Classic Hifi Care

I've wanted one of these for some time. I finally got this one a couple years or so ago, and am thrilled to have it and to have a chance to tinker with it a bit. This topic is a continuation of the Zenith TV topic I started. This topic will discuss the Analyzer and its journey back to proper operating condition. This may be a rather drawn-out project since I'm working on this while I wait for parts for the record player project.

I did some tinkering with this last summer, before the shop was done. I have notes here that I determined at that time it needed filter caps. This fits with my recent experience using the Analyzer on the old Zenith TV. The image out of the Analyzer was poorly focused, did not fill out the screen vertically and the image was just weak. I found I could wiggle the tube in the tuner which would make the image flash more focused and stronger, but only for a moment. The first step I'd like to take is to check B+. This will tell me if the filter caps are so leaky they are dragging down B+ or if I have other problems. A complete recap may be indicated, but I'd like to do a bit of troubleshooting first. I know the controls and switches are all dirty. The color signal out of the Analyzer is very weak, really washed-out looking and the intensity control does nothing. I need to test the tubes, particularly those in the video and vertical circuits. I haven't examined the schematic closely, so I'm flying blind at this point as to specifics. What little I've fooled with this tells me that it will be a worthwhile instrument for what I need it to do, once I get it sorted. All the things people look for that fail in these things seems to be good in this one. I need a set of transparencies yet. I got the service literature online.

Is the Analyzer basically a little RF oscillator that transmits an FM TV signal with selected images (test pattern, etc.) or does it perform analysis itself, like an oscilloscope? I went back and looked at your photos but the test instrument was your CRT tester.

You said "I could wiggle the tube in the tuner which would make the image flash more focused and stronger." Sounds like a argument for pin cleaning before blaming everything on the Analyzer. But the shape, if that's replicated on another TV, then it's likely the Analyzer's output. Too bad you can't wait until midnight and get a test pattern from the TV station after the national anthem played. Oops, giving away my age.

Chris Campbell

The Analyzer basically is a small TV set. IT has all the circuits in a TV set. You can use it to replace a section, such as the vertical section, in a TV for testing purposes. You use the transparencies for cross bars and that so you can do convergence and static alignments. It has a high-voltage section you can use to replace the one in the TV under test. It will also ring flybacks and yokes, although such activity is above my pay grade at this point. The Analyzer is subject to all the faults one would encounter in a TV set. The Analyzer will replace several pieces of stand-alone test equipment used in TV repair such as a signal generator, a color bar generator, a high voltage power supply, even one that will work with a solid state supply. The main purpose I have for the Analyzer is to help me sort the TV in the Stereo Theater I have. It has an issue with the front end of the set, probably in the tuner or in the IF strip somewhere. I can use the Analyzer to inject a signal at video IF and at the audio IF into the IF strip to see if the issue is in the IF strip or in the tuner.

So it's a actually a fairly complex device. Is it worth doing some switch-cleaning before getting more serious? I'll bet it has lots of switches.

Chris Campbell

I had downloaded the service literature for this some time ago. Now I can't find them....

Chris, switch and control cleaning is certainly on the list of things that need done. I don't believe controls being dirty would keep the screen from being filled completely. In a TV chassis, one should suspect tubes or capacitors first. There is a vertical size control, as yet to be located, somewhere on the chassis. The schematic I have is not very good. It doesn't give element voltages. I may just break down and buy a service manual on ebay. According to what I've read, these things are known for having issues with drifted components such as capacitors.

Is it like the one Shango showed on his channel? I think he had one that was used in a TV station to generate the old indian test pattern

Yes, the one I have is like the one Shango has. MIne is missing all its transparencies, except one. The Indian Head transparency is not an "Official" transparency. It was created by the aftermarket. Phil Nelson has listed the transparencies on his website. They can be made, but I'd like to have a set of factory ones.

I removed the outer cabinet on the Analyzer so I could get to the filter cap can. The plan is to cut it with the Dremel tool to take the can apart. Then I'll restuff the can. I tested all the tubes and they were all good. The code on all but the flying spot tube was 239. I'll need to look that up.

The EIA code 239 is for Merit Coil and Transformer. I didn't know they made tubes in Japan. Date codes on the tubes were the first week of 1969, with the flying spot tube being an RCA dated 1972. Maybe it was replaced at some point?

Test this out on an older analog TV you know is working. The RF outputs on most VHF channels including all UHF, so that's easy to check. The test pattern slide (read via internal CRT flying spot scanner) goes out on all the channels, in video form at 40-46 mhz, etc. Sound can be selected.

Signal substitution is the main function of the BK 1077 B and I was made familiar with this in Vo tech which I did for a half day grades 10-12, it allowed me to narrow down where a problem stage was, so i was not going all over looking for bad parts. I could bring a color set's HV up by pulling a plate cap off the horizontal output, etc.

I have one that I got somewhere, with vertical section defect distorting the test pattern output. Its twin is a TV alignment marker generator too, in a matching enclosurehttps://www.radiomuseum.org/r/dynascan_sweepmar ... r_415.html#
Im more committed to using a Sencore VA-48 on TVs, as I don't have time yet to fix/re-dial the BK.

Toshiba, Hitachi, NEC, and Matsushita all made tubes. One myth is that the Matsu's were made on Mullard tooling, it's apparently not true though Mullard did provide input and assistance to Matsushita and my experience with many Japanese tubes has been that they are of excellent quality, as one might expect. Some US brands re-labeled Japanese tubes in the later years, and many Raytheon, Realistic, and International tubes were Japanese made.

Now back to TV analyzer talk...

I appreciate that information, Roger. I didn't realize that Merit made tubes in Japan for Precision B&K. They are labeled "Dynascan".

Dave, my Analyzer has a bulge in the display, kinda like a pumpkin that had been run over by a dump truck. I verified the condition on a CRT set of known good performance. The manual says that is usually caused by a wonky filter cap. The 80uf filter section of the filter can checked open, or severely leaky. I'll start there.....

Some testers used "tube merit" as a synonym for "tube strength", usually older testers.
As for tubes I've seen tubes labelled "Dynascan" made for B&K that were made in Japan, usually Matsushita, and made in UK.
And I'd bet some were US made as well. Like all equipment makers they wanted the customer to come back to them for parts.

I am in the process of recapping the Analyzer. I had some of the caps I needed in stock, had to order the balance from Mouser. There was a hitch on one value of cap, which I documented in another topic. That is the one I need worst. I have the filter cap can cut and ready for new caps. According to the repair information I have read, this should fix the distorted output.

I received the last capacitor I needed in today's post, so I was able to finish the recap project. I did all the filter caps and paper caps except for a .1 uf at 1000 volt cap that nobody seems to have, unless I want to buy 600 at a time. That is in the boost line for the HOT output, so I won't worry about it for the time being. It won't be all that hard to change at a later time. I want to get this thing usable so I can move on.

The service manual says that a pregnant image is likely caused by a leaky filter cap, the 80 uf portion. I replaced that cap with a 100 uf at 350 because I didn't want to just get one of that value, and I needed the 100 uf caps for those little GE stereos I have, sort of a kill two birds with one stone type deal. I haven't connect the Analyzer to a TV yet, that's next, but the image on the CRT fills up the transparency now. I have found the vertical size adjustment, so there is that. I don't know if the screen should be completely filled or not. I had black lines at the top and bottom of the TV screen before, so maybe this is better as well. It pulls 71 watts on standby and 120.85 watts in "on". No smoke, no noise, so maybe I did okay. Next up is repainting the cabinet, then putting it all back together. The cabinet needs to be on and the lid closed in order to get a good image on the TV.

This project introduces my first use of Katie Caps. The sleeve is over the original filter can base, secured by a couple dabs of silicone sealer.

What's the big tube next to the PT?

Bill

That is the flying spot tube that makes the thing work. It picks up the image from the transparency. The CRT shows purple in actual practice. I don't know why the camera makes it look blue.

Thanks, and it looks purple on my computer screen.

Bill

It still may not have enough vertical deflection. I'm trying to find YouTube videos on this thing. I don't know if the CRT should be fully filled out or not. I don't see why you would need it bigger than the transparency, but I don't know for sure.

In case it helps, Tony's Capacitor Corner has a .1uf @ 1600v Metallized Polypropylene
Radial Film Capacitor listed for 64¢

Thanks Ken, I appreciate the heads up. I thought about Tony, but thought maybe Rubycon or Nichicon might be better for use in this case. I put myself through more grief than necessary........