[VHFcontesting] What separates a decent transverter from an awesome transverter?

[N1BUG]

One thing I didn't see on your list that always concerns me is LO
drift. Drift can be a problem for any weak signal work, say a long
haul CW sked during a contest. If you want to do some of the digital
modes it can become a critical issue, even a show stopper.

Since I can neither afford nor get my head around the complexities
of GPSDO locking, I am always concerned about crystal oscillator
drift in transverters. Usually I do the best I can to build and
install some type of crystal heater... with mixed results over the
years.

Sometimes I find things that surprise me. Last summer I measured
drift on two 1296 transverters: a relatively ancient UHF Units and a
relatively newer but not current generation DEMI, both as yet
unmodified. Over a temperature range that caused the DEMI to drift
over 6 kHz, the UHF Units moved just a bit over 200 Hz! I know which
one I will be using if I ever get the rest of the stuff together for
1296.

Paul N1BUG


On 04/24/2018 10:31 PM, Patrick Thomas wrote:
> Hey all,
> 
> Subject more or less says it all... I guess better sensitivity,
> lower noise, better selectivity, and better linearity are the
> essentials in vague and relative terms, but what attributes do
> you look for in a REALLY GOOD transverter?
> 
> Or for those who have gone further into making them... what
> components, construction techniques, etc., make a difference?
> 
> Partly this is a question I hear a lot and only have a vague
> notion of how to answer other than "obviously the expensive ones
> are better... somehow." :)
> 
> And partly it is a request for topics for self-guided
> study/experimentation as I attempt my own homebrew projects.
> 
> Many thanks,
> 
> Patrick - KB8DGC