View Full Version : Oppinions on dealing with a 3DS3 HV rectifier

Electronic M
01-05-2016, 06:25 PM
I'm working on a GE C2 chassis clone....revisiting since I found a C1 schematic among my literature that gave me some usefull info in the horizontal circuit to troubleshoot a NO HV issue....

Anyway my B&K 606 does not seem to have settings for the weird 3DS3 rectifier (which has a shield built in to the bulb)....I've found that my H output tube is getting the correct drive and voltages, and that the top cap of the rectifier gives a healthy arc, but I'm only getting 8-12KV (should be 22KV) out of it.

I think the tube is bad, but I can't test it and I don't have another to sub (and the socket wiring is different from the 3V HV rects I do have).... My question is does anyone think it would be alright to rewire the socket for something like a 3A3? I don't really feel like coughing up $6 for another 3DS3...Especially when I don't know for sure that it is the problem. There is no back on the HV cage BTW.

Electronic M
01-05-2016, 09:59 PM
Well I looked at the wiring (before trying to mod it), and this is just plain weird....The socket was ALREADY wired for a 3A3 despite the set coming with a 3DS3 in it! It's like someone tried the mod I had in mind then put a GE 3DS3 tube in as a later replacement or something. The two tubes have incompatible heater wiring....So the 3DS3 must not have had any heater voltage and yet it was allowing 10KV to pass. It was wired with the filament winding connected to pins 3 and 7 (7 being the CRT and focus divider connection point) with a series filament limiting resistor between pins 2 and 3. Oddly enough it must either be factory or a replacement socket since there is no evidence of the other socket pins being soldered.

I plugged in a 3A3 since the wiring was right and got the 22KV I was looking for.

I'm now tempted to rewire the heater circuit to take either tube, and see if the 3DS3 will work right with actual heater voltage.

Here are the datasheets for the tubes incase someone wants to know the differences in heater wiring.

I feel like something or somebody somewhere is playing a trick on me, but feel better knowing than I did when I was in the dark.

01-05-2016, 10:54 PM
From my experience with the C2, I think that whole chassis was cursed from the start. At the very least, it got cursed by many a service tech!

01-06-2016, 10:52 AM
I would stick with the 3DS3 especially where the HV cage is
wide open on C-2 chassii. Normally I am not paranoid about
such things but x-rays I have no way of seeing, measuring etc.
I did spend years with sets basically in my lap. I know after
20 years I was not "shooting blanks" or have other illnesses
after almost 40 yrs.
It would be fun to get one of those X-ray tags from a tech
& run a 3A3, see how long it takes to expose.
GE did spend extra money on this tube, NOT something they
did often at all. The C-2 was a real gut it out til it barely
runs set.

BTW on the left rear of PCB there are 2 2 watt carbon resistors that
go DOWN in value. They are in the video.

The C-2 is in the top 10 of junky sets BUT if you have a good one
they can give a surprizingly good picture.

73 Zeno:smoke:

01-06-2016, 12:18 PM
If there wuz anything to the Xray menace, all my kids shoulda had two heads and six fingers. :eek:

01-06-2016, 12:19 PM
I can check my stash, i might have a 3DS3

01-06-2016, 02:54 PM
The original socket did not have a resistor in the filament circuit but had a choke going to the CRT anode. The original socket had some gray anti-corona dope in the base of the socket that would eat the terminals up.

Replaced many of the sockets because of corrosion and or arcing.

I used to do about 15 of these sets a week in high humidity areas because the excessive HV caused arcing and failure of the HV rectifier socket.

There is a HV hold down diode some sets had 2, that fails quite often as well as the HV adjust potentiometer. Will cause the HV not to regulate check it with a black screen if the HV is excessive they will have to be replaced. They used a special silicon diode to replace the seleniums (Boost Diode) that were originally used it was rated at 2400v. (I don't know where one could be obtained today but haven't looked)

Wash your hands when handling that 3DS3 that is a lead coating that turns whitish and is toxic.

There is a 39k 1/2w resistor at the front of the printed circuit board (under the CRT high voltage cage side) that causes the horizontal to roll sideways (loss of phase control) replace it with a 1w resistor.

Any 2w carbon composition resistor is subject to be bad just for being there, changed most of them to metal film.

Weak snowy picture can be a bad filter capacitor in the power supply sometimes.

Those sets had a good picture when working properly but keeping them that way was difficult without knowing all of their ins and outs.

Made a lot of money working on these sets when they were current.

They built a 23" model with a very similar chassis.


Electronic M
01-06-2016, 03:09 PM
Well the 3DS3 that came with the set is actually a good tube now that it's socket has been rewired wired to supply it with filament voltage (go figure :D )....Found this out late last night and did not bother to post.
I had to clean the tuner and coax the fine tuning slugs out to a position where it would tune stuff, but it works decently.
The CRT tests weak, but it was able to produce a picture at 10KV yesterday, and does not substantially improve with a brightener so it is what it is.

BTW on the left rear of PCB there are 2 2 watt carbon resistors that
go DOWN in value. They are in the video.

The C-2 is in the top 10 of junky sets BUT if you have a good one
they can give a surprizingly good picture.

73 Zeno:smoke:

I adjusted color, tint, screens, drives, red and blue demodulator balances, and despite color improving and being fairly watchable, it still don't feel quite right....Did those resistors have an effect on the color matrixing?

It feels like an overgrown hybrid Portacolor, and has seemingly worse color than the best portacolor I've owned....Sound is surprisingly nice though....Seems someone thought well enough of it to add an RCA jack connected to the speaker.

Think I may still pop $5 on a correct schematic for it just so that if I ever put it in regular use somewhere, and decide to go through the color circuits with a fine tooth comb, I can.

Here are some pictures of this PB/Teledyne badged C2....It seems to be a low hours set...PCBs are fairly clean, and all the tubes are GE (most blue label). ( ( ( ( ( ( ( ( ( (

01-06-2016, 05:25 PM
Which anime series where you using to test your TV out with?

Electronic M
01-06-2016, 05:51 PM
Which anime series where you using to test your TV out with?
First one is Rosario and Vampire (second season IIRC), the rest are Nanatsu no Taizai (one of the better series I seen lately). I downloaded free fansubs of them and play them on a computer with a graphics card that has an S-video out...It's like having a half vacuum tube smart TV.

01-08-2016, 01:05 PM
Nice to see that C2 working even that much! It's been almost 35 years, since I have touched one, or seen one working at all! IIRC, I only ever repaired two of those sets. I didn't think I'd see one at all, this many years later. Nice!