1960's NZ Murphy Television.

[stromberg6]

Originally Posted by Glenz75

Thanks for the positive responses to this TV guys I think I may be prompted to having a go and seeing whether I can get some life out of this beast. Thankfully it hasn't been moved too far into the depths of my storage area so its nice and easy to move back into the workshop

Attached is the schematic for your interest.

Cheers
Glen

Thanks Glen for posting the schematic. A very good straightforward circuit, but I'm intrigued by the "video control" circuit, V-205A 6CG7. It looks like a variable voltage source that controls the gain of the video amp. Can't recall seeing exactly that setup, and it looks like the picture from that chassis might be very stable across the gray scale, and through minor voltage variations. It's always the "little extras" in circuit design that are most interesting to me. Please keep us posted if you restore it!
Kevin

[dieseljeep]

Originally Posted by maxhifi

i like the clean look of it - nice how it has its own legs rather than needing a stand or taking up space like a console. That tv is worthy of a place in the living room!
I look forward to seeing a picture on that screen!

Almost all the US table model sets had provisions for optional legs. They refered to them as consolettes. Most people prefered custom carts, as they were easier to move.

[ChrisW6ATV]

That is an interesting TV, Glen. I see the name "Murphy TV", though, and think of Murphy's Law (anything that can go wrong will go wrong)! How often did those sets need to be repaired?

[zenithfan1]

Originally Posted by Glenz75

Thanks, yeah its a neat looking set. It has three I.F. stages. I think the super signal was probably a marketing thing but these were good sets so maybe a bit of both. Channel 1 - There used to be a TV channel operating at that frequency in the early days of broadcasting in New Zealand.

Thanks Glen!
からだにきをつけて。
Mark

[Mr Hoover]

Originally Posted by ChrisW6ATV

That is an interesting TV, Glen. I see the name "Murphy TV", though, and think of Murphy's Law (anything that can go wrong will go wrong)! How often did those sets need to be repaired?

Murphy was a famous British TV/Radio manufacturer dating back to the 1930's
they merged with Bush is the early 60's (name comes from the place of the original factory in Sheperd's Bush,West London) and then became Rank Bush Murphy.The main factory was by then near Plymouth in SW England.

In the late 70's Toshiba became involved in a joint venture and it turned into Rank-Toshiba,then the "Rank" part got dropped.The factory closed not long ago with Toshiba moving production to Eastern Europe I believe.

Murphy sets were well built but some models from the 50's had the horizontal output transformer in a can filled with oil....

The UK models of the same vintage as this set were totally different inside,having to cope with dual system 405/625 lines changeover IF/Timebase switches for a start !

Hugh

[rpm1200]

This is a great site with lots of Murphy UK flyers/ads and schematics: http://www.murphy-radio.co.uk/murphybilia/index.html

[Fritze-AR]

Originally Posted by wa2ise

Who knows... Anyway, 45MHz FM was to stop in 1950 to make way for TV channel 1, but it was found that 45MHz had a tendency to propagate long distance to other cities when the solar weather was right (sunspots and such) and that would make a mess of analog AM video modulated television. Before the DTV changeover, you would sometimes see this on analog channel 2. Later TV set makers went from an IF of 22MHz to 45MHz, which would not have worked on a channel 1. And the old 45MHz band ended up with police and fire comms.

Some stations that stayed and/or used native RF channels 2-6 for DTV can be decoded during Sporadic E's (short-skip). Received/DX'd several Low-VHF DTV stations in this manner, including WBRA, KOTA, WPVI, KDLO, WRGB (and pre-"transition" WKYC-DT 2 before they moved to RF 17 post-transition).

But to bring the subject back on topic, nice photos of that TV.

[Glenz75]

Hi, here is a bit of an update on this TV... I got curious and started poking around the chassis and decided to temporarily put in some 100uf filter caps in the power supply and change the boost caps just to be safe and attempt to fire the set up.

Using the variac I wound the voltage up I could hear things rustling and noises from the speaker, then the vertical kicked in, so I wound the variac up a bit more and there was an odd squeal from the flyback, glanced at the 1B3GT and it was lighting up a pretty purple inside! Hmm...me thinks that tubes a bit gassy so I put another good one in and powered on again and this time we had EHT but no picture or even a raster.

Checked voltages around the video stages, all appeared to be ok there and the cathode volts to the crt was within spec. I turned the set off to see if anything would happen and as the EHT collapsed there was a small bright image on the screen....ah-ha... Seemed like the CRT was being cut off. I didn't get much further that night as was very tired.

Looking at it again with fresh eyes I checked the grid volts on the crt base and as the circuit stated this should have been at least 80-90 volts on pin 2 and varies with brightness.
Mine measured around 40 volts on the grid... We have a problem here!
Started checking things in this part of the circuit the resistors in series with brightness pot and a 100k to ground which checked ok but there also were some 0.1uf coupling caps which turned out to be leaky, replaced them and I now get a picture although its lacks width and the verticals all up the creek, but at least the TV is now functioning and its producing sound and a picture of sorts, so a good start so far.

My next move is to investigate the lack of width, the picture is not very bright and the EHT is lower than it should be at full mains voltage so will look into that and then will sort out the vertical which may improve when the width is sorted.

There are a lot of wax paper caps in this one so replacing those will only improve things no doubt and I can bet there are a few resistors that have drifted way off also.

That's all for now. Stay tuned...

Cheers Glen.

[Glenz75]

Hi all here is an update on this one, some slow but steady progress has been made. The set now produces a full and bright picture, a rather big improvement on how it looked when I got first got a raster.

I've changed a handful of components in the line output section, the low value electrolytics and resistors were way past it, so no wonder I had a hard time getting reasonable EHT and width initially.

Treated the vertical to some new bits too which helped a lot but still have an issue with the top linearity, the control is hard at one end, no doubt there will be a resistor/cap thats gone wonky in there or the control itself has gone high, will come back to that later. There is still more work to do.

So that's it for now, some pictures of progress so far....

Cheers
Glen

[mstaton]

Lookin' good! It is very satifying to bring them back from the dead. I'm working on a 1950 Philco. Everytime I get something working great, something else goes wonky. Eventually I'll get it all straight.

[DavGoodlin]

I noticed back cover had that Murphy was distributed by Fisher and Paykel.

One of the "new" brands of front-load washers being sold at upscale appliance stores in the US are Fisher and Paykel, and noted as coming from NZ.

[Glenz75]

Thanks Yes the joys of restoring old TV sets...you disturb something in one area and down the line something else doesn't like it.... Like a chain reaction
I'm itching to do some more on this but time and wee toddlers don't leave me with much energy at the moment at end of the day so end up going to bed! Cheers

Originally Posted by mstaton

Lookin' good! It is very satifying to bring them back from the dead. I'm working on a 1950 Philco. Everytime I get something working great, something else goes wonky. Eventually I'll get it all straight.

[Glenz75]

Thanks for that information I had no idea we were sending domestic appliances to the US. Fisher and Paykel have been an NZ company for years.

Originally Posted by DavGoodlin

I noticed back cover had that Murphy was distributed by Fisher and Paykel.

One of the "new" brands of front-load washers being sold at upscale appliance stores in the US are Fisher and Paykel, and noted as coming from NZ.

[Captain Video]

That is a cute TV and I am glad it is being put to work again!

Those 1960's TVs remind me a bit of my childhood, when I was a kid, in the 1980's I sometimes saw those 60's sets on the homes of older people. It was also common to see 60's portables on bars... those 1960's sets were very common, nowadays they are more or less rare. It's sad to think that so many of them were destroyed on the last decades. People older than me, who grew up in the 70's remember that it was not unusual to see 50's TVs still functional in the homes of elderly people.

[Glenz75]

Thanks Yes its a nice looking TV and I hope to do some more work on it soon.
I also recall as a child seeing many old TVs still going in peoples houses, my grandparents had a valve black and white set right up till the mid 1980's when if finally died and they went an brought a colour TV. Its a shame that so many old TVs have now gone. I used to see them at the rubbish dump all the time and wished I'd saved them.
Cheers
Glen