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

[Greg Mills]

Well here is a collection of thoughts, which turned into a rover list. Once you build two, it gets complicated.

A good sequencer, or at least a sequence of dekeying steps that protects the receiver.Transverters for all bands have the same interface connections. 
Easy way to hook up the external amplifiers.Good LNA's...linearity and NF. Not too much gain.Easy way to adjust for the LO and/or IF drive for different types of mixers. I made a little board for pi pads, or footprints in the mixer section at least.
Light weight 19" rack mount chassis.A controller than can easily switch between a stack of transverters, routing IF/power/key/antennas, etc.
5 years of building, testing, breaking, rebuilding, testing, burning down LNA's, etc. Then it might be ready.
A source of PVG-612 opto isolators.
Good antennas and accurately pointing them within a few degrees. This is as much work as the above.
Never use a switcher for anything. 
Ability to troubleshoot in the field. Make a troubleshooting guide, like a cheesy checklist, "set the onoff switch to the ON position".
A retired guy to also build stuff.
PLL LO's.
Machined surplus band pass filters. But... my 3 GHz transverter has printed filters, and the up/down converted spectrum looks terrible, but if we work someone on 2304, 3456 is just as easy. Bought the basics of it at the Rochester hamfest in 1998, via K2DH.
I designed the upconverters for 10 dB below P1dB, but the PA's are run at P1dB. 
Anything on the air is > nothing. Let it rip.

Greg - K2LDT/R


      From: Patrick Thomas <p-thomas at mindspring.com>
 To: VHF Contesting <vhfcontesting at contesting.com> 
 Sent: Tuesday, April 24, 2018 10:31 PM
 Subject: [VHFcontesting] What separates a decent transverter from an awesome transverter?
   
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
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