[R-390] New R-390A Owner

[Larry H]

Welcome to the 390A world and reflector, Ken.

*Most important before you power it on,* is to make sure C553 in the IF
deck is working correctly (no leaking at all at working voltage).  If it
has not been replaced with a very good quality 600v cap, then it should
be.  If it leaks or shorts under operation, a mech filter can be
permanently damaged.

Also do the other normal checks before and during power on.

Since the speaker audio is 600 ohms, the transformer might have been used
to drive a speaker.

The other stuff might have been used to implement audio derived AVC.

There's a ton of great info on the r390a.net disk maintained by Al Tirevold
and Wei Li.

Have fun.

Regards, Larry

On Mon, Jul 23, 2018 at 3:54 PM, Kenneth Perales <kenperales at comcast.net>
wrote:

> I just purchased  my 390 from a person who got it at an estate sale and
> knew nothing about the radio other than he thought it look interesting. I
> am ex-ASA having served from 1968 to 1971 and put in thousands of hours on
> the 390 in Nam and at Vint Hill Farm Stations as an 05H20 Ditty Bopper.  I
> have looked for years for a 390 that I could afford so I could get back in
> to copying code.  The radio itself come in a wood frame that someone did a
> good job of making it look classy for something out of the military.  I am
> still sneaking up on getting it hooked up and turning it on for the first
> time to see if it still works.  I am going to use a whip antenna on top of
> my flag pole.  Before I turn it on, I have a couple questions for anyone
> who might help.
> First there was what looked like some possible connector I found on the
> floor after unpacking the radio.  I am pretty sure it was not there before
> I unpacked the box.  It looks like it would slip over an 1/8” pin and has a
> threaded opening for a screw to maybe hook up a wire.  Does anyone
> recognize the part.  In the box was some kind of transformer not hooked up
> to the radio that only ever had 3 of the wires connected to anything.  A
> black wire labeled C on one side and two wires one also labled C and the
> other 8Ω  color Gray.  No idea for sure it was used with this radio.  Also
> hooked up to the radio dangling off the back was what looks to be some kind
> of resistor with no markings.  Hooked up to TB103 Slot GND 16 and to TB102
> AGC NOR DIV.  Two other contacts on the black block had been hooked up to
> something.  Any ideas what it might have been used for.  I have attached
> pictures of the items in question.  Any help would be appreciated.
>
>
>
>
> Ken Perales
> Sent from Mail for Windows 10
>
>
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