Happy Thanksgiving to those of you in the U.S.A.
It seems that the 630m
WSPR digital crowd is growing quickly, with more new stations showing up every evening on
the web's
WSPRnet activity page. Most nights see activity from 80 or more
stations, either transmitting or listening in WSPR mode on 630m!
WSPR is the
'Weak Signal Propagation Reporter' beacon-only mode being used by many of the
stations presently transmitting on 630m, especially the U.S. experimental
stations.
Those with the
WSPR software (freeware and easily installed)
usually have the program automatically upload their spots (stations being heard)
to the WSPRnet page so that the transmitting stations are able to see where
their signals are being heard. It also becomes quickly apparent, when examining
the various spots, just how good or bad propagation might be at any given
time.
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| WSPR Waterfall Displaying Detected Signals |
Since WSPR is a non-QSO mode, the ability to observe
propagation conditions, is its major feature. With transmission periods of just
under two-minutes, and a very narrow FSK data information stream, WSPR can dig
into the noise and copy signals that are often inaudible by ear ... some 15dB or
more, past the audible level. Of course, audible signals are also demodulated as
well, and will appear on your list of spotted stations, on the WSPRnet data
page.
If you choose, you can also see your spotted stations in a Map
mode, as shown at the top. This map shows the stations that I was hearing last
night on 630m.
Along with the call and grid locator of the
station being heard, the WSPR software also indicates several other bits of
information, including the signal-to-noise ratio as heard at your location.
Shown below is the decoded output from several stations following the two-minute
transmission period.
| 06:58 | WH2XXP | 0.475662 | -13 | 0 | DM33 | 5 | VE7SL | CN88iu | 1909 | |
| 06:58 | WG2XXM | 0.475709 | -6 | 0 | EM15lj | 5 | VE7SL | CN88iu | 2610 | |
| 06:58 | WG2XKA | 0.475723 | -9 | 0 | FN33lq | 1 | VE7SL | CN88iu | 3833 | |
Note the SNR reports ...
usually, signals stronger than around -14dB will be just detectable by ear with
anything in the + range being pretty strong.
Shown below are the Tuesday
night reports of local station, VE7CNF, and indicates the extensive area over
which his WSPR beacon was reported. Toby is running a modest 5W eirp station
from a suburban-sized lot. Analyzing the reports, it is apparent that many of
these stations rose to audible signal levels at various times throughout the
evening and would have probably been workable on normal CW mode ... even from
the 'burbs!
There are probably many of you already listening to WSPR
signals on HF and have yet to venture down to 630m to see what can be heard. The
improved propagation conditions of late make this an ideal time to have a peek
at 630m and see what you can spot.
Your low-band wire antennas can often hear
surprisingly well below the broadcast band and you may be surprised at what WSPR
can detect. Use the USB mode with your receiver set to 474.200 kHz and, if possible,
upload your 630m MF spots to the WSPRnet. You can also follow up-to-the-minute activity on the
2200m/630m ON4KST Chat page which is always interesting.