[AMRadio] Simpson 260

[Mike Sawyer]

Charlie,
	I am an instrument guy by trade but I haven't worked on any meters
in a very long time. If I were a betting man, I would say that you may have
a turn on the meter coil shorted. Since it is the same amount throughout the
voltage ranges. I am curious to see if it reads current the same way. I
would suspect not and thereby focused on the coil. It's rare that it happens
but that doesn't mean it won't.
Gud luck.

Mod-U-Lator,
Mike(y)/W3SLK



-----Original Message-----
From: amradio-bounces at mailman.qth.net
[mailto:amradio-bounces at mailman.qth.net] On Behalf Of CL in NC via AMRadio
Sent: Tuesday, July 24, 2018 7:18 PM
To: amradio at mailman.qth.net
Subject: Re: [AMRadio] Simpson 260

Thanks for the input from several of you.  As I mentioned, it is not the
electronics of the Simpson meter, the shunts, resistors, etc, this is a
meter movement issue, and I'm just feeding 250MV directly to the removed
meter and not getting the required full scale indication.  You can simulate
this by putting 250MV into the common and 50ua/250MV jack and the range
switch in any position except ohms, but that has the 200K shunt resistor and
the 5K series resistor in the circuit and I wanted to eliminate those as an
issue, so disconnected the whole meter movement.  I did email Simpson and
they said they hadn't made this meter in 40 years, had no parts,  and no
longer serviced it.  Got one interesting suggestion that the magnet might
have weakened over the years, maybe by being near an AC field, but my Eico,
Conar, Heathkit, Lafayette, and Triplett meters have all been right there
with it and they still work fine.  Glad to see the 30 volt battery is still
available for the Triple
 tt, about $16 bucks, but beats 3 nine volters rattling around inside it.

Charlie 
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