[CQ-Contest] Re: 2-Radio Interference

[Tony Field]

> There actually is no 6 dB standard. Collins and Drake shot for 5
> dB, as does the FT1000 and most other rigs. All of them are horrid
> across the scale of the meter.

If I remember correctly, Collins invented the 6db per S-unit convention.  S9
(on a 50 ohm system) was supposed to be 100uv at the antenna or 50uv at the
input to the first receiver stage. Each S-unit was supposed to be a halving
of the voltage - i.e. S8 would be 50uv at the antenna.  Thus, each S-unit is
a 6db step.

The general rule that I have found is that S meters are relatively "linear"
between S8 and S9+60.  Unfortunately, the designers do not consider it
necessary to construct  a log amplifier for the rigs that will produce
reasonable results between s0 and s9.  I understand that designing a very
wide range log amplifier is a very difficult task.

tony field
field at nucleus.com
ve6yp at rac.ca
http://www.qsl.net/ve6yp
http://www.nucleus.com/~field


--
CQ-Contest on WWW:        http://lists.contesting.com/_cq-contest/
Administrative requests:  cq-contest-REQUEST at contesting.com