Re: Getting indication of rf
Neil Smith G4DBN
A simple voltmeter works fine Ben, you can pull a milliamp without much impact, but a 20kohm/V movement is fine. I put the outputs from those at the masthead into a cheap PIC board with multiple analog to digital converters and send the values back over an RS485 link, but other folks use a multicore cable and send back the analogue voltages to the shack end.
If you can borrow a calibrated power meter, you can do a rough calibration of each of the detector outputs as measured by your meter setup. I have a lookup table in memory to convert the voltages to approx power, but a curve plotted on a bit of graph paper is just as good really.
There are also lots of decent single-rail opamps which will work
from rail to rail, but it isn't really worth the effort. A rotary
switch, some trimmer potentiometers and a 50 microamp meter would
On 04/06/2020 11:06, militaryoperator via groups.io wrote: