View Full Version : B&k 1077


TUD1
07-30-2016, 02:07 PM
Got this at the radio club today for the Best Price. It's in okay shape, but the sides are all rusted, and the yoke is falling apart. I plugged it into the variac and brought it up real slow, but the magic smoke still managed to escape. It was pulling over an amp at 60 volts. I'll replace the lytics maybe next week. I only have one slide. It has all the original Dynascan tubes except the photo multiplier tube, which is an RCA. The CRT tests very strong. At first, it tested dead, but after 10 minutes, it started waking up.

davet753
07-30-2016, 02:50 PM
Good Lord, I haven't seen one of those in years. I had one, and a set of the transparent slides to make the test patterns with. An odd piece of test equipment, that's for sure. As I remember, it wasn't used much.

Electronic M
07-30-2016, 08:57 PM
They are super useful for diagnosing, Sweep, and "no signal" problems. Mine gets used every few sets.

Phil Nelson
07-30-2016, 11:10 PM
A 1077 is very handy in some situations. This 1077B article has a schematic and voltage chart, plus scans of the standard slides:

http://antiqueradio.org/BK1077BTelevisionAnalyst.htm

Hope you get yours working correctly!

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

DaveWM
08-01-2016, 12:14 PM
I have a 1076, also find it handy for signal injection. I found a "recapped but does not work now" problem with it by injecting the composite video. Also as mentioned handy for checking yokes/flys (has a test for that) and generating sweep signals to power up horz and vert sweep circuits.

Beware of shot gunned recappers, esp with point to point circuits (easier to mess up than PCB stuff where you cant really wire it up wrong only use wrong values or polariites).

Electronic M
08-01-2016, 01:03 PM
I have a 1076, also find it handy for signal injection. I found a "recapped but does not work now" problem with it by injecting the composite video. Also as mentioned handy for checking yokes/flys (has a test for that) and generating sweep signals to power up horz and vert sweep circuits.

Beware of shot gunned recappers, esp with point to point circuits (easier to mess up than PCB stuff where you cant really wire it up wrong only use wrong values or polariites).

Some PCBs do have spare lead holes in bad places...I've caught myself almost doing that once or twice...

DaveWM
08-01-2016, 05:10 PM
I have seen that where caps have axial or radial holes. Still a lot harder than term strips. That one really had me going. Part of the problem was he said it worked (well yea if you put about 1v RF in at the tuner, you could barely get something that looked like a pic on the CRT). 1076/77 are fun to play with, make shadow puppets!

Electronic M
08-01-2016, 06:08 PM
1076/77 are fun to play with, make shadow puppets!

Fun, but don't do it under florescent, sunlight, and possibly other light sources. IIRC the photomult pickup tube (which ain't common or cheap) is easily damaged by UV produced by florescent lighting (and other sources). My bench is lit by florescents so I try to never have the lid open with the B+ running.

N2IXK
08-01-2016, 06:26 PM
Fun, but don't do it under florescent, sunlight, and possibly other light sources. IIRC the photomult pickup tube (which ain't common or cheap) is easily damaged by UV produced by florescent lighting (and other sources).

Do you have a source for this info? Bright light sources in general aren't good for PMTs, as they cause permanently increased dark current and noise output, particularly in very high gain/low light types (which the one in a TV analyst isn't). But in the specific case of the TV analysts, other than a few seconds recovery time after closing the lid, I have never noticed anything in the way of permanent effects. As far as UV goes, the P16 phosphor used in the analyst CRT is largely a UV source, with only a dim output in the purple end of the visible spectrum.

The PMT used in the TV analyst is a 931A type, by far the most common and cheapest PMT available. NOS ones are all over eBay and hamfests for very cheap prices:

http://www.ebay.com/itm/1-NOS-GL-931A-Vacuum-Electron-Tube-GE-USA-1962-/371693720845

old_tv_nut
08-01-2016, 06:46 PM
When I worked on the CBS/Motorola EVR video player, we noticed that the Hamamatsu PMTs were less noisy than the RCAs, but would become equally noisy if exposed to fluorescent lighting.

I do not know or recall if the output decreased and the extra noise came due to turning up the dynode voltages.

I do not know if they recovered after some time, as we did not re-use the degraded ones and carefully replaced them with new PMTs in a relatively dark room. The players were demo units, so we wanted to cherry pick the least-noisy units.

I speculated that the Hamamatsu PMTS were assembled and packaged in a dim environment and the RCAs came "pre-exposed," but I have no actual knowledge of that. Photoemissive materials are so open to degradation that it could easily have been a difference in processing, not light exposure at the factory.

Electronic M
08-01-2016, 07:47 PM
Do you have a source for this info? Bright light sources in general aren't good for PMTs, as they cause permanently increased dark current and noise output, particularly in very high gain/low light types (which the one in a TV analyst isn't). But in the specific case of the TV analysts, other than a few seconds recovery time after closing the lid, I have never noticed anything in the way of permanent effects. As far as UV goes, the P16 phosphor used in the analyst CRT is largely a UV source, with only a dim output in the purple end of the visible spectrum.

The PMT used in the TV analyst is a 931A type, by far the most common and cheapest PMT available. NOS ones are all over eBay and hamfests for very cheap prices:

http://www.ebay.com/itm/1-NOS-GL-931A-Vacuum-Electron-Tube-GE-USA-1962-/371693720845

Source is Videokarma. Read it in another thread on the 1077/76/75 family, and have observed those words of caution ever since.

kf4rca
08-02-2016, 07:43 AM
The 931 is used in the original 1076. The new 1076B uses a different tube, has more pins. Not interchangeable. I have one of each. I suspect the 1077 uses the newer tube.
The newer tube produces a sharper image.
Be careful when removing the tubes as the keyway sometimes breaks off allowing incorrect insertion.

kf4rca
08-02-2016, 02:00 PM
one has a 4422 and the other has the 931. Both are 11 pin tubes and from what I've read, they should be interchangeable.
The 1076B is distinguishable by the 3 pos'n audio switch and the RCA jack on the back for external audio.
Believe some of these units were marketed for the hotel/motel industry so they could display messages over their MATV system.

N2IXK
08-02-2016, 02:26 PM
The 4422 is one of RCA's "mystery" types in the 4000 series. Many of these had little or no published data available, being modified or selected versions of standard types, usually for sale to a single customer.

I have access to a fair number of internal RCA tube division documents (including a bunch of the 4000 series types) and a shelf full of tube databooks, but nothing on the 4422. B&K themselves suggested the use of the 931A as a replacement type, rather than offering the 4422 as a replacement part. This would lead me to believe that it may have been an "off-spec" 931A that was "good enough" for the intended application (which isn't all that demanding compared to most PMT applications in scientific instruments and such) , and was sold to B&K at a discount. Not all "selected" tubes were "better" than their prototypes, and this MAY be one of those cases.

Only a former engineer from RCA or B&K would be able to give the definitive answer on this one, I'm afraid...

kf4rca
08-03-2016, 07:30 AM
I looked at my RCA Photomultiplier Handbook (ca. 1980) and there is no listing for the 4422. There are other 4000 number tubes all classified for imaging purposes.
There are two 931 tubes listed- an A and a B version. The difference is the formula for the photo-conductive surface.

kf4rca
08-05-2016, 08:05 AM
Some of those B&K's had selenium rectifiers. That could very well be the source of your smoke. If you have vertical linearity problems, change the two 2.2Meg resistors in there.
You can make extra slides yourself. Download the desired image and print it to paper on an ink jet printer. Take that image to Staples or Office Depot and ask them to make a transparency. Tell them extra contrast when they print it on the laser jet. Cut the transparency to the desired size. The transparency will cost about 75 cents.
If the image is too big, you will have to use a graphics program to scale it down. I use GIMP which comes in Ubuntu Linux but I am sure Microsoft has similar programs. I found the desired size is about 300x400.

Electronic M
08-05-2016, 11:16 AM
Gimp was ported to windows ages ago, but the installer is kinda spamy.

kf4rca
08-05-2016, 04:07 PM
They also make it for Mac OS X.
And then there is:
www.resizeimage.net.
There used to be a desktop contraption at Eckerds drugstores that would do it. They only charged if you made a hardcopy of the image. But if you saved it to your flesh drive, there was no charge.

kf4rca
08-06-2016, 06:36 AM
its www.resizeimage.net

kf4rca
08-06-2016, 07:25 AM
the 931 tube is the most commercially successful PMT tube. So there should be lots of them out there.
The following tubes appear to be electrically and physically identical:
1P21, 1P28 (A & B), 931 (A & B), 4832, 4837, 4840, 4552.
The only differences are photocathode material (affecting sensitivity) and glass envelope material.

TUD1
08-06-2016, 01:23 PM
I got a B&K 1076 today from a friend for the Best Price. It is in much better condition than the 1077, so I will be fixing it instead.

TUD1
08-06-2016, 10:52 PM
I plugged the 1076 in today, and there is good news and bad news. The good news is that the magic smoke is still inside, but the bad news is that it has no high voltage. I heard no sounds come from it whatsoever. I won't be bothering with the 1077 anymore. This 1076 is in WAY better shape.

Electronic M
08-06-2016, 11:11 PM
You did not click it to heater only stand by mode did you?

TUD1
08-06-2016, 11:29 PM
No. I made sure it was in the ON position.

kf4rca
08-07-2016, 08:35 AM
it was laying in a pile of junk behind a shopping center. It looked like it had sat thru a couple of rainstorms. One of the pots was completely encrusted in rust (replaced it). But the tubes were intact and no cracks in the circuit boards. I set it out in the hot sun for several days to dry it out and after much scrubbing and scraping I got much of the remaining rust off. I then did resistance checks since I had one to go by. I went thru a whole can of contact cleaner cleaning the switches and controls. When everything checked, I powered it up. To my surprise, no smoke and it worked- well, sort of. I had tremendous vertical non-linearity, so I went thru the vertical circuit. It took a while working on it, off and on. But I always remembered one thing an old chief engineer told me. If it worked before, it can work again.

TUD1
08-07-2016, 10:31 PM
I turned the B&K 1076 on again today, and I got an image! The CRT lit up pale blue. I also manged to find a whole bunch of slides still in the envelope. All I have left to do is learn how to use the thing. It's in exceptionally good condition.

kf4rca
08-15-2016, 04:19 PM
If you think Flying Spot Scanner technology is a thing of the past, you should google Rank Cintel Telecine. That's a high end film transfer device used to transfer 35 mm film to videotape. They have been around since the early 80's. I think they cost around $100K when new. I'm sure you have seen a movie on TV transferred with one. They do not use a shutter as a conventional projector and camera would. You will not find them at a TV station but more likely at a production house specializing in commercial transfer. Many of the Hollywood producers shoot in film and then do the distribution in tape.

TUD1
08-18-2016, 06:36 PM
I hooked the B&K 1076 up to my 1971 Zenith 20BC50, and I actually got an image. The horizontal lock was non existent, but an image nonetheless.

Phil Nelson
09-02-2016, 03:13 PM
Those Analysts are handy devices. My 1077B worked fine after I replaced the electrolytics:

http://antiqueradio.org/BK1077BTelevisionAnalyst.htm

Near the end of that article is a link to a discussion of the different versions of Analyst. It also mentions the book by Milton Kiver, Television Analyzing Simplified, which is the last word on using this gizmo.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html