Rich, Yes, you can buy an HP435A with sensors for big bucks, and you will have power measurement accuracy over a wide range. But there are other less expensive ways (homebrew) ---
Have you considered building an RF Power Meter? Take a look at the one published by Wes Hayward W7ZOI and Bob Larkin W7PUA in QST June 2001 (pg 38ff) and available in the Member's Only section of the ARRL website. There is additional updated information on Wes's website http://w7zoi.net/Power%20meter%20updates.pdf. That meter, properly constructed, will measure down to about -70 dBm and with the companion 40 dB power tap, it will measure up to 100 watts (+50 dBm). When calibrated it can provide very good accuracy. It does require two known signal levels to calibrate (the Elecraft XG1 or XG2 will provide that), and if the front end is well shielded (see Wes's updates) it will be accurate and if carefully constructed, it is good up to at least 200 MHz, more likely 500 MHz. An analog meter can give reasonable readout, but there is provision for attaching a DMM for more precision. This meter is not only good for measuring 1 mW, but even goes down to the nanowatt region. I like mine, and use it frequently. Use batteries mounted inside the enclosure, do not even think about powering such a sensitive instrument from an external supply if you want the isolation it needs for low level signals. The other good and convenient meter (actually computing SWR and power meter) is the Tandem Match - An Accurate Directional Wattmeter (originally published in QST January 1987), which is still a very good meter - without the coupler, it will measure power from -20 dBm (10 microW) to +32 dBm (1.5 watts) and with careful construction should be good to 500 MHz. With the coupler, its high frequency end is determined primarily by the coupler. This is an older design by Elecraft's own John Grebenkemper KI6WX (his call was KA3BLO at that time). FAR Circuits has boards, but I caution you on these boards - they do not have through plated holes and some traces need to have continuity from one side of the board to the other, so you must solder many components on both sides of the board (ask me how I know!). 73, Don W3FPR Richard Hill wrote: > I'm struggling to find a 1 mW to 5W capable RF power meter. I have a DL-1, > but think it is not useful at 1 mW. > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
