Atwater Kent Model 55C

8/18/2008 12:05:55 PMLou

All:

I have an Atwater kent model 55C. In looking at the schematic, it looks like the unit uses a speaker with a field coil. The coil looks like it is powered off of a tap on the negative side of the power supply.

Can I run a high Z PM speaker (2000 ohm) on this radio?

What happens to the PS if the field loading is not there ( i.e. PM speaker has no field).?

Thanks
Lou

8/21/2008 11:19:49 AMNorm Leal

Hi Lou

No, unless you make changes. Model 55C uses a speaker with low impedance voice coil and field. You can use a modern PM speaker and 1,000 ohm 10 watt resistor in place of the field. Keep the resistor near this value. As you noticed field is in negative side of the supply and sets up bias for the 45 tubes.

Norm

:All:
:
:I have an Atwater kent model 55C. In looking at the schematic, it looks like the unit uses a speaker with a field coil. The coil looks like it is powered off of a tap on the negative side of the power supply.
:
:Can I run a high Z PM speaker (2000 ohm) on this radio?
:
:What happens to the PS if the field loading is not there ( i.e. PM speaker has no field).?
:
:Thanks
:Lou