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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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23rd May 2020, 11:00 am | #41 |
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Re: Ferranti 925 mains lead
The link below is to Radio Constructor from 1966 containing a piece from the Dickie and Smith sagas and was kindly sent to me by Geoffk.
It has a uncanny relevance to the issues I have at the moment, starts from page 696. https://www.americanradiohistory.com...RC-1966-06.pdf |
23rd May 2020, 7:08 pm | #42 |
Heptode
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Re: Ferranti 925 mains lead
I note the circuit indicates 7V on mains and explains the anode & screen currents, shows the ballast resistors.
I liked reading that column. |
23rd May 2020, 7:10 pm | #43 |
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Re: Ferranti 925 mains lead
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25th May 2020, 11:22 am | #44 |
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Re: Ferranti 925 mains lead
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26th May 2020, 2:17 pm | #45 |
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Re: Ferranti 925 mains lead
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26th May 2020, 3:06 pm | #46 |
Dekatron
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Re: Ferranti 925 mains lead
It should be alright if you can't get a 33uF, an important thing to remember is selecting a suitable value (and wattage rating) for the silicon rectifiers limiter resistor, according to the valve data the voltage across the filament chain should be approx. 7 volts if everything's ok.
Lawrence. |
26th May 2020, 3:42 pm | #47 |
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Re: Ferranti 925 mains lead
Thanks for the reply. I try to get everything from rs, but every thing I want is on back
order at the moment due to the circumstances we are in and I don't really want to start getting cheap and nasty components. I have some 47uf 450v nichicons here that were too big to use for restuffing on a grundig so Its good to know I can use these. I'll be careful with the limiter resistor. Back in post 34 you said that you thought that the voltage out of the rectifier was low, what should I have had out of that rectifier? poppydog |
26th May 2020, 3:57 pm | #48 |
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Re: Ferranti 925 mains lead
The Trader sheet quotes 100 volts across the reservoir capacitor.
Lawrence. |
26th May 2020, 4:05 pm | #49 |
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Re: Ferranti 925 mains lead
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31st May 2020, 5:21 pm | #50 |
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Re: Ferranti 925 mains lead
Regarding the voltages that I'm trying to measure at the moment, I'm measuring with my neg test lead connected to ground via chassis, It's not supposed to be via the neg of c24/25 is it as would r23 not affect my results??
poppydog |