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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc. |
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24th Jan 2017, 5:22 pm | #1 |
Nonode
Join Date: Jul 2005
Location: Hull, East Yorkshire, UK.
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Forgestone TVs
I remember seeing adverts for these TV's. I believe that they were some kind of DIY affair.
Were they a complete kit that included an unused chassis, or would the builder have to supply a donor chassis & panels in the way you'd make a kit car with an engine, gearbox & running gear. |
24th Jan 2017, 7:45 pm | #2 |
Heptode
Join Date: Jun 2007
Location: Durham, County Durham, UK.
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Re: Forgestone TVs
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24th Jan 2017, 8:14 pm | #3 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
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Re: Forgestone TVs
Hi.
Thanks for the link. I wonder how many of these sets were actually built. I see a very large mains transformer in the power unit which also gave full mains isolation, a rarity for a colour set in those days. Also regulated LT lines as well, another plus point. It was good to see that fibre glass PCBs were used. Looking at the Line/Field timebase board, the line output transformer has a Philips look to it judging by the appearance of the two bobbins. I see that in the RGB output stages use was made of a thick film resistor unit which proved problematic in the BRC 3000/3500 and also in the Pye solid state sets such as the 725 etc. It would be interesting to know how well these sets performed and how reliable they were. They certainly look very good for servicing. Regards Symon. |
25th Jan 2017, 9:07 am | #4 |
Nonode
Join Date: Jul 2005
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Re: Forgestone TVs
I wondered if their offerings borrowed designs one or more major manufacturers? They would have had to use somebody's LOPT, possibly one with a reputation for reliability. The set obviously has a very good PSU, so I am supposing that the rest of the kit was designed with some considerable care.
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25th Jan 2017, 9:42 am | #5 |
Dekatron
Join Date: Jun 2013
Location: East Sussex, UK.
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Re: Forgestone TVs
Wasn't this a collaboration with Television Magazine. I recall the PCB's were available and also the major parts.
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25th Jan 2017, 10:51 am | #6 | |
Dekatron
Join Date: Nov 2003
Location: Near Leeds, West Yorkshire, UK
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Re: Forgestone TVs
Quote:
My memory of it is a bit vague now, but I remember putting a RBM teletext PCB into it (not part of Forgestone's design). ISTR it didn't use the TBA520/530 chips for chroma but a different set of Mullard IC's; cannot remember their types.
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25th Jan 2017, 12:24 pm | #7 |
Dekatron
Join Date: Apr 2005
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Re: Forgestone TVs
Hi
This was quite different to the 'Television' designs. I fancied one but couldn't afford it, instead buying a dual standard G6 from a dealer and spending many happy hours geting the thing to work. The Forgestone TV was well thought out, obviously borrowing parts from other manufacturers such as the Pye 697 tuner head and Philips (?) IF unit. Was the LOPT from a Decca Bradford? The cabinet owed something to the Pye CT205 or perhaps the Decca CTV25 having the speaker at the left. I assume if that thick film unit gave trouble it could always be replaced with discrete components as we used to do on the Pye 725 series. Glyn |
25th Jan 2017, 9:20 pm | #8 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
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Re: Forgestone TVs
Hi.
I think the "Television" magazine design from around 1974 used the power/line timebase from a Pye dual standard, CT70. This used the GY501/PD500 EHT valves as well as the usual PY500A/PL509/PCF802 combination. Regards Symon. |
27th Jan 2017, 1:42 pm | #9 |
Dekatron
Join Date: Apr 2005
Location: North Wales, UK.
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Re: Forgestone TVs
I wouldn't mind seeing a copy of the design of the original 'Television' colour receiver. I think it was earlier - 1972 perhaps?
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27th Jan 2017, 3:50 pm | #10 |
Hexode
Join Date: Mar 2013
Location: Coventry, West Midlands, UK.
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Re: Forgestone TVs
As far as I remember the "Television" project used a tripler rather than shunt stabiliser and EHT rectifier.
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27th Jan 2017, 5:30 pm | #11 | |
Nonode
Join Date: Aug 2007
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Re: Forgestone TVs
Quote:
Keith |
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27th Jan 2017, 5:33 pm | #12 |
Nonode
Join Date: Aug 2007
Location: South Bradford, West Yorkshire, UK.
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Re: Forgestone TVs
Parts 7 to 11.
Keith |
27th Jan 2017, 5:35 pm | #13 |
Nonode
Join Date: Aug 2007
Location: South Bradford, West Yorkshire, UK.
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Re: Forgestone TVs
Parts 12 to 15. Part 1 to follow.
Keith |
27th Jan 2017, 6:19 pm | #14 |
Nonode
Join Date: Aug 2007
Location: South Bradford, West Yorkshire, UK.
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Re: Forgestone TVs
And parts 1a & b to complete the set.
A friend of mine built this TV while at university. I don't know whether he got it to work but did bring the IF board into the lab for us to look at as he was having problems. I believe there were several issues with the IF board which had to be corrected. Keith |
27th Jan 2017, 6:36 pm | #15 |
Octode
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Location: Dorridge, West Midlands, UK.
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Re: Forgestone TVs
When I built mine in 1973 I gave up on the IF board and bought a surplus one from a G8 at Manor supplies, it needed some changes for the interface but worked well.
Chris |
27th Jan 2017, 11:20 pm | #16 | |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
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Re: Forgestone TVs
Quote:
The 1972 design uploaded by Keith does indeed employ a tripler. There was another design entitled "Assembling a Modular Colour Set" by David Robinson from "TELEVISION" magazine March to May 1974 and it did use a surplus power/line timebase from a Pye CT70. The rest of the set was mostly built using surplus panels, mainly RBM. Regards Symon Last edited by Philips210; 27th Jan 2017 at 11:23 pm. Reason: error |
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28th Jan 2017, 12:05 am | #17 |
Hexode
Join Date: Mar 2013
Location: Coventry, West Midlands, UK.
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Re: Forgestone TVs
Ah, I see! Thank you
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30th Jan 2017, 2:35 pm | #18 |
Dekatron
Join Date: Apr 2005
Location: North Wales, UK.
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Re: Forgestone TVs
Thanks Keith for that mammoth scanning job! Interesting reading.
Glyn |
31st Jan 2017, 12:25 pm | #19 |
Pentode
Join Date: Dec 2007
Location: County Durham, UK.
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Re: Forgestone TVs
Here is a picture of my Forgestone 400 set
It's a bit of a beast as far as the cabinet is concerned But the pcb layout is neat & tidy , the huge mains transformer make a heavy set too Chris |
31st Jan 2017, 12:31 pm | #20 |
Dekatron
Join Date: Jun 2013
Location: East Sussex, UK.
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Re: Forgestone TVs
Don't forget the Thorn 2000 series had a mains tranny.
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