1963 Bush TV125CU

Introduction

Before I moved over to colour I started on Black & White Television, I collected in excess of 50 sets before finally moving them along to finance my colour TV collection. I have however kept a couple of sets that are special to me, here is one of them.

Dual Standard

Model: Bush TV125CU
The “U” denotes that the UHF tuner is installed

Year: Released August 1963

Cost: Originally cost £83 11s 5d plus purchase tax

System:405 Line 625 line

Valves: V1 PCC89,V2 PCF86,V21 EF85,V22 EF80,V23 EF80,V24 PCF80,V25 EF80,V26 PCF80,V31 PCF80,V32 PCL85,V33 PCF80,V34 PL36,V35 DY86,V36 PY88,V25 EF80,V26B PCF80,V38 PCL82,V41 PC88,V42 PC86,

CRT: CRT AW47-91

General Information:

tv125-1

tv125-1a

tv125-2

Filter cap C346 snipped and mains applied, low and behold the screen lights up.

tv125-3Some cap changes around the line stage

tv125-4

tv125-5

I carried out the recommend TH32 modification as this set had the original configuration. This involved swapping the positions of TH32 (Thermistor ) with R358 , then changing R358 to a 10R-10W. This saves the thermistor as it now only carries heater current. Also cleaned the system switch contacts

tv125-6

tv125-7

tv125-8

The VHF push button tuner was operating very poorly, the buttons felt sluggish and did not lock correctly. The tuner was removed, gunk removed cleaned and oiled. Smooth operation returned.

tv125-9

tv125-10

tv125-11

tv125-12

Vision buzz from speaker overloaded test card with little or no control over contrast, this all turned out to be VR21 (agc delay) and VR22 (Vision limiter) both being set incorrectly.

tv125-13

Over-wind trouble, HT started at 218V then dropped to around 187V accompanied by loss of width (see below) to the raster. The set was left running, the moisture in the winding seemed to boil off as the HT rose back to 218V along with full width raster. The set was soak tested for 8 hours without issue.

tv125-14

Final two shots show the restored set and the two resulting test cards on 405 & 625 lines

405 Line operation

tv125-15

625 Line operation

tv125-16

 

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PYE625
PYE625 (@pye625)
Member
6 years ago

A great picture with excellent convergence and perfect grey-scale.
(As I’m sure L.Lawry-Johns would have said!)

Another worthwhile and interesting restore.
This site just gets better and better !!

Nuvistor
Nuvistor (@nuvistor)
Member
6 years ago

I liked this chassis, easy to repair and on the whole reliable. They had a few stock faults but I did not have many difficult to repair ones.

Guest
5 years ago

I would love to try a TVs restoration was this an easy one to start with.
Regards
Robin

Geoff Rigby
Geoff Rigby
Guest
3 years ago

The TV-125 chassis was legendary with TV DXer’s. Not only because of its gain especially when fitted with the later transistorised UHF tuner, but because you could separate the cable to the timebase side system switch, mod the video switching to leave it in UHF reversed video modulation and run the IF and tuner in VHF mode to receive VHF foreign signals from Eastern and Western Europe and Scandinavia.

Terry
Terry (@terrykc)
3 years ago

When these sets first appeared, they weren’t fitted with a UHF tuner. These were much easier to ‘convert’ to 625-line VHF if one was in the workshop during a ‘lift’.

We just stuck two small insulated screwdrivers between pairs of the (vertical) system switch contacts which just hung there and connected HT to the VHF tuner and the IF output to IF input!

The beauty of it, using customer’s property in a busy workshop, was that it was instantly reversible to normal operation when required!

I had one of these unconverted sets running on soak test one Wednesday afternoon (half day closing) in 1966 doing a bit of overtime and, as the conditions were right, I did the two screwdriver conversion and found Rai Uno – the first (and only) time I ever saw pictures from Italy.

Apart from old Fred, the electrician, downstairs, there was nobody else in the building. Fred came up to ask me something, so I showed him the test card and explained where it came from. Then it faded out and, a couple of seconds later was replaced by a gorgeous continuity announcer quite unlike any anybody on UK television. There was no sound, of course but after short time she was replaced by the Eurovision card that used to precede such programmes in those days with the originating broadcaster’s initials in the middle. However, in this case it read BBC/ITA! The proigramme started and the opening credits proclaimed WORD CUP ’66.

So we were watching a programme which been sent over a thousand miles from London to Italy and then over a thousand miles back again to us! And it had only started its trip about 25 miles away.

So, does this count as long distance television or not?

Cameron
Cameron
Guest
2 years ago

I have the same one! It’s a beautiful set. Any idea how long it should take to warm up? I’ve been leaving it on for small amounts of time as it hasn’t been used in many years but I don’t think I have been giving the valves enough time to warm up.

Cameron
Cameron
Guest
2 years ago

Hi crusty,

Thanks for your response in turn. Yes, you are right, I was vague previously and so I’ll try to tell you as much as I know so far. Well, it has been used a lot more recently than 40 to 50 years but obviously not as an operating television set due to the analogue to digital switchover. It was checked by a qualified technician a couple of years ago but nothing since then so I’m naturally very cautious. I certainly don’t intend to use it regularly as it is more of a showpiece than anything else. In addition to this, I adore the set due to it’s totally original condition and so I don’t intend to convert it in any way for future use as a functioning television receiver. I have been told by a former television technician that I know, to power it up for a very short period of time every once in a while and to avoid giving it a sudden surge of power after a few years of sitting without any. To cut a long story short, I will not be putting it to any significant amount of use by any means so don’t worry about that. Thanks again for getting back to me, my friend. 🙂

Kind regards,
Cameron.

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