43:04 -0500 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: <85F741CC6AD349C6B042800E2FEFFD62@TomHP> References: <85F741CC6AD349C6B042800E2FEFFD62@TomHP> Message-ID: <1b49d881-92b2-4576-9040-b7aae5621820@ws19ops.com> The only problem I ever had with my R-274 a.k.a. SX-73, which I've owned for more than 20 years, was the shorted audio output tube cathode bypass "bathtub" electrolytic capacitor. The cathode resistor is within 10 percent of its rated value, so it couldn't have been subject to high voltage surge. The receiver is still working great, with no issues. Luckily, otherwise it is completely original and was never modified. 73, Meir WF2U SC ?Sent from BlueMail ? On Jan 1, 2018, 10:59 AM, at 10:59 AM, thoyer wrote: >I'm getting ready to start working on an R-274 that I picked up this >past >fall. A quick survey of the internals shows that many of the capacitors >show >evidence of decay (cracking) and the resistors I did a quick >measurements on >are out of tolerance. > >First order of business will be a complete disassembly and cleaning (it >is >pretty dirty and smelly.....). Then replace any out of spec parts, >reassemble and see how it plays. It is mostly original from what I can >tell >with the exception of a replacement 455kc crystal. > >Looking for advice from those who have "been there, done that" with one >of >these radios before. What should I look out for - what parts are >typical >troublemakers, etc....... > >Just finished an overhaul on an R-390A that came out well and have been >tinkering with these boat anchors for many years so I have some >experience >and a bunch of test equipment. Never been inside one if these so >looking for >advice. > >Regards, > >Tom >W3TA >______________________________________________________________ >Hallicrafters mailing list >Home: http://mailman.qth.net/mailman/listinfo/hallicrafters >Help: http://mailman.qth.net/mmfaq.htm >Post: mailto:Hallicrafters at mailman.qth.net > >List Administrator: Duane Fischer, W8DBF >** For Assistance: dfischer at usol.com ** > > >This list hosted by: http://www.qsl.net >Please help support this email list: http://www.qsl.net/donate.html From 1oldlens1 at ix.netcom.com Mon Jan 1 16:11:31 2018 From: 1oldlens1 at ix.netcom.com (Richard Knoppow) Date: Mon, 1 Jan 2018 13:11:31 -0800 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: <602200306CDF42E1855CBDE930E59129@TomHP> References: <85F741CC6AD349C6B042800E2FEFFD62@TomHP> <006901d3831f$7b68d8d0$723a8a70$@erols.com> <602200306CDF42E1855CBDE930E59129@TomHP> Message-ID: <8f6e44ea-1a0c-2dd7-5155-f1245990564d@ix.netcom.com> I am not sure what capacitors Hallicrafters used in the R-274. It was intended to be their version of the SP-600-JX. I think by the time it was built the problems with the infamous Sprague Black Beauty caps were known. That resulted in a military work order requiring all paper caps in the SP-600 to be replaced with disc ceramics. Hammarlund also began using disc ceramics in its other receivers. Have a look and see whats in the R-274, if it has either disc or dog-bone ceramics leave them alone unless there are symptoms of one being bad. There may also be temperature compensating ceramics in the rig, they are usually tubular ceramics. There is only one in the SP-600. The AR-88 has many dog-bone TC ceramics in the RF section, also almost always good. RCA compensated nearly all of the RF tuned circuits. The Western Historic Radio site has material on the R-274 and I think an article comparing it to the SP-600. There is also a good article on the AR-88 family. I had to replace all the bathtub paper caps in my AR-88 because the seals around the terminals had disintegrated and the oil leaked out. A mess. The paper filter cap is still good! The AR-88 has no electrolytic caps in it. Some of the war-time receivers have Micamold or Solar flat paper caps in the RF section. They will all be bad and should be replaced with polyprolylene plastic caps. The older versions had RCA-made mica caps, which are odd lozenge shaped things, they also will usually be OK. The R-274 had a current regulator on the oscillator and mixer filaments. The regulators are getting hard to come by. National did the same thing on the HRO Sixty. They do help stabilize the receiver when there are line voltage variations. Hallicrafters is notorious for drifting resistors (also National). As a rule of thumb any carbon composition resistor, in any receiver, over about 100K will have gone up in value and should be checked but some lower value ones will also have drifted. Good luck, these are supposed to be somewhat difficult receivers to work on but are good enough to justify the work. On 1/1/2018 11:46 AM, thoyer wrote: > Hi Charlie, > > Well you helped me with my 51S-1's and now the R-274 - one stop shop for > advice! Thanks. > > I'd be interested in the write up you are doing from your overhaul > experiences. > > I have a couple other radios waiting in the wings for some attention that > may be easier then the R-274 (RCA CR-88A and a very early SP-600) but I'm > drawn to the R-274 right now. Both of these had been gon over before by > previous owners but I'm always leary of others work and will walk through > each to bring them up to snuff. This R-274 appears to be all original. > > Looking through the parts list I see that a lot of the pF capacitors are > shown as being ceramic dielectric, I'm surprised they are not mica. Will > there be any issue replacing them with mylar or mica if needed? > > I will look into the Tree Top Circuits board - but that is probably at least > a month away - lots to do first. > > If anyone has interest, I'll be uploading some pictures to my website later > today www.thdesignsinc.com/r-274.html > > > Tom > W3TA > > > > -----Original Message----- > From: hallicrafters-bounces at mailman.qth.net > [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of Charlie T > Sent: Monday, January 01, 2018 11:42 AM > To: hallicrafters at mailman.qth.net > Subject: Re: [Hallicrafters] SX-73 / R-274 Starting Resto > > Along with the usual capacitor suspects, carefully check all those low value > resistors in the IF strip. > Basically, the tuned circuit bandwidth of the IF is around 2 - 3 kHz which > is fine for SSB. > > Various broadening low ? shunt resistors and/or coupling coils are used to > widen the bandwidth in steps. > I just did two of these radios and ALL of those resistors were WAY off in > value, some measuring 3 X their nominal value. > With those higher than spec resistors in place, the bandwidth is never > widened as far as it was designed to be. > > Also, the S-meter & AGC circuit must have been designed by a team of Boris > Karloff & Bela Lugosi. > I never could get it all to work right after screwing with it for many > hours. > > I used a beautiful circuit * board from TREE-TOP circuits in Canada (Where > they have STRONGER Beer) to drive the AGC & S-Meter as well as provide great > sounding SSB AND AM detection. > > Another minor suggestion is to change out the audio output transformer for > one that allows direct connection of a 4 or 8? speaker, but this isn't all > that necessary, just a slight convenience. > > I am in the process of writing a restoration article describing all that I > did. I will be selling one of these radios and will keep the other. They > both are in about the same condition. > > 73, Charlie k3ICH > > *A TREE-TOP CIRCUITS "SB-75" was used with a few slight mods to the board > for the SX-73. > This circuit board is designed to almost be a plug & play mod for the > Collins 75A-2 & 3. > I have used it for the Collins and it works great, so after many > conversations with Bob at Tree-Top, I decided to give it a try for the > Hallicrafters. > I am very happy with how it turned out AND Bob's advice was priceless too. A > very nicely done board AND a clever design. > > > -----Original Message----- > From: hallicrafters-bounces at mailman.qth.net > [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of thoyer > Sent: Monday, January 01, 2018 10:59 AM > To: hallicrafters at mailman.qth.net > Subject: [Hallicrafters] SX-73 / R-274 Starting Resto > > I'm getting ready to start working on an R-274 that I picked up this past > fall. A quick survey of the internals shows that many of the capacitors show > evidence of decay (cracking) and the resistors I did a quick measurements on > are out of tolerance. > > First order of business will be a complete disassembly and cleaning (it is > pretty dirty and smelly.....). Then replace any out of spec parts, > reassemble and see how it plays. It is mostly original from what I can tell > with the exception of a replacement 455kc crystal. > > Looking for advice from those who have "been there, done that" with one of > these radios before. What should I look out for - what parts are typical > troublemakers, etc....... > > Just finished an overhaul on an R-390A that came out well and have been > tinkering with these boat anchors for many years so I have some experience > and a bunch of test equipment. Never been inside one if these so looking for > advice. > > Regards, > > Tom > W3TA > ______________________________________________________________ > Hallicrafters mailing list > Home: http://mailman.qth.net/mailman/listinfo/hallicrafters > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Hallicrafters at mailman.qth.net > > List Administrator: Duane Fischer, W8DBF > ** For Assistance: dfischer at usol.com ** > > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > ______________________________________________________________ > Hallicrafters mailing list > Home: http://mailman.qth.net/mailman/listinfo/hallicrafters > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Hallicrafters at mailman.qth.net > > List Administrator: Duane Fischer, W8DBF > ** For Assistance: dfischer at usol.com ** > > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > > ______________________________________________________________ > Hallicrafters mailing list > Home: http://mailman.qth.net/mailman/listinfo/hallicrafters > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Hallicrafters at mailman.qth.net > > List Administrator: Duane Fischer, W8DBF > ** For Assistance: dfischer at usol.com ** > > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > -- Richard Knoppow 1oldlens1 at ix.netcom.com WB6KBL From w5jo at brightok.net Mon Jan 1 16:50:56 2018 From: w5jo at brightok.net (w5jo at brightok.net) Date: Mon, 1 Jan 2018 15:50:56 -0600 Subject: [Hallicrafters] SX 42 cover plate Message-ID: Hi all, If anyone has a cover plate for the SX 42 variable capacitor I am in need of one. This plate goes on the set with three spacers and the fourth on the side panel. I would appreciate having an original if possible. I have the set playing well and it looks pretty good. If you have one you will sell or trade then please contact me. 73, Jim W5JO From thoyer1 at verizon.net Sat Jan 6 12:24:27 2018 From: thoyer1 at verizon.net (thoyer) Date: Sat, 6 Jan 2018 12:24:27 -0500 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: <8f6e44ea-1a0c-2dd7-5155-f1245990564d@ix.netcom.com> References: <85F741CC6AD349C6B042800E2FEFFD62@TomHP><006901d3831f$7b68d8d0$723a8a70$@erols.com><602200306CDF42E1855CBDE930E59129@TomHP> <8f6e44ea-1a0c-2dd7-5155-f1245990564d@ix.netcom.com> Message-ID: <0598571AA3F8459CB78779C0450A1E26@TomHP> Hi Richard, (and list) Thank you for the info. I'm working the tuning section today and have found most of the resistors way out of tolerance. I also did a sampling of the capacitors. They are spec'd in the BOM as being ceramic and look like the dog bone type. I checked a couple of the 33pf coupling caps and they measure over 50pf. Now my question becomes - since they are spec'd as a ceramic dielectric should I replace them with ceramic or go to a mica style which is what I'm more accustomed to seeing in RF circuits? Tom W3TA -----Original Message----- From: hallicrafters-bounces at mailman.qth.net [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of Richard Knoppow Sent: Monday, January 01, 2018 4:12 PM To: hallicrafters at mailman.qth.net Subject: Re: [Hallicrafters] SX-73 / R-274 Starting Resto I am not sure what capacitors Hallicrafters used in the R-274. It was intended to be their version of the SP-600-JX. I think by the time it was built the problems with the infamous Sprague Black Beauty caps were known. That resulted in a military work order requiring all paper caps in the SP-600 to be replaced with disc ceramics. Hammarlund also began using disc ceramics in its other receivers. Have a look and see whats in the R-274, if it has either disc or dog-bone ceramics leave them alone unless there are symptoms of one being bad. There may also be temperature compensating ceramics in the rig, they are usually tubular ceramics. There is only one in the SP-600. The AR-88 has many dog-bone TC ceramics in the RF section, also almost always good. RCA compensated nearly all of the RF tuned circuits. The Western Historic Radio site has material on the R-274 and I think an article comparing it to the SP-600. There is also a good article on the AR-88 family. I had to replace all the bathtub paper caps in my AR-88 because the seals around the terminals had disintegrated and the oil leaked out. A mess. The paper filter cap is still good! The AR-88 has no electrolytic caps in it. Some of the war-time receivers have Micamold or Solar flat paper caps in the RF section. They will all be bad and should be replaced with polyprolylene plastic caps. The older versions had RCA-made mica caps, which are odd lozenge shaped things, they also will usually be OK. The R-274 had a current regulator on the oscillator and mixer filaments. The regulators are getting hard to come by. National did the same thing on the HRO Sixty. They do help stabilize the receiver when there are line voltage variations. Hallicrafters is notorious for drifting resistors (also National). As a rule of thumb any carbon composition resistor, in any receiver, over about 100K will have gone up in value and should be checked but some lower value ones will also have drifted. Good luck, these are supposed to be somewhat difficult receivers to work on but are good enough to justify the work. On 1/1/2018 11:46 AM, thoyer wrote: > Hi Charlie, > > Well you helped me with my 51S-1's and now the R-274 - one stop shop > for advice! Thanks. > > I'd be interested in the write up you are doing from your overhaul > experiences. > > I have a couple other radios waiting in the wings for some attention > that may be easier then the R-274 (RCA CR-88A and a very early SP-600) > but I'm drawn to the R-274 right now. Both of these had been gon over > before by previous owners but I'm always leary of others work and will > walk through each to bring them up to snuff. This R-274 appears to be all original. > > Looking through the parts list I see that a lot of the pF capacitors > are shown as being ceramic dielectric, I'm surprised they are not > mica. Will there be any issue replacing them with mylar or mica if needed? > > I will look into the Tree Top Circuits board - but that is probably at > least a month away - lots to do first. > > If anyone has interest, I'll be uploading some pictures to my website > later today www.thdesignsinc.com/r-274.html > > > Tom > W3TA > > > > -----Original Message----- > From: hallicrafters-bounces at mailman.qth.net > [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of Charlie T > Sent: Monday, January 01, 2018 11:42 AM > To: hallicrafters at mailman.qth.net > Subject: Re: [Hallicrafters] SX-73 / R-274 Starting Resto > > Along with the usual capacitor suspects, carefully check all those low > value resistors in the IF strip. > Basically, the tuned circuit bandwidth of the IF is around 2 - 3 kHz > which is fine for SSB. > > Various broadening low O shunt resistors and/or coupling coils are > used to widen the bandwidth in steps. > I just did two of these radios and ALL of those resistors were WAY off > in value, some measuring 3 X their nominal value. > With those higher than spec resistors in place, the bandwidth is never > widened as far as it was designed to be. > > Also, the S-meter & AGC circuit must have been designed by a team of > Boris Karloff & Bela Lugosi. > I never could get it all to work right after screwing with it for many > hours. > > I used a beautiful circuit * board from TREE-TOP circuits in Canada > (Where they have STRONGER Beer) to drive the AGC & S-Meter as well as > provide great sounding SSB AND AM detection. > > Another minor suggestion is to change out the audio output transformer > for one that allows direct connection of a 4 or 8O speaker, but this > isn't all that necessary, just a slight convenience. > > I am in the process of writing a restoration article describing all > that I did. I will be selling one of these radios and will keep the > other. They both are in about the same condition. > > 73, Charlie k3ICH > > *A TREE-TOP CIRCUITS "SB-75" was used with a few slight mods to the > board for the SX-73. > This circuit board is designed to almost be a plug & play mod for the > Collins 75A-2 & 3. > I have used it for the Collins and it works great, so after many > conversations with Bob at Tree-Top, I decided to give it a try for the > Hallicrafters. > I am very happy with how it turned out AND Bob's advice was priceless > too. A very nicely done board AND a clever design. > > > -----Original Message----- > From: hallicrafters-bounces at mailman.qth.net > [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of thoyer > Sent: Monday, January 01, 2018 10:59 AM > To: hallicrafters at mailman.qth.net > Subject: [Hallicrafters] SX-73 / R-274 Starting Resto > > I'm getting ready to start working on an R-274 that I picked up this > past fall. A quick survey of the internals shows that many of the > capacitors show evidence of decay (cracking) and the resistors I did a > quick measurements on are out of tolerance. > > First order of business will be a complete disassembly and cleaning > (it is pretty dirty and smelly.....). Then replace any out of spec > parts, reassemble and see how it plays. It is mostly original from > what I can tell with the exception of a replacement 455kc crystal. > > Looking for advice from those who have "been there, done that" with > one of these radios before. What should I look out for - what parts > are typical troublemakers, etc....... > > Just finished an overhaul on an R-390A that came out well and have > been tinkering with these boat anchors for many years so I have some > experience and a bunch of test equipment. Never been inside one if > these so looking for advice. > > Regards, > > Tom > W3TA > ______________________________________________________________ > Hallicrafters mailing list > Home: http://mailman.qth.net/mailman/listinfo/hallicrafters > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Hallicrafters at mailman.qth.net > > List Administrator: Duane Fischer, W8DBF > ** For Assistance: dfischer at usol.com ** > > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html > > ______________________________________________________________ > Hallicrafters mailing list > Home: http://mailman.qth.net/mailman/listinfo/hallicrafters > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Hallicrafters at mailman.qth.net > > List Administrator: Duane Fischer, W8DBF > ** For Assistance: dfischer at usol.com ** > > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html > > ______________________________________________________________ > Hallicrafters mailing list > Home: http://mailman.qth.net/mailman/listinfo/hallicrafters > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Hallicrafters at mailman.qth.net > > List Administrator: Duane Fischer, W8DBF > ** For Assistance: dfischer at usol.com ** > > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html > -- Richard Knoppow 1oldlens1 at ix.netcom.com WB6KBL ______________________________________________________________ Hallicrafters mailing list Home: http://mailman.qth.net/mailman/listinfo/hallicrafters Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Hallicrafters at mailman.qth.net List Administrator: Duane Fischer, W8DBF ** For Assistance: dfischer at usol.com ** This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html From w5jv at hotmail.com Sat Jan 6 12:28:07 2018 From: w5jv at hotmail.com (Doug Hensley) Date: Sat, 6 Jan 2018 17:28:07 +0000 Subject: [Hallicrafters] QST Resizing Message-ID: This months QST is 7 15/16" wide by 10 3/8" tall down from Decembers' 8 1/4" wide by 10 3/4" tall. Does that reflect a change in useful information or do you suppose its strictly a stragedy on postage costs? Cheers ? Doug W5JV From w5jv at hotmail.com Sat Jan 6 12:31:53 2018 From: w5jv at hotmail.com (Doug Hensley) Date: Sat, 6 Jan 2018 17:31:53 +0000 Subject: [Hallicrafters] QST Resizing In-Reply-To: References: Message-ID: The weight also changed from 9.4 to 7.9 ounces. Must be USPS strategy. ________________________________ From: Doug Hensley Sent: Saturday, January 6, 2018 11:28 AM To: boatanchors mailman.qth.net; collins at mailman.qth.net; hammarlund at mailman.qth.net; hallicrafters at mailman.qth.net Subject: QST Resizing This months QST is 7 15/16" wide by 10 3/8" tall down from Decembers' 8 1/4" wide by 10 3/4" tall. Does that reflect a change in useful information or do you suppose its strictly a stragedy on postage costs? Cheers ? Doug W5JV From 1oldlens1 at ix.netcom.com Sat Jan 6 13:27:50 2018 From: 1oldlens1 at ix.netcom.com (Richard Knoppow) Date: Sat, 6 Jan 2018 10:27:50 -0800 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: <0598571AA3F8459CB78779C0450A1E26@TomHP> References: <85F741CC6AD349C6B042800E2FEFFD62@TomHP> <006901d3831f$7b68d8d0$723a8a70$@erols.com> <602200306CDF42E1855CBDE930E59129@TomHP> <8f6e44ea-1a0c-2dd7-5155-f1245990564d@ix.netcom.com> <0598571AA3F8459CB78779C0450A1E26@TomHP> Message-ID: <9de7ec2d-6378-a3fa-990d-9cb3114706c6@ix.netcom.com> I would just leave them alone. They may even be temperature compensating. Unless they are leaky (very unusual for ceramics) or have some other problem there is no point changing them. Mica caps are fine where one needs great stability. In fact polypropylene caps are even more stable. Drifted carbon comp resistors seem to be endemic to Hallicrafters rigs. All carbon comp resistors drift up and the higher the original value the more they drift. No matter what brand any resistor over about 100K should be checked and its likely those over about 250K will have gone quite high. My experience is that Ohmite were the most stable, Allen-Bradley the next best. I seldom see IRC resistors so I don't know about them. IRC must have either been expensive or there was some other problem. They advertised fairly heavily so I've always wondered why there are not more in commercial equipment. Anyway, Hallicrafters seems to have bought bargain basement resistors. So did National. Modern carbon film or metal film resistors are extremely stable, new ones will last forever. On 1/6/2018 9:24 AM, thoyer wrote: > Hi Richard, (and list) > > Thank you for the info. I'm working the tuning section today and have found > most of the resistors way out of tolerance. > > I also did a sampling of the capacitors. They are spec'd in the BOM as being > ceramic and look like the dog bone type. I checked a couple of the 33pf > coupling caps and they measure over 50pf. > > Now my question becomes - since they are spec'd as a ceramic dielectric > should I replace them with ceramic or go to a mica style which is what I'm > more accustomed to seeing in RF circuits? > > Tom > W3TA -- Richard Knoppow 1oldlens1 at ix.netcom.com WB6KBL From bmarx at bellsouth.net Sat Jan 6 16:34:17 2018 From: bmarx at bellsouth.net (Bill M) Date: Sat, 6 Jan 2018 16:34:17 -0500 Subject: [Hallicrafters] [Hammarlund] QST Resizing In-Reply-To: References: Message-ID: <3F15DB18-5A5C-4A31-888C-CA903FB9CDD1@bellsouth.net> Probably a printing cutting or postage savings. Bill W2CQ > On Jan 6, 2018, at 12:28 PM, Doug Hensley wrote: > > This months QST is 7 15/16" wide by 10 3/8" tall > > > down from Decembers' 8 1/4" wide by 10 3/4" tall. > > > Does that reflect a change in useful information or do you suppose its strictly a stragedy on postage costs? > > > Cheers ? > > > Doug W5JV > > > > > > ______________________________________________________________ > Hammarlund mailing list > Home: http://mailman.qth.net/mailman/listinfo/hammarlund > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Hammarlund at mailman.qth.net > > List Administrator: Duane Fischer, W8DBF > ** For Assistance: dfischer at usol.com ** > > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html From barrypfeil at gmail.com Sat Jan 6 17:01:49 2018 From: barrypfeil at gmail.com (Barry Pfeil) Date: Sat, 6 Jan 2018 17:01:49 -0500 Subject: [Hallicrafters] [Hammarlund] QST Resizing In-Reply-To: References: Message-ID: Pretty sure I read it was about costs. Partly paper and printing but mostly (?) postage. BUT, comparing side-by-side, I see it's almost the same width as "Model airplane News" (and a little shorter) and same height as "Car and Driver" (but a little bit narrower). ??????? 73 ES HNY, Barry K6RM On Sat, Jan 6, 2018 at 12:28 PM, Doug Hensley wrote: > This months QST is 7 15/16" wide by 10 3/8" tall > > > down from Decembers' 8 1/4" wide by 10 3/4" tall. > > > Does that reflect a change in useful information or do you suppose its > strictly a stragedy on postage costs? > > > Cheers ? > > > Doug W5JV > > > > > > ______________________________________________________________ > Hammarlund mailing list > Home: http://mailman.qth.net/mailman/listinfo/hammarlund > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Hammarlund at mailman.qth.net > > List Administrator: Duane Fischer, W8DBF > ** For Assistance: dfischer at usol.com ** > > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html From radio at daileyservices.com Sun Jan 7 18:07:02 2018 From: radio at daileyservices.com (Vintage Radio Repair) Date: Sun, 7 Jan 2018 16:07:02 -0700 Subject: [Hallicrafters] Hallicrafters Digest, Vol 166, Issue 3 In-Reply-To: References: Message-ID: <002401d3880c$3b03db90$b10b92b0$@daileyservices.com> I always liked the OLD size of QST, anyway - of course, I always liked the OLD version of QST, period. It was more "meat" and less "filler" Tom - W0EAJ From gharmon at idworld.net Sun Jan 7 18:34:59 2018 From: gharmon at idworld.net (Gary H. Harmon, Jr.) Date: Sun, 7 Jan 2018 17:34:59 -0600 Subject: [Hallicrafters] Sx-115 Parts Message-ID: If anyone has uncovered any SX-115 parts please let me know. 73, Gary H. Harmon, Jr. - K5JWK - HAM Radio and ATARI Archaeologist 6003 Archwood San Antonio, TX 78239-1504 (210) 657-1549 (210) 884-6926 (210) 657-1549 gharmon at idworld.net "Retirement = Every day is a Saturday except Sunday" http://www.grissomroadcoc.org From 1oldlens1 at ix.netcom.com Sun Jan 7 18:35:59 2018 From: 1oldlens1 at ix.netcom.com (Richard Knoppow) Date: Sun, 7 Jan 2018 15:35:59 -0800 Subject: [Hallicrafters] Hallicrafters Digest, Vol 166, Issue 3 In-Reply-To: <002401d3880c$3b03db90$b10b92b0$@daileyservices.com> References: <002401d3880c$3b03db90$b10b92b0$@daileyservices.com> Message-ID: The old QST reminds me a little of another magazine, also from the New England area, "American Photography". From sometime in the 1920s through early 1940s this was the bastion of "pictorial" photography. In the 1940s it changed going to a large format (had been about the same size as QST) and a change in editorial content. It couldn't compete with newer magazines like Popular Photography and eventually died out. Both QST and American Photography segregated their editorial and advertising content. Three or four pages in the front and then many pages of editorial content followed by more advertising in the back. This allowed printing of complete stories without the annoying (continued on p.97). I think advertisers must have hated this but readers liked it. One must realize that QST is an advertising medium and its advertising content is considered far more important than its editorial content. The pressure is on print media due to the shift of "content" to other media so one finds a sort of desperation in presentation. So, we find things being done a little cheaper and a little poorer until they self destruct. On 1/7/2018 3:07 PM, Vintage Radio Repair wrote: > I always liked the OLD size of QST, anyway - of course, I always liked the > OLD version of QST, period. It was more "meat" and less "filler" > > Tom - W0EAJ -- Richard Knoppow 1oldlens1 at ix.netcom.com WB6KBL From kc9cdt at aol.com Mon Jan 8 17:28:40 2018 From: kc9cdt at aol.com (kc9cdt at aol.com) Date: Mon, 8 Jan 2018 17:28:40 -0500 Subject: [Hallicrafters] TO keyer in excellant shape FGS Message-ID: <160d7e3d311-1728-49a17@webjas-vac131.srv.aolmail.net> I have a nice TO keyer...works well looks super nice... Just tested it. $100 shipped Cont US only. 73, Lee, KC9CDT Lee Simmonds Summit DCS 260-403-6936 Cell From w1jhs at twc.com Mon Jan 8 17:35:37 2018 From: w1jhs at twc.com (w1jhs at twc.com) Date: Mon, 8 Jan 2018 17:35:37 -0500 Subject: [Hallicrafters] wanted ps-150-120 Message-ID: <005401d388d1$02db3860$0891a920$@twc.com> I need a second hallicrafters ps-150-120 to go with my ht-44 . Does anyone have one they would sell for a reasonable price? From thoyer1 at verizon.net Mon Jan 8 20:01:41 2018 From: thoyer1 at verizon.net (thoyer) Date: Mon, 8 Jan 2018 20:01:41 -0500 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: <9de7ec2d-6378-a3fa-990d-9cb3114706c6@ix.netcom.com> References: <85F741CC6AD349C6B042800E2FEFFD62@TomHP><006901d3831f$7b68d8d0$723a8a70$@erols.com><602200306CDF42E1855CBDE930E59129@TomHP><8f6e44ea-1a0c-2dd7-5155-f1245990564d@ix.netcom.com><0598571AA3F8459CB78779C0450A1E26@TomHP> <9de7ec2d-6378-a3fa-990d-9cb3114706c6@ix.netcom.com> Message-ID: Update 1/8/18 Been working through the chassis area replacing the out of tolerance resistors - which is basically all of them! I had on 3.3 ohm resistor measure over 200 ohms! So far so good. I should finish up the replacements tonight then I'll start in on the bathtub caps. I'm going to use some of the esisting screws to mount a terminal strip near the electrolytic cap and wire new caps in its place leaving the original in place, just not wired. The AC power input connector housing is pretty rusted so I'm going to have a blank off plate machined at work to enable me to mount a new three prong ac connector to the existing chassis holes. I'll use a Corcom power entry module. While I strive to keep things original (don't ask me what my other hobby is....) I feel this is more of a safety improvement and can easily be reversed if needed. Once I get the caps sorted and the power connector done I'll reassemble everything and break out the variac. Yippee! Latest pics of progress can be seen here: http://www.thdesignsinc.com/R-274.html One note: I do need a 455khz crystal for the crystal filter any suggestions? Tom W3TA -----Original Message----- From: hallicrafters-bounces at mailman.qth.net [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of Richard Knoppow Sent: Saturday, January 06, 2018 1:28 PM To: hallicrafters at mailman.qth.net Subject: Re: [Hallicrafters] SX-73 / R-274 Starting Resto I would just leave them alone. They may even be temperature compensating. Unless they are leaky (very unusual for ceramics) or have some other problem there is no point changing them. Mica caps are fine where one needs great stability. In fact polypropylene caps are even more stable. Drifted carbon comp resistors seem to be endemic to Hallicrafters rigs. All carbon comp resistors drift up and the higher the original value the more they drift. No matter what brand any resistor over about 100K should be checked and its likely those over about 250K will have gone quite high. My experience is that Ohmite were the most stable, Allen-Bradley the next best. I seldom see IRC resistors so I don't know about them. IRC must have either been expensive or there was some other problem. They advertised fairly heavily so I've always wondered why there are not more in commercial equipment. Anyway, Hallicrafters seems to have bought bargain basement resistors. So did National. Modern carbon film or metal film resistors are extremely stable, new ones will last forever. On 1/6/2018 9:24 AM, thoyer wrote: > Hi Richard, (and list) > > Thank you for the info. I'm working the tuning section today and have > found most of the resistors way out of tolerance. > > I also did a sampling of the capacitors. They are spec'd in the BOM as > being ceramic and look like the dog bone type. I checked a couple of > the 33pf coupling caps and they measure over 50pf. > > Now my question becomes - since they are spec'd as a ceramic > dielectric should I replace them with ceramic or go to a mica style > which is what I'm more accustomed to seeing in RF circuits? > > Tom > W3TA -- Richard Knoppow 1oldlens1 at ix.netcom.com WB6KBL ______________________________________________________________ Hallicrafters mailing list Home: http://mailman.qth.net/mailman/listinfo/hallicrafters Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Hallicrafters at mailman.qth.net List Administrator: Duane Fischer, W8DBF ** For Assistance: dfischer at usol.com ** This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html From 1oldlens1 at ix.netcom.com Mon Jan 8 20:37:41 2018 From: 1oldlens1 at ix.netcom.com (Richard Knoppow) Date: Mon, 8 Jan 2018 17:37:41 -0800 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: References: <85F741CC6AD349C6B042800E2FEFFD62@TomHP> <006901d3831f$7b68d8d0$723a8a70$@erols.com> <602200306CDF42E1855CBDE930E59129@TomHP> <8f6e44ea-1a0c-2dd7-5155-f1245990564d@ix.netcom.com> <0598571AA3F8459CB78779C0450A1E26@TomHP> <9de7ec2d-6378-a3fa-990d-9cb3114706c6@ix.netcom.com> Message-ID: What a lot of work! Congratulatons! I would not bother to leave the bathtub caps in place but would remove them and mount terminal strips in their place, maybe I misunderstood and this is what you plan to do. I did the same thing when replacing the leaking oil-filled paper caps in my RCA AR-88A. I have a couple of SP-600s on the back burner that probably need new bathtub electrolytics and will do them the same way. What is the problem with the IF crystal filter? Perhaps its not the crystal itself or perhaps it can be fixed by baking. Even when ICM was still in business they told me they did not have such crystals. On 1/8/2018 5:01 PM, thoyer wrote: > > Update 1/8/18 > -- Richard Knoppow 1oldlens1 at ix.netcom.com WB6KBL From thoyer1 at verizon.net Mon Jan 8 21:11:22 2018 From: thoyer1 at verizon.net (thoyer) Date: Mon, 8 Jan 2018 21:11:22 -0500 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: References: <85F741CC6AD349C6B042800E2FEFFD62@TomHP><006901d3831f$7b68d8d0$723a8a70$@erols.com><602200306CDF42E1855CBDE930E59129@TomHP><8f6e44ea-1a0c-2dd7-5155-f1245990564d@ix.netcom.com><0598571AA3F8459CB78779C0450A1E26@TomHP><9de7ec2d-6378-a3fa-990d-9cb3114706c6@ix.netcom.com> Message-ID: <55AF6711D7FC475393FE16EF925FAC86@TomHP> I did an SP-600 years ago and took apart the bathtubs and replaced the guts. I'll probably go the terminal strip route this time..... The only problem with the crystal is that it was missing from the radio when I got it! -----Original Message----- From: hallicrafters-bounces at mailman.qth.net [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of Richard Knoppow Sent: Monday, January 08, 2018 8:38 PM To: hallicrafters at mailman.qth.net Subject: Re: [Hallicrafters] SX-73 / R-274 Starting Resto What a lot of work! Congratulatons! I would not bother to leave the bathtub caps in place but would remove them and mount terminal strips in their place, maybe I misunderstood and this is what you plan to do. I did the same thing when replacing the leaking oil-filled paper caps in my RCA AR-88A. I have a couple of SP-600s on the back burner that probably need new bathtub electrolytics and will do them the same way. What is the problem with the IF crystal filter? Perhaps its not the crystal itself or perhaps it can be fixed by baking. Even when ICM was still in business they told me they did not have such crystals. On 1/8/2018 5:01 PM, thoyer wrote: > > Update 1/8/18 > -- Richard Knoppow 1oldlens1 at ix.netcom.com WB6KBL ______________________________________________________________ Hallicrafters mailing list Home: http://mailman.qth.net/mailman/listinfo/hallicrafters Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Hallicrafters at mailman.qth.net List Administrator: Duane Fischer, W8DBF ** For Assistance: dfischer at usol.com ** This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html From tombewick at gmail.com Tue Jan 9 06:47:39 2018 From: tombewick at gmail.com (K2bew) Date: Tue, 09 Jan 2018 11:47:39 +0000 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: <55AF6711D7FC475393FE16EF925FAC86@TomHP> References: <85F741CC6AD349C6B042800E2FEFFD62@TomHP> <006901d3831f$7b68d8d0$723a8a70$@erols.com> <602200306CDF42E1855CBDE930E59129@TomHP> <8f6e44ea-1a0c-2dd7-5155-f1245990564d@ix.netcom.com> <0598571AA3F8459CB78779C0450A1E26@TomHP> <9de7ec2d-6378-a3fa-990d-9cb3114706c6@ix.netcom.com> <55AF6711D7FC475393FE16EF925FAC86@TomHP> Message-ID: I did a a SP-600 a while back too and I and became concerned when I found oil in the bathtub caps. So I did a little searching on-line and found the general consensus is they probably have pcbs in the oil, like old telephone transformers, so I would recommend you don?t open them to restuff. Not sure where to get a crystal since I?m hearing all the good Crystal companies have closed, likely from either someone?s junk box or eBay. The radio is looking great , thanks for sharing. Tom -- Sent from my iPad Gmail From kc9cdt at aol.com Tue Jan 9 15:54:06 2018 From: kc9cdt at aol.com (kc9cdt at aol.com) Date: Tue, 9 Jan 2018 15:54:06 -0500 Subject: [Hallicrafters] Hickok 6000A tube tester FS EXCELLENT COND. Message-ID: <160dcb39a1d-1726-20563@webjas-vab101.srv.aolmail.net> Hello everyone, It is a Hickok 6000A I have used for HAM tubes for some time now. It is in excellent cosmetic and working condition. It is one that was recommended to me by several Vintage radio folks. It is a mutual conductance unit. (Was calibrated a few years ago by the Hickok guy before he passed). All tube sockes fine. Includes manual and all documentation for tubes etc. Photos available and even one testing a tube...showing values. I would like what I paid for it a few years ago...$400.00 + help on shipping. Thanks, 73, Lee Lee Simmonds Summit DCS 260-403-6936 Cell From aquinn50 at tx.rr.com Tue Jan 9 17:22:15 2018 From: aquinn50 at tx.rr.com (Anthony Quinn) Date: Tue, 9 Jan 2018 16:22:15 -0600 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: References: <85F741CC6AD349C6B042800E2FEFFD62@TomHP> <006901d3831f$7b68d8d0$723a8a70$@erols.com> <602200306CDF42E1855CBDE930E59129@TomHP> <8f6e44ea-1a0c-2dd7-5155-f1245990564d@ix.netcom.com> <0598571AA3F8459CB78779C0450A1E26@TomHP> <9de7ec2d-6378-a3fa-990d-9cb3114706c6@ix.netcom.com> <55AF6711D7FC475393FE16EF925FAC86@TomHP> Message-ID: <013201d38998$4f311f50$ed935df0$@tx.rr.com> I had this same question when I started. The mil-spec sheet normally lists the type of oil and you can cross reference it from there. -----Original Message----- From: hallicrafters-bounces at mailman.qth.net [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of K2bew Sent: Tuesday, January 9, 2018 5:48 AM To: hallicrafters at mailman.qth.net Subject: Re: [Hallicrafters] SX-73 / R-274 Starting Resto I did a a SP-600 a while back too and I and became concerned when I found oil in the bathtub caps. So I did a little searching on-line and found the general consensus is they probably have pcbs in the oil, like old telephone transformers, so I would recommend you don?t open them to restuff. Not sure where to get a crystal since I?m hearing all the good Crystal companies have closed, likely from either someone?s junk box or eBay. The radio is looking great , thanks for sharing. Tom -- Sent from my iPad Gmail ______________________________________________________________ Hallicrafters mailing list Home: http://mailman.qth.net/mailman/listinfo/hallicrafters Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Hallicrafters at mailman.qth.net List Administrator: Duane Fischer, W8DBF ** For Assistance: dfischer at usol.com ** This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html From 1oldlens1 at ix.netcom.com Tue Jan 9 17:58:08 2018 From: 1oldlens1 at ix.netcom.com (Richard Knoppow) Date: Tue, 9 Jan 2018 14:58:08 -0800 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: <013201d38998$4f311f50$ed935df0$@tx.rr.com> References: <85F741CC6AD349C6B042800E2FEFFD62@TomHP> <006901d3831f$7b68d8d0$723a8a70$@erols.com> <602200306CDF42E1855CBDE930E59129@TomHP> <8f6e44ea-1a0c-2dd7-5155-f1245990564d@ix.netcom.com> <0598571AA3F8459CB78779C0450A1E26@TomHP> <9de7ec2d-6378-a3fa-990d-9cb3114706c6@ix.netcom.com> <55AF6711D7FC475393FE16EF925FAC86@TomHP> <013201d38998$4f311f50$ed935df0$@tx.rr.com> Message-ID: <7e94cce3-442a-6156-8b6a-5506a38295c3@ix.netcom.com> I started writing a long piece about the SP-600 caps none of which may be applicable to the Hallicrafters SX-73/R-274, which may have different caps than the SP-600. Its possible it has oil filled bathtub paper caps, which the SP-600 does not have. I agree with the previous poster that its a waste of time and effort to try to restuff them. Mounting on terminal strips works fine. I had to replace a bunch of oil-filled bathtub paper caps in an RCA AR-88. All had leaked oil from the terminals. This receiver had bottom cover (rack mount type) so the oil was mostly collected there. I washed it out carefully. I mounted new plastic caps on terminal strips and disposed of the old ones. I think all the bathtub caps in the SP-600 are electrolytic types. The ones I opened up were potted in resin, no oil. Again, not worth the bother to try restuffing. I am more interested in performance than authentic underchassis appearance. I don't have direct experience with the SX-73 but they are reputed to have excellent performance when working right so should be worth the effort of restoring properly. -- Richard Knoppow 1oldlens1 at ix.netcom.com WB6KBL From hwhall at compuserve.com Tue Jan 9 19:09:50 2018 From: hwhall at compuserve.com (hwhall at compuserve.com) Date: Tue, 9 Jan 2018 19:09:50 -0500 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: Message-ID: <160dd66cff6-1725-32a25@webjas-vac089.srv.aolmail.net> > general consensus is they probably have pcbs in the oil, like oldtelephone transformers, so I would recommend you don?t open them torestuff > If interested in restuffing, drill one of the suspect caps to extract a few drops of oil. If the drops sink when placed on water, they may indeed be PCB types but it they float or spread on the surface, they aren't. PCB oils aren't like radioactives, mere proximity isn't a hazard. Just don't ingest/inhale it or mop it up barehanded. All the tub caps in my RBM-5 turned out to be common mineral oil and yielded maybe 1/8 cup of oil total or less. Wayne WB4OGM From thoyer1 at verizon.net Tue Jan 9 19:50:43 2018 From: thoyer1 at verizon.net (thoyer) Date: Tue, 9 Jan 2018 19:50:43 -0500 Subject: [Hallicrafters] SX-73 / R-274 Starting Resto In-Reply-To: <7e94cce3-442a-6156-8b6a-5506a38295c3@ix.netcom.com> References: <85F741CC6AD349C6B042800E2FEFFD62@TomHP><006901d3831f$7b68d8d0$723a8a70$@erols.com><602200306CDF42E1855CBDE930E59129@TomHP><8f6e44ea-1a0c-2dd7-5155-f1245990564d@ix.netcom.com><0598571AA3F8459CB78779C0450A1E26@TomHP><9de7ec2d-6378-a3fa-990d-9cb3114706c6@ix.netcom.com><55AF6711D7FC475393FE16EF925FAC86@TomHP><013201d38998$4f311f50$ed935df0$@tx.rr.com> <7e94cce3-442a-6156-8b6a-5506a38295c3@ix.netcom.com> Message-ID: <9AF2C10BDD9F4F9FBF3CEBED8481B811@TomHP> The ones in my SP-600 were the potted style. I think I'm going to just use terminal strips for the new caps in the R-274. One odd thing I found last night was that there was a 5w 3.3 ohm resistor installed in location R105. BOM calls for a 2W resistor in that location. Doing the math the heater current is approx 600mA which would equate to approx 1.1W of dissipation. Maybe they ran out of two watt resistors when building? Tom W3TA -----Original Message----- From: hallicrafters-bounces at mailman.qth.net [mailto:hallicrafters-bounces at mailman.qth.net] On Behalf Of Richard Knoppow Sent: Tuesday, January 09, 2018 5:58 PM To: hallicrafters at mailman.qth.net Subject: Re: [Hallicrafters] SX-73 / R-274 Starting Resto I started writing a long piece about the SP-600 caps none of which may be applicable to the Hallicrafters SX-73/R-274, which may have different caps than the SP-600. Its possible it has oil filled bathtub paper caps, which the SP-600 does not have. I agree with the previous poster that its a waste of time and effort to try to restuff them. Mounting on terminal strips works fine. I had to replace a bunch of oil-filled bathtub paper caps in an RCA AR-88. All had leaked oil from the terminals. This receiver had bottom cover (rack mount type) so the oil was mostly collected there. I washed it out carefully. I mounted new plastic caps on terminal strips and disposed of the old ones. I think all the bathtub caps in the SP-600 are electrolytic types. The ones I opened up were potted in resin, no oil. Again, not worth the bother to try restuffing. I am more interested in performance than authentic underchassis appearance. I don't have direct experience with the SX-73 but they are reputed to have excellent performance when working right so should be worth the effort of restoring properly. -- Richard Knoppow 1oldlens1 at ix.netcom.com WB6KBL ______________________________________________________________ Hallicrafters mailing list Home: http://mailman.qth.net/mailman/listinfo/hallicrafters Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Hallicrafters at mailman.qth.net List Administrator: Duane Fischer, W8DBF ** For Assistance: dfischer at usol.com ** This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html From holden7471 at msn.com Sat Jan 13 12:12:37 2018 From: holden7471 at msn.com (howard holden) Date: Sat, 13 Jan 2018 17:12:37 +0000 Subject: [Hallicrafters] Winter 2018 CW Classic Exchange Message-ID: The CW CX will run from 1300 UTC January 21 to 0800 UTC January 22, 2018 (9 AM Eastern Time on Sunday to 3 AM Eastern Time Monday) AND from 1300 UTC January 23, to 0800 UTC January 24, 2018 (9 AM Eastern Time on Tuesday to 3 AM Eastern Time Wednesday) Suggested Frequencies -- plus/minus QRM Listen up and down 5 to 10 Kc for crystal controlled stations CW 1.810 mc. 3.545 mc. 7.045 mc. 14.045 mc. 21.045 mc. 28.045 mc. 50.100 mc. 144.100 mc. The CX is a no-pressure contest celebrating the older commercial and homebrew equipment that was the pride and joy of ham shacks many decades ago. The object is to encourage restoration, operation and enjoyment of this older Classic equipment. However, you need not operate a Classic rig to participate in the CX. YOU MAY USE ANY RIG in the contest although new gear is a distinct scoring disadvantage. You can still work the "great ones" with modern equipment. BONUSES Up to 2,000 point bonus will be awarded to every CX participant who operates the same model rig as their Novice station. Three QSOs are required. One receiver and one transmitter may be counted and are worth 1,000 points each. Multiple version of the same piece of gear will not increase the bonus. Up to 2,000 point bonus will be awarded to every CX participant who operates a transmitter with 4 tubes and/or less or a receiver with 6 tubes or less. Three QSOs (each) are required. Awards will be given in two classes: 1. Three or fewer receiver-transmitter pairs 2. Four or more receiver-transmitter pairs. Send logs, comments, anecdotes, pictures, etc. to e-mail: Ron K2RP k2rp at arrl.net E-MAIL IS (REALLY) PREFERRED BUT NOT ABSOLUTELY NECESSARY Or by mail to: K2RP 659 Shanas Lane Encinitas, CA 92024 Full details at: http://classicexchange.org/sep17/sep17ann.html Questions? email me! CU on the air for CX! 73, Howie WB2AWQ/7 From robert at isquare.com Sun Jan 14 16:46:45 2018 From: robert at isquare.com (Bob Sullivan) Date: Sun, 14 Jan 2018 16:46:45 -0500 Subject: [Hallicrafters] SX-88 Dial Glass Message-ID: SX-88 dial covers for main tuning and bandspread. Exact size and thickness as original. $65ppd (Lucite, not glass) I have three sets remaining and these are the last I?ll make. 73, Bob W?YVA http://www.isquare.com/personal_pages/ras-hardware.htm

This page last updated 17 Jan 2018.