Air Force Research Laboratory Tracks Sporadic E

[ChrisSmolinski]

Researchers at the Air Force Research Laboratory (AFRL) in New Mexico have discovered a new way to track and characterize sporadic E, which occurs when large structures of dense plasma form naturally in the upper atmosphere. These plasma structures, which occur at mid-latitude locations around the world, can affect radio wave propagation in both positive and negative ways. VHF enthusiasts frequently take advantage of sporadic-E propagation (or E-skip) to work stations outside of their local area.

The new method, developed by Obenberger and collaborators at AFRL and the University of New Mexico, leverages unintentional RF emissions from power lines, and using broadband radio noise, they can map and track dense sporadic-E structures.

Full article: http://www.arrl.org/news/air-force-research-laboratory-tracks-sporadic-e

[RobRich]

Down into upper HF bands as well. Worked lots of great sporadiac E contacts back in my 11m operating days.

Also I remember when 10m was considered a "big deal" among amateurs. Tech license access. Lots of mobiles due to smaller antennas. Even numerous FM repeaters.

Sporadic E probably is the dominate form of 12m and 10m DX during the currently low sunspot cycle, too. Some amateur ops keep a CB or receiver tuned to 27025, 27385, 27555, etc. to keep tabs on possible upper HF openings, but sadly the adjoining amateur bands still often go neglected even when 11m is hopping with DX activity. Sigh.

I think we have before briefly discussed the topic, but are there any significant 11m (25670–26100) shortwave band broadcasters anymore?

Likewise I seem to remember mentioning previously if any pirates have seriously considered the 11m during sporadic E openings. Antennas requirements are certainly small enough for hit-and-run broadcasts, plus a compact yagi or moxon would be easy enough for additional directivity and gain. Just a few watts could cover hundreds of miles during an good opening.

I used to occasionally stumble across STL transmissions around 25000, but most HF-band STLs have long since been replaced with newer technologies. Been quite awhile since hearing one here.

Chris, thanks for the FYI on the research.

[ThaDood]

Well, here's a 11M / 10M list that I've ripped from someone. Maybe from Chris? Anyway, the Radio and TV station Auxiliary Stations are NBFM, but usually have a telephone-like quality. Still, about the closest to broadcasting in the 11M BC Band today. Hmmmm??? Wasn'r Mexico ding DRM experiment in the 11M BC Band?

A search of the FCC database reveals the following:
Frequency
29.790 MHz
29.770 MHz
29.750 MHz
29.730 MHz
29.710 MHz
27.860 MHz
27.765 MHz
27.655 MHz
27.635 MHz
27.615 MHz
27.555 MHz
27.530 MHz
27.510 MHz
27.490 MHz
27.470 MHz
27.450 MHz
27.430 MHz
25.870 -
26.470 MHz
25.990 MHz
25.950 MHz
25.910 MHz
25.320 MHz
25.300 MHz
25.280 MHz
25.260 MHz
25.240 MHz
25.220 MHz
25.200 MHz
25.180 MHz
25.160 MHz
Remarks
4 active licenses, including one repeater system belonging to Van Pool
Transportation (WQMA652)
4 active licenses, including one repeater system and one high power car service
dispatch system in New York City
4 active licenses, including two repeater systems and one high power school bus
dispatch system
1 active license (WQQX896)
6 active licenses, including a 1000w repeater system and several high power
forestry systems
0 active licenses, no previous (expired, canceled, etc) licenses found
0 active licenses, no previous (expired, canceled, etc) licenses found
0 active licenses, no previous (expired, canceled, etc) licenses found
0 active licenses, no previous (expired, canceled, etc) licenses found
0 active licenses, no previous (expired, canceled, etc) licenses found
0 active licenses, no previous (expired, canceled, etc) licenses found
3 active licenses, all less than 5 watts power output
2 active licenses, all less than 5 watts power output
63 active licenses, high power is authorized on this frequency
5 active licenses, specified for itinerant use only per FCC rules
5 active licenses, high power is authorized on this frequency
5 active licenses, high power is authorized on this frequency
Hundreds of Remote Broadcast Pickup licenses, often only used for short periods
3 active licenses, including WBAP-AM's STL on 25.99 MHz WQGY434
transmitting 300 watts
5 active licenses
3 active licenses, including WBAP-AM's STL on 25.91 MHz WQGY434
transmitting 300 watts
1 active license (WQVJ608)
2 active licenses, KA6935 and WPTN464
1 active license (WQVJ608)
1 active license (SHELL COMMUNICATIONS, INC callsign: KA6935)
1 active license (WQVJ608, also licensed for 25.28 MHz, 25.32 MHz, 27.45
MHz, 27.47 MHz)
1 active license (SHELL COMMUNICATIONS, INC callsign: KA6935) also
25.26, 25.30
0 active licenses
4 active oil company licenses, 1 marine HF-SSB shore station license
(WPTM574)
0 active licenses25.140 MHz
25.120 MHz
25.100 MHz
25.080 MHz
25.060 MHz
25.040 MHz
25.020 MHz
4 active licenses, all oil companies, all for mobile operations only
0 active licenses
5 active licenses, oil companies and spill response companies (base stations and
mobiles)
Same licenses as 25.040 MHz / 25040 kHz
5 active licenses, all oil companies, all for mobile operations only
4 active licenses, including Marine Spill Response Corp WNYA617
5 active licenses, all oil companies, all for mobile operations only