JOTA/JOTI (Jamboree on the Air/Jamboree on the Internet) celebrates the scouting movement on the air and on the internet. This years event happens Oct 20-22. On Saturday October 21, a few of the members of EARS will be attending the event with the Sparta Scouts and Venturers at the Sparta Community Hall and setting up amateur radio stations and attempting to contact other groups with similar setups.
Come on out between 12 and 4 and meet other scouting members and talk to other groups via radio.
EARCHI End Fed Matchbox
An end fed antenna consists of a wire fed on its end, the length of that wire is not resonant with any frequency or frequencies you will be using it on. Lengths of a half-wave or multiple must be avoided. The transformer usually used with an end fed wire is a 9:1 transformer. This transformer converts the impedance at the end of the random wire down to about 50 ohms, a value which any modern transmitter can transfer power to and has been designed for.
Notes from W1SFR:
In the case of the end fed random wire, some lengths are better than others because of the harmonic effect of the length of the wire and how that affects the various band on which you wish to operate. Counter to tuning a length of wire like you would with a dipole, with a random wire you don’t want the length to be harmonic on any band. There are ideal lengths that have been mathematically determined to be best for randon wires. Here they are:
29 35 41 58 71 84 107 119 148 203 347 407 423
I have chosen 35′ as the standard length for my antennas, but you can experiment. I have used up to 84′ and the KX3 will still tune all bands but as the wire gets longer so does the resistance so it becomes harder and harder for the tuner to do its job. At 35′ it’s not too short and not too long and works great in every configuration I’ve tried so far.
9:1 unun transformer:
my 9:1 unun using a T130-2 toroid:
The first meeting of the 2017-2018 club year will be held on Tuesday September 12, 7:30 pm at the Elgin Regiment.
Herb Warren, chairman of the War Memorial Site Committee, holds up a model of the future Veterans Memorial Garden. The garden, which will be located in the green space on Moore Street in St. Thomas, will have the Great War soldier, the World War Two/Korean War Cenotaph and a new Afghanistan memorial located in it. (Laura Broadley/Times-Journal)
Our President, Worth VE3BTC, is on the committee to establish the St Thomas War Memorial Garden in St Thomas. St Thomas Ford is offering a donation pf $20 for every one who test drives one of their vehicles on July 15th, for more details, see the flyer.
From the estate of Frank Krack VE3FWN (sk), this 2kw amplifier is for sale, best offer. Contact his son Mike Krack VE3RMS at firstname.lastname@example.org for more details.
Notice: the amplifier has been sold, thank you.
Bit of discussion at last meeting about NVIS. A research paper has been published and is available for reading on this topic
The results are in… see December 2016 QST. EARS competed in the 4A category battery powered and below are our results: