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From: liz@poppyrecords.invalid.invalid (Liz Tuddenham)
Newsgroups: sci.electronics.repair,sci.electronics.design
Subject: Re: Francophones
Date: Sat, 21 Dec 2024 21:50:58 +0000
Organization: Poppy Records
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Cursitor Doom <cd@notformail.com> wrote:

> On Sat, 21 Dec 2024 21:31:51 +0100, Jeroen Belleman
> <jeroen@nospam.please> wrote:

[...
> 
> Thanks, Jeroen. Geez, you just can't win with these bastards. I've got
> a 50 ohm signal generator and a 70 ohm one - but that's not good
> enough for 'em. No, they want me to splash out on a 60 ohm one and
> where am I going to source one of those??

Use the 50 ohm one and add a 10 ohm resistor.to the connection.


> And it doesn't stop there! I thought all my vintage servicing voltage
> reading requirements would be met when I bought an old analogue Avo
> with 20kohms/volt. But now it seems I need to scratch around for a
> 500ohms/volt one.

Parallel a resistor across a modern10 megohm electronic multimeter - or
just shrug and say it won't make mucch difference.if the meter
resistance is a bit higher.

> It seems they're expecting whoever services these
> things to have access to an infinite range of test equipment to
> satisfy whatever whim the manual compiler for the equipment had at the
> time. <making overly theatrical gesture of despair>

I seem to remember Grundig made their own test equipment, so they
probably just quoted the specification of whatever they were using on
the production line at the time.  

A factory I worked in used interference from the fluorescent tube above
the workbench as the signal for the initial test of the audio stages.
One hand on the lamp and one finger on a screwdriver blade touching the
centre tag of the volume control - but I don't think they included that
test in the repair manual.

-- 
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk