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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc. |
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2nd Jun 2019, 4:38 pm | #1 |
Heptode
Join Date: May 2010
Location: Warminster, Wiltshire, UK.
Posts: 682
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Ferguson personal contrast and sound issues
2 issues with this tv . The contrast control does nothing what so ever. The pot tests fine but that’s as far as I have gone. The picture is not to bad even without it working.The other problem is i can only just and just here the sound on 405 lines with the volume control on full i get some background hum so the amps working and it works fine on 625 lines . I know my 405 line feed is good as I have no problem with my other TVs . It does get slightly louder for a fraction of a second if i pull the aerial lead out then put it back in.
Most of the capacitors have been changed but not all. I’m not sure I want to spend to much time on this set as the cabinet is not in the best condition .this set has grown on me abit though . Any help would be appreciated Andy |
2nd Jun 2019, 5:05 pm | #2 |
Dekatron
Join Date: Sep 2003
Location: Near Swindon, North Wiltshire, UK.
Posts: 3,608
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Re: Ferguson personal contrast and sound issues
Is this the little 11" CRT version of the Thorn 900 chassis, model 3629?
For the contrast control issue, there is usually a high value resistor (in the order of 2 -5 MOhms) fitted between the slider of the contrast control and the vision AGC line. This may well have gone o/c or very high value. Last edited by dazzlevision; 2nd Jun 2019 at 5:07 pm. Reason: Added text. |
2nd Jun 2019, 7:32 pm | #3 |
Heptode
Join Date: May 2010
Location: Warminster, Wiltshire, UK.
Posts: 682
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Re: Ferguson personal contrast and sound issues
Thank you Mr Dazzlevision .you are correct that is the same set as in your picture and you are correct on the resistor . It’s should have been 3.9 M but it was over double that. I just fitted a new one and that’s sorted the contrast.
Hopefully someone can give me ideas to the sound problem. Thanks again Andy |
2nd Jun 2019, 9:25 pm | #4 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,147
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Re: Ferguson personal contrast and sound issues
First guess is the sound detector diode, probably O/C J.
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2nd Jun 2019, 10:59 pm | #5 |
Heptode
Join Date: Dec 2004
Location: Newport, Gwent, UK.
Posts: 962
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Re: Ferguson personal contrast and sound issues
I've got one of these and it does display a lovely picture .
Cheers Neil. |
3rd Jun 2019, 1:24 am | #6 |
Heptode
Join Date: May 2010
Location: Warminster, Wiltshire, UK.
Posts: 682
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Re: Ferguson personal contrast and sound issues
Yes Neil so far I would agree he picture is very good
John i will investigat the detector diode when I got abit more time. I guess it’s in one of the If cans . Thanks Andy |
3rd Jun 2019, 2:34 pm | #7 |
Heptode
Join Date: May 2010
Location: Warminster, Wiltshire, UK.
Posts: 682
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Re: Ferguson personal contrast and sound issues
John . Almost spot on . It was a bad joint on a component next to it.
Thanks . Andy |
11th Jun 2019, 3:18 am | #8 |
Octode
Join Date: Jan 2006
Location: Borough of Gateshead, UK.
Posts: 1,420
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Re: Ferguson personal contrast and sound issues
The sound should be strong and powerful on this model. Would've been ideal if they had VHF radio facilities.
Out of interest, does yours have a valves or transistorised UHF tuner? |
11th Jun 2019, 9:19 am | #9 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,147
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Re: Ferguson personal contrast and sound issues
Agree. It employs a PCL86 sound output valve, enough to blow you out of the room!
Ferguson always designed a good sound channel/output stage to provide adequate sound under poor reception conditions. Something other leading manufacturers should have taken a note of. John. |
11th Jun 2019, 2:57 pm | #10 |
Heptode
Join Date: May 2010
Location: Warminster, Wiltshire, UK.
Posts: 682
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Re: Ferguson personal contrast and sound issues
I can’t believe how well this set preforms both picture and sound. It does have a Valve UHF tuner slightly critical about the correct tuning but performance is very good .
I like this set so much I wouldn’t mind a second one for my workshop . Only thing is I want some replacement tuner and knob copper brights but I guess I will have to try and make my own as I’m sure everyone with these sets wants them as well Andy |
11th Jun 2019, 5:47 pm | #11 |
Hexode
Join Date: Mar 2014
Location: Dublin, Ireland
Posts: 398
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Re: Ferguson personal contrast and sound issues
Valve UHF tuner grand now when fed with strong (sometimes too strong) signal from modulator etc - not so great back in the day when presented with weak broadcast signal
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11th Jun 2019, 7:37 pm | #12 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,147
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Re: Ferguson personal contrast and sound issues
The super bright high contrast picture can be put down to the PFL200 video output and sync separator valve introduced in 1964. 21 m/a per volt, a great valve. J.
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11th Jun 2019, 7:58 pm | #13 | |
Octode
Join Date: Jan 2006
Location: Borough of Gateshead, UK.
Posts: 1,420
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Re: Ferguson personal contrast and sound issues
Quote:
My example has a PL500 line output valve, albeit Mullard, suggesting a '60s replacement. |
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11th Jun 2019, 11:34 pm | #14 |
Heptode
Join Date: Dec 2004
Location: Newport, Gwent, UK.
Posts: 962
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Re: Ferguson personal contrast and sound issues
I did have a go at making a replacement bright for my set which was basically the bright from a scrap knob. just don't look too closely at it..
Cheers Neil. |