Hi Al,

In the R1155, V4 is not a 6K8, it is a Osram X66 (CV1099 / VR99) and this tube cannot behave as a 6K8 because the grid 1 and 3 are interchanged between the two types.

73, Jacques, VE2JFE in Montreal

De : [email protected] <[email protected]> De la part de Al Klase
Envoyé : 18 décembre 2022 16:28
À : [email protected]; ARC-5 <[email protected]>; milsurplus@mailman <[email protected]>
Objet : Re: [MMRCG] Hello R1155 Fans

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

Al Klase - N3FRQ
Jersey City, NJ
http://www.skywaves.ar88.net/