There does not seem to be much in it but overall maybe Opera has the advange
because it is more easily generated by a simple old CW TX
keyed on/off
Meanwhile I will stick with CW or in some circumstances QRSS at the faster
speeds ie 3 - 10
G3KEV
----- Original Message -----
From: "wolf_dl4yhf" <[email protected]>
To: <[email protected]>
Sent: Thursday, October 25, 2012 9:20 AM
Subject: Re: LF: WSPR vs. Opera
> Hello Jay and John,
>
> Thanks for the detailed, and carefully laid-out test. Very interesting
> reading.
>
> IMHO Opera was a bit over-hyped in the beginning, making claims which
> were not justified by *fair* on-air tests, and a test like yours
> (simultaneous transmission at equal power levels, using the the same RX
> and TX antennas) brings it back to reality. Testing one day (or even
> one hour) with one mode, and the next day (or hour) with another mode
> isn't fair considering changing conditions (diurnal effects, path loss,
> QRN, etc).
>
> All the best,
> Wolf .
>
> Am 25.10.2012 04:14, schrieb [email protected]:
> > Here is some further info for discussion on WSPR vs. OP.
> >
> > On 8/23/12 WD2XES and WD2XNS conducted a 'heads up' test of WSPR vs
> > OP4 on 136 kHz. The test started at 2230Z on 8/23/12 (in daylight),
> > continued throughout the night, and concluded at 1030Z on 8/24/12 (in
> > daylight). Conditions were normal for a summer evening with typical
> > amounts of static. Distance between XES and XNS is 72 miles.
> >
> > At the WD2XES transmitting end John combined both WSPR and OP4 signals
> > into a common phasing transmitter, amplifier and transmitting antenna.
> > Transmitted power levels were identical for each mode and very QRP -
> > 60 mW or less. WSPR and OP4 frequencies were within a kHz of each other.
> >
> > At the WD2XNS receiving end a common receiving antenna was used
> > feeding a single GPS disciplined receiver. Audio output from the
> > receiver was applied to a single sound card / computer setup which ran
> > an instance of each program.
> >
> > Results can be found at http://www.w1vd.com/WSPROP4082312A.pdf .
> >
> > Notes:
> >
> > 1) At 0230Z John made a significant reduction in transmitted power
> > level to better explore the weak signal performance of the two modes.
> > This produced the desired results with 'at the threshold' receptions
> > through 0420Z. No receptions were noted between 0420Z to 0902Z and
> > were probably due to an increased static level during that period.
> > Signals climbed back out of the noise again at 0902Z and reception
> > continued through the testing period.
> >
> > 2) The OP4 results were 'time shifted' to align with the corresponding
> > WSPR start times.
> >
> > 3) There are a few instances where the OP4 results are not spaced on
> > exactly 4 minute intervals ... this is likely caused by Opera
> > reporting 'slipping' into the following minute.
> >
> > Conclusion:
> >
> > WSPR has an advantage over OP4 in weak signal performance. Also, keep
> > in mind that WSPR requires half the amount of transmission time and
> > transmits more information. In our opinion, OP8 would be more in line
> > with WSPR in terms of weak signal performance. In that case WSPR gets
> > the job done in one fourth the time taken by OP8 and transmits more
> > information.
> >
> >
> > Jay W1VD WD2XNS WE2XGR/2
> > John W1TAG WD2XES WE2XGR/3
> >
> >
> >
> >
>
>
|
