B&K 1077B questions

[govee]

I decide to get my 1077b out as I am working on a GE 10T1 that needs trouble shooting. I picked this up a while ago and made a bad assumption based on limited test. I had previously turned it on an I got a nice purple glow on the front of the crt. I mistakenly assumed all is well. It is not. I tried it first on the the ge that has no picture an deiced i really needed to verify the 1077 works. I hooked it up to my admiral 19a11 and no image. Today I decided to look further into it and as it eats up a lot of bench top space I hooked it up to my flat screen (old non smart) via its cable/antenna connection. There is something there. The flat screen looks like it needs the horizontal hold adjusted. Since there is no such control on it I was wondering if there was a control or circuit in the 1077 would cause or adjust this? The video is a black//purple large rolling block that is about 30 percent of the screen height but full width and is separated by a large static block that would fill the rest of the screen height if not rolling. If I adjust the RF attenuation pot I can make the black//purple image disappear. The tvs input is set to antenna vice cable.

A few images below

Andy