CTC-5 issue

[Hagstar]

My CTC4 did a similar thing and it was a flaky CRT ground strap. I still can't get the OEM one to work reliably and so have a jumper lead as a backup for now.

[bigaudioal]

Originally Posted by Hagstar

My CTC4 did a similar thing and it was a flaky CRT ground strap. I still can't get the OEM one to work reliably and so have a jumper lead as a backup for now.

Good to know. Will check my ground strap too. Thanks!

[benman94]

Al, I think you have a typo.
The shunt reg is a type 6BK4/6EL4. 6BK8 is equivalent to type EF86.
My Hoffman had a screwy 6BK4, acting similar to yours. Replaced it with the last revision (6EL4A maybe?) and that fixed my problem.
Good luck.

[bigaudioal]

Originally Posted by benman94

Al, I think you have a typo.
The shunt reg is a type 6BK4/6EL4. 6BK8 is equivalent to type EF86.
My Hoffman had a screwy 6BK4, acting similar to yours. Replaced it with the last revision (6EL4A maybe?) and that fixed my problem.
Good luck.

Ah crap, you are right. TYPO! 6BK4. Fixed it. Thanks.

[bigaudioal]

Anyone know of a good source that might carry plate caps? Want to replace the cracked one on my 6BK4. I don't have any in my current parts stash. Thanks!

[Zenith26kc20]

Very interesting! When my 25MC233 had a 6BK4 failure high voltage went thru the roof! What is the high voltage on your CTC5? If I remember right they are not capable of ridiculous levels like my 25MC33 (close to 32 KV when the tube died). Sounds like yours went gassy.

[bigaudioal]

Originally Posted by Zenith26kc20

Very interesting! When my 25MC233 had a 6BK4 failure high voltage went thru the roof! What is the high voltage on your CTC5? If I remember right they are not capable of ridiculous levels like my 25MC33 (close to 32 KV when the tube died). Sounds like yours went gassy.

The CTC-5 HV is around 20kV at best. One of the complaints everyone has about it. Whereas most of the other vintage color sets are around 25kV.

[bigaudioal]

Sure makes a nice picture!