Re: [IRCA] SDR Receivers

[Guy Atkins <dx@xxxxxxxxxxxxx>]

Hi Mike,

I changed this thread title since it's not just about Perseus.

I considered the FDM DUO very seriously before deciding upon the KX3 a few
months ago. My main purpose is to use the rig as a very portable,
well-built, high performing and full featured *portable* receiver for the
Tropical Bands, and general SWLing while camping & traveling (plus home
use). I do not intend to use the KX3 in external mode for SDR-type spectrum
display and related features. I already have the FDM-S2 and SDR-Net for
that purpose.

BTW, the Elad USA shop has the FDM-S2 and FDM-S1 on sale for Columbus Day
until end of 10/14 (today!) for $529 and $299 respectively.

Some KX3 vs. FDM DUO deciding factors for me:

   - The KX3 was already available, tried and true, with a large following.
   The FDM-DUO is not yet USA-certified. The FDM-DUOr receiver version will
   follow the transceiver version...sometime.
   - I like the controls of the KX3 much more than the FDM DUO... the KX3
   has a great hands-on feel, and from the looks of the FDM-DUO it seems a bit
   "fiddly" and with too many menus. I have 3rd party protective side panel
   "handles" and Lexan cover accessories on the KX3, so it travels well.
   - I already have the extensive SDR features of the FDM-DUO in the
   FDM-S2, so no need to replicate.
   - The KX3 has a nice built-in Ni-Mh smart battery charger available; the
   FDM DUO needs external DC power.
   - If I ever want to put my ham call to use and try my hand at QRP, the
   KX3 transmits up to 10 watts, versus the FDM DUO that maxes out at 5 watts.
   (Note that many hams recommend an upgraded heat sink to successfully use
   full power.)
   - The KX3 has superb performance specs as you've mentioned. It is among
   the top three on the respected Sherwood Engineering site's receiver test
   results, bested only by the $10,000 Hilberling PT-8000A transceiver, and
   the recently added FlexRadio 6700 ($7,500).
   - You can save $100 with a KX3 no-solder kit as I did.
   - The KX3 has a unique and useful "Pseudo Stereo" mode built-in; it
   makes for less fatiguing listening. (The same feature is found as a tool in
   the SDR-Radio V2 Console software also, for use with a variety of SDRs.)

I think the recovered audio with the KX3 sounds very good. The background
noise of the radio is quite low, and the sense I get of its low noise and
audio recovery reminds me of the AOR AR7030+, one of my favorite
traditional receivers. Too bad the KX3 doesn't have synchronous AM
detection but with 1 Hz tuning resolution for ECSS I don't miss it.

BTW, the Elecraft options I have on my KX3 are the Ni-Mh battery holder
with internal smart charger, the dual-passband roofing filters option, and
the automatic antenna tuner (the tuner is actually useful outside the ham
bands and on MW-- see Thomas Witherspoon's nice KX3 review from a SWLing
perspective: http://tinyurl.com/oc7pnzd

I haven't experienced what you commented on, that noise reduction sounds
better with a more powerful host computer. However, there are definitely
variations in NR approach that makes a difference. I like the choice of
three different NR algorithms in Simon Brown's SDR-Radio V2 Console
software.

Speaking of NR tools, the KX3's internal NR feature sounds quite good to
me. It think it takes a back seat to the NR products of BHI Ltd. in the UK,
however. Their little noise reduction module & keypad kit (NEDSP-1061 KBD) is
well worth the $139 cost from www.w4rt.com. I have one of these installed
in an Eton E1XM between the product detector and amplifer. It is really
excellent for improving audio intelligibility with less of the echo-y
artifacts found in competing products. The BHI Ltd.'s technology is
available in external speaker products, too. In the USA, GAP Antennas
rebrands the BHI devices as the "GAP Hear-It" speaker.

Lastly, I have information on bypassing the KX3's BCB filter but I've not
gotten around to doing that. The signal path needs rerouting around a few
components, and a DC-blocking capacitor gets added on. I'm sure it's SMD
work, but I have some background in that. From what I can tell, the KX3
should have very good performance on MW once the BCB filter is bypassed.

73,
Guy Atkins
Puyallup, WA


> ---------- Forwarded message ----------
> From: Mike Bates <mjbates@xxxxxxxxxxxx>
> To: <irca@xxxxxxxxxxxxxxxx>
> Cc:
> Date: Mon, 13 Oct 2014 18:11:25 -0500
> Subject: Re: [IRCA] Or get a Perseus...
> Hi Guy,
>
> Thanks for the info on the cost of the FDM DUOr, I have not seen anything
> on
> their website yet., I have been watching. I am presuming then that it will
> show up on the website at some point. It may be best to use the FDM S2 and
> something like the Tmate 2 for those who want a more traditional operating
> feel. They show the Tmate 2 on their website for $288.00 ($278.00 on sale
> now)
>
> How is the KX3 as a Mediumwave receiver? I have not heard much about that
> part of it. Everyone raves about them. I believe that the overloading is
> probably better than the ELAD, I would be interested in how good the
> recovered audio is for a given bandwidth in the KX3. From what I have
> gathered, the recovered audio is best with a high powered PC (i5 or i7
> processor). Most of the stand alone ham transceivers don't seem to have
> enough processing oomph to get Noise reduction right. I notice a fair
> difference between my old AMD dual core circa 2006 and my new i7 (most
> recent generation). There is less distortion to the noise reduction. (same
> program). Many ham rigs sound like you are under water when adding noise
> reduction. I would  agree that the resale market for a KX3 will be high. I
> also think that the FDM duo series may be popular with hams.
>
> 73,
> Mike Bates
> Inver Grove Heights, MN
>
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