The ECL80 was used in many other TV sets as the frequency changer. The 1952 Sobell T143 and T224 series introduced the following year use the ECL80 as the frequency changer. The PCF80 was introduced in 1953. The Pye FV1 and FV1C were introduced in late 1951. The 16" CRT FV2C and 14" FV4C 1952. The rather strange Pye V54C is a more advanced development of the FV1.
A long time ago (I got rid of it, perhaps foolishly in hindsight) I had a Sobell T174 console. It was a masterwork in using as few different valve types as possible, where if the valves weren't EF80s or ECL80s it was because they couldn't use those types for that job!
@pye625 Thanks Yep I learnt my lesson on this one too! In another Pye set so thanks I will just check again you never no so thanks Kev.
@till Thanks having a day off today but will give this a try on my next go at the set and I can confirm that C4G has been changed. Kev.
@cathovisor Sounds like my 1953 HMV, although they were "N" series equivalents (N174 seems to ring a bell). Anyway, line oscillator-EF80, frame oscillator-ECL80, frame output-EF80, audio amp/output-EF80. I'm not sure if the audio detector might have been a half EB91! - The other half being incorporated into the 'picture interference limiter' circuit, but as you say, a masterpiece in economy.
One good part of it though, you had plenty of valves to swap around and 'see if the fault went with it'!
Well, thanks again so much to everyone re this and just to keep everyone up to date re my efforts with this Pye FV1 TV. I have done a little bit more I'm a bit slow! I do have a very bright more clear stable raster now on-screen but still, nothing coming through on the RF side there is no sound or vision. I feel it's going to be all those little coloured coded caps in the RF side of things maybe a few have gone bang all ready and scared the life out of me how can such a little thing make such a big bang! Some look a real nightmare to get in to change as well! Can I ask what would be recommended to change this small 0.002 mfd? capacitors with eg what type and working voltage would be best to use here to replace these, there seems like hundreds when you start looking. I will have to get some suitable capacitors and slowly work my way through them. Thanks again will post back when I have one some capacitors and started to change all those caps! Thanks again, Kevin.
Personally I think it's time to start fault-finding by tracing the signal as it's presented to the IF stage, then see what's going on as it works its way through the various parts of the IF and which particular stage is presenting the problem. Don't fall into the trap, that replacing all capacitors in a device as the panacea to getting one working again. The web is littered with plenty of stories where folk state, "I've changed all the caps but its still not working".
If you must change them all, then in the IF stages usually ceramic is the way to go. Keep the leads as short as possible and dressed (positioned) in the same manner as the original. If you don't do this you may find a realignment will be required.
CrustyTV Television Shop: Take a virtual tour
Crusty's TV/VCR Collection: View my collection
@crustytv Thanks very true words indeed about changing caps on mass and I have been there and done just that! And still ended up with a working set! Maybe its time to dig the signal generator out! Mind it's a horrid set in the fact that I now really have to take the tube out and make some sort of rest for it on the bench I feel as well so to get it next to the chassis and can do some positive testing on it all. I will pause for thought I feel, thanks re the info re the caps as well. Kev.
On reflection, a number of years ago I did buy myself oscilloscope which since has been on my workshop shelf, back then was fully working and always wanted to get to grips with using this or at least having a go with it yet at that time I could find no guides to using one in the sense of just getting to grips with the very basic re vintage TV's and what I could do with it and how helpful it might all be re this Pye FV1? Now with plenty of time on my hands, this might be an ideal time to learn does anyone have any advice reusing one or does anyone know any basic good guides I think at the time I looked at a lot of stuff re oscilloscopes and found it all very confusing. All worth thinking about anyway Kev.
does anyone know any basic good guides I think at the time I looked at a lot of stuff re oscilloscopes and found it all very confusing.
You'll find no finer guide on piloting an oscilloscope on the web, than Alan Wolke (Tektronix) "Scopes for Dopes".
It's 2 hours long, skip to 15mins in, for the start of Alan, that’s when it gets good. I discovered this almost 10 years ago now when I first got into using a scope on a PYE LV TV.
There is a full manuscript of the lecture for download here if you wish to have a paper copy as you follow the video. For ease, members with Vrat data library access, can find a copy that has been available in there for some considerable time.
CrustyTV Television Shop: Take a virtual tour
Crusty's TV/VCR Collection: View my collection
@crustytv O thanks that look just what I need I shall be viewing this with great interest thanks. Kev.
Can I ask what would be recommended to change this small 0.002 mfd? capacitors with
Hi Kev, as Chris mentioned above, ceramic types would be ideal. As they are for general purpose decoupling, the values are probably not very critical. However, the working voltage needs to withstand the HT in the set. I have used ceramic disc type capacitors before with great success. I have just oredered some more myself as they may come in handy, a pack of 50x 3n3 500v ceramic disc types from ebay, and the price was very reasonable. These should be fine in your set as deoupling capacitors. For instance, in an Ekco TMB, I used a load of 4700pf as I had no 3ooopf at the time and I had no problems.
As for replacing them wholesale, perhaps it would be good to seek out only the ones which would have been near or at HT potential first. The reason is that you will need to replace these anyway, especially if any have popped. Not only that, it can be difficult to fault-find on a set with IF instability as the whole thing can be paralysed with overload due to it oscillating.
To understand the black art of electronics is to understand witchcraft. Andrew.
Can I ask what would be recommended to change this small 0.002 mfd? capacitors with
Hi Kev, as Chris mentioned above, ceramic types would be ideal. As they are for general purpose decoupling, the values are probably not very critical. However, the working voltage needs to withstand the HT in the set. I have used ceramic disc type capacitors before with great success. I have just oredered some more myself as they may come in handy, a pack of 50x 3n3 500v ceramic disc types from ebay, and the price was very reasonable. These should be fine in your set as deoupling capacitors. For instance, in an Ekco TMB, I used a load of 4700pf as I had no 3ooopf at the time and I had no problems.
As for replacing them wholesale, perhaps it would be good to seek out only the ones which would have been near or at HT potential first. The reason is that you will need to replace these anyway, especially if any have popped. Not only that, it can be difficult to fault-find on a set with IF instability as the whole thing can be paralysed with overload due to it oscillating.
Many thanks for this that is really useful when time allows I will take this very cautious approach to replace the many capacitors in this section. So thanks for the info on the capacitors types that you have used that is so very helpful. Will see how it goes like I said I have to get the whole lot out on the bench so must build and make a safe stand for the CRT and look at doing this next. Will keep you posted of any success or failure as well re the Pye FV1. Thanks again re the great info above Kev.
No problem ?
As for going to the trouble of making a stand for the CRT, I usually just carefully place a CRT face down on an old folded up duvet in a place out of the way. Having made sure that the EHT is completely discharged before removing it from the set first of course.
Whilst there, it is a good time to use a vacuum cleaner brush attchment to remove all the dust from it, then a barely damp cloth to wipe it down with. The screen usually needs a clean too, just long as you NEVER allow the weight of the CRT to bear upon the neck. Support it with your hand yes, but keep any excessive pressure away from that area.
To understand the black art of electronics is to understand witchcraft. Andrew.
Hi everyone.
I noted on this valve V1E the video amplifier there is a Red Discs type Metrosil which I have to say does look somewhat worse for wear all the red paint has peeled off but what would one replace this with today?
Despite the paint flaking off which is to be expected due to its age (60+ years) and power cycling, is it actually o/c? Have you metered it?
CrustyTV Television Shop: Take a virtual tour
Crusty's TV/VCR Collection: View my collection
There is a small paragraph early in the is document of the development of the Metrosil, still in production in Manchester.
https://metrosil.com/wp-content/uploads/2018/11/Why-Metrosil-Brochure-Website.pdf
Frank
Thanks for your kind reply, Yes I have read about these Metrosil before in these older sets a number of years ago and how hard they can be to find a suitable modern replacement component. Now I did unsolder it and cold off the set I get 5k resistance across it now as you say there is no data given about these Metrosil's used in this Pye FV1 set so I don't have a clue if that means it's good or bad? But I assume maybe it's OK! And not a problem. Kev.
Take some voltage reading on the video output valve, your multi meter with a low voltage may give incorrect resistance readings of the Metrosil.
I would have thought if faulty a 470ohm resistor would be a good starting point for a replacement, voltage and current checks can then be made to get a suitable value.
Check the voltages etc with the Metrosil first it may be perfectly ok.
Frank
