Tech-Master NIB TV Kit #5516

[Crist Rigott]

Originally Posted by dieseljeep

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.
All the CRT's at the time were 600 ma, 6.3volt heaters.

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

[dieseljeep]

Originally Posted by Crist Rigott

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?

[Crist Rigott]

Originally Posted by dieseljeep

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?

No, it is not a round tube.

[dieseljeep]

Originally Posted by Crist Rigott

No, it is not a round tube. I'm attaching the spec sheet for it.

I've never seen a set that used one and it goes back to 1953.
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.

[Crist Rigott]

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

[Kevin Kuehn]

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.

[Crist Rigott]

Originally Posted by Kevin Kuehn

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.

[dieseljeep]

Originally Posted by Crist Rigott

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

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!

[kvflyer]

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!

[dieseljeep]

Originally Posted by kvflyer

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.

[Crist Rigott]

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.

[Crist Rigott]

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?

[Kevin Kuehn]

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.

[Crist Rigott]

Originally Posted by Kevin Kuehn

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.

[Kevin Kuehn]

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