10-02-2022, 08:11 AM
The V200 certainly looks more attractive after having a bath.
Peter
Peter
Murphy V200
|
10-02-2022, 08:11 AM
The V200 certainly looks more attractive after having a bath.
Peter
10-02-2022, 08:38 AM
Interesting circular chassis that can be revolved around the bench to get at items. Does not look easy to work on even when you get it in the right place. Never had a desire to do a TV I'm glad to say.
GL Trevor
11-02-2022, 05:24 PM
Hi
I've done some more work today and now have a picture of sorts. After replacing those horrid hunts caps we got some results although the contrast control is intermittent, we also have a line timebase issue with cramping on right (forward stroke) I've a sneaky feeling this is LOPT based but I'm hoping I am wrong. There were a couple of resistors way high in the oscillator but replacements made no noticeable difference. The odd thing T1 has its A winding disconnected and I can't see how the TB would work less the transformer. I'm wondering if the Trader sheet is wrong, will need to have a look at the red book and see.
Cheers.
Trevor MM0KJJ. Member of, RSGB, GQRP, WACRAL, K&LARC.
11-02-2022, 07:20 PM
The line structure looks expanded vertically as well, it closely spaced at the bottom and top but very noticeable in the mid screen. Not familiar with this set so it may be normal or just the interlace.
11-02-2022, 07:37 PM
Hi.
Usual frame issues to be sorted out once the problem with the LTB is resolved
Cheers.
Trevor MM0KJJ. Member of, RSGB, GQRP, WACRAL, K&LARC.
11-02-2022, 07:59 PM
Hi.
This is getting odd unless I've gone bonkers. T1 in the diagram has the A winding missing the B winding is correct and present. There appears to be nothing else different to the diagram only the A winding missing. I'll need to see if there is a feedback winding from the LOPT that could be a later addition or the other way round.
Cheers.
Trevor MM0KJJ. Member of, RSGB, GQRP, WACRAL, K&LARC.
14-02-2022, 02:50 PM
Hi.
Didn't do much with this over the weekend but have spent a couple of hours today. Found a few way out of tolerance resistors and a couple of further capacitors. I've also replaced the 20L1 and U281 with NOS valves a PL38 is on order. There is still some line linearity issues but the result is a lot better with full width now. The LOPT has been replaced at some point and it has an oscillator feedback winding, T1 should be removed but it hasn't, my next job.
Cheers.
Trevor MM0KJJ. Member of, RSGB, GQRP, WACRAL, K&LARC.
16-02-2022, 04:55 PM
Hi
A short video of the results so far. Some little work to be done but a reasonable result. https://youtu.be/Mjxny_yZwck
Cheers.
Trevor MM0KJJ. Member of, RSGB, GQRP, WACRAL, K&LARC. |
Users browsing this thread: |
1 Guest(s) |