AC Civilian Receiver

[Aerodyne]

Joe, I have copied the photo of the inside valve type label and used a combination of Word and Photoshop to create a passable copy as a .jpg file. I don't know the original size of the label but I'd guess it as being about 3" X 5". I will keep the file for possible future use by myself and anyone else who might need it. If you'd like a copy of the file, email me to let me know.
-Tony

[Tedzed1]

Had a bit of free time tonight, so I set about recapping the radio, Barry the bodger has been at it before, as one of the mains smoothers had a replacement RS 8uf electolytic tacked in, but the original was still in circuit, so it actually had four mains smoothers instead of the usual three, so two leaky 8uf in parallel instead of one.

Also if you look at the V1 control grid decoupling waxy, it is positively bulging, so all that remains is a final check, reassembly, and test,
fingers crossed

[Joe]

It's certainly looking better. Let's hope it sounds it too.

- Joe

[Tedzed1]

Well something is not quite right, powered up with the lamp limiter, no more hum now, but lamp lights, then dips slightly, then as the heaters start to warm up, it starts to glow brighter and brighter, 100W clear bulb, gets to about half brightness, then I chickened out, still slight crackle on volume switch, but no reception, any ideas anyone?

(just noticed V1, the frequency changer ECH35 is not lit, and it rattles like a bag of bolts)

[Tedzed1]

Hi, just pulled the valve but lamp limiter is still as bright, how much power to these sets consume?

[Tedzed1]

AGHHHH, don't believe what I did, can I put this down to a senior moment, no prizes this time, but check out the capacitor in the middle of the picture, the point where it is soldered to the tag strip, is where the HT supply comes in from the transformer,
good job I used the lamp limiter, needless to say the radio is now working, a little quiet, but this can now be investigated,

[tiv48]

it happens to the best of us
rob t

[Joe]

For all that I got this working I was disappointed with it as it needed a stupidly large aerial to pick up even strong signals; 300W from 9 furlongs away with nothing worth talking about in between. Yorkie brought his over which seemed about the same but I still thought it ought to be better.

With the recent talk of making new backs I was prompted to have another look at it.

The first thing I did was check the IF alignment. This seemed quite a bit out as when I first connected the sig gen there was hardly anything coming out of the speaker but when I'd finished it was uncomfortably loud. The sound quality now seemed better but not the sensitivity.

I couldn't do the RF as the cap trimmers look like they've had some sort of caps soldered on. Besides that there's no calibration mark due to the drum on the tuning capacitor being a replacement.

I then tried swapping the EF39 for one out of my Ferguson and it then worked much better. The Fergy seems perfectly happy with the 'duff' valve.

I don't know if it gives a clue to its maker but the IF cores stick of top and bottom rather than being accessed via holes in the back of the screening cans.

- Joe