21-CT-55 has a new home - Page 8 - Videokarma.org TV - Video

Electronic M · #1 10-19-2017, 05:33 PM

A few hours ago I found Nick's coil list and edited my post to reflect that.

I've got a 1KVA VRT isolation trans waiting for it. I may put a variac in series to set the line voltage if I don't like what the VRT is putting out. The mains voltage here varies a bit so most tube sets end up run off a VRT anyway.

It will be a while before I get to working on or finishing this set. Plan is to order enough parts for several sets (some of which may be done first), plus replenish my cap stocks to nominal quantities, as a winter stock up. I'm seriously considering restuffing all the caps in the 21CT55 which is going to take time as is checking everything over before power up. As with any early color set with an unobtainium flyback there are going to be a lot meters on it for the first power up with the H out tube connected.

WISCOJIM · #2 10-20-2017, 07:55 AM

Quote:

Originally Posted by Electronic M

I've got a 1KVA VRT isolation trans waiting for it. I may put a variac in series to set the line voltage if I don't like what the VRT is putting out. The mains voltage here varies a bit so most tube sets end up run off a VRT anyway.

You should get one of these for each of your sets.

(see thread: http://www.antiqueradios.com/forums/...?f=15&t=209410)

.

benman94 · #3 10-20-2017, 09:59 AM

Quote:

Originally Posted by WISCOJIM

You should get one of these for each of your sets.

(see thread: http://www.antiqueradios.com/forums/...?f=15&t=209410)

.

That's just a rebadged Sola CVT, and it can't supply the necessary current to a 21-CT-55 anyway. The Colorvolt came out in the late 60s and was limited to about 3 amperes, so about 350 volt-amperes of apparent power.

A CT-100 draws just a hair under 500, I think the 21-CT-55 is about 540 or so. A CTC-4 draws 375 watts, the CTC-7 and 9 chassis are in the vicinity of 360 watts. A nice thought, but not really practical for any 50s roundie. A nice 750 VA or 1k VA unit is superior.

Electronic M · #4 10-20-2017, 01:15 PM

Quote:

Originally Posted by WISCOJIM

You should get one of these for each of your sets.

(see thread: http://www.antiqueradios.com/forums/...?f=15&t=209410)

.

I sort of do....I don't have that exact model that turns it's self on and off, but I've got 4 outboard CVT/VRT units (2 250VA units, a 500 and the HEAVY 1KVA unit), and I've been using my VRTs with remote switched outlets...So in the end the function is similar only I don't have to get up to turn it on and off.

benman94 · #5 10-19-2017, 06:07 PM

I don't restuff as I feel there are few, if any sets, truly worth the effort. To each his own though...

About the inductors, the original white ones are obviously the best fit electrically. Check them and any that aren't open, leave. Some more may open during the restoration, but if any survive, they're worth keeping in my opinion given my experiences with my CT-100 (now John's).

miniman82 · #6 10-19-2017, 09:13 PM

Not sure what troubles you had, but this is my Merrill after total inductor replacement with the new ones from the list I put together. Looked pretty good to me.

Crappy picture and there’s a hint of a drive line, but the color was stunning.

*zenithfan1* · #7 10-21-2017, 06:27 AM

Quote:

Originally Posted by miniman82

Not sure what troubles you had, but this is my Merrill after total inductor replacement with the new ones from the list I put together. Looked pretty good to me.

Crappy picture and there’s a hint of a drive line, but the color was stunning.