[Skimmertalk] red pitaya, for real?

[Nathaniel A. Frissell]

Hi, W4KAZ.

As Pete says, I am also experimenting with the Red Pitaya as a skimmer. 
It works extremely well in software and is quite reliable. I've been 
running one at my house for a couple of months now, plugged directly 
into a shortened G5RV. It seems most sensitive to 20 and 40 m. I've 
recently moved back home, and I am in the process of redoing-my 
antennas, which are poor at best right now.

The pre-amp is probably a good choice. I am working with some students 
at NJIT, we are working on getting a better handle on characterizing 
receiver quality and identifying an effective (and cost-effective) 
antenna situation. This is likely going to be part of a senior capstone 
project for them, so I have good hopes we will be able to come up with a 
good result.

If you are able to purchase a Red Pitaya and have some interest in 
playing with the antennas and matching, I would encourage it! Please 
share what you find here.

73,

Nathaniel, W2NAF



On 08/31/2016 09:17 AM, Pete Smith N4ZR wrote:
>
> I have been experimenting with Red Pitaya(RP)  for several months now. 
> Using it with Pavel Demin's code, it interfaces quite nicely with CW 
> Skimserv, However, without a preamp, in my tests it shows markedly 
> reduced sensitivity above 7 MHz.  This may be due to impedance 
> mismatch - with an 11 dB Clifton preamp between the RP and the 
> antenna, HDSDR reports essentially flat response from 160 through 10 
> meters.  However, my signal source is supposed to be providing an S9 
> signal; the preamplified Red Pitaya only delivers an S7report on HDSDR.
>
> W2NAF and K8GU are also experimenting with RPs -I'm right at the 
> limits of my equipment and technical knowledge, while these guys are 
> PhDs working in research institutions.  I'm hoping they will have more 
> evaluation info for us.
>
> Meanwhile, I'm waiting anxiously for the SRL-2, the successor to the 
> QS1R, which is supposed to be ready relatively soon,. with better 
> performance than the QS1R at a price point around $500.  In the 
> meantime, if you want an interim solution, you might consider a 
> Softrock Ensemble II.  I tested one for several months, using a 
> band-hopping approach (with Skimscan-S by W3OA)..  It's not as good as 
> listening simultaneously on multiple bands, but the price is sure right.
>
> 73, Pete N4ZR
> Download the new N1MM Logger+ at
> <http://N1MM.hamdocs.com>. Check
> out the Reverse Beacon Network at
> <http://reversebeacon.net>, now
> spotting RTTY activity worldwide.
> For spots, please use your favorite
> "retail" DX cluster.
> On 8/30/2016 7:02 PM, kazeringue--- via Skimmertalk wrote:
>> Went out hunting info on possible new QS1R, and found Red Pitaya 
>> discussion.
>>
>> Is there a consensus yet on whether the Red Pitaya is a viable option 
>> as a skimmer?  I would very much like to dump the softrock option, 
>> keeping them running has become a chore.
>>
>> I'd not bug you about it, but the 250 is affordable, but currently 
>> non trivial.
>>
>> 73 de w4kaz
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>