22nd Mar 2020, 9:40 pm | #21 |
Dekatron
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Re: Cossor 483
Many sets are wired with solid rubber insulated wiring. I lift one end, remove the old insulation and slide on new sleeving before resoldering the wire back. Silicone sleeving would be ideal but is expensive, I use PVC.
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23rd Mar 2020, 9:30 pm | #22 |
Heptode
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Re: Cossor 483
Thanks for that chris does the 470pf matter what the voltage is does it have to be 1000v it says type m on old one does that make a difference
Mark |
23rd Mar 2020, 11:02 pm | #23 |
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Re: Cossor 483
The voltage rating of the 470pF isn't critical- anything over 50V should be plenty. As far as I can see it only has to deal with low voltage unless there's a nearby lightning strike in which case all bets are off anyway! The value isn't particularly critical either- anything from 220pF to 1000pF would probably be fine.
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28th Mar 2020, 6:41 pm | #24 |
Heptode
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Re: Cossor 483
Have finished the capacitors and rewiring the resistors are within range so I left them no I'm trying to work out the voltages
LT + and - are blue leads one rad tag other black tag not sure of voltage of these think davebms says this is 2volts? GB-1 = blue lead 9volts GB-2 = purple lead 4.5volts HT- black lead 120volt Then I'm left with 2 unmarked leds 1 green and 1 red I was thinking that the red lead would be the HT+ 120volts and that the green would be the GB+ volt = ? The other thing is how would I connect them all up to modern lead Mark |
28th Mar 2020, 7:12 pm | #25 |
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Re: Cossor 483
Hi Mark
The green seems to be going straight to chassis which would make it LT- The Blue and the Purple seem to be correct. Your missing the LT+ If the red is HT + it will connect direct to C33. GB+ HT- and LT+ all go via switches. Not sure what you mean about connecting to a modern lead? Did you check the Grid coupling auto transformer for continuity they are famous for going OC. Cheers Mike T
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28th Mar 2020, 8:08 pm | #26 |
Heptode
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Re: Cossor 483
More photos I copied the wires like for like with the plugs the same as well I'm not 100% it was correct in first place
What I meant by modern was in the original batteries with lots of trappings there would be internal connection that would give the negative I think Last edited by rockinmark; 28th Mar 2020 at 8:18 pm. |
28th Mar 2020, 8:58 pm | #27 |
Heptode
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Re: Cossor 483
Back card not that clear bu best I can find
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28th Mar 2020, 11:00 pm | #28 |
Rest in Peace
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Re: Cossor 483
Wow that cabinet looks fantastic, well done.
Mike |
29th Mar 2020, 10:44 am | #29 |
Pentode
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Re: Cossor 483
hello all.. mark check post #9 the set requires, two GB -4.5 and -9 volt
they should be the only connections that reversed ?, IE positive to chassis the photo I found, cleaned up, they are 2volt (so you have battery for that) dave |
29th Mar 2020, 10:59 am | #30 |
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Re: Cossor 483
Hi Mark
In total there should be 7 battery connections. It should be easy to identify LT+ GB+ and HT- since they all go to the switch. You can ring them out with a meter. Check the fuse bulb which ISTR on this chassis sticks out the back of the chassis. You can go two ways with replacing the batteries. Build an eliminator or make up your own batteries. I attach snip of all the connections going to the on/off switch. For LT you can if you go the battery route use this type of battery although a bigger version is probably best if your going to run it for long periods. Cheers Mike T
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Invisible airwaves crackle with life or at least they used to Mike T BVWS member. www.cossor.co.uk Last edited by Cobaltblue; 29th Mar 2020 at 11:07 am. |
30th Mar 2020, 11:44 pm | #31 |
Dekatron
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Re: Cossor 483
Where did you get to with the transformer continuity checks suggested by Mike T?
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31st Mar 2020, 1:58 pm | #32 |
Heptode
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Re: Cossor 483
Hi pj I Yeah the ohms of the transformers are all correct I have put in the wanted list that I need a 210spt valve because the one in mine is a vp2
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31st Mar 2020, 2:17 pm | #33 |
Heptode
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Re: Cossor 483
Mike T
would you have any information of cossor extension speakers I'm trying to do a new back card information sticker but there are bits on mine that are unreadably looks like it says Model ?93 and maybe 20,000ohms the other thing is what are the positions of the waveband switch from what I can see it maybe S M L Or maybe someone else knows It still needs more work when i do it properly on my computer been doing it on tablet but its getting there Last edited by rockinmark; 31st Mar 2020 at 2:30 pm. |
31st Mar 2020, 2:49 pm | #34 |
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Re: Cossor 483
Hi Mark
Sorry didn't realise you were after corrections for your new label. Need to check my archive but that's 80 miles away What I have on this PC is a scanned copy of the 1938 Brochure (which has the 48 series sets shown) and here the extension speaker is listed as a 695M Cheers Mike T
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Invisible airwaves crackle with life or at least they used to Mike T BVWS member. www.cossor.co.uk Last edited by Cobaltblue; 31st Mar 2020 at 3:18 pm. |
31st Mar 2020, 3:24 pm | #35 |
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Re: Cossor 483
And some of the 48 series from the same brochure.
Cheers Mike T
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Invisible airwaves crackle with life or at least they used to Mike T BVWS member. www.cossor.co.uk |
31st Mar 2020, 3:47 pm | #36 |
Heptode
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Re: Cossor 483
I managed to get photo through magnifying glass
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31st Mar 2020, 3:54 pm | #37 |
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Re: Cossor 483
695 it is then
Cossor seem to put these extra letters in model numbers sometimes and its not always clear what they refer to. Cheers Mike T
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31st Mar 2020, 7:54 pm | #38 |
Heptode
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Re: Cossor 483
I have reprinted the back board wasn't a good copy so did it from scratch and a good old tea bag if anyone wants a copy to use I will send the file over by email might be similar to other models I would put it on here but dont no if you can
Mark |
7th Apr 2020, 8:53 am | #39 |
Heptode
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Re: Cossor 483
I was given this cossor that was left outside in a shed, it had a little woodworm from long ago but treated anyway, when I looked at the inside you could see the water had got to the plywood. After I took it all apart I split the bottom layers of plywood and re-glued and pressed, some bits was too poor to put back so I used a wood filler. After that had dried I paint stripped the wood that took all the burl wood pattern off leaving me with white wood and no grain. I painted it with a sealer then a light badge colour. Now I had to try to paint a burl wood finish this I did with different colour gel wood stain I spent many hours getting it to what I thought looked right after that had dried I varnished over the top of it all, then it was onto the electronics. I checked all the resistors which was not to far out so I left them. Next step was to change all the paper capacitors which i did do with the help of the forum members (Thanks to everyone). The wires had all gone brittle and I had to change them and sleeve some of the other single strand wires. I still need a on/off knob but I can use the long one I have for now. THANKS FOR EVERYBODY’S HELP
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7th Apr 2020, 9:15 am | #40 |
Nonode
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Re: Cossor 483
Great job, well done Mark.
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