Topband: FT1000 S-meter Calibration

[EVonvaltie@aol.com]

There have been a few recent interesting discussions relating to S/N 
observations and calculations based upon S-meter readings. Let it be known 
that S-units are entirely arbitrary meter markings, serving some higher good 
mandated by the particular manufacturer of the radio in question.

The issue is hereby put to rest by means of a simply performed accurate 
calibration of the S meters on 2 FT1000MP's. I used a highly accurate 
calibrated signal source (HP 8920E) and checked the calibration on all bands; 
there was essentially no difference from band to band except for a few db 
overall offset on 160M.

As suspected the "value" of an S-unit varies from about 2db at s1+ to 10db at 
S10.
Hence, the only way to accurately use S-meter readings is by converting them 
to absolute dbm or dbv by means of this or a similar calibration chart.

I will send a copy of the calibration data to anyone upon email request.

Eric von Valtier K8LV