[Elecraft] SW broadcast to calibrate against.

Dave G4AON elecraft at astromag.co.uk
Sun Jan 13 03:19:23 EST 2008


Calibrating one 1 ppm TCXO against another 1 ppm TCXO calibrator (for 
those with the optional extra K3 KTCXO3-1) would not be a good idea. In 
any event the calibrator is going to drift with time and need 
calibrating itself every year or so.

G4JNT published a 60 KHz off air frequency standard in the RSGB 
publication "RadCom" in April 1994 (Mk 1 version) and March 1996 (Mk 2 
version). I have used his Mk2 version for some years and it works well, 
admittedly it's only good to a short term stability of 1 part in 10^8 
but that's still 50 to 100 times more stable than the TCXO in a K3 you 
are trying to calibrate. Long term the stability matches that of the 
national standard being broadcast. Cost of building is minimal, even 
allowing for the box, switches, paint, etc. I would expect a lot of 
change from $80 or £40.

On eBay GPS and rubidium units appear from time to time, I bought a GPS 
unit part kit, built by the guy who later sold another one:

http://cgi.ebay.co.uk/GPS-10Mhz-FREQUENCY-STANDARD-COMPUTER_W0QQitemZ120166344327QQihZ002QQcategoryZ25399QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

He seems to like making GPS standards, so maybe worth dropping him an 
e-mail?

73 Dave, G4AON
K3/100 #80
-------------------

Rather than a BC station, how about a fairly accurate 10Mhz frequency 
standard like

http://www.aade.com/freqstd/freqstd.html

73 to all
Trevor G0KTN


More information about the Elecraft mailing list