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Re: [VHFcontesting] Icom 756 Pro III-Transverter, and WSJT

To: Les Rayburn <les@highnoonfilm.com>, VHFcontesting@contesting.com
Subject: Re: [VHFcontesting] Icom 756 Pro III-Transverter, and WSJT
From: Tom Carney <tomc@carneysugai.com>
Date: Tue, 05 Aug 2008 18:50:22 -0700
List-post: <vhfcontesting@contesting.com">mailto:vhfcontesting@contesting.com>
Les Rayburn wrote:
> I'd like to operate WSJT on 222mhz during the upcoming Perseids peak on 
> August 12th. I'll be 
using an Elecraft 222 transverter along with a 120 watt brick amp.
> 
> During the recent ARRL UHF Contest, I successfully connected my Yaesu 
> FT-817ND to the 
transverter, and everything worked out great. The only problem is that 
the transverter makes use
of the ACC Port on the back of the radio, which would also need to be 
used by my soundcard
interface. Not a huge issue for that contest, as I simply ran SSB and 
hooked up a straight key for
CW operation.

I've used a XV-222 with a FT-100D and am assuming the connections are 
the same.  The FT-100D uses the ACC port for both Xmit/Rcv control and 
ALC.  One is on the tip, other on the ring of the stereo connector.  So 
you could make your own Y cable.  One end going to the XV-222 for 
xmit/recv switching, the other end for ALC.   I'm assuming the ALC 
voltage comes from the soundcard interface, is this correct?

On the other hand, I have the vague recollection that you don't need to 
use ALC for the WSJT modes.  If not, don't bother with it.  Certainly 
don't take my word for this, not an expert.
> 
> Now I'm wondering if my Icom 756 ProIII might be a better/easier solution. It 
> has a transverter 
output on the rear but the manual is very limited in details. I think 
everyone assumes that if you
know what a transverter is, then you must know how to hook things up! 
(ha, ha). My soundcard
interface is a US Interface Navigator unit, which has custom made cables 
to connect it to the Pro
III.
> 
As W9RAY points out, most transverter output are very low level.  The 
XV-222 has internal jumpers to configure it for from about 1mw to 5 
watts of drive.  I'd guess your is set for 5 watts if you used it 
successful with the FT-817.  You will need to open the top cover to make 
sure.  The manual can be download from the Elecraft site to check the 
jumpers settings.

> I'm currently using the ProII and interface to work WSJT on 6 Meters, so no 
> issues there. 

Assuming the XV-222 is jumpered for 5 watts input, another way to attack 
this problem is to set the 756 to 5 watts output and use the regular 
antenna connector instead of the transverter connector.  (I'm assuming 
you can do this, know you can with the 746).  It a bit dangerous because 
if you forget to set the 756 down to 5 watts, you will blow the input 
attenuator in the XV-222.

Another consideration with the XV-222, it's not rated for continuous 
service (like a WSJT) mode at 20 watts.  Might be OK due to the on-off 
cycle but I'd recommend you limit the power output to 10w.
> 
> So...any idea how the heck I go about this? Any help appreciated. Peak is in 
> about a week, so I 
need to get cracking!

Good luck.

73,

Tom  K6EU aka K6EU/R





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