Seeking Valves

[Mark Hennessy]

Just a thought about the photos - sorry to be a little off-topic - but does your camera have a macro mode? The icon is usually a little flower. Selecting this enables the camera to focus at much shorter distances than usual, which is excellent for close-ups. Lots of light also helps, as the shorter the shutter speed, the clearer things will be.

All the best,

Mark

[Nowhere-Man]

Just a thought about the photos - sorry to be a little off-topic - but does your camera have a macro mode? The icon is usually a little flower. Selecting this enables the camera to focus at much shorter distances than usual, which is excellent for close-ups. Lots of light also helps, as the shorter the shutter speed, the clearer things will be.

All the best,

Mark

I'll see what I can do with the camera. The valves have now been ordered so I'll be powering up again fairly soon. The guy on the phone thinks I may be a bit crazy to spend money on the project but I think now I need to see it through. Actually the valves weren't that expensive and it could have been worse.

[Nowhere-Man]

Just a thought about the photos - sorry to be a little off-topic - but does your camera have a macro mode? The icon is usually a little flower. Selecting this enables the camera to focus at much shorter distances than usual, which is excellent for close-ups. Lots of light also helps, as the shorter the shutter speed, the clearer things will be.

All the best,

Mark

You'll be glad to hear the radio is up and running. Three valves arrived today from Langrex. First I tried to fit the the DH77 and that finally slotted in. The W77 also went in O.K. and finally the X79. I'd had a few doubts on that score and had been prepared for at least one valve to not fit. As it was they all did fit.

I checked the radio carefully before connecting to mains. In fact I discovered a capacitor lead had come off a valve pin so that was unexpected. This had to soldered back on again.

After this, I plugged in through my simple current limiter lamp. Again, I wasn't actually expecting the radio to work straight away so was very pleasantly surprised to hear a station come in loud and clear. I tuned around and managed to get more stations. The frame aerial was plugged in, of course.

So, now, it's safe to say this is all pretty much under control. The radio finally has all its valves back (the ones I got today were pretty small!).

What remains now is the issue of safety. I'll be looking at heat shrink and securing wires, especially the HT wire. I may even look at getting a rectifier tube if one can be found. All in all, I must have spent 30.00 pounds on valves and capacitors.

[Brianc]

Great that it's working. However, we still haven't seen any pictures!Are you going to take any?

[Nowhere-Man]

Great that it's working. However, we still haven't seen any pictures!Are you going to take any?

Sure, I'll take a few pics so you can see how what it looks like. It's a very nice Bakelite radio with a thermometer tuning mechanism. At first I believed it to be a forties radio but eventually it became clear it's early fifties.

It's an easy radio to work on compared with others because you don't need to take the chassis out.

However, I've learned from now on always always to check the valves are present. I paid £20.00 for this radio but had no idea the valves were either absent or damaged.

I can upload some pics of the new valves if you want which are NOS. They came with the original boxes, except the W77 and Dh77.

[Nowhere-Man]

I always tend to associate radios with movies. I like watching old movies. Last night I was watching The Creature From The Black Lagoon and got curious as to when it was filmed. I think it was in 1954 so just a couple of years or a year after my GEC radio was made.

I have one radio as a future project that's 1939 so I was associating that with The Wizard Of Oz and the Great Depression.

Back to the subject at hand, the GEC is a very basic radio design. Very typical of the early radio era.

[Brianc]

I know what the radio looks like as there is a picture in an earlier thread. I would like to see the workings of it and the repairs/replacements that you have made.
Cheers
Brian

[Nowhere-Man]

I know what the radio looks like as there is a picture in an earlier thread. I would like to see the workings of it and the repairs/replacements that you have made.
Cheers
Brian

A large chunk of this thread was on another vintage radio website as somebody else remarked a few posts back. That particular thread contained quite a few digital photos. The thread was eventually closed down by the moderators on that other site at the point where I'd plugged into mains but was getting no audio. At that time, I was sort of baffled because the rectifier was working but no sound at all. Later I discovered I needed to replace my valves I resurrected the thread here in case anyone might happen to have any of the valves I was seeking.

I avoided keeping it on for two long yesterday as I suspect the voltage will be a bit low. What I have to do is to test the Output Tetrode anode again and see what the voltage is compared to the manual. If it's still too low, I'll need to lower my series resistor. The aim is to hopefully get the anode voltages about the same as outlined in the schematic. I will also look into the HT capacitor as it seems to me charge isn't being retained. I have a German set that you daren't touch even 3 hours switched off after powering it up so I ought to investigate.

I may even consider using a valve rectifier and removing my silicon experimental set-up but that depends if I'm lucky enough to get a matching rectifier.

I think it may also be a good idea to fit an inline quick blow fuse in the supply line and secure any wires that could be in danger of working loose.

The next project may be the large HMV stored in my boat. This will be a really big challenge as soldering will be much trickier and one of the waveband screens has been totally wiped clean, leaving no letters. Plus the tuning string has broken. All valves are present

Either that or I could tackle a McMichael set in the garage that has all its valves.

[Herald1360]

Hello NM,

Nice to hear you eventually sorted this one- it was a bit of a marathon!

Chris

Herald1360

[Nowhere-Man]

Hello NM,

Nice to hear you eventually sorted this one- it was a bit of a marathon!

Chris

Herald1360

Thanks Chris, I just got a new grid bias resistor today as I want to get the output tube anode voltage up to spec. I think the grid will be a bit too positive as the bias resistor is 50 Ohms out of spec. First I'll test it that way and if the voltage is still at 245, I will lower that 1 K series resistor.

I'd be foolish to run it too long at too low a voltage but yes it does work fine now all the new valves are there.

Next project will be the 1939 Halycon.