[VHFcontesting] Another DEMI transverter question

[WBR/WF4R]

----- Original Message ----- 
From: <k4gun at comcast.net>
To: "VHF contesting list" <vhfcontesting at contesting.com>
Sent: Thursday, October 30, 2008 10:32 AM
Subject: [VHFcontesting] Another DEMI transverter question


>
>
> As long as others are asking newb questions about transverters, I figure 
> I'll throw mine into the mix as well. For the last two VHF contests, I've 
> been using a homebrew unit attached to my IC746Pro. It was set up by a 
> local club member and its worked fine while I've waited for my DEMI 
> 28-222HP transverter to come in.
>
>
>
> Well, its here now and I'm very excited to have 60 watts out and a modern 
> unit for the next contest. I'm also looking forward to running all 4 bands 
> off my IC7000 instead of having to turn around backwards in the rover to 
> operate 222. Everything seems pretty straight forward, but there was no 
> manual with the unit. I looked on the DEMI web site and found the manual 
> to the standard power model, but not the high power. I also read the 
> product description. I have to confess that much of it reads like 
> jibberish to my non-technical brain.
>
>
>
> Even with that, I have figured everything out except for two last 
> questions.
>
>
>
> 1. The product description seems to indicate that the drive power doesn't 
> matter all that much. Here's the quote: " On transmit, with the proper 
> options, any 28 MHz IF drive level from –20 dBm to 10 watts, will produce 
> +60 watts of output power." Is it really that non-specific? I don't have a 
> watt meter so I'd be quite pleased if I don't have to worry about the 
> drive power as long as its low.
>
DEMI makes a transverter interface kit (TIBK) that would solve the problem 
of power level input to the transverter.  What it does in effect is to 
provide a steady dc level to the ALC input of the IC-7000 thus limiting the 
power output.  The second thing that it does is allows you to hook up an HF 
or in your case a 6 meter antenna to the jack available on the T.I.B. and 
when you switch off  T.I.B.you will have the Antenna attached to the IC-7000 
instead of the transverter, and the PTT line will not key the transverter.

> 2. The IC7000 doesn't have an RCA jack for PTT-ground. I have the 14 pin 
> accessory plug that I have already wired a VHF PTT-ground for my 144 and 
> 432 amps. I will be making a wire to run from the HF PTT-ground for keying 
> this transverter. My question is which part of the RCA plug do I connect 
> that wire to? Pretty remedial question, I know, but I want to do this 
> right.
>

The actual control for PTT would be the center pin of the RCA plug, which 
becomes ground when keyed.

>
>
> Hmmm... I know I said there were only two questions, but while I'm at it, 
> let me make sure of one other issue. Because I'm going to be running both 
> 6 meters and the transverter off the same radio, how do I best handle the 
> PTT-ground? I will have the HF antenna line going to a switch that will 
> divide between my 6 meter antennas and the transverter. When I'm on 6 
> meters, will it hurt anything to leave the keying jack live to the 
> transverter? I had planned on installing a switch so it didn't key it when 
> I'm on 6 meters, but is that needed?
>
>
>
> 2. The IC7000 doesn't have an RCA jack for PTT-ground. I have the 14 pin 
> accessory plug that I have already wired a VHF PTT-ground for my 144 and 
> 432 amps. I will be making a wire to run from the HF PTT-ground for keying 
> this transverter. My question is which part of the RCA plug do I connect 
> that wire to? Pretty remedial question, I know, but I want to do this 
> right.
>
You may also want to check out getting the LDG Electronics RCA-14 breakout 
box for the IC-7000.  I got one and it's really great.  You don't need to 
keep making custom cable connections.  But I find that I have to keep a copy 
of the page from the ICOM handy for quick reference as to what jack is what 
function.

Good luck es 73, Bill, wf4r
>
>
> Hmmm... I know I said there were only two questions, but while I'm at it, 
> let me make sure of one other issue. Because I'm going to be running both 
> 6 meters and the transverter off the same radio, how do I best handle the 
> PTT-ground? I will have the HF antenna line going to a switch that will 
> divide between my 6 meter antennas and the transverter. When I'm on 6 
> meters, will it hurt anything to leave the keying jack live to the 
> transverter? I had planned on installing a switch so it didn't key it when 
> I'm on 6 meters, but is that needed?
>
>
>
> Oh... and so you know, the IC7000 will hold different power out levels for 
> different bands. I can set 10 meters to 10 watts out and 6 to the full 100 
> out.
>
>
>
> Thanks for any advice.
>
>
>
> Steve
>
> K4GUN/R
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