[Lowfer] Selective Voltmeters

[John Reed]

"John D. Farr" wrote:

> Peter
> You can find manuals for most of the HP stuff. About the only complaint I've
> heard about any of them is the lack of noise blanking and agc.

With selective level voltmeters you'll have trouble with intermod from BC band
stations on the LF band.  If you're using a tuned antenna this won't be a
problem but with broadband antennas it will.  The newer HP models (3586) get
around this by looking at the broadband input and automatically switching
attenuators in to prevent intermod (unless you manually defeat this feature).
With the attenuator switched in sensitivity is lower.  If you have one of the
older HP models (312) you either need to add attenuation or a preselector when
using a broadband antenna.  I'm not familiar with any other models.  As far as I
know none of the selective voltmeters has a synthesized BFO.  This means that
for really accurate frequency control (WOLF, etc) the frequency will be off
some.

John Reed