Can anyone tell me what rectifier valve this amplifier used.

Have done a search however cannot find any references.

Thanks for any info.

I expect PA Man will chime in with the answer, once he sees your post.

That looks like it might be a 30 Watt one by the number? What valves are in it? Rectifier may be a 5U4 but there could be a silicon diode to supply grid bias for the push pull as well?

Marc

The PA is a 30 watt model and was given to me many years ago minus its valves (except for the preamps) and the output transformer.

My intention is to use the chassis and power supply for another project. In this day and age just do not toss a good chassis with power transformers on them into the bin.

There are not any diodes for bias and pretty certain the rectifier would be a 5U4 but not sure.

If it is what I think it could be? It's 5U4 as a rectifier with #7199 as a phase splitter for two by #7027-A and has power out for pre-amp etc.

It will possibly have some form of "humdinger" (Potentiometer) as a hum control on the heater winding. That would mean that the heaters float.

Transformer 375-0-375 AC for 400VDC at 5U4 filaments. There may be caps on the mains? Remove / Replace with modern line caps.

Do not measure pin 4 to pin 6 (rectifier socket) unless the meter can handle a minimum of 1KV. Many modern meters won't. Even 375VAC might upset some.

There are a couple of trimpots, one is located adjacent to the two output valves and looks like some sort of biasing adjustment.

The other trimpot is mounted on a small standoff board with a number of components. Seems to be a trimmer adjustment for the radio or pickup inputs.

The only valves left are a 7199 and a 12AX7 in the preamp stage. Along with a couple of potted transformers for the microphone inputs which I will keep.

Don't really know what I will do with them but sometime they might come in handy for something.

There are no caps on the mains, before I power it up will strap in some modern electro's to be on the safe side.

The only thing I am interested in is the power supply stage for another project.

Pity the output transformer is missing as a very well made product. Plenty of care taken for shielding and earthing.

Am not familiar with that one (pic would good).
But AWA had a couple of rectifiers they used from the 40's to the 50's 5V4/5R4 and 6X5.
By far the most common is the 5V4 from a late 40's 15w to a mid 50's 70w (which has a 600-0-600 ht)
The 6X5 appears in Battery/AC amp
60's all seemed to be diode rectifier.
I have not struck 7199's in any on the 11 AWA amps I have
You do see AWA transformers come up on Ebay on occasion but there are plenty of ways around an original tranny

Cheers Josh

That seems to be what this one is, most likely a 5R4/5V4 as it is a 30W amplifier.

Thanks for the help with my query.

No worries, could you still post a pic or 2 as I have not seen that number before.

Cheers Josh

Sorry for the delay, had to mess around with Photobucket and not to familiar with it.

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