George, Jim, Where can we find George's work for these items ?? -Charlie N1RR
On Wed, May 24, 2023 at 5:06 AM Jim Brown <[email protected]> wrote: > George's work on this system is first class engineering, and has > revolutionized TopBand expeditions, allowing simultaneous use of the two > best small signal modes, CW and FT8, by expeditions transmitting high > power. He developed the system so that the expedition wouldn't miss the > one or two "magic" nights during a 2-3 week trip that generated most of > the QSOs. > > But that's a minor achievement in comparison to his Radio In A Box, that > greatly reduces the difficulty of activating islands and other locations > with extremely challenging access. Again, engineering at the highest > possible level. He's been field-testing both systems for contests from > his island in C6 for years, and is currently sailing through Oceania on > another field test. Radio in A Box could have turned that recently very > disappointing trip to a very challenging island into a howling success! > > George is one of those geniuses who live among us and have done so much > to advance the state of the art. I'd like to start a movement to > nominate him for the greatest award the ARRL and world ham radio has to > offer for technical achievement! > > 73, Jim K9YC > > On 5/23/2023 11:25 PM, GEORGE WALLNER wrote: > > I have built, for DXpedition use, a very selective RX front-end for 160 > > m for simultaneously operating CW and FT8 on shared TX and RX antennas > > with 800 feet of separation. The LC filter had 8 dB loss at 1825 kHz and > > it was about 10 dB down from that at 1840 kHz (-8dB at 1825 and -18dB at > > 1840). That is a 10 dB difference, which should be enough to prevent a > > good preamp from saturating. > > > > > > (I also built a XTAL filter that was 40 dB down, but only had a 2.5 kHz > > bandwidth -- OK for a DXpedition that can nominate its RX frequency.) > > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > -- -Charlie N1RR 401-742-7240 <(401)%20742-7240> 8AM - 9PM *E-mail*: [email protected] *Website*: www.n1rr.com *Youtube channel*: NovemberOne RomeoRomeo https://www.youtube.com/channel/UCPDzEf57Ad80cVKOiLZLB7w/videos _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
