Hi Dave,
Thanks for the video. I don't know much about the LO pulling
except from, just now, looking at the schematic. The cathode and
grid-return of the triode section of V4 go directly to ground. So
it's hard to see when the interaction comes in.
The first thing I'd do is swap out V4, a 6K8, in case there is
some internal leakage from the AVC'ed signal grid..
A stitched together copy of the N-schematic is attached.
This was another case of the original .pdf's I was working with
being locked up so I couldn't extract the images. However, today
there is an easy fix for that: Printing the file using Microsoft
"Print to PDF" gets you an unlocked copy. Extract the schematic
images a .png's and stitch them together using "Image Composite
Editor" another free marvel from Microsoft .
Merry Christmas,
Al
On 12/18/2022 12:59 PM, David Stinson
wrote:
Been
working on a "Christmas Present" U.K. R1155
receiver. Playing nicely now, but still have
some issues:
https://photos.app.goo.gl/WiPupJQ7bf6hwCNC7
It's running on well-regulated 135VDC B+.
When I'm not using AVC, turning the gain control
pulls the local oscillator. When using AVC,
it doesn't. Before I start digging-in, is
this something you've seen before?
Also- I need to remove the front bezel in
order to change the discoloured Perspex window.
On the "old" tuning knob, one removed the logging
ring around the tuning knob and the assembly came
off without disassembling the tuning knob/drive.
This N-model has the "new" tuning drive:
https://photos.app.goo.gl/EJQymom4vM9PSDGc8
Does someone know the proper procedure for
pulling this bezel? I don't want to assume
or "by guess and by golly" if I can prevent it.
There appear to be screws to secure the drive which
come from the inside of the bezel.
Thanks, everyone.
73 Dave AB5S