[Milsurplus] minor correction/Fw: RF ammeters / BC442-A

[k2cby]

For what it's worth I bought some BC-442A thermocouples from Fair Radio
about 5 or 10 years ago and they were spec'd (if I recall correctly) at
0.750 RF Amp full scale.

In the BC-442A there is a ceramic cup with a powdered iron (no ferrites in
those days) core. The cup is about 1 inch in diameter. Outside the cup are
two one-turn loops isolated from one another and spaced about  1/2 inch
apart. One loop is in the antenna line. The other loop feeds the
thermocouple.

The reason for this rig - and it's a very sound one - is that thermocouples
blow out not only from over current but also because of an RF arc from one
side to ground.

 

Miles B. Anderson, K2CBY
16 Round Pond Lane
Sag Harbor, NY 11963
Tel.: (631) 725-4400
Fax.: (631) 725-2223
e-mail: k2cby at optonline.net