McMichael 135 (1935)

I fell in love with the beauty from the moment I first laid eyes on her. I bid more that I should have because I mis-typed my bid by over £1000, so it was inevitable that I would win her, paying about £75 more that I wanted too. The dark wood version is less collectible and this one had been restored in the past and was looking quite good, even though she had some nasty faults lying ahead.

A five valve chassis, small one being the signal demodulator diode valve (red shows V2 old and new Top Cap mods

The Repair
Taking it apart is quite easy, four bolts underneath hold the chassis in place, the knobs pull-up from their long spindles, just held by gravity and the tuning pointer pulls off after removing glass display cover with 2 brass screws.. Some of the cables inside mine had been replaced, but originally the whole chassis pulls away from the 2 speakers, by opening multi-pin socket mid cable.

Mc Michael 135 circuit diagram

She had quite a loud mains hum and the large 8-16 uF (C21+C22) smoothers were bridged but with no improvement, so in the end I added a 32uF 400V  to the red cable at the chassis terminal end,  350v line that feed the speaker/ and smoothers, that got rid of the hum, It may been pick-up from all the loose cables. Putting my finger on the P/U socket produced loads of volume, so V4 audio amp was OK. I then checked for GII and anode voltages on V1 & V2, V2 had no anode volts. The anode voltage comes direct from the HT rail via the primary winding of the 2nd IF coil.(L15) I followed the voltage back to one side of this coil only, this tells me that the coil is broken inside the can.

Hole made in side of coil former to retrieve loose wire.

Next I removed the IF coils, photographed the wiring and un-soldered the 4 connecting wires and components. The can is hold by two nuts underneath. To ope te can, remove two nuts at the top and carefully slide the coils from the aluminum can. Careful examination of the feed wires to L15 showed ai had parted company with the soldered tab inside the coil housing. Because it was hard to get at I decided to make a hole lower down in the former and pull the copper wire though it to give me more wire to play with. The wire was then extended to the tag at the top and checked to be working fine (about 40 ohms resistance.) At one time a radio would be scrapped if an IF coil was faulty, but with patience the can be easily repaired. If wort comes to worse you can even remove faulty winding and remake it.

Red shows IF transformer primary winding of L15, and green secondary wining is L16, (no volts on top red arrow)

Having done this repair I still didn't have any anode voltage on V2  (MVS-pen) according to the circuit, when I checked the valves number it was different, an AC/VP1, I checked on line and this was indeed an equivalent for the proper valve (but in the notes it said, some early versions of the valve had the Anode as 'top cap' and others as pin 7 on valve base, so this is where my missing voltage was 'tit's-up', lol  I cut the original TC lead away and fitted a cable from top red arrow in diagram above and the TC of the wrong valve. (AC/VP1)

Bingo the radio came back to life after a prolonged period, a note inside the cabinet refereed to 2004, possibly when they give up on it. I think it was originally sold in Worcester (Ryder's Radio) as a nice little plaque was fitted to the rear for the sellers shop in Worcester, a long way from Hull where it ended-up.
The tuning dial had a mid of it's own, as you let the knob go it would move a little on it's own. It tuned out the be a leather damping strap that had rotted, so I just increased the tension on the pulley chord and that stopped that.

PDF manual is on-line, if you can't find it here an under view

There is something special about this set once working, it has a light bulb in the lid to illuminate the extra big dial with the most clear layout I've ever seen, quality oozes from it every part the light is fitted into a brass cartridge (last repair man fitted a fuse for this)  The cabinet is finished to the highest degree of inlay veneer that moves in a triangular shape at the front. Every set is unique because the cabinet maker would have used different veneer on each one. The set s were sold in 1935 with a Queen Anne legs styled stand, that to my mind was a little over sized and spoils the look. I'm still looking for the right stand for her, it may take time, but for now she has Dansette legs, lol

and finally I recently found this period advert