VK2XV's blog

Recapping on Frequency Accuracy
As you can see from previous entries in my blog I have been delving into why WSPR and ARGO report different audio frequencies with an error of 17Hz at 1500Hz.

If you look at my blogs below you will see I have been puzzled by a discrepancy between what ARGO and Spectran reports as the frequency of an audio tone supplied and what WSPR reports.

I have FINALLY figured out what is happening (I am sure others wiser than me already know this - but I didn't).

I believe the following database entries are bogus as they occurred during a period of severe mains line interference.

2008-12-24 21:36 O75YN 10.140273 -24 1 DM03 +20 0.100 VK2SRO QF56ik 12006 7460
2008-12-24 21:28 O89RRF 10.140174 +9 0 LK77 +47 50.119 VK2SRO QF56ik 11592 7203
2008-12-24 20:54 AF0DD 10.140256 -23 0 PL88 +23 0.200 VK2SRO QF56ik 7051 4381
2008-12-24 20:54 AC8KCS 10.140284 -17 0 JR94 +47 50.119 VK2SRO QF56ik 14141 8787

I have struck a puzzling thing here with regard to frequency calibration with WSPR.

I had got into the habit from my old VK2ZTO QRPpp days of calibrating frequency via WWV.

The process I would follow would be to:-

Having observed WSPR for a number of days (which of course qualifies me as an expert... ;-), I have noticed a puzzling thing. The decoding success does not correlate well with observed signal strength as observed on the trace (at least at this location).

That is, sometimes a very faint trace will decode well and often. But sometimes a strong signal decodes only occasionally (at this QTH ZL2FT is an example - but also other single-skip stations exhibit this as well).

Just when I thought it was a characteristic of strong local (<5000km), the same thing happened for further stations.

The screenshot is here...

http://vk2sro.djirra.com/temp/wspr/GW4BVE_decode.jpg

The orange circle/eclipses enclose the GW4BVE.

The green circles show faint traces of another station undecoded.

Note during the GW4BVE decode time slot (09:54) a jump in frequency from about 50 to about 66. This is not a jump at my end as the other traces show.

Curiously the freq. goes back to about in subsequent TXs...???

My first 17M decode.

Steve VK2SRO

Have been QRV on 30M for about 7 hours and as expected only 2 reports (both VK6DI) so far.

What I didn't expect is this....

2008-12-21 15:46 VK2SRO 10.140150 +4 0 QF56ik +27 0.501 VK2SRO QF56ik 0 0

Is this normal or am I doing something wrong ?

Checked for multiple instances/processes of WSPR on the two PCs running here and found only the one pair (GUI and Console Box) on one PC as expected.

Any clues ?

Steve VK2SRO