HFU HF Underground
Loggings => Other => Topic started by: ChrisSmolinski on March 22, 2013, 1632 UTC
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A ditter network is a set of frequencies where a repeated CW "dit" is heard, in this case about every 3 seconds. It may be that one transmitter is used, that cycles through all the frequencies. The exact purpose of these is unknown, it could be for propagation monitoring.
Observed so far on:
10670
10830
10990
11150
11830
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The frequencies seem to have changed around 1700z:
The low frequencies are S9+ so I assume a location relatively near me.
4300
4360
4430
4640
4710
4780
4850
4920
4990
5060
5140
5220
5300
5380
5790
5880
6600
7100
7300
7400
7520
7640
They stopped at 1724z. This list is not complete, just what I could log before they stopped.
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Observed so far on:
10670
10830
10990
11150
11830
During the time period 1629z (first seen, may have been up before that) to 1644z the frequencies appear to have been (incomplete list, signal stopped before all were found):
7800 *
7920 *
8040 *
8160 *
8280 *
8400 * #
8530 *
8660 *
9050 * #
9190 *
9610
9900 *
10200 * #
10350 *
10510 * #
10670 #
10830 #
10990 #
11150 #
11490 #
11830 #
12190 #
ChrisSmol reported the frequencies from 10200 kHz and down, none of those could be heard here on the west coast. I only had the freqs from 10350 kHz and up.
Frequencies with asterisk ( * ) are the same frequencies as seen here on April 18 of 2012 for an identical signal. This is the signal SW-J and I had a discussion about concerning pulse width and multiple sources. The signal today had the same 3.0 sec spacing and approximately 64 msec pulse width. Frequencies with hashtag ( # ) are the same frequencies as seen on April 28, 2012 with the same signal. Both previous dates more frequencies were found above and below the freqs listed here, but the signal was up for over an hour so there was more time to hunt for them.
Note the reuse of some frequencies, such as 9050 kHz, by several pulse/dit/pip signals, not just the one discussed here.
T!
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The frequencies seem to have changed around 1700z:
During this time period no dits were heard at my location on any freq. I tried a couple of spot freqs as Chris reported them and then concentrated on freqs from 10000 kHz up. I got up to about the 15500 kHz area before Chris reported the signal off, and I never saw a thing during my search.
T!