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<p>I've built many of the Softrock kits, including this one
(starting around 2006 or so). Most of the ones I did were the
80/40 variety. These days, they are rather old SDR technology,
but still work. There may have been articles on them in back
issues of the AMRAD Newsletter. A Google search on Softrocks, QSD
SDR, etc should help.<br>
</p>
<p>This info is not precise, but it gives you an idea. While
Softrocks are an early SDR entry, most of the "better" SDRs these
days use direct sampling instead. The hardware is only half the
radio in this case, the software is just as (or maybe more)
important.<br>
</p>
<p>The Softrocks are a QSD/QSE design, the software on the connected
computer must be able to handle audio I/Q signals. An early
software was/is "Rocky" by Alex VE3NEA (I think). It was simple
but worked pretty well. There are a LOT of other SDR programs
that drive these QSD/QSE radios. PoweSDR (originally from Flex
Radio) is another popular SDR software package - among many.<br>
</p>
<p>The QSD (Quadrature Sampling Detector or Decoder) for receive
basically creates two audio frequency signals (I and Q) from the
RF carrier, which are 90 degrees out of phase, and requires the
software to combine them properly. The QSE (Quadrature Sampling
Encoder or Exciter) hardware does the reverse, it takes in audio
I/Q samples, and puts out a hopefully clean RF signal.</p>
<p>The main issue with QSDs and especially QSEs is that they must be
fine tuned so the I/Q signals are of exactly phased and amplitude
level combined to reduce images and carrier leakage. The Softrock
hardware is rather marginal on these problems. I would NOT plan
to run a Softrock rig into a high powered transmit amplifier, it
will be very marginal on both carrier leakage and multiple images,
possibly failing FCC rules.<br>
</p>
<p>For a more in-depth discussion of QSD/QSE hardware, look for a
series of four articles in QST in 2002/2003 or so, by Gerald
Youngblood of Flex Radio Systems (A Software Defined Radio For the
Masses). That's a good start.<br>
</p>
<p>73, Terry, N4TLF</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 3/22/2021 4:15 PM, Alex Fraser
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:66097a4e-b778-f67a-f13a-cd43072a7c1c@comcast.net">
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<font face="Comic Sans MS">Has anyone had experience with one of
these? Building or hearsay reports appreciated...</font><br>
<h1 id="productName" class="productGeneral">SoftRock RXTX Ensemble
Transceiver Kit</h1>
<h2 id="productPrices" class="productGeneral"> <span
class="productBasePrice">$89.00</span></h2>
The SoftRock RXTX Ensemble Transceiver Kit provides a 1 watt SDR
transceiver that can be built for one of the following five band
groups: <br>
<br>
<ul>
<li>160m</li>
<li>80m/40m</li>
<li>40m/30m/20m</li>
<li>30m/20m/17m</li>
<li>15m/12m/10m</li>
</ul>
<p>This is the web site where you buy 'em <a
moz-do-not-send="true"
href="http://fivedash.com/index.php?main_page=product_info&products_id=7">http://fivedash.com/index.php?main_page=product_info&products_id=7</a></p>
<p>There are links to the schematics on the above page.<br>
</p>
<br>
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