Decca 100

As you're probably aware Gary, the decca 100 series is a development of the 80 series. I just consulted 1977-78 R&TS, indeed 10W -100W so anything in-between, 15W is fine.

Hi Chris
thanks ever so much for that , as i said i used to work for a Decca dealer when i left school . we would take delivery of 25 to 30 at a time .
I"ll keep you all posted with my progress .
Regards .
Gary .

Very reliable set, great performer and good to work on. Check filter cap/bridge rec/ psu thyristor/line op transistor. If lop transistor is u/s the tripler is duff.

Hi Everyone I connected the bulb up and it lit up brightly , i then disconnected the tripler and tried again . this time the bulb stayed off and the set fired up so the tripler is indeed faulty . It"s the original so it"s done well . The date stamped on the bottom of the cabinet is 19th June 1979 . I"ll just have to box it up until i can find a replacement tripler . Anyone got one they could sell me ? . Regards . Gary.

I should have a universal one you can have. I will check.

Hi Malc
that would be great thanks .
Just let me know if you have and i could pop over sometime .
Thank.
Regards .
Gary .

Introduced in late 1976 the Decca 100 series was the first TV receivers made in the UK to employ the in-line gun Mullard 20AX CRT.
With particular problem with the 100 series is the high temperatures around the line timebase area, the 20AX scanning coils demanded high currents. The later 30AX CRT was much better in that respect.
The first A56-500X 20AX CRTs did not display particularly good pictures, not really much better than the delta tubes. However, with the introduction of the A56-510X "Hi-Bri" tubes a much better picture was possible.
A variant of the 100 series, the 80 series, was in my opinion a much better set. Inline 20 and 22" PIL CRTs were employed. Way back in the late seventies I took delivery of Telefunken TV sets which were actually made by Decca R & T. These sets were fitted with 807 chassis.
The sets were so good I decided to become a Decca dealer, one on my better decisions and the first deliveries from the firm was the then new 70 and 90 series receivers.
A completely new range of TVs of advanced design using a single PCB. In 1979 Decca had invested in the most up to date production facilities.
In those days Decca R & T was owned by Racal, however, in the 1981 the company was aquired the Taiwanese Tatung electronics firm. Tatung did a good job with Decca but things started to wrong in the early noughties, about the time LCD TVs were coming in.

Till Eulenspiegel.

Wasn't there some crossover earlier with Decca and Telefunken? I remember particularly a vertical "piano-key" arrangement for the tuners, with green lights in them...?

Hi, folks, RR here, I remember the Decca 100 well, though I thought the 80 was better, less power consumption at the expense of space because of the 90 degree tube. I once repaired a 100 in a damp cellar with no isolation tx, I must've been either desperate for the cash or stark raving mad! but then I always have been into a bit of extreme diy, but I lived to tell the tale. As for Decca sets generally I thought the 120 series was super reliable, I only ever repaired two, one was my mum's which she had for donkeys years and it only ever needed an on/off switch, and the other was a portable which only needed a small part changing on the tube base. A proper single panel job with low consumption. RR.

Wasn't there some crossover earlier with Decca and Telefunken? I remember particularly a vertical "piano-key" arrangement for the tuners, with green lights in them...?

That was Teldec. A joint venture between Telefunken and Decca records. Also responsible for the TED vinyl video disc.

From Wikipedia: http://en.wikipedia.org/wiki/Teldec

Telefunken wanted to increase their presence in the UK hence the rebadged Decca TVs.

The 80 and 100 series was replaced in 1979 by the 90 series and a year later by the 110 series. The 110 series employed the Mullard 30AX CRT A teletext version was developed from the 110 series. It used the Mullard VM6101 text decoder along with a special remote codes converter PCB to control the text unit. Decca did not use the Philips or ITT remote control system.

The 120 series was introduced in 1981, designed for 90 degree CRTs. 14 to 20" PIL. Shortly after the 130 series chassis which employed the 30AX CRT.

Till Eulenspiegel.

I've got 3 100's and an 80 series. two of the 100's are identical to Garys set. and I did get the one going but have had problems with the tuner panel (no signal/snowy picture). and the 26" one does work and has a (disconnected texas text decoder in it) and a nixie channel display etc. and the little 80 also works but has a very dim picture on it. but when your set is going gary it should have a lovely picture. Cheers Neil.

I've got 3 100's and an 80 series. two of the 100's are identical to Garys set.

Hi Neil,
That'll be the CV1051?

Till Eulenspiegel.

Fantastic sets! I bought loads ex rental from Robinsons in Huntingdon. Telefunken also did one with a teak door over the front controls, the piano key switch unit got very intermittent in it's old age and was often the reason that they were sold off, ISTR someone did a replacement unit using a conventional push and turn to tune button unit with hardware to fit. The 80 series with the pil tube was often sold off because the tube was a bit low, I found that the LOPT had a separate winding that fed the tube heaters, if you took one of the wires off, threaded it through the core of the transformer and then re-soldered it back it added half a turn to the winding and gave the tube a new lease of life, often for many years, I was sure the heaters were slightly under-run from new which caused their early ish demise.. like the kt3/k30, if you took half of the turns off one of the heater coils the tube would often come back from poor to perfect! where as if you gave it a tickle on the booster they went down again, often before your eyes! Later on it became an "official" mod with the TX10 to drop the value of the Heater resistor a bit! I preferred the 20" 80 series as they were usually less cooked than the 100, the line timebase panel on the 100 suffered badly from the heat and was often riddled with dry joints, but to be fair the sets had had a fairly long life by then. There was another brand name apart from Decca and Telefunken that they were marketed as with yet again another style of channel selector, grey front, teak cabinet but despite racking my brain I can't remember what it was, a lot of beer has passed under the bridge since then! Rich.

I still couldn't remember that brand name so I contacted my mate this morning who was an engineer for Robinsons, They were sold as Expert... I think it was a buying group for independent retailers. rich.

Expert now a "high street" brand here for independent retailers in the last few years. Not many Independents left.

Hi
Just a progress report , yesterday I was given a NOS. Universal tripler from Chris. Its the type that when used in the DECCA 100 the sixth diode lead has to be joined to the earth lead . Once fitted I switched on and the mains fuse blew . With the tripler disconnected the fuse holds up with sound ,tube heaters lit and a spark from the loptx output lead . I connected the bulb up with the tripler connected and it lit up with no life . I must have left it on too long in that condition as the line output transistor is now shorted . It can only be a faulty tripler .
Any ideas ?
Regards.
Gary.

Hi Gary I would try it with the diode lead disconnected and isolated. I really can't remember what the drill was when fitting a universal tripler to the 100 series. But I do remember on some makes of set it was connected with the earth lead, the KT3 was one, I think... but the two wires when connected to the PCB didn't go directly to earth. Certainly when fitting a universal to some sets the diode lead had to be cut off and not used. maybe the Decca was one? Maybe someone with a better memory can advise? I would get the line stage working again with the tripler disconnected and then try again with the diode lead isolated. I doubt the LOPT is faulty if you say there was a spark with the tripler disconnected, and a final anode short on the tube would be unheard of. Have you checked the flyback tuning capacitor ? that could result in high EHT which would possibly damage the tripler. dry joints on the line panel especially where the plug and socket connectors are fitted also springs to mind, it was a long time ago since I last worked on one of these... Rich.

Bear in mind that this set will have two flyback capacitors in series. The "upper" capacitor will have the usual value of 5 to 10nF and the lower one which is part of the diode modulator width control circuit is usually about 0.02mfd. Both can go low in value and thus cause excessive EHT. Check for dry solder joints on the lead outs on the capacitors. I do not have the 100 series circuit diagram to hand so I'm not sure how the tripler is connected up in this chassis.
Some universal triplers have an extra diode which can be marked as "diode" or as -ve. There is often an internal reservoir capacitor in these triplers and the lead generally goes to ground.

Till Eulenspiegel.

The NOS universal tripler I gave Gary had the original instruction sheet included.

It listed all the sets the tripler could employed in ( there were many listed), It also gave detailed instructions for each wire and what needed to be done when fitted to one of the listed sets. Specific instructions were there for the Decca 80 & 100, therefore no chance of it being installed incorrectly.

I'm stunned however it is faulty, guess it can happen, although I do hope you've not got a fault that is a tripler killer.