New Zealand 1960's Majestic B/W TV

[GLENZ32]

Hi all,

I thought it was time I posted something up about one of the TV sets in my collection that I'm currently restoring.

The one here is a Majestic TV4A made around 1964. As we only got TV here in New Zealand around 1961-2, this set was one that was made in the early days of TV manufacturing. Most of the the early sets were designed here, Philips sets were based on Dutch designs, although the majority of the early black and whites used Philips LOPT's as this Majestic does as well.

I rescued this from going to the tip, the owner said it worked, but upon removing the back and seeing an EF80 with a white cap, I don't think so, he may have got a blank raster and that would've been about it!

So far, to get it to a working state, I've replaced a few components including a 'Hunt's boost capacitor, this was the first thing I changed for obvious reasons! Another dud EF85 in the video section and a tired ECL85, it now gives a picture, theres still a lot of work to be done though, I've only been running it for short periods on the variac as its still got most of the original smoothing filter caps.A full recap is on the cards for sure.

Although there is a problem with the horizontal drive/sync, I had to adjust the oscillator coil quite a few turns on the core, to get a locked picture and sometimes if the hold control is adjusted or signal is removed or changed, the horizontal deflection collapses totally and of course all you see on the screen is a horizontal line!

In this state it also pulls the HT rails down, so something is not right, I've changed the ECF80 which does the horz drive/osc and all caps, checked resistors in that area of circuit. If the hold isn't adjusted or signal condition changed the picture is stable and the set runs quite happily. Any ideas anyone? There is no doubt a dodgy cap or resistor somewhere else more than likely, although thinking about it, could also be the EL500 line output valve?

So thats where I'm at with this currently. I actually quite like the look of this set, has nice doors which close the front away so it looks like a cupboard, not a TV!

Enjoy the pictures,

Cheers!
Glen

[Steve_P]

Recap the line oscillator stage and then try it.

Cheers,

Steve P.

[murphyv310]

Hi.
If the horizontal deflection collapsed you would get a "vertical" line that would fade away.
If you are getting a "Horizontal" line the Frame (field) stage has stopped oscillating or there is an output fault in the frame stage.
Cheers
Trevor

[Hunts smoothing bomb]

Hi Glen,

I hope you get the field/frame fault sorted soon, loose/dry joint maybe.
I like this set, it looks great. I wish there were more British 1960's sets with isolated chassis as I think they are much safer, I think it was only schools receivers over here that used them.

Cheers

[Tazman1966]

Hello Glen.

Good to see that old telly restoration is active all over the world. Once you clarify whether you meant a horizontal line or vertical, then there'll be lots of advice I reckon.

Good luck

[GLENZ32]

AH! Sorry guys I just re-read my post, just a slight typo there, its supposed to say 'VERTICAL' line. Doh!
I have already recapped the line oscillator stage with no change and checked all the resistors around there as well, the voltages are pretty similar to what is shown on the circuit too, guess I've got a oddball fault here.
Cheers
Glen

[GLENZ32]

Hi Tas, I think I could be a rare breed here in NZ collecting old TV's, don't really know of anyone who does apart from myself. B/W TVs are now getting harder to find in these neck of the woods, most of them have long since been buried six feet under. I remember as a kid in the 1980's always seeing heaps of them at the tip, all I used to do was pull the valves and the speaker out, but then one day I bought a small Philips set home and got it going and thats what started me off with TV 'bug'

Originally Posted by Tazman1966

Hello Glen.

Good to see that old telly restoration is active all over the world. Once you clarify whether you meant a horizontal line or vertical, then there'll be lots of advice I reckon.

Good luck

[GLENZ32]

Hi Lee, the majority of NZ's early TV's were isolated. Philips were the only sets that had live chassis, like your english sets all P series valves with huge dropping resistors that always cooked things nicely! The set is a good looker, a slight American style I reckon

Originally Posted by Hunts smoothing bomb

Hi Glen,

I hope you get the field/frame fault sorted soon, loose/dry joint maybe.
I like this set, it looks great. I wish there were more British 1960's sets with isolated chassis as I think they are much safer, I think it was only schools receivers over here that used them.

Cheers

[Steve_P]

Oh. Well try a new EL500 and EY800? (I haven't got the manual for this set.) Also check the valve sockets and the caps around the EL500 and LOPT.

Resolder everything, even if it looks OK. Check resistors for faults and are they in tolerance.

Even wires can go faulty by the way. And check the coils too for faults.

Cheers,

Steve P.

[Hunts smoothing bomb]

Hi Glen,

Try changing the line oscillator valve, (not the EL500, the one that drives it)

I had a fault on a set once where the line ocsillator was intermittent and it turned out to be this valve. Also recheck your work that you have done, try re-working all the joints in the line osc section as even if they look perfect they can indeed be duff!!

Good luck.

Lee

[GLENZ32]

Hi, changing the line oscillator valve made no difference as I swapped the valve out initially, as horizontal sync was already out when I first saw a picture on the screen and turning the hold control fully in one direction this would cause the deflection collapse and then adjusting the oscillator coil quite few turns gave me then a stable picture and its been that way ever since.

Only when you change channels or remove the signal does it fault, but not every time though which is interesting.

This has a couple of OA85 diodes in the sync discriminator, those I haven't checked, but could they really upset the oscillator to the point where it shuts down? Mind you I suppose anythings possible with aged components, caps and resistors can be bad enough at the best of times.
Cheers
Glen

Originally Posted by Hunts smoothing bomb

Hi Glen,

Try changing the line oscillator valve, (not the EL500, the one that drives it)

I had a fault on a set once where the line ocsillator was intermittent and it turned out to be this valve. Also recheck your work that you have done, try re-working all the joints in the line osc section as even if they look perfect they can indeed be duff!!

Good luck.

Lee

[Hunts smoothing bomb]

The line discriminator diodes can certainly fail short or open circuit, check them with your meter and report back.

Cheers

[Sideband]

I'd be inclined to change them anyway. I've had the things go intermittent before now.



Rich.

[GLENZ32]

Good news, the fault is fixed!! It turned out to be the discriminator diodes, one was open and the other was leaky. After replacing them, the oscillator coil is now adjusted back to where it was originally, the sync is spot on and the deflection does not collapse anymore... so with that fault fixed I can get on with the rest of it now Thanks to those who offered advice. Will try and post up a progress report on this as well.

Glen.

[Hunts smoothing bomb]

Excellent news Glen, glad you've got it fixed.

Cheers