[Elecraft] Power Measurement Instrument

[George, W5YR]

Sounds like Steve Weber's "RMS Power Meter" which he kitted a year or so
back. Excellent kit and meter . . .

73/72, George    
Amateur Radio W5YR -  the Yellow Rose of Texas
In the 57th year and it just keeps getting better!
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe
K2 #489      Icom IC-765 #2349     Icom IC-756 PRO  #2121


Ron D'Eau Claire wrote:
> 
> A less-expensive and much more versatile option to the OHR WM-2 is the
> nice r-f power meter described by Hayward, W7ZOI and Larkin, W7PUA, in
> the June 2001 issue of QST. It is based on the Analog Devices AD8307
> chip and looks like it can be built for under $50 using all new parts.
> I'm currently collecting the parts for mine, so I haven't built it yet.
> But every test instrument that Wes, W7ZOI, has described that I have
> built works exactly like he predicts. I am bringing it up now because I
> see a number of posts about power measurement options on the reflector.
> 
> It does NOT require any exotic gear to calibrate and, unlike most
> "commercial" watt meters and kits, allows measurements of very low
> powers. This meter will measure r-f  levels down to less than -70 dBm
> (that's less than 0.1 NANOwatt!) and up to +50 dBm (100 watts) and show
> a response flat within 1 dB to 500 MHz when built as shown.
> 
> As usual, Hayward includes a lot of information about test setups for
> using the device to test low-level oscillators, evaluate filters when
> used with a signal generator and for evaluating impedance matches in
> transmission lines. His "workshop" experiments showing how to use a new
> test instrument have always been a fun exercises of their own that have
> never failed to teach me something.
>