[R-390] Poor man's R389

Mon Mar 13 14:40:47 EST 2006

Hi,

Regarding using various selective voltmeters as
receivers, all of the ones I've used have no AGC.

Bob

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> Today's Topics:
> 
>    1. Re: VFO squirreliness solved FOR GOOD (Tim
> Shoppa)
>    2. Wanted: junker Cosmos PTO's (Tim Shoppa)
>    3. R220-URR (mike Kana)
>    4. Re: VFO squirreliness solved FOR GOOD
> (DJED1 at aol.com)
>    5. Matching info wanted (Barry)
>    6. PTO success (DJED1 at aol.com)
>    7. Poor mans R 389 receiver (Perry Sandeen)
>    8. Re: PTO success (Joe Foley)
>    9. Re: R220-URR (roy.morgan at nist.gov)
> 
> 
>
----------------------------------------------------------------------
> 
> Message: 1
> Date: Sun, 12 Mar 2006 13:12:57 -0500
> From: shoppa_r390a at trailing-edge.com (Tim Shoppa)
> Subject: Re: [R-390] VFO squirreliness solved FOR
> GOOD
> To: shoppa_r390a at trailing-edge.com,
> R-390 at mailman.qth.net,
> 	DJED1 at aol.com
> Message-ID:
>
<20060312181257.3EA9C104000A at mini-me.trailing-edge.com>
> Content-Type: text/plain; charset=us-ascii
> 
> DJED1 at aol.com wrote:
> > entire threaded shaft.  I also resoldered the
> small  caps as Les had 
> > suggested.  I put it in the radio tonight, and it
> tunes  great- no warbles.  The only 
> > problem I have is that it's off about 2 Kc 
> end-to-end, and the variation is 
> > not linear.  I'll tweak the end point and  see how
> close I can come- it will 
> > probably meet the original specs when  completed,
> but won't be as good as a 
> > tweaked Cosmos.
> > Speaking of which, I also tweaked the end point on
> the Cosmos because it  was 
> > out by 1 Kc.  Fixed that right up, but now
> intermediate points are out  by as 
> > much as 1.8 Kc, where they were within 0.4 before
> I touched it.  And  the 
> > strange thing is that all the 25Kc points are off
> the same amount- 1.8  Kc.  All 
> > the 100 Kc points are right on, and the 75 Kc
> points are out about  0.8 Kc, 
> > and also all the same.  Very strange.  I'll look
> at the data  tomorrow and 
> > decide if I want to tweak all those little screws,
> or just put the  end point 
> > adjustment back to where it was.  
> 
> The endpoint adjustment does interact at least a
> little with the calibration.
> 
> A couple kc is the limit of adjustment possible with
> the little
> linearity screws.
> 
> I think that in some cases it may be wiser to add
> some small amount
> of capacitance rather than tweak the endpoint. Maybe
> I'll experiment
> with that tomorrow, AFTER replacing the toilet AND
> seeding the lawn AND
> installing the ceiling fan... (meaning it probably
> won't happen!)
> 
> > While I was in the radio, I found I had a bunch of
> BBODs in the IF.  I  
> > thought I had all Vitamin Q metal caps, but I was
> mistaken.  I don't have a  full 
> > set of replacements, but I did replace C553 with
> an Orange Drop, so at  least 
> > that is taken care of.
> 
> Was C553 a BBOD? The IF decks I've owned had BBOD's
> in a lot of not-so-
> critical-for-leakage places (e.g. screen and
> filament bypasses) but better
> quality metal cans - Vitamin Q's or Westcaps - at
> the filters.
> 
> Tim.
> 
> 
> ------------------------------
> 
> Message: 2
> Date: Sun, 12 Mar 2006 13:23:45 -0500
> From: shoppa_r390a at trailing-edge.com (Tim Shoppa)
> Subject: [R-390] Wanted: junker Cosmos PTO's
> To: r-390 at mailman.qth.net
> Message-ID:
>
<20060312182345.DA29C8C00AA at mini-me.trailing-edge.com>
> Content-Type: text/plain; charset=us-ascii
> 
> You guys may recall my voyage into the heart of my
> VFO (pretty much
> tearing down every single component in the can) a
> few weeks ago.
> 
> In an effort to learn more, I would like to find a
> few truly junker
> quality PTO's for me to tear apart and measure and
> reassemble in
> probably unrecognizable form. Probably prefer Cosmos
> mechanisms but
> I am willing to learn about others. And I am truly
> truly looking for
> basket cases here, whatever I do to these will make
> Frankenstein
> look like a wax job. I am mostly interested in the
> stuff inside
> the can so if parts are missing/lost/hopelessly
> damaged on the outside
> that is fine by me.
> 
> Also interested in junker BFO reactors for similar
> experimentation.
> 
> Will trade NOS tubes (usually JAN or British
> mil-spec) and/or
> 390A RF deck miscellany (springs, clamps, gears,
> etc.) for them.
> I also have some original 390A AC filters. Will also
> part with small
> quantities of cash and a good but used ballast tubes
> if sufficiently
> motivated.
> 
> Tim KA0BTD
> 
> 
> ------------------------------
> 
> Message: 3
> Date: Sun, 12 Mar 2006 10:25:30 -0800 (PST)
> From: mike Kana <aa9il at sbcglobal.net>
> Subject: [R-390] R220-URR
> To: r-390 at mailman.qth.net
> Message-ID:
>
<20060312182530.63151.qmail at web82204.mail.mud.yahoo.com>
> Content-Type: text/plain; charset=iso-8859-1
> 
> Hi All
> 
> I recently picked up a Motorola R220/URR receiver. 
> Did some web searches but didnt find too much
> information on this set.  Just out of curiosity,
> what
> were they used for?  Any information would be
> appreciated.
> 
> Thanks
> Mike
> AA9IL
> 
> 
> 
> ------------------------------
> 
> Message: 4
> Date: Sun, 12 Mar 2006 15:19:15 EST
> From: DJED1 at aol.com
> Subject: Re: [R-390] VFO squirreliness solved FOR
> GOOD
> To: shoppa_r390a at trailing-edge.com,
> R-390 at mailman.qth.net
> Message-ID: <2b2.632f4fa.3145dc43 at aol.com>
> Content-Type: text/plain; charset="US-ASCII"
> 
> Re: was C553 a BBOD? 
> No, it was a glass and metal capacitor.  I checked
> it after pulling it  out 
> by putting 500V thru a microammeter into the cap. 
> Not even one  microamp of 
> leakage.  I checked a couple of BBOD I had laying
> around 
=== message truncated ===

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