SoftRock RXTX Ensemble Transceiver Kit

[Jacek Radzikowski]

If someone wants to dig deeper into the mathematical side of SDR, Lyons'
"Complex, But Not Complicated" is a very good starting point.

jacek
kw4ep


On Mon, Mar 22, 2021 at 5:06 PM n4tlf <n4tlf at wb4jfi.com> wrote:

> 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.
>
> 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.
>
> 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.
>
> 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.
>
> 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.
>
> 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.
>
> 73, Terry, N4TLF
>
>
> On 3/22/2021 4:15 PM, Alex Fraser wrote:
>
> Has anyone had experience with one of these?  Building or hearsay reports
> appreciated...
> SoftRock RXTX Ensemble Transceiver Kit $89.00 The SoftRock RXTX Ensemble
> Transceiver Kit provides a 1 watt SDR transceiver that can be built for one
> of the following five band groups:
>
>
>    - 160m
>    - 80m/40m
>    - 40m/30m/20m
>    - 30m/20m/17m
>    - 15m/12m/10m
>
> This is the web site where you buy 'em
> http://fivedash.com/index.php?main_page=product_info&products_id=7
>
> There are links to the schematics on the above page.
>
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-- 
Given a choice between two theories, take the one which is funnier
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