Tech-Master NIB TV Kit #5516

[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

[dieseljeep]

Originally Posted by 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

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.

[dieseljeep]

Originally Posted by Crist Rigott

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.

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.