This is the last of the items from the Newark Antiques Fair the other week, only cost £30, which I thought was a fair price, I was going to haggle, as the set was missing it’s back, but just as I was about to offer £20, the seller said ‘I’m sure I have the back for it somewhere in the van!’ And he went off into the van and dug it out! Sadly the bottom cover is missing, but I could make one out of a bit of hardboard. I actually saw this very set at the last antiques fair I went to, the one where I found the Cossor dumped in a pile of rubbish! I was quite surprised to see it again.
As I found out, it’s quite a heavy radio, especially when you have to walk for miles with it!
Its turn on the bench has finally come, well, it’s in the drawer under the bench, because the bench is buried under other stuff… The set has its own mains transformer, but for safety (and convenience!) it’s connected to the bench isolating transformer, the variac, and a lamp limiter (probably a bit over the top!). I wound it up slowly, no nasty surprises, dial bulbs lit, but nothing much happening elsewhere. I could see some valves lit, but the rectifier, a U50, was dark, and once removed I could see why, the heater was floating around in the bottom of the bottle! So that’s toast.. I haven’t got another that I know of, but there was a 6X4 sitting on the shelf in front of me! A few croc-clips later and it’s in, bodgery at its best! HT comes up now, but drops back when things get going, some noise could be heard from the speaker, and crackles when touching the aerial sockets with a test lead. The audio coupling cap, C19, was leaking badly, and a replacement was tacked in loosely, which brought the HT up a bit. Trying to tune across MW to find the MiniMod got nothing, just some noise from the iPod’s charger at one end of the band, same for LW, but SW is very lively, I was able to tune in that Chinese station loud and clear, along with a load of others.
My guess is the local oscillator is giving up on LW and MW, but runs ok on SW, the IF is working, as I can find it with the RF signal generator.
Now to pick through and find what’s stopping it, leaky caps is my guess, but I want to find out which one!
@lloyd Are the station markers printed on a card backing Lloyd? I think I owned one of these years back with badly faded printing on the dial. I remember it being very heavy, as to what happened to it I don't know.
Yes, I think they are, and they have faded badly on this one too! I think the MW print was originally red, which has helped it fade more rapidly than the rest of it. Another reason it's so heavy, there's a great big flywheel on the end of the tuning shaft!
Fading of red ink on card backings is a pain in the proverbial. I have an Ekco table gram from 1939 where that has happened (luckily, I have one from a table set I scrapped) but also I have a couple of wartime GEC sets using a similar chassis, both dating from 1943. If you looked at them (especially the Bakelite one), at first glance you'd think it was a BC4650 - except both are MW + 2SW. The wooden one even uses the back of the Bakelite set!
If you were to send me the cards, I have an artist who can retouch them providing it is possible to read them still.
Boater Sam
News flash!!
found the culprit for the lack of oscillation on LW and MW, not a cap, or a resistor! It was L8, completely O/C… luckily I could see a blob of green spot on the surface, a quick dig with tweezers and a blob of solder and it’s now playing beautifully on all bands!
And an added bonus; I found a U50 sat in a scrap Ekco A23 chassis, and it works! So my 6X4 bodge has been removed. It served its purpose though!
