[VHFcontesting] Transverters for Dummies

[Les Rayburn]

Ah...I see. On the back of the unit there is an SMA type relay RF Switch 
made by "Transeco".

It is labeled as:

Switch RF XMSN Line
Spot Fail Safe 28VDC

It has inputs labeled as:

1=NC (Normally Closed, I assume) In=C (Common?) 2=NO (Normally Open?)

The relay is on the RF side.

It is set up for 10 watts of drive from a 144mhz IF rig.

Does that help?

73,


Les Rayburn, director
High Noon Film
100 Centerview Drive Suite 111
Birmingham, AL 35216-3748
205.824.8930
205.824.8960 fax
205.253.4867 cell

--------------------------------------------------
From: "John D'Ausilio" <jdausilio at gmail.com>
Sent: Thursday, July 03, 2008 12:43 PM
To: "Les Rayburn" <les at highnoonfilm.com>
Cc: "VHF Contesting Reflector" <vhfcontesting at contesting.com>; 
<vhf at w6yx.stanford.edu>
Subject: Re: [VHFcontesting] Transverters for Dummies

> 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
>>
>>
>>
>>
>>
>>
>>
>> Les Rayburn, director
>> High Noon Film
>> 100 Centerview Drive Suite 111
>> Birmingham, AL 35216-3748
>> 205.824.8930
>> 205.824.8960 fax
>> 205.253.4867 cell
>> _______________________________________________
>> VHFcontesting mailing list
>> VHFcontesting at contesting.com
>> http://lists.contesting.com/mailman/listinfo/vhfcontesting
>>
>