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Help Identifying Old Westinghouse Tube Amp?

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Pyre

Pyre

Member
Joined 2006
Got this yesterday with a bunch of Hammond transformers.

It appears to be out of a Westinghouse Super Heterodyne model 101 receiver of some sort but I can not find any information online about it. What I was looking for is a schematic or transformer specs. I was hoping to get enough parts out of it to make a 45pp mono amp. It has no driver tubes just two 45's and one 80 rectifier.

It appears the chassis was set up differently at one time and then factory converted to have the tubes horizontal instead of vertical. The sockets are still on the bottom just not drilled out. The badge is installed over one of the holes labeled UX245. Seems odd as the tubes are shorter then the tallest transformer.

It sure looks like an old RCA amp I have seen before but can not remember where or what model.

Any information would be appreciated.

Shane

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.
 
Mr_Zenith

Mr_Zenith

Member
Joined 2009
This is the type of cabinet it was usually installed in (the front is shown here). There were several variants of this old radio, and they all usually consisted of a combined power supply/AF amp on the bottom, an RF chassis mounted above that, and an upward-firing speaker installed on top. The P-P 45's were usually mounted on a wooden shelf screwed to the inside of the cabinet.

One additional note: please be aware that this chassis used the speaker field coil as a power supply choke!
 
Pyre

Pyre

Member
Joined 2006
Mr. Zenith said:
This is the type of cabinet it was usually installed in (the front is shown here). There were several variants of this old radio, and they all usually consisted of a combined power supply/AF amp on the bottom, an RF chassis mounted above that, and an upward-firing speaker installed on top. The P-P 45's were usually mounted on a wooden shelf screwed to the inside of the cabinet.

One additional note: please be aware that this chassis used the speaker field coil as a power supply choke!
Click to expand...

Very interesting, I saw that on the schematic and thought it odd and quite creative.

I can sort of make it out on the schematic but just wanted to double check, is the speaker impedance 10R, is that not quite low for a field coil? I thought they were all 500R+

I was planning on using the parts to build a really vintage looking electric cello amplifier.
 
Pyre

Pyre

Member
Joined 2006
Mr. Zenith said:
The 10 Ohms is actually the voice coil measurement. The field coil is shown a bit left of that; it's actually a 40H choke, with a DC resistance of something like 1330 Ohms.
Click to expand...

Thanks, any idea what I can use for a speaker or will I have to find another fieldcoil. I passed on the chance to buy some 1500R impedance drivers a while back and now I am kinda mad that I did not. Really I only need something that will cover a frequency range of 60Hz to 1000Hz.
 
E

Eli Duttman

Member
Joined 2004
Pyre,

Using the field coil as the 2nd inductor in a CLCLC filter was standard practice.

You don't need a field coil driver. Insert a series combination of inductance and resistance equal to that of the field coil.

The 10 Ω voice coil is problematic. Try an 8 Ω driver and see what happens.
 
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