[Microwave] Rigs that have all mixer injection frequencies derived from a master oscillator

[Dr. Gerald N. Johnson]

On Mon, 2009-04-13 at 22:57 +1200, Dave Brown wrote:
>  I've been looking hard at the Icom 706 recently as it has 1 Hz dial 
> resolution and all mixing frequencies are locked/derived from a 30 MHz 
> master oscillator that can be externally sourced and GPS referenced 
> etc very easily.
>  See this-
> 
> http://g4hup.com/FC/DFS30/DFS30.htm
> 
> The 706 also has the advantage it is getting cheaper all the time as 
> its now no longer current at Icom-although I expect there's still a 
> few new ones available.

I like the FT-857(D). The DSP isn't great though. The optional
mechanical filter for CW enhances weak signals, the DSP doesn't. It also
derives most all frequencies from a single module that is available as a
TCXO to give about 0.1 ppm, enough to meet US federal regulations for
CAP, MARS and other such services. I don't recall that the frequency is
one convenient to lock to a 10 MHz standard, but a synthesizer can take
care of that. Its not all that great a benefit to have the IF controlled
to 1 Hz when the transverter is wandering about kiloHertz or more.

I really like the way I can run CW with it in SSB mode, no stupid
frequency shifts, no mode shifts, just start sending (hard on sequencers
though), and the way that its noise blanker works. I've heard the 706
noise blanker is deficient.

And for two bands, it will compute the frequency offset and hold the
power down to under 4 watts, in transverter mode. Unfortunately reached
by a menu, not a front panel switch.

73, Jerry, K0CQ
>