I found the schematic for an early HRO
(http://www.portabletubes.co.uk/sitefiles/hro1259.djvu), it seems the s
meter is in series with the plate circuit of the last IF stage, so it
measures the plate current. At maximum signal the plate current of that
stage must be close to zero to send the meter to the 60 over nine position.

MRe wrote:
"sparky" schreef in bericht
...
See this picture HR)-60

http://www.universal-radio.com/CATAL...xvr/HRO60.html

it has a meter with the zero on the left.

On Dec 21, 7:39 pm, Kenneth Scharf wrote:
sparky wrote:
Why is the meter 'zeroed' against the right peg, is it
broken?
Or did National design it that way because they had a
backwards meter
circuit that pulled full current with zero signal?
This is a backward meter by National. The meter deflects left
when
current flows.
The radio must have had a backwards meter amplifier then.
Weird.
Guess one could design a proper solid state amplifier to make
it work,
but you'd have to 'zero' the meter at full scale with no
signal.


The AR88 had also a meter with the zero left (when there was a
meter anyway, because many had no meter at all)
It measured the cathode current of one of the IF tubes. (Less
amplification/cathode current means more signal). That leads to
the
somewhat odd 'zero right' configuration

MRe PE1NQr