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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc. |
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29th Jun 2020, 12:43 pm | #1 |
Triode
Join Date: Dec 2016
Location: Nottingham, Notts, UK.
Posts: 36
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Ferguson TX9 Chassis
Hi,
I have a early TX9 chassis PC1001 with the UPC1365 chroma chip, the red is not very strong and take a while to warm up, and was wondering if anyone could give me pointers on what might be the cause ? I have tweaked the red gain and background to get it as good as it is, but its still not good enough. T.I.A |
29th Jun 2020, 12:49 pm | #2 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,844
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Re: Ferguson TX9 Chassis
I suppose we have to suspect the tube too. Is there any flaring on highlights etc?
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29th Jun 2020, 12:52 pm | #3 |
Triode
Join Date: Dec 2016
Location: Nottingham, Notts, UK.
Posts: 36
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Re: Ferguson TX9 Chassis
No, it all looks ok to me, just red takes time to 'warm up' and never really gets bright enough. Also I forgot to mention there is a slight wobble to the picture. I don't know if its related.
Edit:- I am not a TV engineer, I just thought I would mention this in case it gets technical and I ask you to explain in simpler terms. I am very grateful for any info you give, Last edited by Umpa2016; 29th Jun 2020 at 12:58 pm. |
29th Jun 2020, 1:14 pm | #4 |
Heptode
Join Date: May 2006
Location: Accrington, Lancashire, UK.
Posts: 978
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Re: Ferguson TX9 Chassis
It does sound tubey, the tx9 was a mixed bag for tubes. Swap one of the RGB leads over to see if that perks the red up, were the output transistors on the crt base? can't remember! Does the picture gradually improve when the set has been on for say 10 minutes? A picture may help.
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29th Jun 2020, 1:23 pm | #5 |
Triode
Join Date: Dec 2016
Location: Nottingham, Notts, UK.
Posts: 36
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Re: Ferguson TX9 Chassis
No it does not make any sounds - whines or squeals. It warms up and after about 10 mins the red is there, but its not as good as the rest of the colours.
FWIW I did try to take a picture, but for some reason it looks ok on the phone, I guess the phone is more sensitive to red. Just to clarify, this is a tube and chassis - its not really a TV its an arcade game that just happens to use a TV chassis as a monitor. |
29th Jun 2020, 1:51 pm | #6 |
Octode
Join Date: Apr 2005
Location: Peterborough, Cambridgeshire, UK.
Posts: 1,898
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Re: Ferguson TX9 Chassis
One way to see if it is the tube low emission would be to temporarily link out the heater resistor
This will make the heaters brighter and improve the emission if the tube is low. Follow the two heater wires from the tube base to the main PCB I think they may be brown and or black. one will go to the Line output transformer earth the other through the heater resistor to a pin on the lopt. Usually the resistor is blue and flat standing upright and to the left of the lopt. It will be only a few ohms. it may not be the only one of that type though so make sure you get the right one. If you have a circuit you should be able to find it on the diagram and then check the part number on the PCB. If shorting it improves the red and the warm up time it looks as if it is the red gun low emission. You may be able to improve the tube by fitting a lower value resistor. for example try halving the value of what is fitted. I wouldn't leave the resistor shorted out though as the tube may not last too long like that. You may find if you run it for a while with the resistor shorted that the emission is still good when the short is removed especially if the tube has been dormant for an extended period. Rich |
29th Jun 2020, 2:07 pm | #7 |
Dekatron
Join Date: Apr 2005
Location: North Wales, UK.
Posts: 6,918
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Re: Ferguson TX9 Chassis
What's the make and type number of the tube? As said above, some were shorter lived than others.
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29th Jun 2020, 3:10 pm | #8 | ||
Triode
Join Date: Dec 2016
Location: Nottingham, Notts, UK.
Posts: 36
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Re: Ferguson TX9 Chassis
Quote:
Quote:
Sadly there is no info on the tube, all I can say is that it looks to be an original. Fortunately I did manage to get a copy of the original service manual for this exact chassis. To help you all help me please look at the links I have posted of the manual - these show the circuit and component layout. Also there is a picture of the tube - in the hope you can identify it. Board Trace Component Side Neck Wires Neck Wires to Board The Tube Last edited by Umpa2016; 29th Jun 2020 at 3:19 pm. |
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29th Jun 2020, 3:29 pm | #9 | |
Dekatron
Join Date: Sep 2003
Location: Near Swindon, North Wiltshire, UK.
Posts: 3,611
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Re: Ferguson TX9 Chassis
Quote:
On this chassis, the RGB output stages are on the main board, unlike the "big brother" TX10 chassis. Your TX9 chassis doesn't look like it's fitted into a Ferguson TV! Last edited by dazzlevision; 29th Jun 2020 at 3:38 pm. |
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29th Jun 2020, 3:33 pm | #10 |
Dekatron
Join Date: Apr 2005
Location: North Wales, UK.
Posts: 6,918
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Re: Ferguson TX9 Chassis
Hi
R706 on the tube base is your man - it feeds the CRT heaters. If its value is low, say under 2.2 ohms, you can short it out to see what effect this has on your reds. If they improve, then the CRT is worn. Alternatively, as the decoder IC doesn't have auto-greyscale, you could swap the red and (say) green leads over on the CRT base and see whether this gives a better red. If not, then it's definitely a faulty CRT. That's a Mullard CRT, I think. What size is it? This chassis would drive 14 - 22" tubes, of which the 14" were the longest lived, possibly because they were in portable sets and hence used less. |
29th Jun 2020, 3:35 pm | #11 | ||
Triode
Join Date: Dec 2016
Location: Nottingham, Notts, UK.
Posts: 36
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Re: Ferguson TX9 Chassis
Quote:
Quote:
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29th Jun 2020, 3:46 pm | #12 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,844
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Re: Ferguson TX9 Chassis
Isn't there a "service position" whereby the chassis can be temporarily supported vertically, so that you can get access to both sides easily enough?
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29th Jun 2020, 4:19 pm | #13 | ||
Triode
Join Date: Dec 2016
Location: Nottingham, Notts, UK.
Posts: 36
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Re: Ferguson TX9 Chassis
Quote:
The resistor is 2.1 Ohm. What type of package is that resistor ? Is there anything I can do to keep it without burning the tube out ? Perhaps putting a 1.5 Ohm in ? Or am I best just leaving it as is and letting it warm up for 20 mins. Quote:
Chassis Pic |
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29th Jun 2020, 4:43 pm | #14 |
Dekatron
Join Date: Apr 2005
Location: North Wales, UK.
Posts: 6,918
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Re: Ferguson TX9 Chassis
Right - your CRT is low and it probably is an A51-580X. Two options. Either you can get it boosted, or, ideally, cleaned and balanced by a BK machine. Maybe someone near you has one - I'm a bit far away!
Otherwise the resistor could be reduced in value until you get a satisfactory picture. What value is it? Should say on it, maybe 1R8, 2R7, something of that nature. When we know what value it is, we could suggest or even supply a suitable replacement. I must stress that either of these methods are only a temproary fix and the CRT is on its way out. However given that fact, you've really nothing to lose. Luckily you won't need to remove the chassis as you just need access to the CRT base. |
29th Jun 2020, 4:43 pm | #15 | ||
Triode
Join Date: Dec 2016
Location: Nottingham, Notts, UK.
Posts: 36
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Re: Ferguson TX9 Chassis
Quote:
Quote:
What type of resistor is this ? Never seen one like it before. |
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29th Jun 2020, 4:49 pm | #16 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,844
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Re: Ferguson TX9 Chassis
Is it one of those flat, rectangular blue ones?
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29th Jun 2020, 4:59 pm | #17 |
Triode
Join Date: Dec 2016
Location: Nottingham, Notts, UK.
Posts: 36
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Re: Ferguson TX9 Chassis
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29th Jun 2020, 5:42 pm | #18 |
Octode
Join Date: Apr 2005
Location: Peterborough, Cambridgeshire, UK.
Posts: 1,898
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Re: Ferguson TX9 Chassis
The resistor is a 2 Ohm thick film type. you can try either replacing it with a 1 Ohm wire-wound resistor around 4 watt or you can put another 2 Ohm resistor in parallel with it which will have the same effect.
Then run the monitor for a few hours and then try 2 ohms again. if the picture is not satisfactory try a 1.5 ohm resistor and if that cures it leave that in. if not good enough go back to a 1 ohm and if still not good enough go back to shorting it out. you are looking to get a satisfactory display at minimum reduction . If you end up shorting it out the tube will probably be ok if not used for hours and hours on end. At the end of the day you have nothing to lose... |
29th Jun 2020, 7:48 pm | #19 |
Triode
Join Date: Dec 2016
Location: Nottingham, Notts, UK.
Posts: 36
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Re: Ferguson TX9 Chassis
Thanks I'll let you know how I get on.
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30th Jun 2020, 9:29 am | #20 |
Triode
Join Date: Dec 2016
Location: Nottingham, Notts, UK.
Posts: 36
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Re: Ferguson TX9 Chassis
Just to let you all know - I bought a B&K Analyser and rejuvenator that was going on eBay.
I will have a bash at using that. Then if that does not work and I don't blow it up I will do the resistor hack. Worst case is I have to buy a new TV to put in the arcade if it all goes pear shaped I guess. I am trying to keep this thing as original as I can, Its part of British arcade gaming history. |