[AMRadio] Re: [Boatanchors] Sp-600 JX-11 Diversity?

John Flood kb1fqg at yahoo.com
Wed Feb 20 10:19:09 EST 2008

Quick note yes the tag on the turret is J-11.  I guess I invented the "X"


----- Original Message ----
From: K0DAN <k0dan at comcast.net>
To: John Flood <kb1fqg at yahoo.com>; boatanchors at mailman.qth.net; amradio at mailman.qth.net
Sent: Tuesday, February 19, 2008 10:18:17 PM
Subject: Re: [Boatanchors] Sp-600 JX-11 Diversity?


I have a Northern J11 SP600 and it works great. Others have recently 
answered your generic. After you do basic clean up & experimentation, let me 
kno if I can provide any add'l info.


----- Original Message ----- 
From: "John Flood" <kb1fqg at yahoo.com>
To: <boatanchors at mailman.qth.net>; <amradio at mailman.qth.net>
Sent: Tuesday, February 19, 2008 1:33 PM
Subject: [Boatanchors] Sp-600 JX-11 Diversity?

> Greetings Wise ones!
> This weekend a SP-600 JX-11 followed me home (when I was young it used to 
> be kittens and puppies with the odd reptile or amphibian mixed in.) along 
> with an assortment dust, dirt, and seed shells from barn storage but at 
> least the beasties didn't get into the undersides!    In any event this is 
> a diversity version.  I'm trying to I.D. who did the work but I think that 
> it was done by Northern Radio.  I say this as the label details for the 
> int/ext. M.O. and int/ext AGC/BFO controls look identical to those on a 
> National NC-183D/R Northern diversity version that had followed me home 
> some years earlier.  I was wondering if the factory did a diversity 
> version of the JX-11?  If so what did the front panel look like?  This 
> unit has no Xtal freq control and in addition to an IF output on the 
> chassis, there is a second IF out "in a can" with a SO-239 connector and 
> it is attached topside at the rear of the radio.  Sound like a Northern 
> job to youz guyz?
> After a basic cleaning to remove crud, the variac run up produced no smoke 
> signals and the local BCB stations were making noise.  A treatment of 
> carefully placed high tech bike lubricant with Teflon started the 
> transmission spinning again in true SP600 fashion as well as freeing the 
> bandswitch needle indicator that was stuck up top.  A dose or two of 
> Deoxit on the controls helped to greatly improve things and the same on 
> the bandwidth controls contacts started it singing again.  Granted I have 
> yet to touch a single piece of test gear to it but I did notice that the 
> AVC could use a bit more "A".  It tended to overload on the BCB station a 
> mile or so away from me.  Turning down the IF gain (that was maxed out) 
> helped a bit but it seemed to still act as it had more gain than was 
> needed.  Of course, having what look to be all orrigional components, 
> could very well be the cause here with caps gettin old and such, but some 
> time ago didn't someone here comment
> that the way the diversity mods were done gave this type of AVC results? 
> Strange enough, the dial accuracy was spot on in fact, as good as any 
> analog dial I have seen.  More to do to it but another old girl brought 
> back to life is good news!
> Thats the weekend report from here your comments and flames on this beast 
> are welcome.
> Thanks to Mr. Mike for the lead and see ya at NEARFEST!
> John Flood
> _______________________________________________

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