These are sideband(s) wspr is (supposed) to be a qrppp system, but
with large signals then imd / synth noise / spurs will also decode
if there above the decoder threshold ..one of the problems associated
with data transmission as opposed to non complex cw - ook systems ..
where a pure carrier is keyed
the transmitter path has to be many db's better than for normal
voice ... may be from the sound card , as psu type problems usually
result in +/- sidebands x2 mains frequency , but if its switch mode
, then the relationship is not predictable
Unlikely to be the Rx + Ae as wspr is a mfsk system , If the agc
is set 'fast' then psk31 will show a higher imd due to envelope
compression , but will not alter wspr or ros-mf or hf
G..
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From: "IK1WVQ Mauro" <[email protected]>
Sent: Tuesday, November 20, 2012 9:58 PM
To: <[email protected]>
Subject: LF: strange "duplication" of DK7FC WSPR spots
Hi to all,
I see this strange behaviour of the DK7FC WSPR spots:
2136 -24 6.5 0.475614 0 DK7FC JN49 30
2136 1 6.5 0.475641 0 DK7FC JN49 30
2142 -27 6.5 0.475614 0 DK7FC JN49 30
2142 0 6.5 0.475641 0 DK7FC JN49 30
2148 -28 6.5 0.475614 0 DK7FC JN49 30
2148 -2 6.5 0.475641 0 DK7FC JN49 30
At each time slot I receive 2 spots, one strong (0 dB), and the other weak
(-27dB) ..
Is this an artifact of my receiver (RACALL 1792, ant. PA0RDT) ???
73 de Mauro IK1WVQ
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