I would use a two lug terminal strip for the neutral and ground. They are cheap and looks cleaner. Your method works, but a chassis screw could nick the sheathing and it could get hung up on the screen stapled to the top of the cabinet. Good video though.
You used the wrong formula! Voltage drop Cathode / Cathode resistor gives you current in A... 11:18 calculation is wrong: 11.6 V divided by cathode resistor (470R?) = 25mA times (plate V - cathode V= 416V?) = 10.3W 11:55 11VDC - is a depleted cathode in the power tube - schematic says you should see at least 21V 13:22 OUCH 8.53V / 750 ohm = 11mA x 425 = 4.9W --- yes what I said previously: a depleted old RCA tube, have one on my desk that's doing the same thing 14::22 double ouch 7.95v / 1000 ohm= 8mA x 435V = 3.48W
Question, sir. When testing plate voltage, should I place negative lead to chasse, or to cathode? Uncle Doug uses the cathode, but i've seen others recommend neg to gnd. Larger readings occur with chasse reading. Thanks!
@@jaysorensenIBEW plate voltage is measured to ground -- there will still be voltage on the cathode (before resistor and cap) which would explain the difference you're measuring
I see potential here, good luck young man.
Hello, question did you get your ohms on the transformer with the amp powered off and caps discharged? thank you.....
I would use a two lug terminal strip for the neutral and ground. They are cheap and looks cleaner. Your method works, but a chassis screw could nick the sheathing and it could get hung up on the screen stapled to the top of the cabinet. Good video though.
You used the wrong formula! Voltage drop Cathode / Cathode resistor gives you current in A...
11:18 calculation is wrong: 11.6 V divided by cathode resistor (470R?) = 25mA times (plate V - cathode V= 416V?) = 10.3W
11:55 11VDC - is a depleted cathode in the power tube - schematic says you should see at least 21V
13:22 OUCH 8.53V / 750 ohm = 11mA x 425 = 4.9W --- yes what I said previously: a depleted old RCA tube, have one on my desk that's doing the same thing
14::22 double ouch 7.95v / 1000 ohm= 8mA x 435V = 3.48W
Question, sir. When testing plate voltage, should I place negative lead to chasse, or to cathode? Uncle Doug uses the cathode, but i've seen others recommend neg to gnd. Larger readings occur with chasse reading. Thanks!
@@jaysorensenIBEW plate voltage is measured to ground -- there will still be voltage on the cathode (before resistor and cap) which would explain the difference you're measuring
@@zjokka Thanks for the reply. Cheers
If it's safe and not going to hurt anyone okay but if not well done for spotting. The aml does sound good though.
cool job, like👍
Awesome, but just a little disappointed at the melted PT yellow wire sheathing.
Didn't Joe Walsh record a lot of James Gang with a champ ?
I have a '66 vibro champ that just started producing intermittent static. Someone told me years ago what that likely is if it does that. Anyone?
Probably the preamp tube. Tap on it with a pencil and see if it's reactive to that. If so, replace.
@@drew945101, thank you.
It was actually pretty revelatory to see the distorted wave form. Something clicked there.
I've have a 65 that looks like a hack learned on it at some point. If anything happens to it, I'll send it your way.
You can contact me either to facebook or instagram 👌