[VHFcontesting] Transverters for Dummies

[John D'Ausilio]

not enuf info .. the demi can be configured for common or split IF,
and common or split RF .. you don't mention if the relay is on the IF
side or the RF side .. and you'll probably have to go back to your
donor and ask if it's not evident from the connectors (or lack
thereof) .. then there's the question of what drive level it's set up
for, could be anything from 0dbm to some amount of power, again you'll
have to ask the donor ..

other than that, make sure that whatever signal you use for t/r to the
transverter comes up a few 10's of milliseconds before the IF output
comes up, or you can fry the IF relay (if it's high level) ..

de w1rt/john

On Thu, Jul 3, 2008 at 1:13 PM, Les Rayburn <les at highnoonfilm.com> wrote:
> Ok, I confess. Just prior to the VHF June Contest, local guru Jimmy Long, W4ZRZ loaned me a very nice Down East Microwave 2304-144 transverter. It's equipped with an SMA relay and already adapted for "N" connectors. He also supplied me with a nice long loop yagi for the 2.3ghz band. It was a wonderful gesture on his part. I stumbled through a "Thank you", but didn't have the guts to tell him that I didn't have a clue has to how to hook it up and make it work!
>
> I didn't have time to tackle the installation prior to the contest, but think I may find time this weekend. I've also since ordered a DEMI 222-28 transverter for use on the 222mhz band.
>
> My "plan" was to use both of these with an Icom 746Pro that is currently not being used for anything else. I'm going to mount the 2304-144 in the attic only about four feet from the antenna, hopefully allowing for most of it's 1 watt of power to make it into the air. The 222 transverter will be in the shack, feeding a Mirage 120 watt amp.
>
> I've downloaded the manuals for each from DEMI, and printed out their "Interfacing DEMI Transverters" section too. But truthfully it hasn't helped much....
>
> I know that I need to make a connection to the PTT line on the radio, most likely from the ACC port on the back, and feed them an RF drive signal. DEMI mentions that they make a "DEM Interface" that attenuates the 25 watt and separates transmit and receive lines for simple hook up.
>
> My definition of simple and theirs may vary.
>
> So, with hat firmly in hand, and red cheeks, I turn to you the collective exerts on all this. What the heck do I need to do in order make all this work without smoke testing anything! Is there a "transverters for dummies" guide on the web somewhere? Anyone else using a IC-746 as their transverter rig?
>
> Any and all help appreciated. Next time I promise to just confess immediately. Jimmy Long can be a pretty intimidating guy, in my defense!
>
> 73,
>
> Les Rayburn, N1LF
>
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> Les Rayburn, director
> High Noon Film
> 100 Centerview Drive Suite 111
> Birmingham, AL 35216-3748
> 205.824.8930
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