5F6A Bassman Thermal Image

[robrob]

I have a Seek Thermal Imaging camera for my Android phone so I thought I'd take a pic of the 5F6A '59 Bassman chassis at idle temperature so we can see what's hot and what's not. I was surprised to see the power tubes are hotter than the rectifier tube.

[IMG:831:430]https://robrobinette.com/images/Guitar/ ... _Image.png[/img]

1. V1 Load Resistors. 2. V2B Cathode Resistor. 3. Socket mounted V2A Load Resistor. 4. B+4 Voltage Dropping Resistor. 5. Phase Inverter Load Resistors. 6. B+3 Voltage Dropping Resistor. 7. Pilot Light. 8. Rectifier Socket mounted Backup Diodes and .01uF 3KV disk capacitor.

[IMG:831:439]https://robrobinette.com/images/Guitar/ ... Image2.png[/img]

[xtian]

I love it!

Looks like the amp was on a desk with tubes horizontal so heat would not rise into the chassis?

Very cool tool. I want that integrated into my heads-up display on my safety glasses.

[vibratoking]

Very cool. It would be really nice to have a colormap so the actual temps could be correlated to the colors.

[ToneMerc]

I have a Seek Thermal Imaging camera for my Android phone so I thought I'd take a pic of the 5F6A '59 Bassman chassis at idle temperature so we can see what's hot and what's not. I was surprised to see the power tubes are hotter than the rectifier tube.

[IMG:831:430]https://robrobinette.com/images/Guitar/ ... _Image.png[/img]

1. V1 Load Resistors. 2. V2B Cathode Resistor. 3. Socket mounted V2A Load Resistor. 4. B+4 Voltage Dropping Resistor. 5. Phase Inverter Load Resistors. 6. B+3 Voltage Dropping Resistor. 7. Pilot Light. 8. Rectifier Socket mounted Backup Diodes and .01uF 3KV disk capacitor.

[IMG:831:439]https://robrobinette.com/images/Guitar/ ... Image2.png[/img]

Are the power tube plates really hotter or is what you seeing really just the larger plate structure of the those tubes?. Ocassionally, when burning in a build I will use my Fluke IR gun to measure the temps of the OT tubes.

TM

[robrob]

Are the power tube plates really hotter or is what you seeing really just the larger plate structure of the those tubes?. Ocassionally, when burning in a build I will use my Fluke IR gun to measure the temps of the OT tubes.

I'm just going by the larger and whiter white (hot) spots on the power tubes so it's a precision guesstimate

[robrob]

Looks like the amp was on a desk with tubes horizontal so heat would not rise into the chassis?

Yes. The shot is vertically downward into the chassis. I had to stand on a bar stool to get the camera high enough to get the whole chassis.