[amsat-bb] Re: Icom 9100

Jonathan Guthrie ka8kpn at brokersys.com
Mon May 17 16:22:40 PDT 2010

Full duplex transceiver?

Back in the dim dawn of history, there used to be those who constructed 
transmitters that were separate from receivers.  Although constructing 
such a thing is beyond me, I would like to see someone create a device 
that was intended to feed the input of an upconverter.  I can already 
get general-coverage receivers at reasonable cost.  If I'm computer 
controlling one or the other of them, or both, there is no real 
advantage to having the in the same physical box.

I can understand why such a thing might be less than perfectly useful 
for those who want a portable station, but it would seem to me to be 
just fine for someone who wants to operate a fixed station.

On 05/17/2010 05:38 PM, tosca005 at umn.edu wrote:
> On May 16 2010, Sebastian wrote:
>> Perhaps others such as DEMI, will see this as an opportunity and come up
>> with alternatives?
> Well, keep in mind that DEMI's strength is in transverters, and what is
> hard to obtain for satellite operation from most common-place existing
> equipment is a full-duplex transceiver. I don't think that DEMI is likely
> to start building transceivers, but if you had a true full-duplex
> transceiver, they would have transverters available to upgrade the radio to
> the satellite bands needed.
> Here's a thought: buy two SoftRocks for a lot less than the price of the
> Flex 5000 -- one would be the v6.3Rx/Tx and the other could be the V9 Rx
> only. This would net you two independent receivers and one transmitter, and
> with clever wiring, selection of VHF&  up transverters, and maybe a little
> bit of software development, you could turn that into a software-defined
> radio that would be capable of full-duplex cross-band operation. (The V9 Rx
> would be the primary receiver, the receiver in the V6.3Rx/Tx would be
> "spare" or "extra" or even ignored.) You'd need to configure the
> transverters with "split IF", and use two coaxial relays to route the 28
> MHz SoftRock IF Rx and Tx separately to the correct receive and transmit
> transverters. A bit of innovation/homebrewing would be needed for
> convenient band-switching, since you would need to switch two different
> transverters into the correct "position" depending on the mode: V/U vs. U/V
> vs. V/S vs. U/S vs. L/S vs. L/U vs. whatever other modes you wanted to
> support. But 4 transverters (145, 435, 1269, and 2400 MHz) would give you
> lots of satellite modes. Oh, don't forget there are some birds with HF
> links and the SoftRock can do HF natively too...
> If only I had the time to work on such a thing...
> Ideally, the transverters would be dual frequency, so that you could tune
> to 432 terrestrial or 435 satellite; 1269 satellite or 1296 terrestrial;
> and 2304 terrestrial or 2400 satellite. Newer DEMI transverters with the
> synthesized LO board can be configured that way, at least on the higher
> bands. Then you'd have not only a kick-@$$ satellite system, but also an
> outstanding weak-signal terrestrial system.
> Unfortunately, DEMI is once again revamping their lineup of products. Of
> course, this is good for us who want the latest and best, but bad for us
> who want something right NOW. Prices and specs are a little bit harder to
> obtain from DEMI right now, but I expect that the wait will be worth it.
> 73 de W0JT
>> On May 15, 2010, at 9:43 PM, Michael Tondee wrote:
>>> I guess once I put the upcoming V/U module in my Flex 5000 I'll have
>>> that amount of money in it but I won't have had to spend it all at once
>>> and IMHO I'll have a markedly better radio. Also one that isn't outdated
>>> a day after I walk out of the store with it.
>>> On 5/15/2010 7:22 PM, Mik Forsythe wrote:
>>>> Just left Dayton a few hours ago. Icom said that it is basically a
>>>> 7600 and a 910. It is bigger than the 910. It was in a display case so
>>>> I can't tell you what the feel was like of the weight. Price is in the
>>>> $4,000.00 range so that will kill a lot of the satellite market if you
>>>> ask me.
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