B&K 1077B Rev G TV Analyst

[Tom9589]

Does anyone know of a source for the waveforms for a 1077B B&K TV Analyst, Rev G? I've got the manual, but not the supplemental sheet with the waveforms.

[kf4rca]

Not sure about the 1077 but my 1076's (I've got 2 of them) didn't come with a waveform chart.
What problems are you having?
If its vertical, I suggest changing all the 2.2M resistors in the unit. Most DVMs won't read that high accurately.
That's what was wrong with mine.

[Tom9589]

I got a waveform chart with my 1076 Manual. The vertical circuit is different between the 1076 and 1077B. In particular, the 1077B has a solid state stage to generate the vertical trigger pulse.

My problem is vertical instability. The raster on the CRT flickers in size which causes the test pattern on the TV under test to do likewise. I'm going to get a can of freeze spray today and will try that on the components in the vertical circuit.

[kf4rca]

My 1076(a) manual did NOT come with a voltage or waveform chart. It does have a tube placement chart.

[Tom9589]

Here is what I got when I ordered a manual from B&K. B&K was notorious for changing circuits and not incrementing the model number even though the changes were significant. I know of three different Color rainbow circuits on the 1076. Mine was the earliest which did not have the 189 KHz oscillator which generated the "keyed" rainbow display.

[kf4rca]

Thanks for the scans! All I got was the booklet and an 11x17 copy of the schematic.
What is the difference between the 1077 a and b?
The 1076 b had an RCA jack on the rear for external audio and a 3-position slide switch to select off-tone-ext.
Also it had a different phototube than the a version (octal vs 11 pin).

[Tom9589]

I know of three different versions of the 1076 and all were called the 1076, no suffixes. The oldest, which I had, has only a Rainbow generator, not a Keyed Rainbow generator. It has only a 3.56 MHz crystal and a 6AN8 tube on one of the main printed circuit boards. The second version has a Keyed Rainbow generator and has a 6AN8 and both a 3.56 MHz and a 189 KHz crystal mounted on a small printed circuit board mounted to the backside of the front panel. The final version has a 6J9 tube and both crystals on a separate printed circuit board. I don't know where this printed circuit board is located. If you have this version, be sure to remove the 6J9 and have a close look at it. It is a 10 pin tube, just like a normal 9 pin miniature tube with the 10th pin in the middle of the other pins.

I only know of the 1077 and 1077B TV Analysts. There are two versions of the 1077B. The first (which I have) uses a sub-multiple of the 189 KHz oscillator to sync the horizontal oscillator. The later version uses two ICs to form a divide by 12 divider which converts the 189 KHz to 15.750 KHz to sync the horizontal. Mine seems to work fairly well. It locks in very well.

Now if I could just figure out what is causing the vertical instability.....

[Electronic M]

Originally Posted by kf4rca

Thanks for the scans! All I got was the booklet and an 11x17 copy of the schematic.
What is the difference between the 1077 a and b?
The 1076 b had an RCA jack on the rear for external audio and a 3-position slide switch to select off-tone-ext.
Also it had a different phototube than the a version (octal vs 11 pin).

I'd love to see the audio input version schematic and see what it'd take to add that to my 1077.

[Tom9589]

Go to page 56 of this link. The external audio input is connected to the grid of V7A (12AT7).

https://archive.org/details/BKModel1...tructionManual

[kf4rca]

what you could do is get one of those voice recorder chips and wire it into the external audio jack and then you'd have a Talking B&K Analyst.
https://www.ebay.com/itm/17481633283...wAAOSwyABca9Sp