Hi everyone, thought it was time I posted up on here, mainly have been lurking reading everyone elses threads for about the past year or so.

I collect and restore vintage tv sets made in New Zealand, for those who are not aware, television only started here in 1960 and we went to colour in 1974... NZ was bit behind back then..

The TV in question here is rather unique as it was a very low production set and I knew the person who built this, he was a radio maufacturer who made sets from the 1930's to the 1950's under the brand name "Telerad" and in the 1960's made this Telered model of TV using all left over radio parts and contructed on two radio chassis. There is a long winded introduction about this on Videokarma, but I'll try and keep it short here for my first post.

This TV came out of his house after he died in 2007, it was buried in a back room with stuff piled on top of it. He became a hoarder in recent years and the house was ‘full’ of test gear/valves/components/radio cabinets etc. Unfortunately some of it was dumped but a lot was rescued and found new homes. I got about six Tektronix scopes, heaps of components and some other bits and pieces including three brand new unused radio cabinets for my Telerad sets.

This set is probably the only one left in existence, I have no idea how many TV’s he made as this was the only model, he probably did tell me but I can’t remember and I highly doubt that there are any others that have survived.

The tuner and line output stage are all Philips, so is the picture tube (Miniwatt AW-59-90) and deflection yoke.

It is hard to believe that this TV was made in the 1960’s as the chassis/valves/components looks like something out of the 1950’s!

Here is the valve line up, the majority of them are octals: All I'm going by is the hand drawn valve location chart that was taped to the back cover.

Tuner ECC88/ECF80
1st IF 6SH7
2nd IF 6AC7
3rd IF 6SH7
Sound IF 6SH7GT
Sound Det 6SQ7
Audio Amp 7C5
Video Det 6AC7
DC Restorer 6SA7GT
Peak Detector 6SA7GT
Sync Amp 6SA7GT
Sync Sep 6SH7
AGC Gate 6SA7GT
Line Multivibrator 6SA7GT x 2
Vert Osc 6SA7GT
Vert Amp 6L6
Line Output EL36
Boost Diode EY88
EHT Rect DY87

So there’s quite a mixture of valves there and he used a lot of 6SA7’s! Anyone know why?

Also a Rola 12 inch dual cone speaker was used for the sound, the one shown in the photo is not the original. I have the original speaker for it.

In regards to the circuit diagram, well there isn’t one and this is going to make the repairing/fault finding/restoration a lot harder! I can see head scratching/frustration and swearing in the wind with this one!....

But fortunately I do have a complete spare chassis so this is going to be my only saving grace.
I have no idea what circuit design he based this on either so its going to be an interesting journey bringing this set back to life.

He put a note in the set saying it was last run in 1987 and that it has a horizontal sync fault. Do I dare wake it from its 24 year slumber?

When I got this back in 2007 I found the main filter caps had let go and the terminals were eaten away so I temporarily wired some filter caps in and replaced the rotten power cord… I never did get around to putting any power on it though. Everything else looks ok underneath and I’m toying with the idea of slowly bringing the set to life with the variac and seeing what happens.. I know this is a bit risky but at least if the set show signs of life I will then know what stages are working and as I don’t have a circuit it maybe the only way to get voltage readings etc. Hopefully the picture tube and lopt are ok.

Since then I checked the CRT which tested strong then powered it up slowly using the variac and the set came to life displaying an image shown in the photo, not bad for starters at least its generating EHT and the vertical stage is working even with its issues, nothing that can't be sorted there....There's just a blank raster so I'll have to fault find the tuner/if/video stages to see where the signal is getting lost, more than likely a component or valve failure maybe...I will fully recap this and check/change resistors that are off and go from there with power ups in between to make sure I haven't made it worse by disturbing things along the way!

Will post up progress reports along the way when time allows

Thanks for reading this far...

Cheers
Glen.

More Photos...

And more...

It is sure strange to see those old style resistors in a set with a modern looking CRT! You may already know this, but to read the color code on those resistors the order is body, end, dot. Those capacitors will certainly be leaky. With a little luck, the set will work fine after replacing the caps.

Hi Tom, yes the line up of components used in this a mixed bag for sure! Alan never threw anything out so he would have used everything he had left from his radio manfacturing days over to build this TV. With the 1960's CRT it does make the whole arrangment seem rather odd, but that is what makes this Tv a little 'special'... Thanks for the tip on the resistors, I know how to read those things anyway...I've checked a couple of those Solar .1uf caps on my bridge and yep they are leaky thats for sure... Cheers Glen

Wow, is that a neat set!
Looks like it will come back to life for sureeeeeee.
They even correctly fused hv supply.
Strange the tubes. A 1950's 9 pin damper tube, yet, tubes straight from the late 30's.
Very interesting....
Apparently very neatly wired....
Bill Cahill

Hello Glen and welcome to ARF. That set is quite unique for sure. I just can't imagine how much work it took to build all of the circuits by hand and then have them work. And for sure, it was not a kit television. I will look forward to following this tread. Since my daughter recently moved to Melbourne, Vic, this thread is even more interesting to me.

Cheers,

Glen, every time I see details about that TV, it gets more fascinating. The cabinet design is definitely 1960-era, tubes (valves) and capacitors typical of the 1940's, and I hadn't noticed the body/stripe/dot resistors, but those are definitely 1930's vintage! Yet, the set has the bulging-CRT design common in the 1970's and 1980's in Europe and elsewhere, perhaps including NZ (but not the USA). Was that CRT mounting style typical for the earliest NZ sets?

Hi Bill, this is definetly a ''one out of the box'' type of TV. I'd love to know what circuit he copied or dreamed up for this... Alan always prided himself on making things well and going by this is just an example. His radios which I have a couple of are built the same way and using the same components too!

Hi Don, and thanks for the welcome. He must have spent hours making this... I remember him telling me that sometimes he'd work from dawn till dusk and then into the night till about 3am then he'd sleep for a few hours and up again and at it! He said he enjoyed this sort of thing, a workaholic he was for sure!

Hi Chris, in regards to the CRT mounting question, no it wasn't, all of our early sets had the CRT bolted to inside of the cabinet front so when you pulled the chassis the crt stayed behind. The set is pretty fascinating in more ways than one! Cheers

Seeing those 30's and 40's era parts driving a 60's-70's era CRT, is like finding a Betamax deck with home made 50's tube electronics driveing it!

I've been following this restoration with great intrest at VK, and will continue to do so.

Good luck geting it working again!

Tom C.

Update... I traced the video fault one of those horrible solar filter can 10+10uf caps, one side had gone shorted that supplies the B+ voltage to the video amp section.
Temporarily put in a new 10uf 400v cap in place, turned it on and snow appeared, turned the tuner and was greeted with a picture!

It was quite an historical moment in a strange way to finally see it working after 24 years!

The horizontal hold/sync is very touchy so there's still more work ahead but hey good progress already. I'm quite chuffed to be honest.

This is going to spur me along to continue the revamp of the electronics. Can't wait to get rid of all those Solar caps.

Earlier today I had a window of spare time while our son had his afternoon nap and went down and started testing all the tubes with the PACO and I found that every 6SA7 tested bad.... I confirmed this again with my AVO Mk4 VCM and all of them had very low anode current and very low ma/v indicating they were past it.

Luckily I have a stash of NOS Kenrad 6SA7's, these also came from Alan's estate so I installed a total of seven new 6SA7's in the set. I made a point of checking the new tubes and they were spot on as to be expected.
But just so weird how all of them were low? The weak tubes are all Tung-Sol. See Photo.

So that's pretty much it for now, I guess the work has only really started...now the fun begins!

Progress Update - One section has been totally recapped and most of the resistors have been replaced. Some checked fine, others were way off.
The area I did was in the horizontal drive/osc/sync section. The horizontal sync is now stable and the picture locks in perfectly.
I have to admit that some of those old components were a little tricky to get out, some of the caps were buried underneath others, thankfully I took upclose photos and drew some rough diagrams so to resolder all the new parts in the right place.
I also checked those mica caps just to be 'sure to be sure'...They all checked fine.

Have now started on the vertical section....And that's where I'm at.

Photos are of the repaired area and the dead bits including a slighty better picture showing a test pattern this time.

Cheers
Glen

aaaahhhh, on the air analog television again............

Too bad it's on the other end of the world.......

Great to see progress and I really appreciate participation by our friends in the Southern Hemisphere.

Here is a rather belated update on this restoration, have been busy with other things of late.

The vertical section has now been totally recapped and all resistors replaced, most of them were way out of spec and the result is now a nice even picture that fills the screen! I can adjust linearity and height now without any problems.

I also tidied up the smoothing cap arrangement in the voltage doubler circuit for main B+ that runs the whole set. I actually had some identical new old stock filter caps which surprisingly reformed to near perfect so I installed those, they should be ok, generally I'd just put new ones in, but in this case I thought I'd try them and see how things go. I will replace rectifier diodes but for now they can stay there.

I think my next move is to replace all the electrolytic caps that are still in place and there are about 1/2 a dozen or so.

Since the original speaker and output transformer were missing I connected another speaker that had an output transformer with it and tested the audio side and thats working fine too, there's no video buzz or off tune noise and sounds good, so the alignment has held up pretty well. At least thats something I don't have redo! That's all for now.

Hi all, Good news, this project is coming to an end....It's nearly done.

Over the past few months I've been slowly picking away at it, replacing components here and there, haven't had much time to really spend on it only in the past few weeks has some real progress been made.

Every single paper and electrolytic capacitor has been replaced along with several resistors in which some were way out of tolerance, others were ok but decided to replace anyway for peace of mind. Replaced the rectifier diodes and the screened cable going from the tuner to the 1st IF as the orignal was all stiff and no doubt its dielectric properties would have gone a long time ago.

Fitting some of the new electroytics, I had to compromise as to where to put them as the originals were buried in places and restuffing the original cans, I wasn't even going to go there but managed to put the new ones in various places so it still looks tidy. I had to mount some on a tag strip as the area would not allow me to put the new ones in place as they would have been right above the B+ droppers and in amongst other components.

I did though encounter a couple of faults which had to be sorted, the first one was width related. From cold the width was fine and the control could be adjusted to suit, after about 5-10 minutes the width would increase in size and get to a point where it was too much and it was affecting the boost voltage and the control had to be turned hard to one end which I didn't like so I set out find out what was causing the issue.
In the end it was width control pot, obviously heat and voltage was causing the resistance to change after time. Luckily the pot on the donor chassis was ok, so I put it in and now the width and boost voltage are stable - phew!

The other problem kind of led me on a wild goose chase in a way, again it was a resistor causing the problem, after about 1/2 hour I noticed the contrast would reduce and picture would get a bit washed out and I had to adjust the AGC control to compensate as it warmed but even hard at one end it wasn't good enough.
I started with the tuner and did find a 5.6k inside which has risen to about 20K, but that didn't fix it so started poking around with the scope and confirmed that it wasn't the front end causing the problem. Next I moved to looking around the AGC gate/sync area and eventually found a 22k resistor that was heat sensitive, spraying it with freeze would restore the contrast to normal but something interesting is that while it was faulting, touching anything around there with meter probes would boost the contrast level, but after the new resistor was put in, this had very little or no effect, must have the capacitance of the meter probes compensating for the fault!
This one did take a while to find in between getting constantly interupted while in the middle of it all, but got there in the end!

So there we have it, too queer faults both caused by resistors this time, not capactiors for a change!

At this point in time all I have to do now is make up a lead/plug for the speaker and output transformer and put that and chassis back in the cabinet.

I have decided to leave the chassis surface alone as it had originally been sprayed with silver paint and don't want to disturb it by cleaning. You can see it starting to flake off in places but it isn't not going to rust away. I might just give the chassis top a light spray with some silicone anyway.

So all going well the next update should be of the set all back together and playing.

Attached are recent photos and the final pile of dead bits.

Stay tuned...

Cheers

Glen

Hi guys - Its done, the Telerad is finally all back together in its cabinet and is complete!

I have to say though its been an interesting project to say the least and it took me a lot longer than I'd expected to finish it and I learned a few things along way as you do with anything like this. The bit I didn't like was not working without a circuit, there's always a degree of uneasiness with something as rare and odd as this, but thank goodness I did have that spare junk chassis and the heap of photos I took to fall back on especially if I'd undone a part of the circuit to replace some components and then left it like that for a week or two!

I also reckon that this Telerad was set number ten that he made as there is a code on the back of both chassis, this one is '1510' and the donor is '1503'.
Thinking back I do recall Alan saying he used a prototype set in his living room for years and that one is the junk chassis as I saw where it came from after it had already been thrown in the skip complete with CRT etc and smashed by someone helping with the clean out at the time before I could stop him!

Now I can sit back and enjoy watching it. There are a few DVDs I've been putting aside just so I can see them on this, so looking forward to doing that.

Hopefully the set will behave itself, now its back together. The cabinet is really well built and does look nice.

I'm sure if Alan were still alive he'd be tickled pink to see his only remaining set in existence going again.

Thanks for following this thread and should anything else come up in regards to the Telerad I'll post an update. Some final photos for your enjoyment.

Cheers!
Glen

Glen, Fantastic Job. Very well done, you have definitely raised the bar to a new level.

Enjoy it in good health!

John S.