mike wrote:
David J. Windisch wrote:

(subj: Need Source for Diode in TS-1285/URM-120 Wattmeter 2-30 MHz
Plug-in
Sensor)

Hi, all concerned:

The diode looks like a 1N23-type, with cathode (arrow) toward tip.

Has marking ALPHA D4190A.

TIA & 73,

Dave, N3HE



The Sierra manual claims it's a silicon diode
Bomac BL-161.
mike


It is simply a 1N21 which has been selected so that the meter will read
full scale on the lowest range of the plug-in. I have found a suitable
replacement for one of my plug-ins by trying a number of diodes until a
full scale reading could be achieved. This will require recalibration
of the plug-in, which is not a trivial task, unless the wattmeter reads
correctly for a known power source.

Do not forget to wrap the diode with tape, per the instruction manual.

Bob, W6NBI