[AMRadio] Best AM BoatanchorReceiver or AM


Brett gazdzinski brett.gazdzinski at verizonbusiness.com
Sun Oct 1 20:22:33 EDT 2006


I have the KIWA filters in the homebrew, and for my
money, they work as good or better then a mechanical filter.
4.5 or 5.5 Kc is just that, outside the passband its gone!
I like AM qso's every 5 kc as long as the signals are clean,
if someone is distorted and splattering, nothing helps.

Brett
N2DTS


 

> -----Original Message-----
> From: amradio-bounces at mailman.qth.net 
> [mailto:amradio-bounces at mailman.qth.net] On Behalf Of Jim Candela
> Sent: Sunday, October 01, 2006 6:50 PM
> To: Discussion of AM Radio in the Amateur Service
> Subject: Re: [AMRadio] Best AM BoatanchorReceiver or AM 
> RiceboxReceiverDiscussion
> 
> Jim,
> 
>  I lover your term, 'Aflak'! Pardon me, but I am going to use it..:-)
> 
>   That Sx-117 is a pretty neat receiver. I was just looking 
> at the specifications at the following sight:
> 
> http://www.dxing.com/rx/sx115.htm
> 
> The IF selectivity at .5, 2.5 and 5 khz @ -6db is pretty 
> tight for AM, and I bet that is why you did pretty good on 75 
> yesterday with 3 AM signals spaced 5 Khz apart, and a duck on 
> either side. My Sp-600 with a 3 and 8 and 13 khz options just 
> did not have the right bandwidth position for the conditions. 
> There was also an Aflak at 3918 Khz running an amplifier, and 
> was about 150 yards from my home. The SP-600 could not handle 
> it, S-meter would go down about 1/2 what it was, and 
> undetected SSB came right through the speaker - loud too. The 
> R75 with preamp off, and attenuator off had no trouble with 
> the 3918 Aflak.
> 
> In defense of that SP-600, later during the traders net the 
> QRM subsided, and I opened the Super Pro to 8 Khz, and turned 
> up the audio. It was clear as a bell, and the audio from 
> those guys really came through nicely. Then the signals 
> faded, QSB, selective fading, noise, etc. came in.
> 
> The R75 sync detector has issues, and many complaints. That 
> said, if you use the passband tuning (say +/- 2.4 khz), with 
> AM sync ON, it locks every time. With normal AM tunining mine 
> seldom locks. The Kiwa mods take care of that, and several 
> other issues.
> 
> http://www.kiwa.com/R75.html
> 
> Jim
> JKO
> 
> 
> 
> 
> 
> ----- Original Message ----
> From: Jim Wilhite <w5jo at brightok.net>
> To: Discussion of AM Radio in the Amateur Service 
> <amradio at mailman.qth.net>
> Sent: Sunday, October 1, 2006 11:33:28 AM
> Subject: Re: [AMRadio] Best AM BoatanchorReceiver or AM 
> RiceboxReceiver Discussion
> 
> Jim I listened to the same groups as you yesterday on an SX 
> 117.  I did not 
> have any trouble copying each of the groups.  While some of 
> the aflack noise 
> could be heard, it did not affect my copy that much.  I 
> turned on the HRO 60 
> with the D coil in the General Coverage mode and was able to 
> copy very well 
> with it.
> 
> I am about 500 miles North of you and was using a dipole and 
> an inverted L 
> on both receivers.  I didn't try the NC 183D but it tends to 
> be almost as 
> selective as the HRO.  I also have an R 75 and I really don't 
> see that much 
> of an improvement in reception.  I do not have all the 
> filters in it as you 
> do, but the S- AM mode does not help that much.  Also my R 75 
> does not have 
> any modifications.
> 
> 73  Jim
> W5JO
> 
> 
> 
> > Hi All,
> >
> >   Yesterday morning on 75 meters we had at least 3 AM QSO's going on
> > simultaniously. It was glorious! I heard QSO's on 3880, 85, 
> and 90. At the
> > same time there were SSB groups on 3878, and 3894.
> >
> > At my QTH (central Texas) with my equipment, my SP-600 was 
> useless. Yes I
> > could use the 3Kc IF bandpass position, and tune off center 
> to favor one
> > sideband or another. As soon as the audio midrange would 
> brighten up I'd
> > hear QRM from an adjacent channel. Switching in the 8kc 
> position resulted 
> > in
> > a maddening array of signals besides the one I was wanting to hear.
> >
> > Then I switched to my Icom R-75 with 3 mechanical filters 
> that are about
> > 2.4, 3.5 and 6 khz in bandwidth. I could hear all 3 QSO's 
> Q5 in AM with 
> > the
> > 3.5 Khz filter, but it was no fun because the upper mids, 
> and all highs 
> > were
> > gone. Then tune off 1 Khz, and much better or turn on the 
> synchronous
> > detector, offset the passband tuning 2.4 khz (or 3.5), 
> select the 2.4 
> > filter
> > (or 3.5), and golly Gee! Nice sounding AM on all 3 QSO's so 
> long as you 
> > pick
> > the better sideband.
> >
> > As the morning went on the QRM went away, and all we had 
> was the traders 
> > net
> > on 3890. Now the SP-600 ruled until the signals started 
> dropping from
> > daytime propagation kicking in. Now I was experiencing QSB, 
> selective
> > sideband fading, and occasional impulse line noise. Switch 
> back to the 
> > R-75,
> > turn on the noise blanker, and synchronous detector. Back 
> to Q5 again!!
> >
> > This is not a tube versus solid state issue. Chuck Wa0zhh 
> has a all tube 
> > HB
> > receiver that has most of the modern features, and his receiver can 
> > probably
> > blow the doors off my R-75. Chuck likes old style octal 
> tubes too like the
> > 6L7 in his noise blanker circuit.
> >
> > So how would a R-390 have done yesterday, or a NC-183D, 
> Bretts HB tube
> > receiver, or one of Darrel's HB tube receivers?? Just curious.
> >
> > Jim
> > JKO
> 
> 
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