AK 308 getting there

[Radio Fixer]

Well I cant let David have all the limelight with his AC77.

The wiring on this beautiful radio was mainly shot. Touch much of it and it simply crumbled away so it was strip and re-wire. I did detailed layout diagrams, and the A3 printer was essential for clarity (photos on their own are not good enough).

It is 1934 and an export set so has LW and is 230V. Over here it would have been a 2 chassis job but the US never did table radios that way as far as I know. 8 tubes, tuned RF, 2 IF stages and PP so it will perform well I'm sure. SW's go up to about 22Mhz.

Wax Caps are not re-stuff as the cases fell apart but are dummied from styrene tube. Many were good for leakage but some were O/C which is unusual.

Soon ready to tube up and test and then put back the rubber tyre tuning cap drive and the waveband scales which are mechanically moved up and down to the slot in the cabinet bezel.

The cabinet was refinished last summer, not completely but wounds in the black trim filled and re-sprayed, also a couple of holes in the LH side filled and then the whole cleaned, sanded with oh so fine paper and shot with a few coats of satin lacquer.

The first chassis pic was as it came to me ...trust mine looks better. Took me quite a while but at least there was no rust to deal with as David had. The chassis is nickel plated and the coil cans look as if they are from nickel sheet but with un-corroded ali. tops.

Be a BVWS Bulletin article later in the year and hopefully a front cover picture, if the Editor agrees its worthy, it certainly is to me

   
   
   
   

Gary

[Joe]

Very nice indeed.

- Joe

[pwdrive]

A nice pro Job there Gary, it looks the part for sure, I like the caps.

Lawrence.

[Radio Fixer]

Thanks guys!

The heater wiring was interesting as that could have been a bon-fire if someone powered it up, really bad. It was 7 strand and tightly twisted measured 0.7mm diameter and with the cascade way of wiring the start would have been carrying more than 7A. Now the silicon rubber sold at Swaps (the thick stuff) is 14 strand and again tightly twisted comes out at 1mm and but is only rated as 3A. So back in the old days they were a lot more optimistic on current carrying capability than today.

Gary

[pwdrive]

Is it a pentagrid mixer Gary?

Lawrence.

[tiv48]

All I can say is what a fantastic job.
Rob T

[AlanBeckett]

Those under-chassis Pictures put a whole new complexion on the term 'Rat's nest'.
I'm glad it wasn't me. Well done.

Alan

[pwdrive]

Is it a pentagrid mixer Gary?

Lawrence.

Silly me, I didn't count the valve base pins....

Lawrence.

[ed731pdh]

You comments about wiring reminded me of when I was a mere lad (7-ish) and my old man had to sort out a ground floor ceiling rose that went bang when the light was turned on, this being an old Victorian house. After lifting the floor boards and finding the rubber coated cable perished, rubbing the cable between finger and thumb he ended up across the room, out the door and halfway down the landing to the fuse box before he found a decent section to tee into with a J box. That was the end of that, a full rewire needed.

Guess who learnt very quickly about pulling through?

Not as bad as a friends house, he had rubber coated cable in a lead jacket.

[Yorkie]

Wonderful job Gary. Crikey - you certainly take on some scary tasks - it looks a complex set and not one for the faint-hearted!

The article will be an excellent follow on from the Integra in the Winter Bull. (Lots of helpful restoration tips in that article). Rat's nest indeed - at least the Integra had some semblance of order, with under chassis tag-strips. I saw an Ekco AC76 a while back, I couldn't believe how untidy the under-chassis layout wiring was. The AC77 under chassis is chaotic too - not much at one end but all bunched up at the other, though at least the power supply is on a separate chassis in the AC77.

I guess that in the mid 30s design concepts were still evolving 'on the hoof', but I'd have thought that with enough foresight, sets could have been better laid out, easier and less labour intensive to build, with less risk of errors creeping in. In the Ekco A22 on the other hand, with it's accessible tagstrip around the outer periphery on the chassis apron, it's evident that much thought went into all aspects of the design and construction.

Always fascinating to look at each wire and component in an old set and to know that someone long gone will have wired up their own little bit countless times, day in, day out as the sets passed down the assembly line: cut the wire to length, poke it through the hole in the tag, solder it, pass it one, cut the wire to length, poke it through the hole...