[Drake] R4 Problem?

[Garey Barrell]

Bob -

It sounds like your BAND oscillator, PreMixer or PTO have quit.

Can you actually TUNE signals when the Preselector peaks?

If not, what happens if any one of the above stages quits is that you 
are peaking the Preselector on the 5.645 MHz IF frequency.

It may be as simple as dirty bandswitch contacts on the BAND oscillator 
crystal selector wafer.  Possibly just exercising the switch, or a bit 
of DeoxiT, will clear it.

The setup is the PTO  at 5.455 MHz is mixed with the BAND oscillator at 
18.1 MHz for (40M) in the PreMixer.  The difference frequency (12.645 
MHz) is selected and applied to the First Mixer where it is combined 
with the 7.000 MHz incoming signal to produce the 5.645 MHz IF signal.

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-B, C-Line&
TR-4/C Service Supplement CDs
<www.k4oah.com>


Bob Macklin wrote:
> I have not been listening to the bands for several weeks. Last night I tried to use my R4A to listen to a group on 7190.
>
> I could not hear any activity so I tried tweaking the preselector. I was set for 40M. But I found the maximum background noise from the preselector when it was tuned to the 80M region.Then set up for 80M. I found the maximum noise from the preselector when I set it to the 40M region.
>
> This morning I put the receiver on the bench with the signal generator. I can find the 80M and 40M signals just fine where they should be but the noise peaking of the preselector is not where I expected it.
>
> The preselector does peak a signal jut like it should. I am just wondering why I get the maximum background noise at a different position of the preselector.
>
> I live in a RF HOLE!
>
> Bob Macklin
> K5MYJ
> Seattle, Wa.
> "Real Radios Glow In The Dark"
>
>