SoftRock RXTX Ensemble Transceiver Kit

[Alex Fraser]

It was the Scare Crow in the Wizard of Oz.  He spouted it off after he 
got his brain.

On 3/22/2021 5:44 PM, Jacek Radzikowski wrote:
> Aaaaand the forgotten link: https://dspguru.com/files/QuadSignals.pdf 
> <https://dspguru.com/files/QuadSignals.pdf>
>
> Jacek
> kw4ep
>
>
> On Mon, Mar 22, 2021 at 5:36 PM Jacek Radzikowski 
> <jacek.radzikowski at gmail.com <mailto:jacek.radzikowski at gmail.com>> wrote:
>
>     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
>     <mailto: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
>>         <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
>
>
>
> -- 
> Given a choice between two theories, take the one which is funnier
>
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