Gents, the bottom line is to remember that the Bird is a 50+ year old instrument with 50+ year old technology (I used a Model 43 Bird servicing radios at Lockheed while in college in the mid 1950's - the same instrument many Hams covet today).
There is nothing "magic" about the Bird. It was *great* in 1950 but it's simply not as good or no better than many wattmeters on the market today using modern technology, even when it's freshly calibrated. And the quickest way to screw up the calibration is to bang the slugs around in a box. Those robust "hardware"-looking slugs are the most sensitive part of the instrument. In the original Birds, they traveled in a well padded enclosure with a little well for each slug (and the meter has two wells for additional slugs). Even so they were recalibrated *every year* to maintain accuracy. But very precise power measurements are simply not important when looking at transmitter outputs, etc. (Unless you are trying to get the FCC engineer to recertify a transmitter, which I did several times a week on ships in the early 1990's. In that case, HIS Bird is what counts, nothing else, Hi!). For lower levels, such as 5 watts or less, the oscilloscope or peak reading voltmeter monitoring the RF voltage across an accurate dummy load is the best way to make more precise measurements. The Elecraft DL1 20-watt dummy load includes a peak reading RF detector that works with your DMM perfect for this. If you want to "roll our own" download the DL1 manual. It has the schematic of the peak reading detector and the formula to use to convert the readings into watts. Ron AC7AC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
