[pskmail] Re: RSID sensitivity and other topics

  • From: John Douyere <vk2eta@xxxxxxxxx>
  • To: pskmail@xxxxxxxxxxxxx
  • Date: Thu, 28 Jan 2010 10:49:16 +1100

Hi Rein,

This is good news. RSID is so critical to the speed adjustment
features of Pskmail.

Thor8 fits just in a minute of scan. For my server, when I had it in
THOR8 mode default, I set two minutes on the same frequency and set
the mode for the second minute to "XXXX" so that fldigi did not reset
the modem (and thereby clear the data it was receiving, which
otherwise defeated the purpose of the 2nd minute on the same mode).
Maybe that could be a change in the sever code: if same mode as
previous minute, don't send the dtring to Fldigi so that connections
accross scanning minutes can be completed. Maybe always send the mode
for the minute zero just to make sure.

I had very low s/n and QRMed/QRNed links ups with this mode. Extremely
sensitive and robust.

I had a go at the Winmor servers in Australia and it seems to be
working well. Very good control of the timing (one package), but seems
to have an ack packet every data packet or so plus more, so more or
less the same in turnaround time since timeouts are synchronous unlike
Pskmail.

Throughput on 80M NVIS/ground wave is around 500 bytes per minute with
bandwidth set at 1600Hz. Works fine with 500Hz BW too but probably
slower (I didn't check the speed).

So a good complement for me to access email services when going bush.

Not sure what the license cost will be for final version thought and
that could be an issue, but obviously less than a hardware modem.

Also, I posted the Pskmail "advertisement" a few days ago but only got
one question from an interested OM. I may need to make a few
presentations at club meetings around Sydney.

Regards,

John




On Thu, Jan 28, 2010 at 2:48 AM, Rein Couperus <rein@xxxxxxxxxxxx> wrote:
> I performed some tests to see how sensitive the RSID decoder is when 
> connecting in a slow mode.  method: wait until SM0RWO switches back to 
> PSK500R reduce power  and connect in the test mode, repeat until it does not 
> work anymore... The test path is 1500 km North-South, frequency 10147 kHz, 
> channel clear.  Here are this afternoon's results:  PSK125R: 1 Watt to 
> connect, RSID switching at 500 mW (block incomplete at 500 mW) MFSK32: 500 mW 
> to connect... RSID switched at 200 mW, (block incomplete at 200 mW) THOR22: 
>  2 Watts to connect  (RSID switched at 300 mW, block incomplete at 300 mW). 
>  This test was around 15:00 UTC, already getting dark in Stockholm...  The 
> server timing needs to be tweaked for the slow modes (MFSK16, THOR8),  timing 
> is too short at the moment.  Also, a connect request in THOR8 takes so long 
> the chance is big the server switches back to PSK500R  during the packet... 
>  Generally, to me it looks like the sensitivity is plenty, also for QRP work. 
>  73,  Rein PA0R     --
> http://pa0r.blogspirit.com
>
>

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  • » [pskmail] Re: RSID sensitivity and other topics - John Douyere