[R-390] IF Transformer Question and New Intro

Mon Apr 8 21:27:06 EDT 2019

I remember when I was a schoolkid back in the early 80’s and the R390-a started showing up in the Fair Radio Sales catalog.  I drooled over them!  Then I got various Realistic DX-nnn receivers over the years before getting a Drake R8B and an Icom R-75.  I lost interest in getting an R-390a all these years until I saw the one I bought.  It had to be mine!  All I can say is wow!!!  So it has no sync detector but, so what?  It sounds incredible…  

From: Larry H <larry41gm at gmail.com> 
Sent: Monday, April 8, 2019 9:09 PM
To: jgedde at optonline.net
Cc: Larry J. Haney <larry41gm at gmail.com>; R-390 Forum <r-390 at mailman.qth.net>
Subject: Re: [R-390] IF Transformer Question and New Intro

John, welcome to the group.  These are a marvel, aren't they.

All 3 of the 'IF's have 2 slugs (top and bottom) accessed through the one top hole in the IF can.  You need a special tuning tool to access the bottom slug through the top slug.

The exception is the Z503 which looks like an IF, but is not.  It's a single tuned coil.

Has the killer cap C553 been replaced, yet.  Do not continue to operate until it is.

Have fun with your new toy.

Regards, Larry

On Mon, Apr 8, 2019 at 5:53 PM <jgedde at optonline.net <mailto:jgedde at optonline.net> > wrote:

Hiya Fellas,

My name is John and I'm not only a new R-390a owner but a new member of the
group.  I found a R-390a for sale online and I got good vibes and bought it.
It cost a small fortune to have it shipped to me, but I scored a working
R-390a and I'm having a ball with it.

My R-390a is a true mongrel.  Motorola power supply, Teledyne IF Strip, EAC
AF section, Collins front panel - all circa 1962/3.  As for the crystal
section and the RF deck I'm not that far into it yet to know who made them.
Nonetheless, this receiver is a solid performer and just get's better as I
tweak it all back into health.

Here's my IF transformer question.  In an attempt to readjust the 455 kHz
section, I cracked two stuck slugs in the transformers - one is backed out
almost all the way.  No worries there as I have some new slugs on order from
Fair and can get them out using the old coping saw blade trick.  My question
is that the Y2k manual and the TM's list two slugs in each transformer.  It
says something about drilling or punching a hole in the cans to access them.
My cans have an existing hole at the top but from what I can see, there is
only one slug in each transformer.  Am I missing something?  Since I
monkeyed with the slugs, I have lost some performance.

All in all, the R-390a is a masterpiece and runs circles around my modern
Icom and Drake stuff.  The R-390a is amazing at pulling intelligible audio
out of the mud.

John

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