[pskmail] Notes and questions related to last weekend's tests
- From: "John Douyere" <vk2eta@xxxxxxxxx>
- To: pskmail@xxxxxxxxxxxxx
- Date: Tue, 29 Jan 2008 11:22:19 +1100
Hello, I did some more experiments with Pskmail last weekend while camping
and here are my notes and questions:
1. PSK63 vs 125 vs 250: I found that again the faster speeds more than
compensate for the loss of sentivity in getting the packets across intact.
Maybe in low noise, low signal would PSK63 be better, but I haven't come
across this condition yet in practice.
2. DominoEx: I had another go at this mode with little success. I am
insisting with this mode because I still think that it should be good for
QRN (static crashes) conditions. Looking more closely at the issue, this
mode takes far longer than the PSK modes to synchonize. Typically my
client's fldigi would only get the synchronization right at the end of a
short packet (in DominoEx11 mode). Solution may be to improve the sync speed
in fldigi or alternatively add a sync string at the beggining like the old
"rrrrrr" just for this mode. Rein, any suggestions? I am happy to change and
test the code on the Pskmail side.
3. Some timing questions: when the client sends a packet and the server does
not receive it properly, the timeout seems very long (roughly 10 to 15
seconds). Since it takes no more than 1 or 2 seconds for the server to start
transmitting a frame would it be ok if the client waited say 4 seconds for
an <SOH> character and assumed no reply? I have tried to change the client's
timeout but it does not seem to alter this issue. Rein, how is this timeout
calculated and where can I find the logic in the code? Thanks.
4. I have updated my Mandriva distribution to the latest versions of Pskmail
client and server. All functions work but when I do a Getpos from the client
I get a "position unavailable" as a reply. I checked on findu and all the
positions are updated correctly both in unproto and connected mode. What am
I doing wrong? Where should I look for more detailed feedback on the server?
Otherwise had good success with this system. The CW filter I added last
week in my server does help with the city QRM. I managed to linkup to the
server on 40M with only the FT-817 bare at 5 watts with a dipole in the
trees at 4 meters above ground. Right up to PSK250 speed. QSB would affect 1
in 3 or 4 packets but it would get the job done at the end. Great stuff.
Regards,
John (VK2ETA)
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