Hello all, I guess it's high time for a television restoration. Well, I will attempt one ! ?
The eagle eyed among you might have spotted this set on ebay. I was thinking about making an offer, but it "sold" and vanished only to appear again a day or so later! So I put an offer in and eventually agreed a price of £65. Now, that may seem quite a bit of money for a set that could be in almost any condition internally. The LOPT being one concern of course, as I know these are somewhat fragile to say the least. Not only that, I wonder if the cabinet is meant to be black..... Could someone have painted it ? Is it a VC4 chassis ? What is the model ?
Well, these questions and more will be answered next weekend when I go to collect the set. In the meantime, here below are the vendors' photo's for your perusal....
To understand the black art of electronics is to understand witchcraft. Andrew.
Only saw a couple of these, no idea what was wrong with them now. Looking forward to the back being removed, see what’s inside.
Frank
Hi Frank,
there's a topic in the vintage-radio forum about a similar set:- https://www.vintage-radio.net/forum/showthread.php?t=158042
Way back in the sixties these were one of the first new sets rented out in my fledgling business. My sets were the RGD version but later on that brand was discarded by STC and all sets were delivered as KB.
VC4 was introduced in 1966. STC had at last given up with expensive twin panel CRTs and as the company had sold Brimar to Thorn-AEI you'll find most of the valves in the VC4 will be sourced from Mullard. CRTs from Mullard or Brimar.
Til Eulenspiegel.
I have the set in the workshop now and it is a model KV 013. It appears to be in pretty good shape generally.
What I thought was black paint covering the set is in fact black rexine and it is original.
Here are a few initial snaps....
To understand the black art of electronics is to understand witchcraft. Andrew.
That should clean up quite nicely, Andrew. At first glance, the chassis looks quite similar to the VC52 chassis in my KV125.
This is silly.... the thing just plain "works" !
All I have done is to give the chassis a once over for any serious shorts, re-formed the main electrolytics, applied power slowly, and with full mains, the result is shown below. An adjustment to the VHF fine tuning control and height only being required. Naturally, some cleaning and further adjustments will be needed with reference to the service manual.
To understand the black art of electronics is to understand witchcraft. Andrew.
The KV013 dates from 1968 and is referenced in 68-69 R&TS page 562, it uses the STC VC4 chassis. This chassis being comprehensively covered in the 67-68 volume of R&TS, page 491 and runs to 10 pages. In light of the set working, little point in scanning ?
I'm sure you're aware but the Achilles heel of this series of set is the flaky LOPT both the overwind and primary, fingers crossed yours proves to be the exception
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Philips VHF tuner and not sure but possibly a Philips UHF tuner and a transistor one at that.
The set doesn’t look like it’s had much use, that CRT looks brand new, is there a label in the bottom of the set, perhaps a Mullard CRT, I can see a Mullard valve.
Nice one for the collection and not too large.
Frank
The PCL86 and 805 are Mullard and the PL36 and PCF802 are Thorn devices. The remainder valves are all Brimar so probably original. I can find no lable to indicate the make of CRT.
I have cleaned the chassis of dust plus the system switch. I removed the LOPT from the chassis in order to clean it, and remove the already cracked and flaking off bitumen covering of the overwind. I could see no benefit leaving it in place.
I have had the set running for over an hour already and the LOPT is only luke warm so it appears not to be under any stress. I have not yet operated the set on 625, but I will only activate the system switch with the set switched off.
To understand the black art of electronics is to understand witchcraft. Andrew.
Word of warning about the VHF tuner if it’s the type I think it is. They don’t like pressure on the channel change knob, if you lay it on it’s face, support the set so the tuner knob has no pressure on it.
The raised mask around the CRT will help but some support on the tuner side of the cabinet would be useful.
The tuner has a small plastic wand with a metal (brass?) insert, about 3 cm long. The plastic breaks and the fine tuner won’t work, coils are printed on PCB biscuits so cannot be adjusted. The tuner wand screws in, can be a but fiddly to remove but possible, I did them in the field, once one as been done the next one you come across will be easy.
Frank
Thanks Frank, I will be careful.
I think I was lucky in that the set has been stored all this time indoors and not suffered from any damp. Apparently, it belonged to the former owner's grandad and he kept the set covered up.
I never even bothered to test the CRT, I was more concerned about whether the LOPT was working or not.
To understand the black art of electronics is to understand witchcraft. Andrew.
Hi Andrew, really great to see this set in more detail. Like you I assumed the cabinet had been painted black maybe in the 1980s! Must look great and rather unusual in rexine. My own (ex)example as referred to in the UKVRR link further up the thread is a standard teak version and yes the crt would be a Brimar if original.
Your set looks to have 1967 date codes stamped on the IF cans in the close-up shots, which would tie in with it being in the shops in 1968 as Chris mentioned earlier.
Some years ago a late friend of mine had a pristine KB set with this chassis and flipped standards with it running. By some quirk of fate the system switch jammed halfway and the LOPT fried. He was not happy! So yes you are well advised to switch off when changing standards, but with a picture as stunning as you've got on 405, who needs 625 anyway? It'll never catch on....
Sadly I've had almost zero time for vintge tv for months and months, due to health issues with elderly parents and now an imminent house move, but I hope to get back to the hobby before too long.
Anyway, great result! ?
Steve
Hi Steve, thanks for your input and encouragement ?
Some years ago I had a 23inch KB with similar chassis and popped the LOPT by changing standards whilst powered. I sure won't tempt fate again !
To understand the black art of electronics is to understand witchcraft. Andrew.
Some years ago I had a 23inch KB with similar chassis and popped the LOPT by changing standards whilst powered. I sure won't tempt fate again !
Odd, because they were designed to do so: the usual method was to arrange contacts on the system switch to break the supply to the screen grid of the line output valve whilst the change was being made. I can't imagine having to turn a telly off before watching BBC 2 would have been a selling point!
Yes- and of all the manufacturers, the standard switches of the STC group sets (KB etc) seen well engineered with a particularly positive 'snap' action, so I don't know what can go wrong. Compare those to sets such as the Philips Style 70 and Bush TV125 series where the speed of the bowden cable actuation is entirely at the mercy of the user.
As Catho rightly says, these sets were designed to be switched between 405 and 625 at will when in service.
Steve
and of all the manufacturers, the standard switches of the STC group sets (KB etc) seen well engineered with a particularly positive 'snap' action
Trouble is, it used to lead to the knobs breaking because of the high operating force; if you look at the KV025/125 sets, depending on their age the '405' and '625' legends swap position - the ones with '405' to the right have a modified linkage to lower the operating force.
I feel that it is wiser to put as little strain on the LOPT as possible, there are bound to be voltage spikes when the standards are changed whilst powered. Even if the line stage is inactive during the switch, there will still be a pulse surge when it is brought back into operation suddenly. Probably not an issue back when sets were newer, but LOPT's are obviously not easy to come by now.
To understand the black art of electronics is to understand witchcraft. Andrew.
After a good clean up of the set today, it was time to relax in front of Fawlty Towers on 405. Then, a short test on 625 and all seems pretty good.
To understand the black art of electronics is to understand witchcraft. Andrew.
