Share:
Notifications
Clear all

Project 1969 Philips G22K511 Missing I/F & LOPT, Conversion

Page 14 / 34
 
crustytv
(@crustytv)
Vrat Founder Admin

Your memory regarding the G6 is quite remarkable Marion, I'm super impressed. It reminds me of John when he first saw a 2000 and 3000 in my workshop, he instinctively knew where everything was just by laying his hands in the belly of the beast, despite not having seen one for many years 😎

Crusty's Collection: Read the repair blogs
Crustys Youtube Channel: If you want to follow me on Youtube, please consider subscribing
Vrat FaceBook: Follow us

ReplyQuote
Topic starter Posted : 11/04/2021 4:56 pm
Jayceebee
(@jayceebee)
Noble V-Ratter Registered

Yes, that short gentle hum when switching on was always sort of reassuring even if the set remained lifeless.

John.

ReplyQuote
Posted : 11/04/2021 5:00 pm
crustytv liked
Katie Bush
(@katie-bush)
Famed V-Ratter Moderator

@crustytv

They should do it! The originals, as I recall, were just a plain grey component with no markings at all. The main thing is for the PTC to rapidly drop the current flowing in the circuit, and settle out at almost zero, with just a residual current through R1064 to keep the PTC from cooling down and resetting.

ReplyQuote
Posted : 11/04/2021 5:08 pm
crustytv liked
crustytv
(@crustytv)
Vrat Founder Admin

As a diversion from the stresses of the Chroma panel refurb, I removed the tuner. This has got to be one of the most simple tuner extractions. One locking screw at the base and out it comes.

20210412 135127

John has been mapping the floating wires and plugs to and from the SS harness prior to DS IF installation. John wanted me to confirm the grey wire (12V) was connected to the base of the BC108 as we don't want to go shoving 12V in the wrong place. I can now confirm it is indeed as stated, to the base of the BC108.

tuner1
tuner2
tuner3
tuner4

Crusty's Collection: Read the repair blogs
Crustys Youtube Channel: If you want to follow me on Youtube, please consider subscribing
Vrat FaceBook: Follow us

ReplyQuote
Topic starter Posted : 12/04/2021 1:59 pm
Katie Bush
(@katie-bush)
Famed V-Ratter Moderator

Those tuners aren't bad at all, and they can be/could be repurposed very easily to other makes. It's basically the same multi-band VHF/UHF tuner as used in the DS sets, only that for some reason Philips decided to omit two button, thus reducing its functionality, but also reducing its domination of the cabinet facia.

Watch out for that transistor though, they did sometimes do funny things! - I only ever once remember Granddad having to do an "exchange replacement" (New tuner installed, old one back to CHS for reconditioning).

On the IF board, I have a strong recollection that the DS board was entirely hard wired to the rest of the chassis, and that the SS board had a couple of multi-pin (Molex type) plugs in addition to the hard wired connections, but when all is said and done, they are both basically the same circuit(s) with the omission of a system switch and associated parts for VHF reception. The component layout may appear different, and that may confuse the task of wiring up all those (loose ends). The main thing is, it's doable, and as such, I think it was easier to fit a DS panel into an SS chassis, than t'other way round.

I'm waiting to see what the decoder has to say for itself. It may actually play ball from the word 'go', or it may by a total nightmare. As I recall, most of the issues we had were centred around the reference oscillator (watch out for the crystal!) and the PAL bistable switch (look carefully at those lok-fit transistors). Keep an eye out for dry joints and/or broken tracks/pads where the chroma delay line is mounted. In early sets, at least, the delay line was a big chunk of glass hanging on those pads, and they didn't like to carry all that weight. CDA amp/outputs weren't generally bad, but the valves were worked hard and the rule of thumb was to replace the PCF200s on sight - which is why I still have those used ones. A low emission PCF200 can be rooted out by swapping any two of the three, and observe the result on screen.

ReplyQuote
Posted : 12/04/2021 4:00 pm
crustytv
(@crustytv)
Vrat Founder Admin
Posted by: @katie-bush

On the IF board, I have a strong recollection that the DS board was entirely hard wired to the rest of the chassis, and that the SS board had a couple of multi-pin (Molex type) plugs in addition to the hard wired connections

Correct again 👍

Meanwhile, moving away from the tuner and back at the chroma panel:

In addition to fixing the missing trace on V7001, I've just tidied up another problem area. This involved making good on and original repair and fixing other missing tracks by using insulated wires, making them follow the original path. This damage impacted R7271, which was completely out of circuit. R7282 and L7635, all these components being in the reference oscillator cct.

refo

The next real problem area to tackle with regard to track failure, is around V7003 colour AGC - Colour killer. After that its just dry joints.

20210412 173316[1]

Crusty's Collection: Read the repair blogs
Crustys Youtube Channel: If you want to follow me on Youtube, please consider subscribing
Vrat FaceBook: Follow us

ReplyQuote
Topic starter Posted : 12/04/2021 5:34 pm
Katie Bush
(@katie-bush)
Famed V-Ratter Moderator

Always a good plan to follow the original path of broken/missing tracks. It may sound frivolous to some, but any other route can, and sometimes does, introduce interference/noise into a signal path which can lead to hours of fruitless effort.

I'd forgotten the earlier pictures of that decoder.. So, no, I don't think it's going to play ball from the word 'go' but you never know, it might surprise us all.

ReplyQuote
Posted : 12/04/2021 6:00 pm
Jayceebee
(@jayceebee)
Noble V-Ratter Registered

The grey lead I can see is connected to the BC108 base so this is in fact the AGC input, the 12v supply is the red/black which makes sense. Something that threw me and I had to study the pictures for sometime to work out what was going on but the whole tuner body is effectively at 12v, not grounded! so don't go putting your meter -ve lead there when testing. Bizzare, I don't quite understand why they have done that. Only Philips. I wonder why the need to add that Lorlin electrolytic as it's not shown on the circuit or layout.

John.

ReplyQuote
Posted : 12/04/2021 7:48 pm
crustytv
(@crustytv)
Vrat Founder Admin

First full view of the component side of the chroma panel. Baked around PCL86/PCC85/PCF200.

20210412 203645
20210412 210447

Most notable is R7293 180R has overheated and has melted the plastic holder for the adjacent electrolytic C7114 100uF, which has also spewed electrolyte at its base. These are cathode components for the AF/amp output PCL86. Interesting that it and the other two valves are missing, did they melt! The big question is what must have happened to cause R7293 to have a meltdown.

20210412 203844

R7272 22K in the reactance stage has been creatively constructed from three separate resistors.

20210412 203855

Contrast control R1167 is not original either

20210412 211455

Delay line has a date of September 1968

Crusty's Collection: Read the repair blogs
Crustys Youtube Channel: If you want to follow me on Youtube, please consider subscribing
Vrat FaceBook: Follow us

ReplyQuote
Topic starter Posted : 12/04/2021 8:53 pm
crustytv
(@crustytv)
Vrat Founder Admin

The fact I will be fitting a dual standard IF, another required modification John pointed out to me was the DS/SS brightness control (R1069) fed via the IF panel, they use different values. Single standard using 2.2K and the Dual being 5K. If the 2.2K was left in situ, adjusting the brightness could be a rather fierce affair. A hunt in my stores, and I find a 4K7 Lin pot that has the correct length shaft, so in it goes.I also cleaned and lubricated the tuner as it was rather gummed up.

dsbright
ssbright
20210413 132016
20210413 124913

Crusty's Collection: Read the repair blogs
Crustys Youtube Channel: If you want to follow me on Youtube, please consider subscribing
Vrat FaceBook: Follow us

ReplyQuote
Topic starter Posted : 13/04/2021 1:17 pm
Jayceebee
(@jayceebee)
Noble V-Ratter Registered

Here you go, wiring details to fit the DS G6 IF into the SS chassis. There’s only one modification to make and that’s in the brightness control circuit as I mentioned. It’s taken longer than I anticipated due to me checking everything very careful and the idiosyncrasies of the Philips manuals like the fact that no interconnect details such as plugs and sockets are shown on the schematic.

The Mod to the brightness circuit is as follows.

1. Change the control to 4.7K ( I see this already has been done)

2. Fit 47K 1 watt resistor from bottom end to chassis.

3. Connect top end of the control HT3

And that’s it, a mod may be required to the audio section but let’s see what we get as it stands.

G6 DS IF wiring

John.

ReplyQuote
Posted : 13/04/2021 11:08 pm
crustytv
(@crustytv)
Vrat Founder Admin

@jayceebee

Hi John, thanks for the final diagram for the insertion of the DS IF.

I need to ask two things and sorry if I'm being a thicko but as I've always maintained, the only stupid question is the one not asked, that then leads to mistakes.

First I need to establish the baseline about the SS brightness control. R1069 a 2.2K Lin pot has three connections. One end goes to the chassis via R1094, a 3.3K resistor. The middle to PL3/4 and the other end to HT3 via R1093, a 15K resistor.

Now here comes my confusion, your diagram shows R1093, now a 47K going to chassis instead of R1094 and no resistor between the other end of the control and HT3 which used to be R1093, PL3-4 remains the same.

Is this as intended, that R1093 will now go to chassis and R1094 is removed entirely from the circuit.

brightmod
ssbright

Obviously it goes without saying, but for the benefit of those looking in, I need to solder the system switch pads into the 625 position.

Crusty's Collection: Read the repair blogs
Crustys Youtube Channel: If you want to follow me on Youtube, please consider subscribing
Vrat FaceBook: Follow us

ReplyQuote
Topic starter Posted : 14/04/2021 8:19 am
Jayceebee
(@jayceebee)
Noble V-Ratter Registered
Posted by: @crustytv

Is this as intended, that R1093 will now go to chassis and R1094 is removed entirely from the circuit.

That's correct, the clamp circuit around the PFL200 varies considerably between the DS and SS, the SS using TR2146 and the DS a zener X2154 in the cathode of the luminance output section of the PFL200.

We need to change to the DS version to allow correct operation of the brightness. If you look at the DS circuit it shows R1093/4 as 2 x 100k in parallel going to chassis from the bottom of the pot, R1093 in the SS goes to a -24V supply which is no longer used, the DS has the top of the pot tied directly to HT3. For neatness I've changed R1093/4 to a single 47k 1W but if you wish to use 2 x 100k that's absolutely fine. Hope this clears things up.

One more thing regarding the wiring of PL2 and 3, I've shown them as viewed from the top of the plug and the numbering is mine as none are shown on the circuit.

John.

ReplyQuote
Posted : 14/04/2021 10:13 am
crustytv
(@crustytv)
Vrat Founder Admin

Brilliant John, thanks for the further explanation, it all now makes more sense to me. I will modify R1069 as you first described. 👍

I cannot as yet do any further work until the DS IF arrives, so for now the G6 project will halt until then.

Crusty's Collection: Read the repair blogs
Crustys Youtube Channel: If you want to follow me on Youtube, please consider subscribing
Vrat FaceBook: Follow us

ReplyQuote
Topic starter Posted : 14/04/2021 12:34 pm
Katie Bush
(@katie-bush)
Famed V-Ratter Moderator
Posted by: @crustytv

Most notable is R7293 180R has overheated and has melted the plastic holder for the adjacent electrolytic C7114 100uF, which has also spewed electrolyte at its base. These are cathode components for the AF/amp output PCL86. Interesting that it and the other two valves are missing, did they melt! The big question is what must have happened to cause R7293 to have a meltdown.

Extremely leaky decoupling cap? I do recall that those small 'ally-clad' electrolytics lead a hard life up there, and to that extent I'd replace them all. It would be interesting to see what they come back as on test, but I'd guess they'll have dried out, changed value and have bad ESR. Some will have survived better than others.

Posted by: @crustytv

R7272 22K in the reactance stage has been creatively constructed from three separate resistors.

Not an uncommon sight in times gone past, and in most cases, done to help dissipate heat being radiated from the resistors, though I can't remember if there were any really 'hard-pushed' components in that neck of the woods.

Posted by: @crustytv

Contrast control R1167 is not original either

That one is a bit weird, and at first glance I was wondering if that was someone's attempt at 'retrofitting' a tint control - The early G6s had a tint control feature right there, but that was discontinued long before even the DS models ceased production. But, that's not all - Why on Earth are there two aerial sockets? This is meant to be an SS set, and I've never seen an SS with two aerial sockets! And, it doesn't stop there! This decoder has the early 'house brick' sized chroma delay line. By now, they were down to a 'half thickness' version at least, and in reality, a 'cig-packet' sized version in the latest ones I ever saw.

It's almost as though someone has really Frankensteined something weird out of this. I'm even wondering if this was an Irish version? That at least would account for the VHF/UHF aerial inputs. The tuner would have been capable of of both, and was selectable by the band setting pushrods behind the channel selector buttons (multi-band tuner).

I can't figure the decoder though, that's right out of the Ark!

Posted by: @crustytv

Delay line has a date of September 1968

Well that can't be right! - Can it?

This has to be a very early decoder! Possibly even one with the tint control.

Now, those valves 'up top'? As I said earlier, they were pushed hard, and generated a lot of heat, which is why the PCF200s were replaced on sight. They weren't expensive, so why not? They did get cooked to a crisp, but I don't think they ever got hot enough melt the glass, besides, if they were that hot, I'm pretty sure the PCB would have caught fire before the glass melted.

ReplyQuote
Posted : 14/04/2021 3:13 pm
crustytv
(@crustytv)
Vrat Founder Admin

Hi Marion,

I'm not an expert on Philips, Thorn is more my area of interest, so I'm prepared to be re-educated on Philips.

As far as I was aware the G6 was produced from 1967 to 1971, with the single standard being released late 69. The G6 continued production until 1971 when it was replaced by the G8. In 1971 G6 and G8 were both in production, the G6 final year and the first introduction for the G8.

Regarding the aerial configuration of the SS G6, in my single standard manual which is dated August 1969. The manual clearly shows the single standard having two aerial connections one UHF, one VHF.

Regarding the delay line in my SS G6, I guess a 1968 delay line is not out of place in this single standard, it's highly probable Philips had a load of delay lines in stock and used what was to hand. Furthermore, the DS and SS manuals both show D7018 as physically the same size.

Finally, Gary has one of the last single standard G6's produced in the final production year 1971, it also has the two aerial sockets UHF/VHF and has the exact same large delay line.

Gary & David working on his 1971 SS G6

gpg6

In conclusion, are you sure the G6 used smaller delay lines? It certainly does not look like it did. I had a 1967 DS G6, it had the large delay line. My manual shows in 1969 the SS had the large delay line. My 1970 SS G6, has a large delay line and finally Gary's final year (71) production SS G6, has a large delay line. Based on the timeline I present, I'm not sure when they would have had time to introduce a smaller delay line. Could you be getting mixed up with the Thorn 3000? That started with the DL1 delay line and over the years progressed to the DL50.

Maybe the little grey cells are playing tricks, but if you're 100% sure it  would be fascinating to know if anyone else came across one.

Crusty's Collection: Read the repair blogs
Crustys Youtube Channel: If you want to follow me on Youtube, please consider subscribing
Vrat FaceBook: Follow us

ReplyQuote
Topic starter Posted : 14/04/2021 4:34 pm
malcscott
(@malcscott)
Noble V-Ratter Registered

@crustytv Every G6 Dst/Sst i have seen has used the DL1 delay line.

ReplyQuote
Posted : 14/04/2021 5:48 pm
crustytv liked
Katie Bush
(@katie-bush)
Famed V-Ratter Moderator

Hi Chris,

You're probably right about the grey cells - I did have an anaesthetic yesterday. 🥴😵‍💫 but I have seen G6 decoders with various types of delay line, even one with a tiny blue delay line about a quarter inch thick by about three inches square, like something out of the Japanese sets. With regard to the VHF/UHF sockets, I honestly don't remember seeing any SS sets with both, but if seeing is believing, yours and Gary's tell a different story. I'm seriously thinking I need to see my GP about memory issues. 👵

One thing I am positive about, is that the sets with the smaller delay lines gave the best pictures! The best set I ever saw was the one I sold to my brother, and that would have been one of the last of the G6 range, with the push through maskless, square CRT. It was quite a performer in every respect. Only downside was the huge 'barn doors' in lieu of the more popular  bi-folds or vertical roller-shutter style.

Fetch a JCB and we'll dig up all the wrecked sets that he buried about 30 years ago! 😟🚜

ReplyQuote
Posted : 14/04/2021 6:04 pm
colourmaster
(@colourmaster)
Reputable V-Ratter Registered

Hi Chris, your SS G6 is a very early production set as it has the brown wood effect control panel . If you look at the brochures If 1969 the 22" SS G6 is there available with the Dual Standard versions. After that year the G6 SS then had the popular sliver control panel .

ReplyQuote
Posted : 14/04/2021 9:31 pm
crustytv
(@crustytv)
Vrat Founder Admin

G6 Mini Update

My project G6 is a single standard, hence would have had a pluggable IF panel. The dual standard IF being donated to this TV, would have been hard-wired into the TV. However, so I can make the DS IF pluggable, I've made an interface module. This will allow me to hard-wire the DS IF to this module, I'll mount it as a stand-off on the DS IF, then the TV's SS harness can just plug into to the module, making the DS IF removable.

Any other connections that are not part of the two PL plugs will have posts and plugs attached to this board and linked accordingly.

20210415 121944
20210415 122002

Crusty's Collection: Read the repair blogs
Crustys Youtube Channel: If you want to follow me on Youtube, please consider subscribing
Vrat FaceBook: Follow us

ReplyQuote
Topic starter Posted : 15/04/2021 11:49 am
ntscuser liked
Page 14 / 34