Two BRC 2000 CTVs needing attention.

[radioman]

I always keep speakers out of scrapped equipment, be that TV's, radios, cars etc. - especially given the difficulty of finding suitable new replacements....plus it saves money  
Regarding the auto-transformer idea for impedance matching, would the tapped secondary of a 100V line type work or is the inductance too low ?

Andy

[Refugee]

I always keep speakers out of scrapped equipment, be that TV's, radios, cars etc. - especially given the difficulty of finding suitable new replacements....plus it saves money  
Regarding the auto-transformer idea for impedance matching, would the tapped secondary of a 100V line type work or is the inductance too low ?

Andy

There might be a small capacayive effect from the primary on a 100V line transformer.
I should not make that much difference though.

[ppppenguin]

The problem with using a 100V line TX (or a mains TX for that matter) is the high voltages that will appear on the original primary. Not nice. OK for a quick test, but I'd rather not leave it like that.

[Geordie McBoyne]

EHT problems in the Marconi 4701, it's too high and can't be adjusted. Tried the EHT tripler unit from the Ferguson 3700 and that one is useless, no EHT. As for the Marconi tripler, it's most likely the bleeder resistor in the tripler module has gone open circuit. Actually, the BRC 2000 circuit diagram shows the resistor as a VDR. Connects to the focus control and from the bottom end of focus pot to the base of the EHT voltage sensing transistor in the EHT generator module.

Geodie McBoyne.

[ppppenguin]

In theory the EHT tripler can be opened up and the VDR replaced with a string of VR37 or other high voltage resistors. No idea how hard that might be to do.