Great to see the Defiant lit up Andrew, CRT looks good. ?
Marc
BVWS member
RSGB call sign 2E0VTN
Thanks all, yes the heater voltage and current was slightly too high so I have re-installed the 30 ohm resistor that I removed when I added the extra valve for the black level modification. The CRT heater voltage is now at 6.4 volts whereas it did peak as high as 7 depending upon mains variations.
The 30 ohm 5 watt resistor was re-installed along with it's tag-strip in the space below. This new CRT is a belter !
To understand the black art of electronics is to understand witchcraft. Andrew.
Arrgg!!!
Silly me didn't see page two of the story ? The result with the Mullard CRT is excellent, The Plessey chassis sets are very good and with the Mullard tube the set should last another 60 years too. Nice job indeed.
Cheers,
Trevor.
MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member
Lol, yes....it has been quite a story.
But now at long last, things are purrfect. By the way, 8 out of 10 owner's said their cat's prefer Mullard. ?
To understand the black art of electronics is to understand witchcraft. Andrew.
This now brings into question as to what I should do with the old CRT. Do I neck it and dump it, or hang onto it just in case someone starts up a re-gunning business? Hmm....could be waiting a long time though. No, it will be better out of the way. What is the point of hanging onto a useless lump of implosive glass?
To understand the black art of electronics is to understand witchcraft. Andrew.
Neck it and chuck it.
Might be good for a non working display set or even try the non destructive reactivation method, it works on some tubes but not always.
Cheers,
Trevor.
MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member
I have removed the base (I'll keep that), snipped the stem and let the air in. It'll be off to the rubbish dump soon.
To understand the black art of electronics is to understand witchcraft. Andrew.
Might be good for a non working display set or even try the non destructive reactivation method, it works on some tubes but not always.
I had tried every means known to man to breath life into the old CRT, but as can be read previously, it resulted in only a temporary stay of execution.
To understand the black art of electronics is to understand witchcraft. Andrew.
Well done Andrew, the results were worth the wait! The picture looks lovely.
It gives me hope that I may one day be lucky enough to find a CME1703 or AW43-88 to replace the necked one in the Ultra 17-70 I pulled from a skip in the next street last year.
Steve
Thanks Steve ?
I did have plans to look for a set on ebay that contained a suitable donor tube, but then the 43-80 popped up. It was a chance I couldn't miss, and for £25, was worth it. Of course it was a gamble to buy an untested tube, but I could hardly say no. The odd's were against me.... it was miles away, did it even have a vacuum, was the heater even intact....the list goes on. For once though, I was very fortunate.
I'm sure you will obtain a tube for the Ultra, just bide your time.... ?
To understand the black art of electronics is to understand witchcraft. Andrew.
I have reinstalled the chassis into the cabinet and the new CRT is quite at home. I think I can now say this set is finished and complete.
To understand the black art of electronics is to understand witchcraft. Andrew.
