[BC] Rainstorm drowns out KSJS signal

[Thomas G. Osenkowsky]

> I always thought that a LOW RF ammeter reading meant FEW listeners...
> the higher the current, the more radios were drawing power....

I guess it's time for me to jump in here and help out.
I've probably been doing this job for a couple of
weeks longer than some of you so kindly permit me
to educate and explain.

Thermocouple RF ammeters will show an increase in
antenna or common point current with modulation.
This will be more evident on talk formats, especially
those with long pauses. FCC Rules require the current
be recorded without modulation.

If a transmitter is modulated 100% with a pure sine wave,
the antenna or common point current will increase 22.5%.
This is because the required modulator power is one-half
of the carrier power. Heavily processed music formats will
show a higher, sustained RF current due to the nature of the
modulation impressed on the carrier. This being said, even
though the antenna current appears greater, the field intensity
at carrier will remain the same. When properly tuned, a field 
intensity meter will measure carrier, not sideband FI.

There may be a larger number of listeners due to the increased
perceived loudness, but not due to increased coverage (field
intensity) given the higher antenna current. Delta RF ammeters
will show an increase or decrease in current which is due to
carrier amplitude regulation (formerly known as carrier shift)
and do not have the same characteristics as their thermocouple
brothers under modulated conditions.

Tom Osenkowsky, CPBE