[Hallicrafters] S meters

[Paul Galpin]

Ken wrote:.....

I have seen an "S" meter circuit that Hallicrafters published which
enabled one to add an "S" meter to Hallicrafters receivers which
normally came without one, such as the S-38.

However, the one thing that that bulletin did NOT mention clearly is that
the meter must be mounted upside down in order to both read
"correctly", and in order for the calibration procedure mentioned in the
bulletin to make sense.

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My SX16s both have a purpose made left-deflecting meter, i.e. zero current
is at the right-hand side. You could play around with the coil springs on a
standard meter to make it L-deflecting, but upside down might be a better
idea. Great fun can be had taking the scale off, scanning it in and
recreating it with the scale  upside down in an image programme like PSP.
This is also good for recreating old, cracked, or disfigured scales.

The basic circuit idea seems to be to connect one end of the meter to a
point whose dc voltage varies with signal strength (RF anode, IF anode,
cathodes, etc.) and a point of similar constant voltage which can be
accurately set to balance the meter at zero signal.

Paul Galpin
ZS2PG