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Philips TVette (11TG190AT)

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sideband
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Today I had several hours of playtime so decided to complete the transplant. Que the Dr Kildare music....(shows my age)!

 First I replaced the two pre-sets mentioned in the post above. The old PCB was unscrewed but I left all the leads except two connected. The remaining leads are  long enough to move the PCB to one side and fit the replacement PCB in it's place. The idea being that I could do a one-for-one transfer of the leads. Everyone has their own idea about replacing complete PCB's that have a large number of leads connecting. I did this a lot at Philips and I found that the one-for-one method worked fine. Those with less confidence I would suggests LOTS of good clear and close digital photos or if you prefer make a good diagram on a piece of paper with the connections clearly marked. I still use these other methods as well.

 

So at 5:30pm, the wiring of the replacement PCB started. Everything went well, no leads broke off from anywhere else (always a danger) and finally at exactly 6:30 the last wire was soldered into place. A visual check was then made of all the connections. The main supply rail is 11 volts and the CRT heater is connected directly across the supply. Of course at this stage I had no idea what the supply would be as the set 11V pre-set had been replaced. GOLDEN RULE.....leave the CRT base unplugged so if the supply is excessive, the CRT heater won't be damaged. Connect a meter between chassis and the collector of the AD149 on the chassis (not the one on the PCB) and switch on. Surprisingly the meter read 10.82 volts so the pre-set didn't need adjusting. I could also hear the line whistle which varied with the line hold control. There was some sound activity when the volume control was advanced and also evidence of a slight frame buzz that varied with the frame hold control. OK as the LT supply was correct, switch off, fit the CRT base and switch on again (still monitoring the LT supply which again showed 10.82V). I also connected an aerial fed from the Aurora. The test tone came up and some seconds later an unlocked raster appeared. An adjustment of the line and frame hold controls produced a very reasonable testcard. The immortal words of Dr Kildare echoed in my head.....'He's gonna be.....alright'!

A slight adjustment of the height and linearity controls and a very good testcard was the result.....and the contrast control works!!

I'm going to devise a crowbar type of protection for the CRT heater in case the power supply ever develops a fault and the 11 volts heads towards 15....A zener and a fuse seems the simplest.

I declare the transplant a complete success. It was a lot less problematic than I expected. With an unknown replacement PCB you never know what you may find wrong. I shall just soak test it now and keep a check on the 11V supply rail.

My thanks to JayCeeBee for sending me the panel and allowing me to complete the repair at last.

 

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First shows the old PCB unscrewed and moved to one side and the replacement PCB mounted in its place. Second shows the replacement PCB fully wired. Third shows the LT supply when first switched on at 10.82 volts. Fourth shows First Light after CRT base was fitted. Fifth shows TC from Aurora after line and field hold were adjusted. Sixth shows TC after frame linearity, height and contrast were adjusted. Seventh shows off-air picture with Aurora fed from digi box. 

 

 

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Topic starter Posted : 08/11/2020 10:34 pm
PYE625, ntscuser, turretslug and 2 people liked
irob2345
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Those early Philips "Tinyvision" designs were always good. In Australia at about the same time we had the Kriesler 49-1, a very popular little cube-shaped TV that was robust and rarely gave any trouble. Almost all the electronics were on a single fold-out PCB - nice.

This was Kriesler's first transistor TV and also their first portable - they got it right on the first attempt.

https://www.radiomuseum.org/r/kriesler_miniscope_pt1_49_1.html

Is the AD149 in the pictures mounted on any sort of heatsink? Or is that the vertical output?

Are you running on 405 lines there?

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Posted : 09/11/2020 6:17 am
sideband
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The AD149 on the PCB is not mounted on a heatsink and yes it is the vertical output. There is another AD149 in the PSU that is mounted on the metal chassis with a mica insulator. That only runs warm. 

The picture shown is 405 lines from an Aurora standards converter. My 625 line source is not connected at the moment. Trying to sort out the signal distribution. 

That Kriesler was probably quite sensitive seeing as it used silicon transistors in signals circuits. The Philips is all germanium

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Topic starter Posted : 09/11/2020 9:14 am
irob2345
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@sideband

Yes it was early days for silicon. Philips had just started making silicon transistors at their Hendon plant in South Australia.

There are also germaniums in there and even a valve!

Yes it was quite a hot little performer, widely used by antenna installers at the time. A very straightforward, easy to follow design, I used it to train TV service techs transitioning to transistors in the late 60s. The circuit layout even looks like a valve TV.

That huge (by comparison) Philips turret tuner with the printed circuit biscuits can be seen. It was later replaced by a much smaller (and cheaper to make) tuner, the design of which Philips bought from AWA.

Kriesler 49 1
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Posted : 09/11/2020 11:56 am
sideband
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Posted by: @irob2345

@sideband

 

There are also germaniums in there and even a valve!

There's a DY51 in the Philips as well.

Not sure when the first transistor TV appeared in Australia (unless it was the Kriesler above) but the first all-transistor set to appear in England was the Perdio Portarama https://www.radios-tv.co.uk/community/black-white-tvs/perdio-portarama/ in 1962. 

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Topic starter Posted : 10/11/2020 9:10 pm
irob2345
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@sideband

No Australian manufacturer ever released a TV with all germanium transistors, at least, not that I ever saw.

So the earliest contenders are:

  • Astor 10A chassis (1965?) The TV that did NOT save the company!
  • GE T9P1  (1965?) A very short model run, replaced by a chassis using Compactrons!
  • Healing 1252 (1966?) (I never saw one of these)
  • Pye T25 (1967) Reliable but spoiled by cheap looking plastics.
  • Kriesler PT1, 49-7 chassis (1967)
  • Philips T12 (1968)  The short-lived modular chassis
  • AWA P5 (1969) A very stylish design   https://www.radiomuseum.org/r/amalgamate_p5_54_01.html
  • HMV Z1 (1969) Late to the party and the subject of many recalls.

 

 

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Posted : 11/11/2020 2:05 am
Nuvistor
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Were Compactrons popular in Australia?

I don’t think any UK sets used them, may have been some in Japanese sets but I don’t remember them if they did.

 

 

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Posted : 11/11/2020 12:40 pm
irob2345
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Let's just say Compactrons were around but not popular.

GE released a slightly modified US design with an external (!) 240 to 110v transformer. This was claimed as a feature for some reason. Initially they had no competition in the small portable market. After AWA released the very successful (and markedly superior) P1, GE had Ferguson Transformers make an internal transformer in a fluro lighting ballast format which was bracketed off the speaker and the tuner. The GE was the cheapest TV you could buy.

National (Panasonic) used Compactrons for Line Output/Damper (38HE7 from memory) in locally assembled portable TVs. These TVs were surprisingly outdated designs when they appeared but they sold well.

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Posted : 12/11/2020 12:03 am
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