Crawley Amateur Radio Club

This article first published in the CARC Newsletter of April 2000 remembers the pioneering work on LF done by Derek G3GRO and Lech G3KAU sadly both now SK. Having just about recovered from the weekend’s activity and travelling upto Puckeridge again yesterday (Tuesday18th) to recover the remaining bits of gear including tables and chairs etc and the loading coil and variometer used by all of the operating groups involved, I  thought that I would post an initial report of the activity pending a more detailed study of the logs and incoming reports. Firstly, thanks to all those who participated and to all those sent in signal reports and messages of encouragement. The exercise was arranged at very short notice and word spead around the LF operators living within reasonable reach of the site to invite one or two groups of operators to take part. Apart from the Decca mast and an RF thermo-couple ammeter , none of the original equipment such as loading coils etc was used. For 136Khz ope...

First published CARC Newsletter April 2000 For a little while I have been interested in a type of HF propagation mode known as NVIS sys tems. This short article summarises what I have found out about subject.  WB5UDE (see below) gives a good introduction to the subject. “NVIS, or Near Vertical Inci dence Skywave, refers to a radio propagation mode which involves the use of antennas with a  very high radiation angle, approaching or reaching 90 degrees (straight up), along with selection  of an appropriate frequency below the critical frequency, to establish reliable communications  over a radius of 0-200 miles or so, give or take 100 miles. Many of us have used this mode when  making nearby contacts on 160 meters or 80 meters at night, or 80 meters or 40 meters during the  day. We may have thought of these nearby contacts as necessarily involving the use of  ground-wave propagation, but many such contacts involve no groundwave signal at all, or, if the...