Polo 20 chassis compatible tubes?

[georgek]

I've got a spare Polo 20 chassis but no tube. Does anyone know which tubes will work with it?

Thanks!

 

[tb2000]

Any A48 tube with a standard (not minineck) neck should work. Remember though the deflection yoke needs to be a low impedance one - approx 2-4 ohm horizontal and 12-15ohm vertical. Any of the 900/E, 9000, 9000/A ones and also WG ones will work such as ones for the standard neck K7000 for example.

 

[georgek]

Thanks. My other Polo 20 has an A51 so would any A51 work too?

 

[georgek]

Pulled this 19" tube from an old TV. Would it work with the Polo 20?

 

[gunblade]

you will need to read the impedance of the vertical and horizontal windings of the deflection yoke

 

[georgek]

2.1 ohm and 12.3 ohm so assuming ok from the numbers tb2000 quoted?

The neck board from my Polo fits but is 12 pin whereas the tube has 10 pins. Is this an issue? Sorry for the noob questions!

Thanks!

georgek2023-01-26 10:24:44

 

[gunblade]

should be ok, on some tubes you need to desolder a pin on the crt socket but i think your case you may be alright

 

[tb2000]

If your image seems too bright you might need to change the heater resistor on the neckboard. That's quite a late production A48 crt and may have a more efficient heater in the neck with lower power requirements.