Advance D1/D regenerative receiver conversion?

[Tyso_Bl]

While looking under the workbench for lost / orphan screws etc, found an Advance D1/D sig genny, I sort of remember getting it at a silent key sale at a rally about three years ago, didn't want it but it came as a job lot. I've been using it as a foot rest for a while now.

Its in quite nice condition, seems to work OK, but I've not any real use for it, I've opened it up, nice 50:1 reduction drive, 65+65pF tuning cap, a very elegant coil wavechange turret, power supply, dual triode, couple of octal triodes in sockets, mod transformer, triple screened cabinet... my wine lubricated imagination starts seeing it as a basis for a 0V2 or even an 1V1/2 regen receiver.

Would I be wrecking a piece of classic test gear? or just re-purposing it (in modern parlance). I've another sig genny (an E2), which covers most of my alignment needs.

Your thoughts and suggestions appreciated.

I think that would be a super project, loads of knobs for regen etc.. After all all a regen radio is an oscillator that doesn't quite oscillate. Any chance of the circuit, I am sure loads of suggestions will spring from that.

Would I be wrecking a piece of classic test gear?

No, not in my opinion as, a) it's yours and b) it was rescued from the landfill.

Second thought, with all those valves how about a transceiver?

[Radio Wrangler]

A super-regen IS a transceiver

David

Tricky doing morse on the regen knob though.

[G8UWM-MildMartin]

Perhaps keep it unmodified and fit for its original purpose (always a handy thing to have around), enhance with one of the cheap but rather good DFM modules available nowadays (maybe in a separate screened box and maybe add a buffer amp.), and build the additional circuitry for a direct conversion receiver (just a mixer and high-gain audio amplifier), then add a tuned RF stage once it's working?
Then replace it with a modern DDS oscillator.
Then add IF stages and filtering (with suitable changes to the DDS offset programming.) and AM and FM detectors.

[Radio Wrangler]

Use the sig gen as-is as the driver for a TX strip and the LO for a direct conversion Rx?

David

[ms660]

For SW regen I would rewind some of the osc coils to cover down to top band so there is full SW coverage, feed that into a mixer then a tunable regen detector, use a nice SLF capacitor along with a small fine tuning capacitor for the regen detector, throw in an RF amp as well.

Lot of hassle though.

Lawrence.

[Herald1360]

Originally Posted by merlinmaxwell

Tricky doing morse on the regen knob though.

FSK using the tuning knob? Or better a few pFs in series with a morse key across the tuning capacitor?

[RF Burn]

Originally Posted by Radio Wrangler

A super-regen IS a transceiver

As a lad I built a (Practical Wireless?) CQ2 2 Metre superregen. As an experiment I tied a small audio transformer primary into the battery lead of the set and applied some audio to the secondary of the transformer from a small amp fed from a microphone - result was a low power transmitter, not best quality but definitely readable using slope detection on a 2 Metre receiver...

[Tyso_Bl]

Some interesting comments, it does look like this project will go ahead, I've been curious about how the RF section was built, took the cover off, one thing leads to another, and its in major sections now.
I don't really wan't to over complicate things by turning it in to a tranceiver or superhet, it not the right place to start from, my past experience of regens is that the major hassle was decent mechanical construction, something this sig genny does seem to have.

The next question is of technology, valve or solid state? Much as I do like valve tech there doesn't seem to be any benefit so it's going solid state for this one, there isn't enough room to put in a decent audio stage, an RF isolation stage, as well as a separate regenerator and infinite impedance detector, that the sort of circuitry that looks favourite, it will also leave room for bateries and charger, plugs /leads etc.

A bit of breadboarding has been going on in the odd spare minute I have, but this really was the wrong time to start this!