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I'm an avid MW DX'er and longtime ham operator. Some time back, I developed an interest in longwave listening. I never knew low power navigational beacons had the ability to travel so far! Many of these only run 25-watts and travel a thousand or more miles at night under good condition. It was fascinating for awhile, but the ham bug has once again bit, and I recently bought a pristine Yaesu FT-1000D transceiver....so frankly, I need money! Anything radio related that is not being regularly used will be sold here over the next couple of weeks. This includes this excellent longwave antenna. The L-400B is an active e-field antenna for the longwave band. It employs a high-gain preamplifier built into the approximately 2' long antenna probe. There is also a filter that greatly attenuates frequencies above 560Khz to avoid overload from strong MW stations. Power for the antenna is provided by two 9V batteries fitted inside the little control box that is situated in the shack. The 50' of mini coax provides both signal and power for the preamp. The unit requires no tuning. The antenna probe mounts on a mast with a simple compression clamp. The gain of this antenna is tremendous. In fact, I found it had too much gain, especially when mounted high and in the clear. The gain is perfect for VLF. For example, I can receive WWVB quite well and also in the "lowfer" experimental frequencies around 190Khz. Above about 250Khz, the gain starts to become excessive unless the antenna is mounted low. I built the simple LF Engineering-recommended 20dB attenuation, which plugs inline between the control box and receiver. This attenuator tamed down this hot preamp and the result is an excellent performing LW antenna that beats the pant off any homebrew loop I've tried. With this antenna, I've logged dozens of very low power non-directional beacons as far away as northern Manitoba and Ontario, as well as some 400-watt NDB's in Florida, Puerto Rico, etc. Some of my loggings were published in the January 2007 issue of Monitoring Times, in the "Below 500Khz" column using this antenna and a Drake R8B receiver. The antenna was purchased new in October 2006 and installed in early November. It was removed this month and still looks nearly new. There is some minor checking in the neoprene sleeve which cushions between the antenna and mast. Otherwise, the antenna is in excellent condition and performs as new. Complete details and specifications may be easily found on the LF Engineering website. Includes the antenna complete with approximately 50' of mini coaxial cable, all supplied accessories including the control box, wall-wart power supply for the control box (never used), two mounting compression clamps, 20dB attenuator unit, patch cable to run from control box to receiver (or attenuator to receiver) terminated with a PL-259 connector and instruction manual. (Lf engineering l-400B longwave lw active antenna was posted and is owned by: Saundra Gibbs) |
S-gibbs@chicagopartsnetwork.com (Saundra Gibbs) for more information.
