Newly found VEF Spidola

[stevehertz]

Thanks for the info and photos. As soon as I get some time to myself I'll dismantle the set and begin work on it.

Oh, on that note, earlier I tried to unscrew the aerial plastic top cap. Gripping the last (thinnest) section of the aerial firmly so that it didn't slip, I 'unscrewed' the top cap. But although it rotated, it didn't 'screw off', just rotate. Sounds like the threads have gone in the tip, but curiously it isn't loose or anything like that. Not sure what to do, I don't want to end up with the tip being permanently loose such that it can't be used to extract the aerial.

[Techman]

Perhaps if you turn the plastic cap while pulling lightly upwards. If the thread has been stripped in the cap, perhaps a drop of Araldite could be dropped into the hole and the cap screwed on and then unscrewed before it's completely set so as to have a tapped thread. It doesn't look as if it's possible to remove the aerial assembly up through the top of the case separately from the rest of the chassis, due to the top double fixing lug. It's worth noting that the aerial incorporates a switch so that it only electrically connects to the set once the final section has been completely extended.

When I removed the chassis I remembered that I'd had it apart before, probably when I was quite young - I remembered seeing how the tuning drive cord and spring traverses across the lower half of the speaker. I lost one of the four battery cover knurled fixing screws (two on each side) while changing the batteries and I thought I'd dropped it inside the works, as I couldn't find it anywhere else and thought it must be stuck inside somewhere. Having taken it apart I couldn't find the screw stuck anywhere in the innards, so ever since it has had one odd screw holding one of the battery covers in place.

[stevehertz]

I've now removed the chassis from its case. The following has been done: turret springs cleaned, tranny bases cleaned, volume pot drilled and cleaned, various dry looking joints resoldered, on/off switch drilled and cleaned, plus a set of contacts that I'm not sure of their function at the rear of the aerial and earth socket 'block' cleaned. But still no stations. I've started to check the electrolytics and having lifted just two as yet, both exhibit leakiness. Now, I'm struggling to understand the markings on the electrolytics. The two are marked as follows (as near as I can tell):

1st one:
10MK 6B
IX - 64

2nd one:
20MK 4B
VII - 64

I'm thinking that in the case of the first one it's 10uF 64V ? similarly, the second one, 20uF 64V?

[frsimen]

10MK 6B is 10uF 6V, 20MK 4B is 20uF 4V.

The circuit diagram shows the radio is powered from 9B = 9 volts.

The other characters could be a date code for 1964.

Paula

[stevehertz]

Thanks Paula. I had considered that the '6' and '4' were the voltages but I've never seen electrolytics rated at such low voltages.

Otherwise yes, the Roman numerals were the months for the year '64.

[stevehertz]

Well, something like 22 leaky capacitors later it's 'kinda' fixed. It wasn't until cap number 14 was changed that there was any sign of life at all. Given how many of these sets I have read about that needed little or nothing doing to them, I think I drew the short straw!

But anyway, while MW and all the SW bands work fine, LW is mute apart from the audio noise as the volume is increased. It has to be something associated with the tuning circuitry for that band.

[Techman]

I did a search and had a quick skim through those old threads on these radios and I was just thinking the same that they mostly seemed to work after a bit of fettling of the usual faults. Perhaps one of the answers is that these threads were all around fifteen years ago and it could well be that sets that had been left dormant since perhaps the late 60s had just managed to survive capacitor wise until 2006-8, but another 15 years on has been the final straw. My set has never been left for decades without having some sort of short term use every now and again over those years, so that's probably helped it survive.

As for the non-working long wave, my first guess would be that it's most likely to be something on the turret biscuit for for that band. Failing that, perhaps the oscillator doesn't like running below a certain frequency - a bit like the old ECH81 valve that starts to kill the oscillations at lower frequencies as it ages, killing off long wave on some sets. You might think that it'll always be the higher frequencies that suffer first, but this isn't always the case.

[stevehertz]

Good points you make there Techman.

One 'plus' is that with the set dismantled I've been able to dunk the plastic case into a bowl of hot soapy water and give a thorough cleaning with a variety of brushes. It now looks like a new one, no grime in the corners of that fascia grille!

[stevehertz]

Lack of Long wave reception now sorted. The individual sections or 'faces' of the turret tuner can simply be lifted off - no wires to disconnect! - and so can easily be checked for dry joints etc. On examination there appeared to be two wires potentially fouling other components, a potential dry joint, and another fine wire that looked like it was being trapped by the adjacent band section. Addressing these brought R4 into play, but I found that by 'twisting' the chassis, it could be made to come and go. But anyway the aforementioned issues must have done something at least. So I re-cleaned (again, again) the turret spring contacts and LW is now stable.

I just need to address the aerial spring contact that has come adrift from its plastic mounting - basically an Araldite job but not as easy as it sounds as it's very difficult to access. Otherwise the cabinet has come up like new thanks to a thorough toothbrushing in a bowl of hot water followed by a rinse, paper towelled dry and left overnight next to the dehumidifier. Photo shows it 'as is' currently not put back together.

Oh, it was 23 faulty caps, not 22, there was another one on the front of the chassis below the turret assembly.

[stevehertz]

I had to unsolder and remove the aerial spring contact in order to clean it as it had gone black, and poking at it with a cotton bud soaked in switch cleaner had no effect. Once out I was able to use a glass fibre stick. I then used 5 minute Araldite to fix it back in position. The set is now finished and works a treat, especially on SW with my long wire aerial. Previously I'd never had any interest in Russian trannies, and in all honesty I was only drawn to this one because of its 'strange' but in a way attractive looks. I don't think I'll be looking to start a collection of Russian trannies though as most of the ones that I have seen just don't float my boat, they're rather ugly and utilitarian. Maybe if another, different colour or something Spidola came my way I'd be interested.

[Reelman]

That's very, very nice Steve and a great job done.

I believe that this was the first model imported and is worth more than the later ones.

Peter

[stevehertz]

Thanks Peter, and a little factoid there, nice to know.

[stevehertz]

How many times have you 'finished' a set then it comes back to bite you? Me? lots, and here it is again..

After an hour or two listening to it working perfectly well, it decided to periodically go mute for a few seconds and then come back on without any assistance or prodding. The batteries fitted were not the best, so I put it down to that and replaced them with brand new ones. And now, it works but it's very quiet.

Two things that haven't been looked at yet are, firstly, there are two 500uF caps* strapped across the 9V HT, and secondly the detector diode that I assume is Germanium? Of course it could be 'anything', but opinions please on those two things? Thanks

* I'm struggling to see what function these relatively high value caps fulfil being as the set is battery (DC) powered. If it's is for RF filtering of the HT, then surely a lower value cap would be better?

[ms660]

LF filtering so far as I can see.

Lawrence.

[electronicskip]

Originally Posted by stevehertz

How many times have you 'finished' a set then it comes back to bite you? Me? lots, and here it is again..

After an hour or two listening to it working perfectly well, it decided to periodically go mute for a few seconds and then come back on without any assistance or prodding. The batteries fitted were not the best, so I put it down to that and replaced them with brand new ones. And now, it works but it's very quiet.

Two things that haven't been looked at yet are, firstly, there are two 500uF caps* strapped across the 9V HT, and secondly the detector diode that I assume is Germanium? Of course it could be 'anything', but opinions please on those two things? Thanks

* I'm struggling to see what function these relatively high value caps fulfil being as the set is battery (DC) powered. If it's is for RF filtering of the HT, then surely a lower value cap would be better?

I dont know anything about these radios let alone ever even seen one but really a lovely find.

[stevehertz]

Originally Posted by ms660

LF filtering so far as I can see.

Lawrence.

Thanks Lawrence, but what "LF" does it have to filter? It's being fed by a battery?

[ms660]

Originally Posted by stevehertz

Thanks Lawrence, but what "LF" does it have to filter? It's being fed by a battery?

The battery has an internal impedance which also increases as the battery voltage decreases with use.

All circuits are potential dividers.

Lawrence.

[stevehertz]

Originally Posted by ms660

The battery has an internal impedance which also increases as the battery voltage decreases with use.

All circuits are potential dividers.

Lawrence.

Ok, thanks.

[majoconz]

I have a lot of pics of inside and out, also a sketch of all the connections to the PC board. I'm not at home at the moment - convalescing after a pretty severe operation at my stepdaughter's - but I'll post when I get back home - probably between Christmas and new year.

[stevehertz]

Originally Posted by majoconz

I have a lot of pics of inside and out, also a sketch of all the connections to the PC board. I'm not at home at the moment - convalescing after a pretty severe operation at my stepdaughters - but I'll post when I get back home - probably between Christmas and new year.

Hi, thanks for the kind offer but TBH not a lot of help to me. I've had this thing apart so many times down to PCB level in order to change all those caps etc and I'm very familiar with the layout etc and could even answer questions on Mastermind about it. Hope you feel better soon.