[hpsdr] PowerSDR + Ozy/Janus + Softrock TX/RX

[Joe - AB1DO]

Hi Don,

Here goes an attempt to help you along [comments in line]. Off the bat I 
will say that I am not very familiar with the SoftRock, totally unfamiliar 
with the TxRx version and very familiar with PowerSDR as used with the 
SDR-1000.

Hope this helps,
73 de Joe - AB1DO

Don Kay wrote:


> Hello hpsdr!
>
> I am using  Ozy & Janus  with my 80/40 meter Softrock TXRX 6.1 and I have
> been having a blast, but I have accumulated a few questions on the
> operation of
> PowerSDR. Coming from the softrock persuasion I may need some hand holding
> from you SDR-1000 owners who are more familiar with  this software.
>
> First, the noise floor seems a little optimistic. The overall
> sensitivity is as good
> or better than when using my main sound card (a "Mia" budget pro-audio 
> card
> from Echo Audio) but the noise shows up at -175 db. I'm getting signals
> at 55 db
> above the noise which don't even budge the S-meter.  Is this expected
> with the
> current release?

[AB1DO] It is my understanding that the noise floor is not so much a 
function of PowerSDR as it is of the sound card. At Dayton Bob N4HY 
mentioned that he has experienced a 40dB noise floor improvement with Janus 
over the Delta-44, i.e.within a few dB of the quantum limit! The caveat: 
currently the SDR-1000 delivers so much gain (it was originally designed for 
consumer sound cards), that Janus needs an attenuator in line to handle the 
signal. On arrival from TAPR, the corresponding jumper is set such that this 
attenuator is in-line. This amp/attenuator chain destroys to a degree the 
noise performance. By removing the amplifier and attenuator the improvement 
is around said 40dB. Not being familiar with the SoftRock, you may be 
experiencing some of this. Janus is indeed truly spectacular.

>
> Second, how do I run digital modes? I have tried experimenting with VAC 
> and
> both Hamscope and  Multipsk but all I've succeeded in doing is locking up 
> my
> computer so badly I have to power cycle it. I imagine this is a knobs
> problem but
> I have looked through the production PowerSDR manual and it doesn't
> cover the
> subject very well. Is there some documentation specific to digital modes
> somewhere?
>

[AB1DO] IMHO digital mode operation is described in detail in the manual on 
pages 144-165. If you go to the Knowledge Base on the Flex-Radio website and 
search for digital modes, psk, rtty, vac or some such you will be able to 
find more info on operating digital modes with the SDR-1000. Try first 
setting up one of the digital programs described in either the manual or one 
of the articles. If that works, then try Hamscope or Multipsk. Also, if you 
can be a little more specific about exactly what goes wrong, that might 
help.

> Third, the softrock needs a PTT input from the computer as well as the I/Q
> in order to transmit. Normally the "Rocky" software  for the softrocks 
> will
> assert a PTT *output* to the softrock whenever the keyer is activated. I
> don't
> see any mention of a PTT output from Janus/Ozy mentioned in the manual, 
> just
> inputs. Is a PTT output available?

[AB1DO] Don't know if the Ozy has a PTT output, nor if the FPGA firmware 
will invoke one at this stage. However, you might try using your keyer as 
described in pages 138-139 of the manual and see if this helps (also see 
pages 92-94).

>
> I hope you are all enjoying these boards as much as I am. Thanks in
> advance for
> any advice.
>
> 73 - Don (ki6fom)


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