View Full Version : How hot should the focus rectifier get?


LukeSimon
12-26-2022, 06:06 PM
Using my thermal camera, I can see that the 1V2 focus rectifier diode doesn’t get nearly as hot as the other tubes. It appears to reach only 95.1F whereas the vertical output tube is much hotter at 351F. The room carpet is 74.6F, so the focus diode is hotter than room temperature, but not by much. Is this normal?

http://www.videokarma.org/attachment.php?attachmentid=205176&stc=1&d=1672099390

init4fun
12-26-2022, 06:16 PM
I can state with certainty that HV rectifier tubes (1V2, 1B3, etc) do not run nearly as hot as so called "power" tubes in normal operation :thmbsp:

Electronic M
12-26-2022, 06:59 PM
Only time I ever felt an HV or focus rectifier get unpleasant to hold levels of hot was on black Friday when I was restoring an 8" RCA...The 1V2 HV rect in that set was gassy and glowing BRIGHT violet. It was somewhat unpleasant to touch even a couple minutes after switch off...I didn't have access to tubes so since HV was only 5KV I replaced it with 6 1N4007s in series.

Electronic M
12-26-2022, 09:18 PM
Only time I ever felt an HV or focus rectifier get unpleasant to hold levels of hot was on black Friday when I was restoring an 8" RCA...The 1V2 HV rect in that set was gassy and glowing BRIGHT violet. It was somewhat unpleasant to touch even a couple minutes after switch off...I didn't have access to tubes where I was at so since HV was only 5KV I replaced it with 6 1N4007s in series...which worked well.

ARC Tech-109
12-28-2022, 04:17 AM
Guess I should send a 1V2 to central PackersLand, a gift from VikingLand ;)

Electronic M
12-28-2022, 11:23 AM
Guess I should send a 1V2 to central PackersLand, a gift from VikingLand ;)

Thanks. It's the thought that counts. :thmbsp:


I actually restored that set while on vacation and didn't bring any tubes... I'm sure I have a 1V2 somewhere, but when that somewhere is 6 hours drive away and you have 1N4007s you get ideas...:scratch2::D

Happy Holidays!

ARC Tech-109
12-28-2022, 01:06 PM
Have done the 1N4007 thing with FM xmitters in the past. A string of those and a tube of RTV is better than duck tape... might ruffle some feathers :D