I have acquired a 3 valve regenerative radio.
Valve line up is 6C6, 42 & 80. The ARTS&P sticker indicates 1935. What do you think?
Thanks,
Gary

Cabinet is interesting: If its not to be a shelf queen? One should be able to get a speaker & use resistors to replace the field (Which appears to be missing).

I just love that dodgy looking shield on the 6C6 Pentode. It has character, missing a tall top cover, if it is original & that's up for debate.

How bad is it inside the pan?

Marc

It has a Amplion ED speaker, underneath is not too bad. It will make an interesting project to get it going.

I found three 3 valve Eclipse circuits from 1933 & 1934. These circuits use a 57 & 2A5 which are 2.5 volt versions of a 6C6 & 42 respectively. Is it possible that the power transformer may have been changed at some stage to suit 6.3 volt valves? Or is it all original? There might be something here you can work with.

Eclipse 43 45 56 303 304 S3 Circuit Diagram

Transformer looks original. It might have taps. The oldest Eclipse circuit for 3 valves I have is a battery set in the 1938 Radio Trade Annual. But it is a superhet. I would appreciate a copy of the circuilts you have? Email is on my profile.

It is not inconceivable that a transformer heater change was one change & the valves the other, with no actual change to the circuit, as like several valves in that era., the only change, was either the base, or the filament voltage and the rest was the same as it always was.

Marc

I have an 1931 Astor Aladdin 3 valve regenerative console receiver. It has a similar looking chassis to yours. It was in quite good original condition when I obtained it as luckily it had been stored in a dry place for many years. After replacing some perished wiring with new cloth covered hook up wire and installing new capacitors underneath the chassis and a new three core power cable it worked quite well. I left the original capacitors in place but disconnected for appearance. The resistors were all original wire wound and still within the original1/4 ohm range and did not require replacing. The power and audio transformers, RF coil, valves and dynamic speaker were all in good condition with no shorts or open circuits.The receiver is working well. It is not as sensitive as a superheterodyne receiver, but with a good aerial and an earthed chassis via a new three core power cord it easily receives all my local stations with good volume.
With a regenerative receiver you do need to adjust the amount of positive feedback via the rheostat on the tickler winding on the RF coil when you tune in a new station. With too little feedback the audio signal will be weak. With too much feedback the detector/RF valve will oscillate resulting in a squealing speaker, and the receiver will start transmitting a carrier signal causing interference to any nearby receivers tuned into the same frequency which is illegal. Apparently this was part of the reason why the regenerative receiver design was phased out.

Hi Sam,
When you say the chassis is similar to your Astor. Could mine be an Astor? What is your valve line up?
Thanks for the schematics Kent.

Just fired it up. only a 6.3V filament winding. Makes a noise like it is trying to receive. Transformer looks original. All high voltage wiring exposed on top of the chassis! I'll have to put a cover over it.

Circuit is very similar to the Series 43 that Kent sent. So I would guess that this must have used the later 6.3V valves.

More info, it is listed on the HRSA website as 1937.
http://www.hws.org.au/RadioHistory/manufacturers/Eclipse.htm.

Hi Gary, the chassis on the Astor has a similar layout, but has Phillips valves with 4 volt filaments, an E452T detector/RF amplifier, E443N output, and a 80 rectifier. The tuning gang is on top of the chassis on the Astor with the dynamic speaker mounted underneath as it is a console model.

I hope you are not running that with old electrolytics & wax paper caps in it? It may struggle to not cook something. However you now know that the valves are likely working enough to get it going properly.

If parts not replaced? It says 500v on the wet so replace with 500V not 450V and make sure the wets are not in circuit, or left in circuit. Once one has got rid of all of the wax papers, tired electrolytics (all), dodgy wiring & dud resistors as you go. Sets run a hell of a lot better & all you have to do then is recalibrate the IF's etc. and that is not a big job. Wet afternoon project.

Marc

Hi Marc, I disconnected the original electrolytic capacitors and installed new 600 volt rated capacitors under the chassis in the Astor Aladdin and powered it up very slowly with a variac after checking the transformer for shorts, replacing rotten wiring and checking the resistors are within spec while keeping an eye on the HT voltage. As it is a TRF regenerative receiver there is no intermediate frequency to calibrate, instead I have to adjust the amount of feedback the detector/RF valve receives so it doesn't oscillate.

I remove the inside of the wet electrolytics, clean out the inside. Then epoxy a 22μF 450v radial electrolytic inside. Epoxy the positive lug into the end with a wire protruding for the negative. It’s a lot of work but I have seen wet electros leaking in the past and damaging the cabinet and chassis.
Sam,
The speaker socket on this radio is on the underneath of the chassis. I'll post a picture of it to see if its like your Astor.

My issue with this is that if it has wax paper caps, these can seriously impinge on bias as they are all likely leaking to an unpredictable level. Plate to grid coupling caps leaking can send the bias on the grid positive and that will affect performance to a significant level.

I would expect that to be some form of biased detector with a high cathode resistor for plate detection & to give enough voltage swing to drive the OP valve.

Values are critical and this type of detector is notorious for distortion. The valve is run near cutoff, so even its deterioration can impinge. Shielding is critical so that needs to be fixed, you will not hear supersonic oscillation but it will cause problems. 6C6 is supposed to have an internal shield tied to cathode ... but the book says..

Info I have is for 6J7 (electrically same) Rk10K; Rg 250K 250V B+; Grid -4.3 (with respect to cathode..... measure across cathode resistor with high impedance meter). SG 100V. (AWA)

Marc

Here it is restored;

The schematic was drawn from the HRSA article, April 93. Unfortunately the nice bakelite pot was beyond repair. The radio is shown with the wrong knobs. I am trying to locate a correct set.

Eclipse Circuit Diagram