[R-390] deaf below 8MHz (R-390A)

[atfu]

Many thanks, Larry, for the swift response. Looking at the signal path,
it really ought to be a 1st mixer problem. Naturally, as I still have to
warm up to the radio, I am hesitant to remove the RF-module.  So I
follow your suggestions in the order of least invasiveness.

1. I turned the three var caps C283-x in the 1st var IF a couple of
times to resolve possible contact problems. No effect.

2. I took a good look at the contacts of the mixer and osc tubes, V202
and V207. Cleaned everything again. No effect.

3. Tomorrow I'll look at the Y201 crystal in HR-202. I'll report.

4. Then S208 will be next on the list. Don't even want to think about
that yet

Best, A

Am 20.05.2019 um 13:42 schrieb Larry H:
 > Andre, Welcome to the r390 group.  I know that you will enjoy the
R-390A.  Sounds like you've done some good things to it already.
 >
 > The 1st mixer is not used above 8.0 mh, so is probably the 1st place
to look at.  A common problem is the switch segment S208 is not lined up
correctly, removing B+ to the 1st osc screen below 8 mh.  Another
problem is a bad contact on the crystal, it's housing, the osc tube or
mixer tube.  And don't forget about the 1st var IFs, see if their
movement is working correctly.  Have fun.
 >
 > Regards, Larry
 >
 > On Mon, May 20, 2019 at 3:52 AM atfu <atfu at gmx.de
<mailto:atfu at gmx.de>> wrote:
 >
 >     ...
 >     After replacing paper caps in IF deck definite
 >     improvement on all bands above and including 8 MHz, below that --
NIL,
 >     including no cal signal. ...