Cossor 917 woes

[Murphyv310]

As yet I've not got the replacement valve holders. The paxolin bases are very poor in this set
At least I've been able to make a temporary repair on the other faulty base in this one before the new ones arrive.

[boater sam]

Now you are  a man that likes a challenge Trevor, how about taking this on----------

https://www.ebay.co.uk/itm/Old-Vintage-R...EBIDX%3AIT&_trksid=p2060353.m1438.l2649


Its a hateful HMV 1808 to start with, condition is err,  desperate? A problem set even when new.

Lots of spares with it, not all TVs but it looks complete except with no back.

I dare you.

Sam.

[Murphyv310]

Hi Sam.
I'll pass on that one I think.

Good progress today with the failed control replaced, the vibration dampers replaced on the RF deck, used grommets and washers to tension them as there is no way I'd be able to source anything like the originals. Did some recapping on the RF deck as well and a couple of Electrolytic caps too.
Shed now locked up and no more work till Monday, really need to give my back some rest, bending is not good for it.

[Murphyv310]

Hi.
After two days more work it was time for a test.
Unfortunately I don't have the 10 inch Cossor tube.
Although I have access to a 9 inch Mullard CRT I was uneasy about using this for tests. The mounting angle would need to be correct to inhibit any stress on the glass and if I had to move the chassis to make adjustments or take voltages I didn't want to go round that particular route.
So I thought of using the MW6-2 again like I did in the Pye B16T. So I cobbled it all up only to find an issue with its scan coils with smoke being the result. So I then just sat the MW6-2 on the chassis with the Cossor scan coils but no focus coil. This actually worked and hidden in the blur you can see the frame and line lock up and there is a picture. I discovered the brightness control was faulty which I need to replace. Tomorrow I'll try and add the MW6-2 focus coil and see if I can resolve a better picture.

https://youtu.be/VsgWJBkcpEw

[Murphyv310]

Hi.
I managed to get the picture focused on the MW6-2, I also did a video here: https://youtu.be/k3H5BiE9gPs
After the photo and video I replaced the brightness control and did a further test and soak, no issues and everything seems fine.
Managed to square up the scan coils and there is no corner cutting etc so we can see that these little tubes can really run with a totally different type of scan coils. All good fun.

[Panrock]

I'm starting to follow this with interest. The set couldn't be in better hands.

Steve

[LENINGRAD T2]

Hi Trevor,
Hands that heal. Another successful resuscitation. The MW6-2 is perfect even at low voltages. I have several Russian small radar tubes that you may find useful when testing and repairing TV. I am happy to send them, as long as new customs regulations are not an obstacle.

Adam.

[Freya]

Nice work Trevor, you are on my subscribed Youtube list. Enjoy all your videos.

[Geordie McBoyne]

As mentioned in an earlier post the Cossor 916/7 RF unit in the special Beau Decca TV chassis is giving problems. The mixer-oscillator valveholder is suspect. The mixer-osc valve is a CV4014, mil spec version of the 6AM6.

Geordie McBoyne.

[Murphyv310]

Hi.
That is indeed very kind Adam. I'm happy to pay customs. Been doing this for many years when buying capacitors from Canada and when I bought Aurora standards converters directly from Darryl in the US. Its important to mention that these items are secondhand but its also important to state a value even if its low. A friend recently tried to send a bumper to Slovakia as a gift and it was rejected. Even my wife when she worked in Dubai and got shirts for her dad had to pay duty which is correct. Perhaps a down side to the recent changes but only to be expected.

This may be helpful. https://www.gov.uk/government/publicatio...post-users