On 12/7/2011 1:20 PM, Merv Schweigert wrote: > I am sure that spark gap days are back, but no one mentioned the > gap was between the ears.
Well, actually yes. I have a couple of Coast Guard friends from Vietnam, and awhile back, one of them pointed me to a LORAN-C upgrade at some of the stations. The previous equipment was sort of standard OSC->PA architecture using BIG tubes. Many ran in the half-MW range, the station at George WA was originally 1.6 MW. After the "upgrade" it was running 1.2 MW. The upgrade replaced the TX with an Accufix TX from Megapulse. No tubes, no oscillators, no solid state amplifiers. A bank of SCR's discharged a large capacitor bank into a resonant circuit coupled to the antenna. [sound familiar?] Other than a large adjoining room filled with very high-tech control equipment, cesium clocks, and bunches of software, it was basically a 1.2 megawatt, well controlled spark gap. After the properly shaped pulse was formed, the rest of the damped wave was eliminated by a circuit aptly named The Tail Biter. Since the antenna was part of the resonant circuit, the control circuitry included an auto tuner that compensated for real-time antenna variations. LORAN-C was shut down a couple of years ago, but some of the antennas remain [mainly top-loaded monopoles]. I wonder if a KAT500 would be able to load one on 160m? 73, Fred K6DGW - Northern California Contest Club - CU in the 2012 Cal QSO Party 6-7 Oct 2012 - www.cqp.org ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
