[Amps] Bird wattmeter

[Paul Christensen]

> While we're on the subject of Wattmeters, Has anyone here had an
> opportunity to compare the Array Solutions PowerMaster with N8LP's
> LP-100 Digital Vector Wattmeter? If so, an objective comparison of the
> two would be interesting.

The LP-100 was designed with a special emphasis placed on the directional 
coupler in order to attain a very high degree of port directivity and 
isolation, and is an instrument that is capable of more than just VSWR and 
power monitoring: the LP-100 is capable of measuring complex Z where other 
wattmeters made for amateur applications cannot.

In terms of absolute accuracy for the vast majority of HF applications, 
nearly any wattmeter capable of reasonably flat frequency response over the 
desired measured range is wholly adequate to probably the 5-10% level -- and 
that includes the Bruene type of balanced bridge.  I cannot think of many 
power monitoring applications for amateur use which requires anything better 
than about 10% accuracy over the HF spectrum.

I own an LP-100, Array PowerMaster, Alpha 4510, and a Bird 43P.  Each reads 
probably within 5% of each other.  I also own the Radiocraft 3000Pro.  For 
an analog meter, it offers some unique features that the high-performance 
units don't.  The designer doesn't boast of its absolute accuracy and the 
coupler is nothing more than a Bruene bridge.  But of all the meters I have, 
it probably gives me the fastest indication of what's going out into (and 
back from) the antenna.

The digital bar graph wattmeters use an arbitrary scale that, to me, are not 
always as useful as watching a simple moving-coil meter with peak hold 
capabilities.

Paul, W9AC