Repair service help for a ferguson 991T

[AdrianPH]

Not sure if this should be in this forum or the wanted section so sorry if I picked the wrong one.

I have a Ferguson 991T that I have worked on to the best of my abilities it was my first attempt at a TV to get working, and modern components have been used rather than re-stuffing old caps etc.  I recently fitted a better MW36-24 to the set and that has improved things to good effect, but I still have issues with the set such as echo's on vertical lines, this to me does not help focus etc. 
It was suggested that the set have been tuned at some time for better signal rather than bandwidth and even though I have tried my best to tune the IF back according to the manual, the vertical lines are still there, so I suspect some ringing.  I had a few replacement vales fitted during my work on it such as the EHT section and a few others.  It  works reasonably enough to view, it still has a few niggles and I believe it could be better.

So I am wondering if I can ask for the services of anyone with more knowledge/familiarity with TV's to look over it.  I will have to consider transporting it from the Blackburn area to where one may be and collecting again it some point later, so the distance could become an issue.

Costs covered etc, I am not asking for freebies.  So if anyone has the time and inclination please contact me via pm, or on this thread.

Cheers

Adrian

[peter scott]

In general, manufacturer alignment instructions take you to a good starting point but if you want the best bandwidth and step response you need to spend quite a lot of time making tiny iterative changes whilst watching the effects on the a test card image. After a while you'll learn what does what.

Peter

[AdrianPH]

Hello Peter; I imagine one can after practice, but would assume it takes time to acquire the skills when doing that to recognise the effects.

Many years ago I used to do the odd CB and Amateur radio repair, when the set's finally came to me, something would have failed and the set gone deaf, rather than look for a faulty component the owner many a time, went down the have a twiddle of the cores eventually bringing it to me as I had the gear for transceivers, so after finding a faulty component would then have to go through the RX and possibly TX alignment if they had twiddled too much.

My gear is all narrow band, I have no Wobbulators or sweep generators for TV if's and even though I have tried to use my spectrum analyser and sweep generator to the best I can, I am unhappy with the lines. It is possible it is not the IF, could be a peaking circuit, a high damping resistor etc, I believe that someone with time in the trade would have a lot better knowledge on the faults than my own approach.

Adrian

[peter scott]

Test Card C is a better monitor than any instrument. Simultaneous display of bandwidth and step response. I did try using my spectrum analyser but it's a very indirect view of what you are trying to achieve.

   

Peter

[Murphyv310]

Adrian.
Can you post up some pictures please of test card C showing the verticals and the gratings

[AdrianPH]

I can post a new picture tomorrow, but I had some in a thread on the other forum here is a link to the post with the pictures before a tube change.
https://www.vintage-radio.net/forum/show...?p=1300461&postcount=126
I do not have the brightness as high now so not as pronounced.

Adrian

p.s. it was pronounced as ringing in that thread.

[peter scott]

If you use a large white vertical bar as the video signal you might be able to see if it was from the video amp. detector or last IF using your scope.

   

Peter

[AdrianPH]

Hi Peter, the only video generator I have is the hedgehog 2 so a bit stuck with generating such a signal, I will have a think if I can generate something like that, I am not really geared up for TV work.

Adrian

[AdrianPH]

Lets see if I can get the Labgear CM7091 from the auction site.

I think I see the logic in your proposal Peter, if I see a nice switch from black to white and back again in the detector stage then it must be in a later stage if there then I will have to see if I can see it in the IF, need to get an isolation transformer.

Adrian

[peter scott]

If you have still or video camera that can give you an analogue video output you could connect that to your Hedghog. You could aim the camera at my image and have the camera record it as a still image.

Peter