[R-390] Diode load

[K7iou1]

Hi Larry, just got done checking the 1st and 2nd oscillators and both are correct. Looks like a serious alignment is needed. Someone's been in there before as the transformer covers are reversed from 1st & 2nd oscillator circuits with notes in the manual.
15 MHz is dead on.
28 MHz 400k off
7.293 MHz 8.295 1.003 MHz off
Other bands little or no receive.
I will use Cramolin, Deoxit on all tube sockets & connections. Previously used it on module  harness plugs.
Audio working. SSB rectifier removed.
Thanks to all for your help.
de k7iou

On Mar 26, 2015, at 4:31 PM, Larry H <dinlarh at att.net> wrote:

Hi David,  If the 2nd xtal osc is off a lot, check its switch alignment.

Regards, Larry

From: Larry H <dinlarh at att.net>
To: K7iou1 <k7iou1 at gmail.com> 
Sent: Thursday, March 26, 2015 1:23 PM
Subject: Re: [R-390] Diode load

Hi David,  Good and BAD news.  As for the diode load Navy mod - Make sure that the center conductor of the coax does not touch anything.  It sounds like its ok now.

As for the off freq, check the 17mc osc frequency - you can disconnect the mini coax j221 and feed it to rx or counter.  If its very close its fine.  If good, try the 2nd osc at j415.  Since its been sitting for a while, you could be a victim of 'bad contacts' due to corrosion.  Wiggling and /or removing and replacing tubes and crystals can sometimes resolve these issues.  If you use a deoxit, be very careful in application - use a Q tip.  Spraying can be a problem.

Also,  you should check the filter killer cap c553 asap.

Regards, Larry



From: K7iou1 <k7iou1 at gmail.com>
To: Larry H <dinlarh at att.net> 
Sent: Thursday, March 26, 2015 12:58 PM
Subject: Re: [R-390] Diode load

Yes, I did that and audio is now working but...,

Slow progress, I found it receiving on 11M with audio but signals received are low.
Carrier Meter adjust full clockwise, top of chassis.
Gain adjust full counter clockwise, top of chassis.
 
My Icom receive freq. 27.025 guy running excessive power as you could hear the transmitter grown and the ring when he PTT. Indicated receive Frequency R-390A was 28.985
I then tried 40M Icom 7.293 and hit transmit while hunting for it and with BFO on I heard it ring at 8.805. With BFO off I would only heard a slight pass through.
Ideas?



On Mar 26, 2015, at 12:50 PM, Larry H <dinlarh at att.net> wrote:

Hi David,  I looked at the mod schematic you posted and see no mention of changing the need for the 14-15 jumper for diode load.  The audio mod looks good to me.  I'd install the jumper and see.

And no I don't think the audio agc gadget could hurt anything if it shorted.

Regards, Larry

From: K7iou1 <k7iou1 at gmail.com>
To: "R-390 at mailman.qth.net" <R-390 at mailman.qth.net> 
Sent: Thursday, March 26, 2015 10:24 AM
Subject: [R-390] Diode load

Previous owner did a audio mod.
The jumper for diode load is out but with his mod I don't know if I can install the jumper. 
I posted it here on AMfone
http://amfone.net/Amforum/index.php?topic=38117.0
Schematic of mod at bottom of my last post.
73
de k7iou
______________________________________________________________
R-390 mailing list
Home: http://mailman.qth.net/mailman/listinfo/r-390
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:R-390 at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html