Tech-Master NIB TV Kit #5516
 

Guys,

I won this 1955 TV kit NIB at an auction today. It does not come with a CRT.

The parts haven't even been removed from the carton! I talked to the seller and he said that he removed the instruction sheet to see what CRT it uses, but he didn't have that type. Otherwise completely unmolested. Because he already looked at the instruction sheet, I pulled them from the envelope.

What a find!

Of course the real question is should I keep it this way or build it?

Photobucket isn't cooperating so no pictures right now. I did post some pictures over on ARF.

I wouldn't have any reservations building that. Looks like any 70 degree electrostatic focus CRT could work, but I'm guessing that chassis is set up for a 17" tube, like a 17HP4.

http://i452.photobucket.com/albums/q...pskffw6mag.jpg

Some pictures.

http://i1060.photobucket.com/albums/...psjs5iwtmv.jpg

http://i1060.photobucket.com/albums/...psprlmg0df.jpg

http://i1060.photobucket.com/albums/...psd4alkswo.jpg

http://i1060.photobucket.com/albums/...pscv31txbv.jpg

http://i1060.photobucket.com/albums/...psmlptpeus.jpg

http://i1060.photobucket.com/albums/...psctpnlkyw.jpg

http://i1060.photobucket.com/albums/...psydywvpbm.jpg

Kevin,
Thanks for the reply. I needed that info for a CRT! Where did you get it? Was it a page from an Allied Catalog or such?

I also think it uses a magnetic focused CRT. There is a fly-back transformer and the schematic shows a HV lead going to a 2nd anode on the CRT.

I think the ad has a typo.

The listing is from my 1956 Burstein Applebee Co. Radio Master catalog.

Magnetically deflected, but electrostatic focus, unless your kit came with a electromagnetic focus coil? Your build manual must share some information on compatible picture tubes?

OK, I'm confused. There doesn't appear to be a focus coil used in this TV.

Here is the schematic:

http://i1060.photobucket.com/albums/...ps7jictfwd.jpg

The manual suggests "A low-voltage electrostatic or self-focus picture tube is recommended for use with this receiver."

That's because it's intended to use an electrostatic focused CRT. Which is nothing more than a DC voltage that connects to the CRT's focus pin. I think on a 17HP4 it's G4, but I can't make it out on your schematic.

https://frank.pocnet.net/sheets/127/1/17HP4.pdf

On the schematic, pin 6 is grounded.

That makes sense. Notice the -56-310v range for pin 6 on the17HP4 spec sheet. My experience has been that those electrostatic focused types are not very sensitive to what voltage that pin gets tied to. So they basically are self focusing. Don't think I've ever seen a electrostatic focused set with an adjustable control?

OK.

I've looked up some CRT's that would work:

17HP4
17TP4
17CGP4
17CP4B
19QP4
20HP4
20HP4E
20LP4
20MP4
21FP4D
21AFP4
21YFP4

Get new caps instead of using the wax caps that came with it, also use new electrolytics too.

Be careful, it looks like a hot chassis set.

And be sure that the CRT you use has the same heater current as that of the heater string.

It's a low B+ hot chassis design, similar to the AC-DC Emerson set I just restored.
The CRT used would be a 17HP4, 20HP4 or a 21YP4. I would stick with the 17HP4 type, as the design is a slightly lower high voltage supply, intended for smaller screen sets.
I see it uses the tried and true synchro-guide horizontal circuit. :thmbsp:
All the CRT's at the time were 600 ma, 6.3volt heaters.

Will do on all counts. Thanks

Yeah, I checked the specs and a 19QP4 is a 12K CRT. That would be a good one too...right?

Isn't the 19QP4 a Dumont type round tube?
The number is not familiar to me and I've seen a lot of old TV's, but not real many Dumonts.
Unless you meant, 14QP4? :scratch2:

No, it is not a round tube.

I've never seen a set that used one and it goes back to 1953. :scratch2:
Unless, you already have one, I don't think that one would be that easy to source. It's hard enough getting the more common types for the old sets.
I jumped on the chance to get a NOS 14QP4 for my Emerson 1956 model AC/DC set. The original was a 14HP4, but I knew the Q was a perfect sub.

Here is a list of CRT's that I pretty sure will work. Of course there are others, I just haven't taken the time to do more research. I sent off an email to EFT because they list about 6 from 17" to 21" that will work. I'm guessing that a 19FP4 and a 19KP4 if there are such animals would work also.

17CGP4
17FP4
17GP4
17HP4
17LP4
19QP4
20FP4
20GP4
20HP4
20HP4C
20CP4
20MP4
21AFP4
21FP4
21KP4
21MP4

Keep in mind the width and length of your chassis. There may be yoke(neck length and height) issues with mounting the larger CRT's on that chassis.

Yes, I've been thinking about that. Thanks.

The ones, I would go for is the 17HP4 or the 20HP4C. Those are the only ones that will fit without a problem. Some of the types shown are metal cone types.
Also, if you buy the tube from that source, MAKE SURE THEY TEST IT BEFORE THEY SEND TO YOU! :thumbsdn:

I know that I am a little late to the party. But I too support building the kit and with new capacitors as mentioned above. I recently acquired an NOS Knight-Kit oscilloscope kit and I am in the process of building it. I have found my capacitors to all be still good. (The kit is from 1966 and most likely the tubular capacitors are Mylar). Resistors are mostly drifted high however. They are replaced.

If you intend to build it, keep us posted and we love pictures!

The HV caps in there are high quality and are perfect for the boost circuit in GE PortaColors. :thmbsp:

I did a little poking around without disturbing the kit. There are some pieces that are wrapped in newspaper. It was from the Obituary section! It listed someone who died on January 6, 1957.

I think the kit was designed in 1955, hence the #5516, but this kit shipped sometime in 1957.

The dates on the drawings IIRC was October 1955.

Looks like ETF has 2 CRT's that would work.

A 17LP4B which is a good used aluminized CRT that operates at 12-14Kv.

A20MP4 which is a new CRT that operates at 14Kv.

I'll have to do a quick check to see if the 20MP4 will fit. Though I do think it will.

Any thoughts or comments on using a used aluminized 12Kv CRT vs a new "plain" 14Kv CRT?

I just replied to your post over on the other site. IMO that aluminized CRT will be very fun to watch and much easier to handle while working on and moving it around. Not to mention big is not necessarily better when one collects many of very similar objects. ;)

Thanks for those thoughts.

I did check and the chassis will handle the 20MP4 easily. Matter of fact the 17LP4B might be a challenge. I'll have to check it out more closely though.

I see that tube prefers about 14k anode voltage. I'm sure it will work on less, but it may not be optimal, especially as it grows tired with use. Someone else will know better than I.

http://tubedata.tigahost.com/tubedat...9/1/17LP4B.pdf

The 17LP4 is used in the Emerson low B+ chassis. It has the cylindrical face plate like the 17QP4. Back in the day, they were more expensive and not as common as the 17HP4.

The tube compliment is similar to my low B+ Emerson AC/DC set. MY set has the 14HP4, but the Sams states the set came through with a 14HP4, 17LP4 and a 21YP4. Somewhere in Riders it states that the 14" was the only one designated as AC/DC, even though the circuitry is similar.
It seems, the B+ wouldn't be high enough, running on 120 volt DC, to operate the larger CRTs.

I did a little checking on other TV schematics from my Beitman's disc. I checked in the 1955 issue which is the same year the 5516 drawings were signed off.

As with most schematics from the manufacturers of the same time period, most were very similar. The Emerson chassis 120245D is very similar to the 5516 and it can use a 17LP4 or a 21YP4 CRT. It uses 14.5Kv with the same B+ and other voltages.

All-in-all, I looked at 6 different schematics (all string filament) and they went from 13.5Kv to 15.5Kv with similar tubes and B+ voltages.

Now, this is just me thinking, that if I were selling TV training and making kits to support that training, and TV's were getting larger screens then I would design a set that would support the trends. The chassis is certainly large enough for a 20MP4 and will fit with no problems at all. The design uses 3 IF stages and uses basically the same amount of tubes as most consumer TV's of the time. It's not like they scrimped like on my AMC 116T or a Muntz etc.

So I'm thinking that it will handle the 20MP4 without problems. I'm sure we all agree that the 17LP4B will work hands down. Anyway, it will last a lot longer than me. I don't plan on watching B&W TV 8 hours a day. Though, it is nice to see some of the TV shows when I was a kid!

You'll likely be fine with either CRT. Of course you could hold off on the CRT purchase until after you have the set operating with an 8XP4 test CRT, at which point you'll have a better idea of the sets supply capabilities. I'm surprised if your manual or schematic doesn't specify the B+ and anode voltages. But as you suggest the circuits of that time period would have been very common.

The schematic shows +130V and +260V but no HV value.

I've found that the 17, 20, and 21 inch tubes that specify a minimum ultor voltage will usually work WELL below the minimum recommended; a slight twist of the brightness control will usually suffice. Hell, my Philco 48-1000 refuses to put out more than about 6.5 kV, but the 10BP4 in it still shows a nice watchable, if not terribly bright, picture.

I agree, although I believe there becomes more of a focus issue as the deflection angle increases.

I checked my Riders index and they cover the 5516! The index lists 18-3 and 21-13. I have Riders for TV vol. 2 thru 12. IIRC Tech-Master 630 chassis is covered in volume 4. Riders included not only the electrical but also mechanical info. Screw sizes etc. I'm thinking that maybe this information would also be included for my 5516 chassis.

Does anybody have these volumes and could you check to see what Riders shows? It would be really appreciated if I could get a copy of those pages.

Thanks.

Well, I started messing with the kit. I went up to the copy place and made copies and pdf's of the 6 instruction sheets to assemble the TV, the instruction booklet that goes into alignment and troubleshooting. The booklet also has the schematic which again I made a large copy and then pdf it. Also a large sheet that covers the IF strip instructions was copied and pdf. The pdf's are huge like from over 1mb to just under 5mb. I'll share those with everybody if I knew how. I also have copies and pdf of the Supplementary sheets. Basically if it came with the kit, it was copied and pdf!

Over the years the chassis cad plating has turned a yellowish green both on the top and underneath the chassis and yoke support. I have several pictures that show how bad it was.

http://i1060.photobucket.com/albums/...pszzxhswoa.jpg

http://i1060.photobucket.com/albums/...ps2klpkxan.jpg

Here is a picture of the IF Strip from the bottom:
http://i1060.photobucket.com/albums/...pspbrdncca.jpg

I did inventory and took a lot of pictures of each bag. That will be a separate post.

Here is another view of the bottom of the chassis:

http://i1060.photobucket.com/albums/...psixfofflp.jpg

Here is proof that it was aligned:

http://i1060.photobucket.com/albums/...psl8ckdkqc.jpg

I cleaned the chassis, yoke support, tuner, etc to get rid of the cad plating. I read somewhere that simple Green works great. It does! What I did was to pull the tuner, IF strip, filter caps, Selenium rectifier, fly back transformer, vertical output transformer, rubber grommets, all the pots, the HV rect. tube socket, etc. If I could unscrew it, it came off. This made the job a lot easier. I first masked off the tube sockets both top and bottom, then I would spray on some cleaner and then rub it around then after a few seconds I used a terry cloth to scrub and wipe the chassis clean. In reality, not much scrubbing. I also would use an acid brush and Q-Tips where needed. Once cleaned I would do the same thing again only with rubbing alcohol to further clean the metal.

Once that was done both top and bottom, I then used some Brasso to "even" out the look of the metal. Only this was done on the top, sides, and both sides of the yoke support. After that I wiped down the metal with WD-40. I then installed new rubber grommets. Here are some pics now that I'm done.

Here is the bottom of the chassis with everything installed back in that is going to get installed for now.
http://i1060.photobucket.com/albums/...psqlk6t8ob.jpg

Here are some different views of where I am :

http://i1060.photobucket.com/albums/...psobtheikt.jpg

http://i1060.photobucket.com/albums/...psjb2y9noy.jpg

http://i1060.photobucket.com/albums/...psweg317ou.jpg

http://i1060.photobucket.com/albums/...pspgxueagb.jpg

http://i1060.photobucket.com/albums/...psvjmrejt2.jpg

http://i1060.photobucket.com/albums/...psxqdvmj83.jpg

http://i1060.photobucket.com/albums/...psd1cjutbm.jpg

http://i1060.photobucket.com/albums/...ps8hnmm3pt.jpg