Jeffrey griffin <kb2m@...>

Hi Rob, always good information in your posts. Can you explain the differences, as you see it between the direct receivers from  Flex radio vs the Icoms? I have a Flex 6500 and on occasion use the  4 avaliable slices. I find them very useful. I don’t understand why the 7610 can receive only two separate signals. There must be a difference in how the direct receive frontend  is done by both manufactures. Do you have any input on this?


Oh, and to keep this on subject I also have a K3 I bought in 2007, I have upgraded to K3S specs, I would never sell…


73 Jeff kb2m


From: <> On Behalf Of Rob Sherwood
Sent: Saturday, May 04, 2019 12:59 PM
Subject: Re: [Elecraft-K3] SDR


From my perspective, the term SDR (software defined radio) today is virtually meaningless.  A K3S is a superhet down-conversion radio with lots of DSP software programming in the tail end of the radio.  The TS-890S is also a down-conversion superhet, but with a direct sampling bandscope and waterfall display.  It also has software programming that can be upgraded by a firmware flash.  The newly released FTdx-101D is a hybrid like the TS-890S. 


The Flex transceivers are direct sampling radios, as are the IC-7300, IC-7610 and IC-9700.  There is an embedded OS in the Icom radios and lots of firmware upgradable software. 


All the Apache radios are direct sampling, and some of the software is in the radio, but a lot of the processing is in the PC.


I am not a programmer, so I don’t know if it is possible to write code to run on Windows,  Apple and Linux platforms without separate binaries. 


If you are looking for an Elecraft “SDR”, I assume you are meaning a direct sampling radio.  Direct sampling has advantages and disadvantages.  Most of the time the architecture doesn’t matter much, but if you are operating Field Day, or have another ham a mile away, a down-conversion radio like the K3S will not overload nearly as easily as a direct sampling radio, if both stations are on the same band at the same time.  On the other hand, the contest DX K3S package is on sale for $5959.95, while an IC-7610 cost between $3000 and $3100.  The direct sampling radio has a cost advantage, and the hybrid TS-890S and FTdx-101D are both under $4000.  These are all great radios, but there are times with the K3S wins hands down.  (I am assuming the FTdx-101D will test out well, and I’ll know that in a week.)


73, Rob, NC0B




From: [] On Behalf Of N S via Groups.Io
Sent: Saturday, May 04, 2019 8:41 AM
Subject: [Elecraft-K3] SDR


I wonder if Elecraft is ever going to replace the K3S with a true SDR radio that provides the processing in the rig and uses the front controls and or a low power computer to interface with it.  Similar to what Flex is doing.  I would also like the PC software to be generic platform independent so that it can run on Windows, Mac, or Linux.  I'd love to see Elecraft join the competition or maybe even jump ahead of the SDR competition.  It would also be nice to have a SDR that was STABLE in the VHF/UHF bands, unlike the new Icom 9700 which drifts and can't seem to stay on frequency.

Just thinking out loud.....



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