Murphy V280 Restoration

[murphyv310]

Hi.
On my travels last week I was up in the North of Scotland, I was at Aberdeen, Peterhead & David Simpson's place just outside New Deer.
David had been given a Murphy V280 to keep hold of until I arrived, he was holding onto it from another forum member for me to repair.
Now this has a nice story, the lad that owns it had heard of me when I had the shop and before I was a member on here, unfortunately at the time when he was looking to get the set repaired I had just closed down so he couldn't contact me. It was only after he joined the forum recently that he was able to to get in touch. So I now have the chassis to wave my magic wand at and get going.
The set itself has a nice history too, it was found by the chap when his parents and the chap (a teenager at the time) moved into the house, the set worked so he commandeered it for his room, he used it up to the time he got married and then used it up to the 405 line switch off.
So after 25 years of slumber, a sudden wake up didn't really work too well, so hence the reason I have it now.
I will do a little during the week but will concentrate on it at the weekend.
One thing I need to sort out though is the LOPTx which went up in smoke, fortunately I have a few Murphy trannys so I think the line stage should be an easy fix.
The whole set needs a good old clean but I will revert to my usual tactics with the pressure washer, so as I have said many times before, "watch this space"!

[murphyv310]

Hi.
I had some time this afternoon to give the oil soaked chassis a clean along with the tube.
I gave it my usual go over with the hot pressure washer and TFR, also a good hot rinse.
The chassis was blown dry with the compressor and hot air from the hairdryer, the tube was refitted and the set is now on the bench which has a 250w tubular heater mounted underneath this will chase any remaining dampness out.

I had a look at the lopt which has some carbonisation around the U25 anode connection. I will repair this and I am sure the LOPTx will be serviceable.

[murphyv310]

Pcture of the LOPTx (sorry about the 30 line definition)

[FERNSEH]

Hi Trevor,
The Murphy V280 is a much better receiver than it's predecessor, the V240/250 series. For starters the later models have a single 0.3amp heater chain having taken advantage of a new range of valves from Mazda in 1956. The dual 0.1 and 0.2 amp heater chains that were used in earlier AC/DC sets including the V250 was an awful arrangement. All the Mazda valve adherants were stuck with it, Ekco, Ultra and Murphy.
The V280 was the standard receiver having direct line sync and mean level vision AGC. The V280A version has gated AGC and flywheel line sync.

I do like the use of the pressure washer to clean the chassis, the metalwork looks like new! Just look at the standard of the construction, there was no other TV manufacturer who took the trouble make such a quality product.

DFWB.

[oldticktock]

Hi Trevor looks fantastic, obviously your experience and knowledge enable you to do this. I would have wrongly thought the power behind a pressure washer would blast it to kingdom come. I always remember HKS rollicking me for using a brush with the potential to disturb or break things. I don't think I would ever gain the confidence to do what you do but wow what a result! it looks new.

Looking forward to this thread

Chris

[Framer Dave]

Trevor, sorry to be a pain, but what is TFR? "Hot pressure washer" I can understand. I think I would like to try your cleaning method - the results are remarkable. I have recently put the entire innards of a Pye Fenman II (not the speakers!) through two cycles in the dishwasher, and left it for a fortnight in the airing cupboard. Electronically it's brilliant, I'm listening to "Just a Minute" on it now, but it still needed quite a bit of hand finishing.

Sorry to dirvert the thread away from your excellent V280.

Kind regards,

[Sean Williams]

TFR - Traffic Film Remover - great stuff on aluminium!

[murphyv310]

Spot on Sean, wonderful stuff on ally and on caked on Murphy transformer oil.
I don't yet know if I am working tomorrow if not I will attack the line transformer.

[Heatercathodeshort]

Hello Trevor, Nice start on that V280. Murphy receivers of this period were quite rare even in the mid sixties. I think they suffered from massive capacitor failure, especially the I.F. decouplers. Well built and as David has said, the first Murphy to use the .3amp Mazda television valve range. What took Mazda so long! Not sure about the jet wash so will be watching with interest. Our garage unit would blow the components off the chassis, no kidding. Regards, John.

[DuncanLeece]

Dear all

I don’t know if I am more amazed by the speed and quality of Trevor’s work, or the interest shown in my old TV. Yes: I am the chump who connected the poor old Murphy to a brand new standards convertor my wife bought as a present, plugged it all in, and fried the LOPTX. We live and learn.

Just thought I would record, for those who like to know such things, that I believe this set is actually a V280C model, as it is the console version, rather than the table-top kind. Trevor has not seen the cabinet, of course! I think it has quite nice simple lines.

As Trevor said, I got this set when I was about twelve or thirteen (circa 1973/4) when it was left in a house my parents bought. I was never much into watching TV and only ever had one of those set-top aerials, so the picture was rubbish, and consequently, the set was very rarely used.

However, I love music, and got a similar era Pam radiogram (which I also still have) from a jumble sale, and cobbled together some old flex wire to use the TV as an extension speaker. It all sounded surprisingly good.

Andrea and I married in 1982, and rented a wee flat. We had no money, and TV was a very low priority, and rarely watched (far better things to do with our evenings!!) so we just stuck with the old Murphy until the end of 405.

Somehow, we never could bring ourselves to dump the old set, and now, assuming Trevor can pull off his usual magic, we will greatly enjoy watching the occasional old film on it; because guess what, we still think current TV programmes are rubbish. So some things do not change.

Kind regards
Duncan

[murphyv310]

Hi Duncan.
Thanks for posting the wee story, I have not felt too grand today so haven't touched it. The LOPTy will be OK and I am sure I will have a picture by Sunday.
Take care.

[Colourstar]

That's one clean chassis! I wouldn't have thought the combination of pressure washer and vintage television chassis could ever have a good outcome. How wrong can you be?

Duncan, your set is in good hands!

Steve

[murphyv310]

Now come on lads my head is too big as it is

[FERNSEH]

Hi Trevor,
I have no infomation for the V280. Does the line timebase employ a self oscillating circuit, or is a 6/30L2 valve used as the line oscillator?

DFWB.

[murphyv310]

The V280 uses a 30F5 in the line oscillator, a winding from the LOPTX is used for feedback and also for the gated AGC.

[Danny]

Hi i hope this doesnt suffer the same fate as my v280 ! it had similar lopt trouble i opend and drained the lopt replaced the eht rect . the set worked well for about an 1hr then the overwind fried. i then tried the tripler trick wich worked well. so i fited it all back together. a forum member said veg oil was ok for the lopt so it was refilled with this.
upon trying the set once more before puting it back in its cab the frame started to cramp and roll ! so more investigation then a screetch and line failure the lopt primary had now failed . ive tried lopt other lopts in place of the murphy one but cant get correct line form . so if anyone has a spare lopt im in the market. i have another of these sets but the lopt looks diffrent and i dont want to cannabalise one set for the other. excellent picture when working though if you do a search there should be a picture of my set on here. were these lopt unreliable and is this the real reson for not to many of these sets left ?. Danny

[murphyv310]

At the time when Murphy oil filled LOPTs were still in everyday use the only real problem was the choke or resistor in series with the U25/26 heaters went O/C. The transformers were replaced for this, other than seals bursting and the oil getting lost they were fine.
It's different now though, the oil can get contaminated with water, and one that has no oil in it the transformer can get saturated with moisture.
This one had an empty can so the tranny is sitting on a tubular heater for a few days.

[murphyv310]

The LOPTy has been baking for two days so I have now cleaned off all the carbonisation from the paxolin. I have also repaired the poor connections on the U25 and also replaced said valve as I don't want to dismantle the LOPTy again, I also have used some hot melt glue around the the parts that have flashed over. Hot melt is an excellent insulator and does not break down in vegetable oil. The transformer has been reassembled with new spacers and the top has been peened over and sealed. As yet oil has not been introduced into the can but that will be done when the underside of the set is complete. I have given the set a taste of AC but it has only been up to 170v and from memory these sets are reluctant to start below 200v.
After tea I will give it a little more mains volts and see what transpires.
I also have replaced the 30P4 screen decoupler, the G1 coupling cap, boost cap & boost de-coupler. also NOS 30P4, U329, 30F5 & U25.

[murphyv310]

Well with 180v of mains the line timebase started and lo and behold a picture of sorts.
I didn't run it for long with the lopt dry so from now on in I would assume the set should be complete for the weekend.

[murphyv310]

Hi.
Great progress then the flop. I have now replaced all wax caps, some out of tolerance resistors, cleaned the turret and filled the lopt with oil.
Perfect results straight away and the set ran faultlessly for 2 hours then sudden lack of width smoke and decaying EHT.
So we need another LOPTx.
I think I will graft in a V310 loptx, whether it will work is another story and whether I can get a suitable line pulse for the AGC is also going to be a challenge!