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Old 5th Jan 2021, 6:59 pm   #24
em536716
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Join Date: Dec 2017
Location: South East London
Posts: 301
Default Re: My newly found Marconi 707

Here I am currently testing the EHT and trying to see if I can get a spot to appear on the tube. All bleeding resistors apart from one read open, surprisingly the rest in that chain are just under 1meg, so on the money!

I’ve also checked all my AC Volts apart from EHT, and seems fine.

Thankfully managed to repair the switch last night but called in to bed once I had realised I put it on backwards and was wondering why it still wasn’t coming on!

I’m having a little bit of trouble getting the right amount of EHT though. No where near 2KV but about 1.5KV at 230 and not able to get much of an indication on the Emiscope tube face either.

R86 which feeds the Anode of the CRT states a value of .15m, and R59 feeds C76 from C77. What does M mean, meg? Not quite familiar with reading values written out like this, or confident with reading such old resistors!

R86 reads over 2megs, which doesn’t appear right to me.

As I’m writing this, I decided to ramp it up on the veriac again, a lot less voltage this time... I think my EHT rect might have failed. More to follow soon.
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