How do u see No. on tube that is not easily visible??? I know couple tricks-----breath on tube, rub it in ur hair [if u have hair] any suggestions

Jim

Try looking for the number is bright light. If nothing works send a photo of the tube. Most older types can be limited down to a couple types.

Norm

:How do u see No. on tube that is not easily visible??? I know couple tricks-----breath on tube, rub it in ur hair [if u have hair] any suggestions
:

Put it in the freezer for a couple minutes, then breathe on it might work.

marv

:How do u see No. on tube that is not easily visible??? I know couple tricks-----breath on tube, rub it in ur hair [if u have hair] any suggestions
:

:How do u see No. on tube that is not easily visible??? I know couple tricks-----breath on tube, rub it in ur hair [if u have hair] any suggestions
:
Tube is definitely an eye tube, either 6E5 orr 6U5, Not beenable to verify which. Any physical way to tell, like looking inside glass or other???

Another idea is to catch a close up reflection in a mirror, either before or after fogging.

marv

::How do u see No. on tube that is not easily visible??? I know couple tricks-----breath on tube, rub it in ur hair [if u have hair] any suggestions
::
:Tube is definitely an eye tube, either 6E5 orr 6U5, Not beenable to verify which. Any physical way to tell, like looking inside glass or other???
:

Hi

Difference between 6E5 and 6U5 is sensitivity. A 6E5 eye closes around -8 volts while it takes -22 on a 6U5 grid.

Compare it in a radio to a known number eye tube. Most tube testers change plate voltage to open and close eye tubes. These can't tell a difference between types.

Norm

:Another idea is to catch a close up reflection in a mirror, either before or after fogging.
:
:marv
:
:::How do u see No. on tube that is not easily visible??? I know couple tricks-----breath on tube, rub it in ur hair [if u have hair] any suggestions
:::
::Tube is definitely an eye tube, either 6E5 orr 6U5, Not beenable to verify which. Any physical way to tell, like looking inside glass or other???
::
:
:

:Hi
:
: Difference between 6E5 and 6U5 is sensitivity. A 6E5 eye closes around -8 volts while it takes -22 on a 6U5 grid.
:
: Compare it in a radio to a known number eye tube. Most tube testers change plate voltage to open and close eye tubes. These can't tell a difference between types.
:
: Norm
:
:
:
::Another idea is to catch a close up reflection in a mirror, either before or after fogging.
::
::marv
::
::::How do u see No. on tube that is not easily visible??? I know couple tricks-----breath on tube, rub it in ur hair [if u have hair] any suggestions
::::
:::Tube is definitely an eye tube, either 6E5 orr 6U5, Not beenable to verify which. Any physical way to tell, like looking inside glass or other???
:::
::
::
:
:
Another idea is to run the filament at 6.3 volts and measure the current. If it is 150 ma. you have a 6AB5.
If it is 300 ma. it is either a 6E5 or 6U5.

All the Best,

Bill Grimm

:How do u see No. on tube that is not easily visible??? I know couple tricks-----breath on tube, rub it in ur hair [if u have hair] any suggestions
:
Many tnx guys. Got a Airline here that uses a 6U5. Will try tube in it.