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 Previous: BPL NEWS - VIDEO AVAILABLE |  Next: NCVEC Committee Studying New Entry-Level License Class |
 Laurence Howell, KL1X, in his Anchorage ham shack. |
NEWINGTON, CT, Aug 7, 2003--An Alaska amateur has launched a beacon on 136 kHz under an FCC Part 5 experimental license. Laurence Howell, KL1X (ex-GM4DMA), reports his WD2XDW CW beacon from Anchorage (BP41xd) has been on the air in shakedown mode daily from 1500 to 0500 UTC at 137.77389 kHz. It will go live 24/7 starting August 9 at 0100 UTC. Howell ran the beacon all night for the first time August 5, checking for hot components and making sure the forced-air cooling for the MOSFET transmitter and toroidal inductors was sufficient.
"A lot of experimenters are still reeling after the recent refusal by the FCC to allow a 136-kHz allocation to the Amateur Service," Howell told ARRL. "This Part 5 license approval is most welcomed by the experimental community."
In a Report and Order in ET Docket 02-98, the FCC in May unexpectedly turned down ARRL's petition to grant 135.7 to 137.8 kHz to amateurs. In its denial, the FCC cited arguments put forth by power companies that amateur operation in the vicinity of 136 kHz might interfere with power line carrier (PLC) systems used by electrical utilities to control the power grid. The ARRL expressed its disappointment at the news, noting that several European countries already have LF allocations in the vicinity of 136 kHz.
The WD2XDW
beacon is being used for propagation experimentation within the
US and to check transpolar propagation to Europe on paths over the high Arctic.
It's transmitting very slow-speed
CW--so-called "QRSS" transmissions of one dit every six seconds--at up to 2 W
ERP.
 One view of the KL1X 136-kHz beacon antenna system. The vertical section of the LF antenna is 8-gauge stranded wire. An 80-foot tree supports the other end of three-wire top loading element. Three 45-meter wires also radiating for some 270 degrees around the tower. |
The beacon's antenna is a 32-meter (105 feet)
wire vertical with a capacity top hat, about 1 mH of base-loading inductance--a
14-inch diameter solenoid coil--and a killer ground system that covers several
acres. For starters, close in it has a 100-by-100 feet buried chicken wire mesh
complemented by 110 40-meter radials, four 25-meter radials with 8-foot ground
rods at the ends and four 4-meter radials with ground rods at the base. Rounding
out the ground system are four 550-meter radials--approximately a quarter
wavelength on 137 kHz--with ground rods at their ends.
 The other end of the beacon antenna capacity top hat, which consists of three pieces of 12-gauge wire, each 55 feet long. |
The homebrew transmitter, capable of 400 W output, will put 2 A of RF current into the antenna system, which--despite the extensive ground system--remains pretty lossy at LF. Howell says the fact that the antenna is "nested" in the midst of Kincaid Park forest contributes to additional losses. On the plus side, the site is on a spit that juts into Cook Inlet, so, as Howell put it, "the signal does have good possibilities."
While he's received no reports to date, he
expects his first to come from Steve McDonald, VE7SL, in British Columbia, some
2200 km to the south. Europe is more than 7000 km away, and, Howell says, "can
be a tortuous path through/under/over/around the Auroral Oval, twice or once
dependent on the state of the sun." Howell notes that Alaska is still in a
period of 24-hour daylight, but he expects things to heat up on LF in late
September or early October when openings to Europe may be possible.
Experimenters use software such as Argo
to "copy" the weak-signal LF transmissions.
 The WD2XDW beacon transmitter, opened up in the KL1X workshop for some bench testing. |
Howell said he hopes his beacon and "others in the pipeline" will promote a better understanding of complex propagation modes associated with what he termed "this fascinating part of the spectrum."
"New low-signal detection modes, algorithms, transmitting modes, aerial designs/results are making me--licensed since 1974--feel like a novice!" Howell said.
Howell's experimental license is good until
August 1, 2005. Just how long the WD2XDW LF
beacon will remain on the air from Alaska is up in the air, however. Howell
says his time in The Land of the Midnight Sun is drawing to a close, and he'll
either move back to the UK or elsewhere in the US. He says he hopes if he
remains in the US he'll be able to move the beacon with him to his new
location.
| Previous: BPL NEWS - VIDEO AVAILABLE | Next: NCVEC Committee Studying New Entry-Level License Class |
