See my test results of the K3EXREF: http://www.kl7uw.com/K3EXREF.htm
When installed and referenced to a good 10-MHz external source the TCXO will be periodically corrected in frequency to keep the K3 on frequency. The display on REF*CAL merely indicates the value the TCXO has been offset to keep the radio on frequency and is not the freq. error. You need to measure the RF frequency with an accurate freq. counter to measure that. I have a counter that is locked to a Rubidium good to +/- 5E-11 and the max error at 50-MHz was +2-Hz (2/50,000,000) The value displayed on REF*CAL will start at 49.380 and they shift over about 30-minutes as the TCXO heats and stabilizes. K3EXREF keeps the radio on freq throughout this warm-up. Without K3EXREF the radio would shift freq with the TCXO (within 1ppm = +/-1E-6). Before the K3EXREF was available you had the option to entering a fixed offset to correct frequency (which should be done after the TCXO has warmed up and stabilizes). The number displayed is a similar offset but now controlled periodically by the external reference source, keeping the K3 more accurate. 73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 50-1.1kw?, 144-1.4kw, 432-QRT, 1296-?, 3400-? DUBUS Magazine USA Rep [email protected] ====================================== ______________________________________________________________ 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
