CAKE Notes Jan. 27, 2018

CAKE  Session Notes Jan 27  2018

Cap opened our session with the news that Dave Rank KO6RS had passd away. Dave was a renowned scientist and mentor to many. Ron knew him well and will pass on some details to be included in Short Skip.

The fine weather lifted the spirits of those attending our meeting, present were Reed N1WC, Kerry K3RRY, Eric KK6IZY, John AI6LY,Cap KE6AFE, Ray W6LPW, John N5HBN, Jim K9YC,Ward AE6TY and me Ron W6WO

The first topic was “Trees” just as featured in QST. Much discussion ensuued, too bad Tom KW6S wasn’t with us to relate the unsucessful effort to poke a vertical wire up about 60 ft in a redwwod tree without climbing it. It was interesting to learn why palm trees might be better than deciduous, one more reason for a beach side vacation. HI

As previously mentioned Kerry is deeplyinterested in the technologies involved with space exploration and how useful the books published by Haynes Workshop Manuals are.This lead to a general discussion on errosion of Tribal Knowlege as John N5HBN puts it.This is a subject of significant concern to our ASAT community due to uncertain launch dates and mission objectives.

John AI6LY described how he determined the Azinuth directionality of his 40m Yagi  by making audio recordings of received noise as he turned his antenna. This unusual approach produced excellent plots. I think we might use the HF beacons as world-wide signal sources for other bands

Jim K9YC showed the pair of high power baluns/transformers he has built. Baluns are cause celebre for Jim and we can rely on him in this field. Somone mentioned that transformers are complex components and tough to fully understand. Ron agreed entirely and commented this is rather odd because detailed equivalent circuits were developed in the 1930s.

Ron mentioned that he will read anything written on antennas by Jack Belrose VE2CV. A book entitled International Antenna Collection, Edited by Dr George Brown M5ACN contains an article by Jack entitled “A brief overviwew of the perfomance of wire aerials in their operating environments”. The book arrived from the ARRL on the very day that I gained the small tuneable loop antenna built by AC6KW. Now I fully admit my knowledge of such antennas is vanishingly close to zero, This being the case I found a section called “The Truth about Loops  by Professor Mike Underhill G3LHZ”. This was so irresitable I have yet to read  the item by VE2CV. I measured the AC6KW loop and found it tunes from 9.85 to 16.5 MHz with respecable SWR and could be used on 30m for WSPR and on 20m.

Loop full view

AC6KW Loop Antenna

Ward can always be relied on for challenging questions and today it was related to NEC, the Numerical Electromagnetic Code used in antenna modelling programs like EZNEC. Ward asked “can NEC give misleading answers and if so would this likely be due to the data it operated on or some inherent limitations in NEC itself” ? This is a tough one and deserves more than a casual response. I will dig into it and would like to hear other comments before offering my response.

Now temporarily saturated by Tribal Knowlege, no fake news here ! Please keep in mind we would like to visit places of interest including “open shack” invitations

73 Ron W6WO  BCNU  Feb 10

PS answers to my Quiz questions are 8mW for a NVIS ground path of 400 km and 5W for 20,000 km