[R-390] Diode load

[Roger Ruszkowski]

K7IOU,
 
So inject 455 into the IF deck,
Turn the BFO on and see if you get a tone out.
Check for -7 volts on the diode load with 150 micro volts of 455 into the IF deck.
 
If you get no audio out touch a jumper across the diode load and see what you get.
30 seconds of audio will not hurt the rest of the receiver.
 
what do your modification semantics show you as happening around the diode load.
If the diode load I snot on the changes then you have to believe nothing is changed at the diode load.
 
As the diode load has DC on it, use a decoupling cap and inject some audio into the diode load and
see what audio you get out. A 1/2 volt or less of audio should be good going into the diode load.

Roger AI4NI.
 
 
 
-----Original Message-----
From: K7iou1 <k7iou1 at gmail.com>
To: R-390 <R-390 at mailman.qth.net>
Sent: Thu, Mar 26, 2015 1:24 pm
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
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