Dynatron CTV 9A. Some advice for a vintage TV novice please.

[Grundi68]

Hello all.

I have just bought a Dynatron TV. DYNATRON CTV 9A and I bought it as it has the same cabinet style as my Dynatron radiogram. Trouble is the mains cable has been cut off.

I wanted to see if the set works and I will put a new cable on as there's enough left on the back to reconnect one. On this set there are two cables at the rear of the set. I think one is for a wired remote which wasn't given to me and the other is a mains cable. I'm guessing the black 3 core cable is the mains and the grey two core is for the missing remote. There is a small pocket on the back of the set where the remote would have sat when it wasn't being used.

I suppose I could take off the back to see which cable leads to the mains transformer but I don't want to go looking around inside this delicate old valve set. I suppose I am safe in thinking the 3core is the mains cable cause it has a earth in there. Any suggestions please?

[Nicklyons2]

I think you SHOULD take the back off and check carefully. If the set is so delicate you don't think it will stand having the back removed it isn't in a fit state to plug in ! You may be suprised to find the cables aren't as you imagine.

[Michael Maurice]

Can you tell us what colours are the wires inside the black and the grey cable?

As Nick says the cables are probably not as you think. I'll bet that the mains cable is the black one.

Originally Posted by Grundi68

I suppose I could take off the back to see which cable leads to the mains transformer

I doubt it has a mains transformer, the mains cable should go to the switch possibly via a fuse

[bobbyball]

This set uses the PYE hybrid chassis - the 693-697 series, which is well known to "old timers" in the trade. I have several of them!!

The mains lead should be the grey one, with two cores brown and blue (Live and Neutral) .

The set uses the "live chassis" technique with one side of the mains connected to the chassis common earth, this MUST be the Neutral. There is no mains earth conection to this type of set.

As for the wired remote control, it was able to control volume, colour and brightness as well as change the channel. It may also be able to turn the set on and off but I think only the later models had this feature. It would have needed a wire with more than three cores though! If it is like the later sets there should be a "dummy" plug inside that connects to the socket the remote control would have done, again the later sets are like this but the earlier ones may have been "hard wired".

One thing more important than anything else: if you are not sure "which" is the mains lead, DO NOT PROCEED until you are.

There is a "mains transformer" in these sets to provide LT rails but the valve heaters (seven valves) are in series via a thermistor. Depending on the version of the chasiss (and there were several) it will either have a metal chassis with the line timbase, tripler and mains transformer etc, on the right hand side looking from the back, or a similar and electrically identical version using a large (and delicate) PCB, in the same place.

As I said above if you are not sure which does what, and are not familiar with this type of set, do not connect it to the mains until you are or know somebody that can help you with it. It's a great looking thing and well worth getting going but it's not something for the "begionner" with all due respect.

Best Regards

Robert

[Tazman1966]

Good advice above from Robert, Michael and Nick. I would also strongly suggest that you enlist the help of a fellow forum member - there are several telly fans reasonably local to you.

This set uses the Pye 697 chassis using the PCB type line timebase board. Shame that the remote cable has been snipped too but as Robert says, you can get round that. The grey lead is indeed the mains one.

I've had a couple of Dynatrons in my possession in recent years - a CTV7 using the Pye 693 chassis and a CTV16 using the 697. Both were excellent sets but I now have a far more run of the mill basic Pye CT205 version - takes up less space! I also have a Pye CT71 dual standard version. With care and time taken on correctly setting them up and with a good CRT of course these are capable of good performance. The colour fidelity in particular being good (in my opinion!)

You'll also find many threads on these sets and their variants here on this forum, just do a search.

Good luck and for safety's sake and for the long term health of a lovely television, get someone to help if you're not "au fait" with the insides and workings of a colour television.

[Grundi68]

Thanks for all the good advice given here. You're right. the grey lead is the mains lead. I plugged her in and switched on. sound came on first the tube took a while and there was a musty dusty smell coming from inside but went away after five mins. The top of the screen has a black area with teletext lines on it.

I wanted to adjust the height and width of the screen because I recall doing this with old TV's in the 70's but I will leave alone for now. I really would like it if I could arrange a meet at my house here in Bournemouth with one of the more experienced members of the forum to have set her up. she so good looking I'm so pleased after waiting all these years that I have found a set to match my Dynatron radiogram that has the same cabinet style. I just wish my friend who gave the Radiogram to me was still with us today as I just know he would be green with envy. LOL.

Thanks for advice given.

Regards Andrew.

[Heatercathodeshort]

Yes, excellent advice. Do not plug it in without help. J.

[bobbyball]

I think I might even have the cable remote - somewhere!

If I do find it you might as well have it if you wanted, just for the cost of postage...

Robert

[Grundi68]

Robert. Thanks for the offer of the remote. I would give you somthing for it. I somtimes pop up to Stockport as I visit my parents there. Would it be OK if I collected it from you sometime within the next 2 months, as I live in Bournemouth and pop up there from time to time?

Regards,

Andrew

[ntscuser]

I thought I'd mention here as I'm unable to find a suitable thread elsewhere that I watched the 1970 Trooping of the Colour on a Dynatron at a shop in Kenilworth. It may have been built around an ordinary Pye chassis but it was by far the most accurately setup colour TV I'd seen up until then. I'm not sure whether that was entirely due to the manufacturer or a measure of the the quality of their dealers?

It was housed in a relatively plain teak cabinet but still beautifully finished right down to the tiny brass hinges on the doors.

[Grundi68]

I switched on the tv yesterday. It looks as if this tv needs a good going over. I switched on and left her running for 5 hours and after 5 gours I lost the picture. sound was still working but there is an annoying slight hiss that that sounds like an fm radio when its tuned between stations and is most noticeable with the volume is turned to its lowest settings and the tube will have no picture and there is somthing there on the screen, just lots a lines of colours spinning from right to left across the screen. the next day after I turned her off overnight she working again for 45 mins and then no pic on the screen.

this set is full of valves. someone once told me that valve sets are not that relaiable. would this be the case with my ctv 9a? who could a take this set to to have it fixed?

[Grundi68]

I have just spent a few monents looking over the net and by what I have read, the Pye hybrid chassis - the 693-697 seems to be a big pig to keep working normally. You'll have to forgive me if I sound naive since I am a novice in the vintage TV world but it sounds like TV repairmen back in the day had to make many modifications to this set to get then to run.

Maybe I'm panicing right know but it sounds as if I have gone and bought something that once fixed this time will never will be far away from a work bench at some point. I had hoped once fixed I could run the TV one or two nights a week but I think it may cost a small fortune to keep it going.

Trouble is I've always wanted to own a nice looking valve set such as this Dynatron for example but I have plenty of patience. I suppose I really need an old timer who knows what he is talking about when working on these old sets. any offers? I'd be happy to pay someone fix her up good and proper.

One question that I have to ask. What happens when the tube is on the way out? I suppose tubes for Pye TV's maybe as hard to find as hen's teeth.

[bobbyball]

Andrew I'll try and find the remote for you, I have seen it relatively recently (but where?) so there is hope...

Just let me know when you are "in the area"...

Robert

[paulsherwin]

Valve era colour TVs do need a lot of maintenance - that's why almost everybody rented them rather than buying them outright. If you don't have much expertise and any realistc prospect of acquiring it, you'd be better off selling this TV on to somebody who can maintain it.

[Mike Phelan]

Seconded. The hybrid Pye chassis does need quite a few modifications to get it working with reasonable performance, and even then they were not the most reliable IMHO.

A starting point has to be learning how everything works!

[Heatercathodeshort]

It's not just a simple matter of replacing a few components, then sitting back to enjoy watching it. The 693/697 chassis was reasonably reliable once the stock faults were sorted.
Receivers of this age require the expertise of experienced service guys to get them into good working order, set them up correctly, and to carry out routine fault finding and repair.
It is impossible for you do do this without a good basic knowledge and the fact that you switched on a dormant receiver for over five hours with faults proves the point.
There may be someone near you that can help you out with the basics but it would be a daunting task without workshop facilities. Another problem is that the Dynatron is such a heavy lump that it cannot be easily transported and the work will probably have to be done in situe and that makes the job very difficult.
It's rather like buying a 1973 Morris 1000 and expecting to rebuild it in your bedroom.
Please don't think I'm having a personal dig at you. At least your willing to have a go and ask questions. That is what this Forum is all about. I don't know your capabilities regarding radio repair, valve technology and the added complications of television, particularly early colour receivers. It's just the simple fact that this knowledge takes years to learn and more damage and personal injury can be incurred if your not aware of the dangers. Regards, John.

[Nickthedentist]

If this isn't for you, I would let it go to an enthusiast and get yourself an empty Dynatron cabinet which seem to be plentiful on eBay. Then hide a modern set in it and you'll then have something more to your liking.

N.

[Tazman1966]

Shame I'm not nearer to you. I'd keep it running for you.

I reckon too that with only a few hours use each week and as John says with some of the stock faults sorted and a bit of preventitive maintenance it would be pretty reliable. It's not as if it's going to be your every day set is it?

On and off during the year, my vintage colour sets get rotated around as our dining room sets and as such then get used for a few weeks every day for a couple (at least!) of hours every day and I wouldn't say that my Pyes are any less reliable than the others.

[ekcopyephilips]

You lucky so and so,

I would LOVE a Pye colour chassis set of the late 60's early 70's era. They are as rare as hen's teeth and I have never seen any for sale unless the Dynatron versions in their huge cabinets. Don't you have a set of this era Tas? An Olympic?

Mike

[Tazman1966]

Sure do Mike!

Originally Posted by Tazman1966

... but I now have a far more run of the mill basic Pye CT205 version - takes up less space! I also have a Pye CT71 dual standard version...

The CT71 is the Olympic and I forgot to mention the CT152 which uses the 691 chassis.