1967 Philips G25K502

G6 Chassis

Model: Philips G25K502 (G6)


System:405 Line Black & White – 625 Colour

Original List Price : £341. 14s 4d

V1301 A63-11X 25″ Shadow-Mask CRT
V2001 PFL200 Luminance Output and Sync Separator
V2002 EF80 Line Sync amplifier
V4001 PCF802 Line reactance and oscillator
V4002 ECC81 Frame oscillator
V4003 PCC85 Frame buffer/Fly-back suppression
V4004 PL508 Frame output
V5001 PL509 Line output
V5002 PY500 Boost diode
V5003 PD500 Shunt stabiliser
V5004 GY501 EHT rectifier
V5005 EY51 Focus diode (EY87 fitted on this set)
V7001 EF183 1st Chroma amplifier
V7002 EF184 2nd Chroma amplifier
V7003 PCC85 Chroma A.G.C. /Colour Killer
V7004 PCC85 Auto White shift/CRT protection
V7005 PCF200 R-Y amplifier clamp
V7006 PCF200 G-Y amplifier clamp
V7007 PCF200 B-Y amplifier clamp
V7008 EF184 Burst amplifier
V7009 PCF802 Reactance/reference oscillator
V7010 PCL86 A.F. amplifier output

Power Consumption: 400W

Semi conductors


Rectifiers & Diodes: 45

This 1st generation colour television was part of a suite of sets released by Philips in 1967. All for the start of colour transmissions within Great Britain on the 1st of July of that year. For a Hybrid ( Valve & Transistor) set, it has a whopping 21 Valves  which is a huge count normally reserved for all valve black and white 405 sets, power consumption of the G6 is a whopping 400W ! This particular set has a date stamp of 21st December 1967.


The G6 Television is designed for reception of both colour and monochrome pictures on 625- lines and monochrome pictures on 405-lines. For reception the PAL de-lux system is employed, using glass delay line in the chrominance channel to give best quality of colour and easier tuning.

The G25K502 cabinet is finished in ‘Canaletto’ walnut veneers with the loudspeaker mounted below the CRT. The two-tone silver and antique silver control panel is fitted to the right of the tube.

Found: Thanks to Mike Burton for donating it to my collection
Photo of the set as it is now, sitting on the workshop bench, just glad I built it strong enough and large enough to take such a mighty beast.

g6-1g6-2 g6-3g6-5 g6-6 g6-7 g6-8 g6-9g6-11

Chrominance Panel


I.F. Panel


 Convergence Panel


Time-Base Panel


CRT Base Panel


Line Output Panel


The EHT Generator


Fuses and Centering


Update: Legs

I’m tempted to just plug it in and see what gives, we shall see.

On another note the cabinet and legs, the original legs seem to have been missing since this set surfaced in the 1990s. However I do seem to have a set supplied with it, they are Philips legs but from another Philips cabinet. Thankfully they use exactly the same fixing methods as the G6, I assume they’re from a smaller model. The adaption will entail removal of a section of the back of the leg so it sits flush to the cabinet side. Then a simple move of the key lock plate, so it aligns with the cabinet screw head.

leg1 leg2 leg3 leg4

Update: Power up

Although it had not been powered up since 2009/10 I decided to just plug it in and see.

The valves began to glow and after what seemed and absolute age a full raster appeared. Good so far!

Next I connected the test card generator sending a B&W test card to the 625 side. Tuned in, a good black and white card was presented. I then switch the generator to produce a colour card and the colours appeared, quite weak and difficult to photo. The green blocks at the bottom don’t photo well but are much clearer than shown. All in all a pretty good start thus far. Will do the grey scale firstas its looks a bit on the blue side, then take it from there. Also a check of the stabiliser circuit as its dull and watery colours.

fl2 fl1 fl3 fl4

Update – Cabinet Strengthen

The top of the TV cabinet was very loose on one side this has now been glued and clamped. The drawer at bottom housing the convergence board needed work too otherwise it was in imminent danager of loosing its front. The fluted grill had come away from the left and the grill over the speaker cracked and pushed in. I removed the speaker, managed to push the grill out the glued and screwed the front into position. This damaged I believe has occurred over the years due to the legs being missing. The drawer scrapes the ground every time it was used. Hopefully once the legs are adapted this will not be a problem any longer.
I plan to carefully flatten the entire cabinet and refinish just like I did on the Decca CTV22C


X2151 ( OA81) AGC amp was O/C.

Line stabilisation was high on both standards which is not good, adjusted line stabilisation for 585V on 625 (R5040), 470V on 405(R5041).

Adjusted Shunt stabilisation (R5053) for 1.2V across the 1K resistor and set the ACC pre-set (R7179), followed by doing a Grey-scale.

I now just need to sort out the convergence and a little bit of frame bounce.


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raymond sheldon
raymond sheldon
5 years ago

I was working on these from 1972 but only the single standard one. I’ve not long retired so spending some time to sort my office out I found the service manual that I bought from C.E S. it brought back some happy memories. I think the last time I repaired one of these was circa 1975. Low luminance fault which turned out to be the black level clamp BC148.

I left the trade altogether around 1979 working for Telefusion.

In my garage I found a vectorscope, oscilloscope, bar generator, AVO8, degausing wand and a lopt, PL509,PL509 and PY500 all from the G6. Also a GY501 & EY51, the equipment still works! and low and behold a SONY C7 Betamax. I put a tape in and it works perfectly!

I wonder if modern tvs and equipment will still work after 40 yrs,!!

Thanks for the pictures,,brought a smile to my face

5 years ago

Hi Chris, very interesting! This set used to belong to me, the LOPT failed and I bought a a brand new old stock (still boxed) CES part and fitted it back in 2007-8
I never got the set going properly (baby on way etc) and I sold the set to Mike Burton for the price of the LOPT!

It’s looking pretty good, any luck on the leg front?


4 years ago

My dad now passed worked as an engineer and taught me the trade especially the phillips G6 and the Later G8 very reliable but the convergence panel notorious for faulty Pots and also very weak Lopt stage , I’ve still got the the service manuals ( Lopt stage ) and so forth. I also have the service manual for an earlier b/w finlandia with an oil filled transformer to prevent overheating power consumption of 500 w !!!!

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