Thermomillammeter: Constant use or tune-up only?

[stevef]

I have a very old Weston 500mA unit.  I think it may be the type with internal thermocouple.  I'd like to use it in a low-power CW transmitter.

Is it best to only use it for tuning-up and then bypass it during normal CW operation?  or is it harmless (to the meter) to leave it in the antenna lead always with the needle bouncing around?

Thanks,
Steve KK7UV

[k4kyv]

Leaving it in line all the time won't hurt it because of the needle bouncing around.  Chances are, the meter will be too sluggish to follow the keying, unlike what you normally see with the plate current milliammeter.

But ALWAYS disconnect it from the antenna whenever the station is not in use.  Otherwise it WILL eventually be destroyed by lightning.

[W7TFO]

Most TX with an ammeter in the output line are there all the time.

BC stations usually short the one at the antenna base 'case lightning tags it.

A cool old knife switch across yours might be just the thing, tho, to keep the movement from 'aging' too quickly.

73DG

[stevef]

Thanks Don and Dennis.