Would anyone have any technical information on a AWA Radiola 4 1925? I have one which I'd like to eventually restore but need the voltages and battery connections.

We would love to see some pictures?
Does it look like this?

http://www.radiomuseum.org/r/amalgamate_radiola_iv_4_2.html

That is one nice old set. All the valves are the same can someone explain to me as to how this works. Its probably a simple answer but I am interested.

There was one in HRSA Action 35 birthday. oz radios.com. Described as Radiola 4 C7/60. Those things follow a fairly common plot. Where there is a "Grid leak" resistor, it's normally out of spec & needs re-coring with a new resistor.

The OP valve will dictate how one sets up a speaker. Most of those were either headphones or a high impedance "Horn Speaker".

Not a lot of complexity. I have a 1924 Gillfilan Bros (USA) set here for repair.

Marc

The use of a common triode for both RF and AF stages was not uncommon in the 1920's, after all there weren't that many types to choose from. The AWA33 was first manufactured by AWA in 1925 and the museum site lists the radio as being a TRF with regeneration and two AF stages so it was most likely a single RF stage followed by a regenerative detector followed by two audio stages a fairly common arrangement for the time.

The AWA33 was similar to a UV-199 but with a different base.

As Marc noted above the detector is most likely a grid leak type and the resistor is almost always out of spec.

Joe

The main traps are polarity and the fact that a lot are top wired and the data sheets show bottom wired (sockets often labelled). I always check all of the caps in those as well, some of the Mica types used in them are indestructible & some not.

Some use different voltages on each stage & generally the "Leaky Grid" (infinite impedance) detector is restricted to below 45V (UX201A) otherwise it needs a "C" battery.

These are not overly complex when affecting repairs. A lot is commonly deteriorated wires, Monkeys that know not what they are doing & Rodents.

Marc

Here is a good explanation of TRF radios.

https://en.wikipedia.org/wiki/Tuned_radio_frequency_receiver

TRF is not as complex in its operation as superheterodyne however, if you understand it, that gives a better chance of fixing it. Having a group of tuned RF amps in series, in some cases with TRF's, sees them share an issue with a superheterodyne with a leading RF pre-amplifier.

Some cannot come to grips with the fact that if all of the tuned circuits bringing in signal from the antenna and amplifying it are not on the same frequency it gets blocked, or seriously attenuated. That is common when the previously mentioned Monkey gets at it.

Hi Rudy,

I have one of these sets and a copy of the instruction manual - with circuit and voltages. If you send me a message I will forward it to you. What is the serial number of your set?

Robert

I have one of these sets and a copy of the instruction manual - with circuit and voltages

Would you be wiling to have a copy placed on the Radiomuseum site?

Hi GTC,

Yes I'm 100% into sharing info and advice (if useful!). I'm a member of Radiomuseum, so I'll post it there, plus a few pictures of the actual set. I have an AWA 'sealed set' with a slightly smaller cabinet - I'll post some pictures of that as well - just need the time to di it all.

Robert

Thanks Robert, that's a great attitude.