Hello-
I have a small qty. of NOS National Company S-meters from an old CB
shop. I
can furnish a JPEG on request, should have a few extra to sell. Can someone
help me in using these meters : The pointer resides at full scale, rather
than at the low scale as most meters. I guess you would say the meter
pointer is
"backwards", however the meter scale is normal { not "backwards"}. How would
you compensate for this in S-meter circuit?
Thanks, Byron, WA5THJ

Is it a NC57 Tuning Meter??? as shown at

http://www.io.com/~nielw/nat_list/SM57.HTM

Lionel VK4NS

Byron Tatum wrote:
Hello-
I have a small qty. of NOS National Company S-meters from an old CB
shop. I
can furnish a JPEG on request, should have a few extra to sell. Can someone
help me in using these meters : The pointer resides at full scale, rather
than at the low scale as most meters. I guess you would say the meter
pointer is
"backwards", however the meter scale is normal { not "backwards"}. How would
you compensate for this in S-meter circuit?
Thanks, Byron, WA5THJ

Is it a NC57 Tuning Meter??? as shown at

http://www.io.com/~nielw/nat_list/SM57.HTM

Lionel VK4NS

Byron Tatum wrote:
Hello-
I have a small qty. of NOS National Company S-meters from an old CB
shop. I
can furnish a JPEG on request, should have a few extra to sell. Can someone
help me in using these meters : The pointer resides at full scale, rather
than at the low scale as most meters. I guess you would say the meter
pointer is
"backwards", however the meter scale is normal { not "backwards"}. How would
you compensate for this in S-meter circuit?
Thanks, Byron, WA5THJ

The pointer resides at full scale, rather
than at the low scale as most meters. I guess you would say the meter
pointer is
"backwards", however the meter scale is normal { not "backwards"}. How
would you compensate for this in S-meter circuit?

If the meter simply reads the plate current of an RF, mixer, or IF tube
controlled by the AGC, then the stronger the signal, the less current, so the
meter needle will move right as the signal increases.

Almost every RX S-meter works off the tube current, but uses a resisotr bridge
to make the meter see *more* current as the signal decreases the plate current.

Just to muddy up the discussion, most classic Panasonic "canoe anchor" SW
portables have their S-meters actually read backwards -- strong signal pushes
the needle left! Whose idea that was, I'll never know, but the Japanese do
drive on the wrong side of the road (so why don't Racal sets read backwards too
:-) -- Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.

The pointer resides at full scale, rather
than at the low scale as most meters. I guess you would say the meter
pointer is
"backwards", however the meter scale is normal { not "backwards"}. How
would you compensate for this in S-meter circuit?

If the meter simply reads the plate current of an RF, mixer, or IF tube
controlled by the AGC, then the stronger the signal, the less current, so the
meter needle will move right as the signal increases.

Almost every RX S-meter works off the tube current, but uses a resisotr bridge
to make the meter see *more* current as the signal decreases the plate current.

Just to muddy up the discussion, most classic Panasonic "canoe anchor" SW
portables have their S-meters actually read backwards -- strong signal pushes
the needle left! Whose idea that was, I'll never know, but the Japanese do
drive on the wrong side of the road (so why don't Racal sets read backwards too
:-) -- Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.