Wartime Civilian Radio Battery Model

[coopzone]

Hello,

I'm just starting a preliminary look at a chassis i have for one of these radios. I don't have a case. So far things are looking not too bad. All the valves still present and they at least check out on heater continuity (not yet attempted to power them up!). It has all the major components ie IF cans, tuning cap, switches, volume control etc etc. They all look OK.

That's about all the good news so far! As I said, no case, output transformer, speaker, knobs or battery connectors.

So my next steps will be to get it up and running as a chassis, I'm reasonably hopeful about this - the main issue is the rubber wiring all needs replacing - Ouch! thats going to take time!

Then the case.. But I can only find a few photos on line to give me an idea of what it looks like. None show the radios as having a back to them - does anyone know if they did have a back and what it looked like?

Also has anyone got the dimensions for one of these sets?

Thanks

Derek

[David G4EBT]

The Battery version didn't have a back for ease of battery changing/charging, and there being no safety issues.

[60 oldjohn]

The plain Pinewood cabinet is 11.5" x 17.75" x 8" (inches) from RR. It is actually bigger than the mains version.


John.

[FIXITNOW]

I have one so if can help with any measurement pictures etc just ask

here a few I have already

Vince

[coopzone]

Thanks for the photos and the cab size.

I've just realised that the, not sure what you call it, frequency indicator panel and the round circle of metal with the pointer on it are also missing. More fun to be had there then!

The IF can covers on this one are home made, but i have to say someone did a real good job of them. I've just finished re-wiring them and re-fitting.

What are people running these on, battery sizes etc. I have found the 2v 8.0AH cyclon battery on RS but it's £20.00! (A bit steep for my limited funds!) and i assume from the trader sheet the HT can be anything from 50v-150v (so that will be a load of 9v pp3)

I was thinking of a mains adapter while testing, i have a few LM317 1,5-27v regulators, i've added up the heaters and it totals 450ma. So should be ok as long as the LM317 is on a heat sink.

Derek

[Cobaltblue]

Out of curiosity does your set have the U code stamped into the rear of Chassis?

Some manufactures fitted coil cans others not.

Cheers

Mike T

[coopzone]

It's a U7 Murphy.

Couple of photos showing the top of the IF cans and serial number, the same number is also printed on the back.

[wartime sounds]

Hi Derek,

As David states, the battery version did not have a back as the AC version did.

A paper copy of the operating instructions, similar to that found on the AC model (but including the valve line up) was stuck inside the case located on the side near the Speaker.

Please see below some pictures of a U7 battery receiver from my collection, non restored but you can see the IF cans and where the Battery or adaptor would have been located. The paper on the floor of the case is the instructions for the after market adaptor in the picture and not anything to do with the actual receiver.

The front dial plate and knobs are exactly the same as the U7 AC version.

Hope this helps.

Peter

[coopzone]

Thanks for the info, the IF cans on mine sort of look the same, or at least the 2nd IF does. The 1ST IF's case has been replaced by a home made version it looks the same except the "fold" in the join is no longer there. It's now a overlayed and screw through to hold it in place.

As I said it's a good job and i will be keeping it as-is.

And I've just fired it up for the first time and it works! Got a couple of staions on my test piece of wet string. So time to proceed with the batteries and case (eventually). The case may have to hand on a little while since i'm recovering from a broken wrist!


Derek

[coopzone]

The radio is now working very well. I managed to build a 2v / 120v PSU to test it with.

I started to rebuild the front panel, attached photo showing version 1 of the rebuilt tuning scale. I'll probably re do the graphics on this later but it will be ok for use while rebuilding the cabinet around it.


Derek

[coopzone]

Hi everyone,

Just a quick update. The radio is now 100% working. After all the normal suspects (waxies) have been replaced!

so far,

Capacitors checked and or replaced.

IF alignment (it was way out!)

RF alignment, again quite way out (i think we may have had a mr. fiddler working on it at some point)

Found a new output transformer and speaker. (missing on arrival)

Rebuild of the tuning dial and scale (missing on arrival)
All the rubber cables replaced or stripped and re-covered.

all controls cleaned

I've put a couple of photo up to show the new parts.

Still to do,

New case and build a PSU for it. Been given the all clear on my broken wrist so should be able to start the case soon.

Does anyone have three control knobs that maybe suitable for it? Willing to pay a reasonable price and postage - you never know if you don't ask you don't get!

I'll try and keep posting updates as i work on this radio.

Derek

[Richard_FM]

Well done for getting this working, especially as the battery sets are rarer, & many have been fudged for alternative power sources and / or LW tuning.

I've recently become more interested in the wartime sets, especially after reading Jon Evans (aka Duke Nukem) site, along with some threads here.

[coopzone]

At last!, I have nearly finished my new wooden case for this radio. I know it's not historically accurate, but it was never meant to be, it's 'in the style of...'

So at last i am proud to say, from an old rusty chassis, missing the output transformer, speaker, all the tuning indicator, scale and of course the case! It's nearly finished. Just a bit of polish etc and we are good to go!.

After the case, i'm going to save my coppers up for a 2v battery and a set of knobs!
(does anyone have a set, still looking for something suitable)

Attached photos

[davebms]

Re battery item 183036400025 (ebay) may be a possibility not a lot cheaper than cyclone ..I have one (not in a radio)lasts ages

dave

[coopzone]

I'll consider that battery - don't thinks it's as good as the RS one that one is 8AH should give about 25 hours usage Cost £17.20. And the one on ebay at 4.5AH should give around 13.5 hours cost £14.78. But it is smaller and may look better in the case.

[coopzone]

My mistake the RS one is actually £20.64, with VAT

[davebms]

well it probably is me not understanding but I flattened a cyclone and it
would not charge back up.. the manufactures charge regime , got me confused !! the ebay one is no problem

dave

[AC/HL]

They're both lead acid technology, fully discharging is the quickest way to destroy them.

[emeritus]

According to a colleague at GEC who was a battery expert, you can sometimes revive flat lead acid batteries by connecting them to a DC supply via a high resistance, such as a low wattage 12V bulb. It can take weeks before the bulb lights, indicating that charging current has started to flow. Success is more likely if the battery is flat from self-discharge due to lack of use rather than discharge on load. It has worked for me, but the capacity has been less that half nominal.

[G6Tanuki]

Cyclon cells - and their larger brethren the likes of Varley "Red Tops" use Absorbent Glass Mat - the electrolyte being held in what amounts to 'blotting paper' between the plates (which are made of lead sheets rolled up - same fashion as an electrolytic capacitor!)

They don't handle excess charge- or discharge well. For general 'hack' radio-applications I'd stick with traditional small SLA gel-cells: I use a 2AH-rated couple of these to power my Roberts R707 and with regular, loud use they last a week or so between recharges.