On 27 May 2011 15:21, Bob Camp <[email protected]> wrote: > Hi > > You also may want to avoid an oscillator with much 10 MHz content in it. All > sorts of odd things can happen with spurs when you have unplanned stuff on > the main reference. Another thing to look closely at is - how much of the > radio tracks the reference? On some radios, they don't really lock everything > up. You get better performance, but not quite what you would expect. > > Bob
Yes, a band-pass filter would seem sensible here. To the best of my knowledge, everything is locked to this 20 MHz, so there should be a significant improvement. However, I must admit as to wondering whether its worth the bother. I have a Yaesu FT-ONE, which is a pretty poor design, despite it was the top of the line Yaesu transceiver in its day (~1982) costing $3000. It has a synthesizer for 100 Hz steps and then uses a varicap diode to get the 10 Hz steps! This is not very stable, but in practice is stable enough. There's nothing much one can do about that - perhaps keeping the temperature constant in the vicinity of the varicap and other critical components would help. But it also suffers from the use of more than one reference, so hard to really stabilise. The Kenwood TS-940SAT should be a lot more stable anyway. The Kenwood actually seems a lot better technically to me, despite it costs only $2000 and was released about the same time as the Yause FT-ONE. The Kenwood TS-940S has a built in ATU (not even an option on the Yaesu FT-ONE), FM (optional on the Yaesu FT-ONE), TCXO (not even optional on the Yaesu). I might however look at using a TCXO o OCXO in the Kenwood. Dave _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
