Where the Birds got a great reputation as the "Standard" was that every time
an FCC engineer would show up on site with the FCC test equipment to check
the output power of a transmitter, he would be carrying a Bird.
And he was a lot 'easier going' if there was a discrepancy and the
maintenance tech drug out the station's Bird and showed that the discrepancy
was in the meters. I even had one FCC field engineer doing the annual
inspection on a ship tell me "Don't bother to change the output power. I'll
have this meter checked at the lab and give you a call if there's an issue."
That, and the incredible ruggedness of the Bird design has given them a
mystique all their own...
I have no idea how accurate they really are. As far as I'm concerned even a
20% error is meaningless in terms of range and signal strength in
communications equipment. I think the one I was hauling around on ships in
the early 1990s had a calibration sticker on it dated in the 1960's.
Ron AC7AC
--------------------------------------------------
Lab cal is done by puting power through it measured with a known standard.
Adjustment is done with pot acessable after prying off metal label. Check at
highest and lowest and in the middle somewere. Bird rates them at +/- 5%,
but I have yet to see one better than +/- 10%. They are great for rugged
outdoor use, and peaking signal, but no one I know relies on them for
precise measurements of power.
Roy AB7CE
NIST RF Lab Tech
_______________________________________________
Elecraft mailing list
Post to: [email protected]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com
