jFarley,
For the short pulse ditter, as in the thread you started and I responded to, the answer is yes, the transmission sequence appears to go from low to high frequency. In addition to what I posted ChrisSmol showed images of this network doing this last year. (
http://www.radiohobbyist.org/blog/?p=1155 as well as posting here)
For the long pulse I am less sure, but it does appear to be doing the same thing, low to high frequency sequence. The issue on the long pulse is that I am almost positive I was hearing multiple networks, at least 2 of them on different frequency sets, and while they appeared to both be sequencing upwards it was hard to separate which frequencies, and time slots, belonged to which sets.
A lot of speculation below, trying to put together the picture in my head, based on several peoples past reports as well as my own observations:
I strongly believe, am sure in my own mind without a lot of proof other than common frequencies, that the short pulse ditters and the long pulse dashers are part of the same networks. If that is true then we have at least three pulse widths possible in this network; about 62 msec, about 125 msec, and about 1.5 seconds. I seem to remember having seen another width, also, maybe about 90 msec, I will have to look closer at my old recordings of similar signals. Also, we seem to have three (or more) pulse repetition intervals; 3.0 sec, 6.0 sec, and 10.5 sec. Sometimes we appear to have multiple networks (I think only 2) on one set of frequencies, and at other times they appear to be on separate sets of frequencies.
Assuming only one transmitter/frequency on the air at any given time (unproven), and assuming no overlap of pulses, then using the pulse width and pulse repetition interval we can calculate the maximum number of time slots in a network. For example the 1.5 sec / 10.5 sec version could have 7 time slots, and I have seen each of those 7 time slots filled with one empty (assumed I missed a freq). A 0.125 sec / 3.0 sec version (what I believe we might have seen in yesterdays 6 second version, two interleaved networks of 3 seconds) we would have room for 24 time slots. Or if only one network of 0.125 sec / 6.0 sec then it would be room for 48 time slots. And in a 0.0625 sec / 3.0 sec version we would have room for 48 time slots, unless it was 2 interleaved networks also, and then it would be two times 24 time slots.
Whatever it is appears to operate infrequently, often with months between noticed operations. It could be that people just miss it, or maybe it really does operate only in short burst with months between them.
This signal (assuming they are all related) is almost never reported outside the US.
A general bearing from my location (Mojave Desert, California) is East. A general bearing from a listener in the US north east was SW to S. As I suspect two sources I have no idea if my bearing and the other bearing are to the same source. Using remotes I have noticed if seems to be strongest on central USA remotes, like CO and MN, and this would generally support the bearings.
One other thing that I feel might be related to this network, but have absolutely no evidence to support. Some of the chirpsounders that sweep the HF band hit a few isolated frequencies with a pre-beep (just before the chirpsounder sweeps past a cw pip is sent). This pre-beep is about 62 msec long, about the same length as has been seen by this ditter network before. I do not have a complete list of frequencies that the chirpsounder pre-beeps, but I know some of them do it on 6750, 9050 and 15625 kHz, freqs that keep showing up on these ditter/dasher networks.
T!
Topic: Dasher network, multiple frequencies, June 16, 2013, from 0235 UTC on (Read 3783 times)