SoftRock RXTX Ensemble Transceiver Kit

[Jacek Radzikowski]

Aaaaand the forgotten link: https://dspguru.com/files/QuadSignals.pdf

Jacek
kw4ep


On Mon, Mar 22, 2021 at 5:36 PM Jacek Radzikowski <
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> 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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Given a choice between two theories, take the one which is funnier
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