In respect of milking radio transmissions, Tesla proved that could be done in 1912. We now have alternators and Mobile phone charging with Radio waves.

I believe that the Post & Telegraph, or Radio Telegraphy ACT's as far back as the early 1900's; it was illegal to make & use devices for the purpose of tapping electrical power from telegraphy. That would actually cover fixed lines as well as RF that came later and there were prosecutions.

Probably worth tracking down for interest.

Marc

Part 3 uploaded.

I apologise for the late response. I've been away for a few days.

If you are playing around with superhet's take a look at AWA R301A. I got the golden handshake version to fix, this has an added 6A6 as the push pull. Ist IF is a band pass filter. The production model is back biased the special is self biased. There is a DX switch despite it having AGC.

Built without a budget, I have not seen many tube radio's that can out perform it.

Marc

Thanks Fred for a well-written, well thought out project.

I have an STC mantle of that vintage that my mum was given during the war. Similar circuit with the cathode rheostat but with an electrodynamic speaker. It was put together as a special favour during the war, mum worked for an advertising agency.

It has a model number stenciled on the chassis but that model bears no relationship to this actual radio!

Excellent article as always.

The "racing station around 2SM" I take it would be the ex-2WL on 1314. For those outside the area, it was a commercial station in Wollongong but it moved to FM (Wave-FM 96.5) many years ago. The antenna is south of Wollongong in what was a flat swamp not far from the sea. The frequency and facilities were taken over by the TAB racing radio, so keeping up the good signal strength.

Great comprehensive content Fred. I hope you are publishing it for access to others like Silicon Chip or HRSA. It’s too valuable to be just hiding here.

Yes Dave I am writing a "SC" friendly version of the project as I go.

Then I can only submit it for consideration.
No guarantee of ever being published.

All in hand just occupying a lot of time.
There is endless work in writing a mag article that is friendly to the editor and publisher.

Cheers, Fred.

Having an article pending for SC (possibly next month). I am actually the editor for the Vintage Radio Club of NE Vic. and come form a technical background mainly in chemistry.

One of the major issues is having an article edited by someone outside of the profession at hand and is also a beef with Cert IV in training and assessing.

However, Rod Champness & I were as one (often checked each others offerings: It only needs the changing of one word; One punctuation mark, or the changing of a sentence, to completely screw up a technical work and make it meaningless; making the author look like an imbecile.

Marc

I have completed part 4 of this riveting series about the 1940 Little General with the build of the cabinet and dial.
I come to some conclusions about the set and why it was so successful.
I'll send part four to Brad to pin to the front post with the rest.

Fred.

Part 4 uploaded.

This has been an excellent series of articles on what was ultimately Australia's most popular kit radio.

Fred, you're amazing as always. It's just fantastic would you can do.

Guys, thanks for that.
I hope everybody gets something from my writing.
The feedback is what makes it all worthwhile to a writer.

I have sent off a much shorter version to SC to consider for the Vintage section.
This is a very competitive slot in SC so don't hold your breath.
It could be a year or never, just depending on what the editor needs for the health of the magazine.

On that point most of the mags I have written for are simply no longer in print.
I am so glad I am not writing for a living!

Cheers, Fred.

To see how easy it is to add regeneration to an IF stage I simply taped a short bit of wire to the IF valve grid lead and poked it down the vacant hole in the IFT2 can.
This gives you plate to grid feedback.
The IF can is full of plate energy and the length of wire poked down the hole is the adjustment of feedback.
It is like magic.
With a short piece of wire inside there is no effect.
As you poke the wire down the volume starts to come up.
Too much and the stage bursts into oscillation with screaming whistles.
Note you can hear a change in volume as this is a non AVC set.
If you do this with AVC active you will not hear any volume change as you are changing the stage gain and the AVC loop will correct the level.
On a production set this would be done under the chassis and with a small capacitor or a mystery wire soldered between points.
The aim of this feedback is to make the set more sensitive with higher overall gain.
So if you see a strange capacitor or two bits of wire going no where on a set now you know what it is all about!


Fred.

Photo uploaded to Post 28.

Bearing in mind that any amount of radiation flying around can end up being regeneration and the detector first audio, is with modern caps the worst area for them assisting in instability from induction & radiation. One notes on reflexed sets, there is often a pF cap plate to grid on the 1st AF tube.

That wire may be having a similar effect, but with length, also acting as a radiator? It would be interesting to see what happens to the stability, after wrapping a "Goat" (tm) shield around the 1st AF tube. Many sets like the Airzone & Peter Pan on the bench, have that albeit the Peter Pan is a reflexed set.

Marcc