[AMRadio] 100TH and 250TH advice and or comment


Jack Griffin jtg4300 at yahoo.com
Wed Aug 26 12:06:19 EDT 2009


I have some 100th's that show a blue glow when the HV is applied. Is this a sign of gas or just normal.
Thank you, Jack

--- On Wed, 8/26/09, amradio-request at mailman.qth.net <amradio-request at mailman.qth.net> wrote:

From: amradio-request at mailman.qth.net <amradio-request at mailman.qth.net>
Subject: AMRadio Digest, Vol 67, Issue 15
To: amradio at mailman.qth.net
Date: Wednesday, August 26, 2009, 11:38 AM

Send AMRadio mailing list submissions to
    amradio at mailman.qth.net

To subscribe or unsubscribe via the World Wide Web, visit
    http://mailman.qth.net/mailman/listinfo/amradio
or, via email, send a message with subject or body 'help' to
    amradio-request at mailman.qth.net

You can reach the person managing the list at
    amradio-owner at mailman.qth.net

When replying, please edit your Subject line so it is more specific
than "Re: Contents of AMRadio digest..."


Today's Topics:

   1. Re: 100TH and 250TH advice and or comment (John Coleman)
   2. Re: 100TH and 250TH advice and or comment (rbethman)
   3. Re: 100TH and 250TH advice and or comment (Brett Gazdzinski)
   4. Re: 100TH and 250TH advice and or comment (rbethman)
   5. Re: 100TH and 250TH advice and or comment (crawfish at surfmore.net)
   6. Re: 100TH and 250TH advice and or comment
      (ronnie.hull at glowbugs.com)
   7. Re: VACUUM TUBES (Bernie Doran)


----------------------------------------------------------------------

Message: 1
Date: Tue, 25 Aug 2009 17:04:33 -0400
From: John Coleman <jc at pctechref.com>
Subject: Re: [AMRadio] 100TH and 250TH advice and or comment
To: Discussion of AM Radio in the Amateur Service
    <amradio at mailman.qth.net>
Message-ID:
    <689F280218C08F4481B381DE76738FE401BD87B383DD at P1EC1EVS02.HMC1.COMCAST.NET>
    
Content-Type: text/plain; charset="us-ascii"

I think there is at least some truth to this Lee, but I am not sure of why.  By the same token though I have run 250ths for quite some time and with many hours of no use both winter and summer without air conditioning.  They seem to always work the same even though I may only fire them up once or twice a year (much to my dismay).  So I really don't have any good answer for this.  If all the tubes in question were assemble into the 610 at the same time then maybe you could just pass this off as "it was finally time that the air leak got to them".  Don, K4KYV and Tim, WA1HLR have discussed this sort of thing quite a bit as well as deterioration of cathode coatings in both directly heated tubes and indirectly heated tubes.  You may want to consult with them about this.  One thing is for certain, if the final tube is weak then it will be very difficult to get it to produce a wave form output that matches the audio wave form, and it gets worse as the
 power demand goes up.
73
John

-----Original Message-----
From: amradio-bounces at mailman.qth.net [mailto:amradio-bounces at mailman.qth.net] On Behalf Of LEE BAHR
Sent: Tuesday, August 25, 2009 2:20 PM
To: Discussion of AM Radio in the Amateur Service
Subject: Re: [AMRadio] 100TH and 250TH advice and or comment

John Moan (forgot his call and spelling) (SK) in San Antonio used to run a 
few BC-610s.  He always rotated his 100TH and 250TH tubes to keep gassing 
from forming in them.  He had about a dozen BC-610s and around 17 R-390A 
receivers in his shack.   I think he used to say it was bad to lie them on 
their side too.  He seemed to know what he was doing and swore the cycling 
of the tubes was neccessary to keep them alive.  He claimed storing these 
tubes would kill them in time.  I am only talking about 100TH and 250TH 
tubes.

Lee
w0vt
Houston



------------------------------

Message: 2
Date: Tue, 25 Aug 2009 17:17:33 -0400
From: rbethman <rbethman at comcast.net>
Subject: Re: [AMRadio] 100TH and 250TH advice and or comment
To: Discussion of AM Radio in the Amateur Service
    <amradio at mailman.qth.net>
Message-ID: <4A9454ED.4090702 at comcast.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Sorry Lee!

I've also been putting in some moulding in the house.  (Probably 
misspelled it too!)  It is a Honey-Do day with the wife off.

I'm still trying to figure out why some that sit and have been used, 
versus the ones IN the radio that have sat are the ones that are the 
ones showing the "gassy" indications.

Then there is the T-213 that has sat for several years, and the tubes 
are all crystal clear.

I am finding neither rhyme nor reason.  I'm at the befuddlement point!

Bob - N0DGN

LEE BAHR wrote:
> John Moan (forgot his call and spelling) (SK) in San Antonio used to run a 
> few BC-610s.  He always rotated his 100TH and 250TH tubes to keep gassing 
> from forming in them.  He had about a dozen BC-610s and around 17 R-390A 
> receivers in his shack.   I think he used to say it was bad to lie them on 
> their side too.  He seemed to know what he was doing and swore the cycling 
> of the tubes was neccessary to keep them alive.  He claimed storing these 
> tubes would kill them in time.  I am only talking about 100TH and 250TH 
> tubes.
>
> Lee
> w0vt
> Houston
>
>  
>
> ______________________________________________________________
> Our Main Website: http://www.amfone.net
> AMRadio mailing list
> Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/
> List Rules (must read!): http://w5ami.net/amradiofaq.html
> List Home: http://mailman.qth.net/mailman/listinfo/amradio
> Post: AMRadio at mailman.qth.net
> To unsubscribe, send an email to amradio-request at mailman.qth.net with
> the word unsubscribe in the message body.
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>   

-- 
+------------------------------------------------------------------+
|             AM Amateur Radio Operator    N?DGN                   |   
+------------------------------------------------------------------+
| Bob Bethman                \\\|///     " The absence of a danger |
|                           \\ ~ ~ //      signal does *NOT* mean  |
| rbethman at comcast.net      (/ @ @ /)      that everything is OK " |
+-------------------------oOOo-(_)-oOOo----------------------------+



------------------------------

Message: 3
Date: Tue, 25 Aug 2009 18:26:18 -0400
From: "Brett Gazdzinski" <Brett.Gazdzinski at verizon.net>
Subject: Re: [AMRadio] 100TH and 250TH advice and or comment
To: "Discussion of AM Radio in the Amateur Service"
    <amradio at mailman.qth.net>
Message-ID: <71CD31B11AF34375BEFDCB470C70505A at brettPC>
Content-Type: text/plain; format=flowed; charset=iso-8859-1;
    reply-type=original

I have a modulator that uses four 100TH tubes, it has had the same tubes for 
the last 25 years, they look clear, and work fine.
I have a bunch of spare 100 TH and TL's, all look ok last I looked...

I have noticed a bunch of white tubes in the 7 and 9 pin tube stashes, maybe 
the seals fail, the pins rust, or something happens and the air gets in.

You have a lot of thermal cycling on tubes that get used, from cold to very 
hot, to cold again, but tubes just sitting going bad?

Brett




----- Original Message ----- 
From: "rbethman" <rbethman at comcast.net>
To: "AM Radio List" <amradio at mailman.qth.net>
Sent: Tuesday, August 25, 2009 12:06 PM
Subject: [AMRadio] 100TH and 250TH advice and or comment


> Question:
>
> I have noticed that the 100THs and 250THS that are in their original
> boxes, either not used at all, or maybe use for less than an hour to
> test them, seem to be doing fine.
>
> Their envelopes are crystal clear an can not see any sort of defect.
>
> Then the ones that are in one of the two BC-610s that has the hours on
> it, even though it last performed flawlessly, now appears to have gone
> gassy with some milky white inside the envelope.
>
> Is this perhaps due to over heating or maybe I should phrase this as the
> convection cooling of these radios since they do NOT have fans.
>
> Ideas?  Comments?
>
> It has always been metered and watched with a scope for observing
> waveforms, and the wattmeter is the newer Model Bird with peak reading
> built-in.  (However true they really are!)
>
> Bob - N0DGN
>
>
> ______________________________________________________________
> Our Main Website: http://www.amfone.net
> AMRadio mailing list
> Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/
> List Rules (must read!): http://w5ami.net/amradiofaq.html
> List Home: http://mailman.qth.net/mailman/listinfo/amradio
> Post: AMRadio at mailman.qth.net
> To unsubscribe, send an email to amradio-request at mailman.qth.net with
> the word unsubscribe in the message body.
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html 



------------------------------

Message: 4
Date: Tue, 25 Aug 2009 18:53:57 -0400
From: rbethman <rbethman at comcast.net>
Subject: Re: [AMRadio] 100TH and 250TH advice and or comment
To: Discussion of AM Radio in the Amateur Service
    <amradio at mailman.qth.net>
Message-ID: <4A946B85.60502 at comcast.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Brett,

I'm thinking the thermal cycling, a number of years of use that is for 
the most part intermittent, followed by then sitting for another year 
and a half has been what broke the back.  So long as the intermittent 
use was a rather regular periodic interval, I was heating them up and 
getting them full use.

I got medical issues that wouldn't let me enjoy the big AM rig, and it sat.

I started trouble shooting a problem, and I find the three of them are 
now gassy.

Yet the second radio only got used for about two hours since I got it, 
(I can only run one at a time. LOL), and it has now sat for over four 
years AND it has NO gassy tubes.

I trying to understand why ONE did and the OTHER did not.

Then it could just be those tubes were going anyway.  Although I doubt 
it.  They all can in the original Mil issue packaging.

It is all strange!

Bob - N0DGN



Brett Gazdzinski wrote:
> I have a modulator that uses four 100TH tubes, it has had the same tubes for 
> the last 25 years, they look clear, and work fine.
> I have a bunch of spare 100 TH and TL's, all look ok last I looked...
>
> I have noticed a bunch of white tubes in the 7 and 9 pin tube stashes, maybe 
> the seals fail, the pins rust, or something happens and the air gets in.
>
> You have a lot of thermal cycling on tubes that get used, from cold to very 
> hot, to cold again, but tubes just sitting going bad?
>
> Brett
>   



------------------------------

Message: 5
Date: Tue, 25 Aug 2009 21:43:19 -0500 (CDT)
From: crawfish at surfmore.net
Subject: Re: [AMRadio] 100TH and 250TH advice and or comment
To: "Discussion of AM Radio in the Amateur Service"
    <amradio at mailman.qth.net>
Message-ID:
    <1504.208.86.68.20.1251254599.squirrel at webmail.surfmore.net>
Content-Type: text/plain; charset=iso-8859-1

John Mohn was W5MEU. I remember him talking about that one night over 20
years ago.I have an old 450TL that I want to use. I guess I need to bring
it up slowly with a variac feeding the filament transformer to keep the
inrush current from wrecking the filament, or is that an issue?
                                                   Joe W4AAB


> I think there is at least some truth to this Lee, but I am not sure of
> why.  By the same token though I have run 250ths for quite some time and
> with many hours of no use both winter and summer without air conditioning.
>  They seem to always work the same even though I may only fire them up
> once or twice a year (much to my dismay).  So I really don't have any good
> answer for this.  If all the tubes in question were assemble into the 610
> at the same time then maybe you could just pass this off as "it was
> finally time that the air leak got to them".  Don, K4KYV and Tim, WA1HLR
> have discussed this sort of thing quite a bit as well as deterioration of
> cathode coatings in both directly heated tubes and indirectly heated
> tubes.  You may want to consult with them about this.  One thing is for
> certain, if the final tube is weak then it will be very difficult to get
> it to produce a wave form output that matches the audio wave form, and it
> gets worse as the power demand goes up.
> 73
> John
>
> -----Original Message-----
> From: amradio-bounces at mailman.qth.net
> [mailto:amradio-bounces at mailman.qth.net] On Behalf Of LEE BAHR
> Sent: Tuesday, August 25, 2009 2:20 PM
> To: Discussion of AM Radio in the Amateur Service
> Subject: Re: [AMRadio] 100TH and 250TH advice and or comment
>
> John Moan (forgot his call and spelling) (SK) in San Antonio used to run a
> few BC-610s.  He always rotated his 100TH and 250TH tubes to keep gassing
> from forming in them.  He had about a dozen BC-610s and around 17 R-390A
> receivers in his shack.   I think he used to say it was bad to lie them on
> their side too.  He seemed to know what he was doing and swore the cycling
> of the tubes was neccessary to keep them alive.  He claimed storing these
> tubes would kill them in time.  I am only talking about 100TH and 250TH
> tubes.
>
> Lee
> w0vt
> Houston
>
> ______________________________________________________________
> Our Main Website: http://www.amfone.net
> AMRadio mailing list
> Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/
> List Rules (must read!): http://w5ami.net/amradiofaq.html
> List Home: http://mailman.qth.net/mailman/listinfo/amradio
> Post: AMRadio at mailman.qth.net
> To unsubscribe, send an email to amradio-request at mailman.qth.net with
> the word unsubscribe in the message body.
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>



------------------------------

Message: 6
Date: Wed, 26 Aug 2009 08:13:58 -0400
From: ronnie.hull at glowbugs.com
Subject: Re: [AMRadio] 100TH and 250TH advice and or comment
To: amradio at mailman.qth.net
Message-ID:
    <20090826081358.s10fo0snwg08wgsc at host58.secureserver777.com>
Content-Type: text/plain;    charset=ISO-8859-1;    DelSp="Yes";
    format="flowed"

This has been an interesting thread to be sure. Gentleman I have 3  
450TL's that I got from Geoff a few years ago and I have two used  
known good 250TH's that I have no use for.

I would be willing to trade all 5 for a usable 3-1000Z. The 450TL's  
are nib box the boxe's are falling to peices.

I also have a filament tranny that would work for those 450TL's that I  
would be willing to throw in.

Ronnie - W5SUM


Quoting crawfish at surfmore.net:

> John Mohn was W5MEU. I remember him talking about that one night over 20
> years ago.I have an old 450TL that I want to use. I guess I need to bring
> it up slowly with a variac feeding the filament transformer to keep the
> inrush current from wrecking the filament, or is that an issue?
>                                                    Joe W4AAB
>
>
>> I think there is at least some truth to this Lee, but I am not sure of
>> why.  By the same token though I have run 250ths for quite some time and
>> with many hours of no use both winter and summer without air conditioning.
>>  They seem to always work the same even though I may only fire them up
>> once or twice a year (much to my dismay).  So I really don't have any good
>> answer for this.  If all the tubes in question were assemble into the 610
>> at the same time then maybe you could just pass this off as "it was
>> finally time that the air leak got to them".  Don, K4KYV and Tim, WA1HLR
>> have discussed this sort of thing quite a bit as well as deterioration of
>> cathode coatings in both directly heated tubes and indirectly heated
>> tubes.  You may want to consult with them about this.  One thing is for
>> certain, if the final tube is weak then it will be very difficult to get
>> it to produce a wave form output that matches the audio wave form, and it
>> gets worse as the power demand goes up.
>> 73
>> John
>>
>> -----Original Message-----
>> From: amradio-bounces at mailman.qth.net
>> [mailto:amradio-bounces at mailman.qth.net] On Behalf Of LEE BAHR
>> Sent: Tuesday, August 25, 2009 2:20 PM
>> To: Discussion of AM Radio in the Amateur Service
>> Subject: Re: [AMRadio] 100TH and 250TH advice and or comment
>>
>> John Moan (forgot his call and spelling) (SK) in San Antonio used to run a
>> few BC-610s.  He always rotated his 100TH and 250TH tubes to keep gassing
>> from forming in them.  He had about a dozen BC-610s and around 17 R-390A
>> receivers in his shack.   I think he used to say it was bad to lie them on
>> their side too.  He seemed to know what he was doing and swore the cycling
>> of the tubes was neccessary to keep them alive.  He claimed storing these
>> tubes would kill them in time.  I am only talking about 100TH and 250TH
>> tubes.
>>
>> Lee
>> w0vt
>> Houston
>>
>> ______________________________________________________________
>> Our Main Website: http://www.amfone.net
>> AMRadio mailing list
>> Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/
>> List Rules (must read!): http://w5ami.net/amradiofaq.html
>> List Home: http://mailman.qth.net/mailman/listinfo/amradio
>> Post: AMRadio at mailman.qth.net
>> To unsubscribe, send an email to amradio-request at mailman.qth.net with
>> the word unsubscribe in the message body.
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>
> ______________________________________________________________
> Our Main Website: http://www.amfone.net
> AMRadio mailing list
> Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/
> List Rules (must read!): http://w5ami.net/amradiofaq.html
> List Home: http://mailman.qth.net/mailman/listinfo/amradio
> Post: AMRadio at mailman.qth.net
> To unsubscribe, send an email to amradio-request at mailman.qth.net with
> the word unsubscribe in the message body.
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>





------------------------------

Message: 7
Date: Wed, 26 Aug 2009 11:38:36 -0400
From: "Bernie Doran" <qedconsultants at embarqmail.com>
Subject: Re: [AMRadio] VACUUM TUBES
To: "Discussion of AM Radio in the Amateur Service"
    <amradio at mailman.qth.net>
Message-ID: <000701ca2663$46f416e0$8119fea9 at bernie>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
    reply-type=original

I am suggesting that anyone with an interest in Vacuum Tubes check the web 
site CPI :: Eimac
 click on library and go through the Eimac publications about how to care, 
design, use, etc for  tubes. when you go through these docs, you will know 
more about vacuum tubes than 99% of the people you talk too.    Bernie W8RPW 




------------------------------

______________________________________________________________
AMRadio mailing list
Home: http://mailman.qth.net/mailman/listinfo/amradio
Help: http://mailman.qth.net/mmfaq.html
Post: mailto:AMRadio at mailman.qth.net


End of AMRadio Digest, Vol 67, Issue 15
***************************************



      


More information about the AMRadio mailing list

This page last updated 23 Oct 2017.