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Old 31st Jul 2023, 1:57 pm   #1
bionicmerlin
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Default Ferguson Courier 3 (1400)

Had this tv a couple years kicking about. It’s got quite a few issues And been seriously got at .
The first problem I’m stuck on is the brightness. It’s at about 80% and not controlable.
I have checked to pot and nearby resistors and they are ok.
I get 54 volts on pin 7 on the tube and it only differs by about half a volt by turning the brightness knob. Fully up or down.
With the set off if I connect a meter between chassis and pin 7 I get a reading between 178k and 438k depending on the brightness knob position. So something should be doing something.
Am I overlooking something stupid Or my lack of knowledge
Any help appreciated as always Andy
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Old 31st Jul 2023, 4:30 pm   #2
Bobdger
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Default Re: Ferguson Courier 3 (1400)

O/C Brill pot. measure across the pot about 470k, this is part of the divider with a 220k resistor. Bob
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Old 31st Jul 2023, 4:54 pm   #3
dazzlevision
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Default Re: Ferguson Courier 3 (1400)

If the 0.47uF capacitor (C39*) that couples the video signal to the CRT's cathode is very leaky or short, that will have a significant effect on the operation of the brightness control.

Is R122 (22kOhms), the CRT's grid return to chassis OK? Ditto for R121 (150kOhms) and R119 (220kOhms).

The CRT's pin 3 (first anode) should be in the region of 500 to 600Vdc. If it's low, C100* (0.1uF) could be leaky or short, or R132 (3.9MOhm) could be o/c.

*If it's a TCC/Hunts/Erie or Dubilier brand that's quite likely. These will all have axial lead-out wires, rather than radial (although they are probably vertically mounted, to conserve board space).

All the resistors mentioned above will be Erie carbon composition printed circuit board mounting types, which have a tendency to go high in value as time passes, especially those subject to a higher operating voltage (such as R132).

It's also possible that there is an inter-electrode leak within the CRT (e.g. grid to cathode).
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Old 2nd Aug 2023, 11:22 am   #4
bionicmerlin
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Default Re: Ferguson Courier 3 (1400)

Bob and Dave .
Thanks for your reply.
Thanks for your help.
It was the brightness pot in the end .
It tested ok in the set and even out of the set . But on the off chance I substituted for another one and it’s working.
I also checked the voltage at pin 3 on the CRT base.
It was reading low at 410 volts . C100 and R132 replaced . The cap was definitely leaky and the resistor about 30% higher. Than it should be. After doing this the voltage is now about 440 volts .
So far the picture is pretty good.
The set has lots of other issues that I will get down to in due course.
I’m sure I will want more help later Andy
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Old 2nd Aug 2023, 1:58 pm   #5
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Default Re: Ferguson Courier 3 (1400)

Glad to hear you've resolved the immediate problem.

Your set is an early model in the 1400 chassis production run, so (unless its had its chassis swapped over in the past) it will benefit from several production changes, which are listed in a 1400 series service manual supplement. Some produced a greater benefit to the chassis' performance than others. I can post it here if you wish (after checking, I don't think it's available on Paul Stenning's service information website).

Your set will certainly have several TCC/Hunts/Erie/Dubilier paper capacitors fitted, most of which by now will be somewhat leaky (or even s/c, especially the two "S" correction capacitors: C107 0.1uF 625 and C108 0.3uF 405).

In particular, there was a mod to the "Width" pot circuit that avoids the risk of the original 1MOhm pot overheating. The series resistor R143 changes from 220kOhm to 680kOhm and the pot to 2.2MOhm).
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Old 8th Aug 2023, 10:38 pm   #6
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Default Re: Ferguson Courier 3 (1400)

Dave .
Bit of a late reply. The next problem was lack of sound but excessive hum. That’s sorted now just a broken earth cable to the volume control. Not easy to spot though. I’m just slowly going through the caps . I do have just about every piece of downloadable material for the 1400s. And some good info thanks to Johns (HCS ) check list . So I should have all the upgrades info. Thanks Anyway Andy
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Old 20th Oct 2023, 11:14 am   #7
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Default Re: Ferguson Courier 3 (1400)

Back again .
One of the next things I’m having problems is the sound. Plenty of volume but is sounds a bit distorted, almost a slight scratchy slightly tinny sound.
My first thoughts were the speaker. After trying 3 others that dosnt appear to be the reason .
Any suggestions would be helpful Andy
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Old 20th Oct 2023, 12:33 pm   #8
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Default Re: Ferguson Courier 3 (1400)

Quote:
Originally Posted by bionicmerlin View Post
Back again .
One of the next things I’m having problems is the sound. Plenty of volume but is sounds a bit distorted, almost a slight scratchy slightly tinny sound.
My first thoughts were the speaker. After trying 3 others that dosnt appear to be the reason .
Any suggestions would be helpful Andy
Is the problem present on 405 (AM sound) and 625 (FM sound), or just one line standard?

Does your audio/RF source work correctly on other sets?
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Old 20th Oct 2023, 12:56 pm   #9
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Default Re: Ferguson Courier 3 (1400)

Dave .
Temporary I have put in a 625 tuner out of a scrap set as the original has been messed with.
So to answer the question it’s the same on 405 and 625.
. In my workshop I have the Ultra version of the same set I use all the time for general viewing . So I’m using that source and know it’s fine. Thanks Andy
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Old 20th Oct 2023, 3:35 pm   #10
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Default Re: Ferguson Courier 3 (1400)

OK, that seems to rule out the IF and sound detector stages, as the effect is present on both line standards.

I would first measure the dc voltages on the 30PL1 sound valve, to see if they are comparable with those given in the service data.

If you have a spare 30PL1, try substituting that.

Failing the above, I'd check that the cathode decoupler electrolytic C83 (50uF) hasn't gone very low capacitance, as that would attenuate the lower audio frequencies (it may well be a Callins or TCC type - see below).

I'd also check that the capacitor across the primary of the audio output transformer (C127 0.01uF) isn't a paper dielectric type that has become leaky and do the same for the anode to grid coupling capacitor C80 (0.022uF).

Check that C85 (5000pF - part of a series connected tone correction network with R98) isn't a paper type, which may have become very leaky.

Check the pentode's cathode bias resistor R96 (270R) and the triode anode load resistor R92 (270k) haven't gone well out of tolerance.

Have you checked/replaced C81 and R97 (12uF and 470R - HT decoupler network)? If the original, C81 will probably be the dreaded black Callins or TCC coloured plastic cased type, both of which tend to go open circuit.
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Old 21st Oct 2023, 2:54 pm   #11
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Default Re: Ferguson Courier 3 (1400)

Dave hi.
Before I asked for this last bit of help I did try a new 30PL1. It made no difference so I put the original old valve back in.
Now after reading your advice I’m there checking over everything you said . Something dosn't feel right. I double check the valve again and realise it’s shorter than than the new 30PL1. Someone had Infact put a 30FL1 in its place.
That’s something I will remember now to check the right valve is in there in the first place next time.
Anyway with the new valve it sounded the same. In fact I did check everything else you said and traced it to R92 being open circuit. The sound is now as it should be.
Thanks so much for your help.
I’m going to look at why the UHF tuner is not working next. So I might be back for more help soon . Andy
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Old 21st Oct 2023, 3:09 pm   #12
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Default Re: Ferguson Courier 3 (1400)

Hello Andy,

Glad that you've found the actual component fault (R92 o/c) and the previous repairer's human error (wrong valve fitted) fault!

Unless the RF amplifier has been "zapped" by a static discharge (lightning strike in the area) down the aerial cable, the main UHF tuner fault is bad contact of the ganged variable capacitor's rotor (moving part) with the several earthing springs soldered to the metal "chassis".

In addition, there was a change in value of two of the resistors soldered to feed-through capacitors on the outside of the tuner, to eliminate squegging - IIRC (but unlikely to be the cause of "no signals" faults).

Regards,

Dave
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Old 28th Jan 2024, 10:16 pm   #13
bionicmerlin
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Default Re: Ferguson Courier 3 (1400)

Dave .
And anyone else who have helped .
I’m very behind in my projects and try to thank people who have helped me.
I have had the set working very well on 405 . I have had to change almost all the pots due to being faulty or damaged.
Going back to the UHF tuner not working. Someone has I assumed taken out the earthing springs and re soldered them . I did take them out to double check then solder them back in . Still not working . It’s not looking good as someone has gone over almost all solder joints on all the components with a to big a soldering iron and made a mess of everything. . I’m not going to go any further with the tuner as I think I have a spare one but can’t find it . As a temporary measure I just got a push button tuner inside The cabinet preset to one channel. Andy
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Old 1st Feb 2024, 12:39 pm   #14
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Default Re: Ferguson Courier 3 (1400)

Hi Andy,

All Callins caps need changing!

I have a 1400 Courier and found one Callins electrolytic had gone almost short circuit. Also any Hunts need replacing. There was one brown Hunts in my set which I replaced. Also the resistors used in this set have a strong tendency to change value. Sometime quite considerably.

I check any that were particularly in the anode or cathode circuits and ended up changing quite a few.

Good luck.

Another Andy!
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