« Posts tagged VHF

Spring VHF/UHF Contest

EARC testing for the upcoming spring VHF/UHF contest.

VHF/UHF Field Day Survey closing in 1 week 14/10

First, this Proposal for changes to scoring of Australian VHF/UHF Field days. This proposal outlines the rationale for these field contests, examines how well they meet their aims, how the current scoring system works and reveals some anomalies in the scoring system used. Then the reasons for changing the scoring system to one based on distance worked, and removing the link to grid squares worked, are explained and some details are provided of how that change can be made.

The Survey


John Moyle Field Day 2012

The contest takes place on the 3rd full weekend in March each year, and this year runs from 0100 UTC Saturday to 0059 UTC Sunday, 17 – 18 March 2012.

The aim is to encourage and provide familiarisation with portable operation, and provide training for emergency situations. The rules are therefore specifically designed to encourage field operation.

Contest Rules:
The contest is open to all VK, ZL and P2 stations. Other stations are welcome to participate, but can only claim points for contacts with VK, ZL and P2 stations. All VK, ZL, and P2 stations can claim points for all contacts, with any amateur station in world, as long as valid serial numbers are exchanged.

Single operator portable entries shall consist of ONE choice from each of the following (e.g. 6 hour, phone, VHF/UHF):
a 24 or 6 hour;
b Phone, CW, Digital or All modes;
c HF, VHF/UHF or All Bands.

Multi-operator portable entries shall consist of ONE choice from each of the following (e.g. 24 hour, phone, VHF/UHF):
a 24 or 6 hour;
b Phone, CW, Digital, or All modes;
c HF, VHF/UHF or All Bands.

Home and SWL entries may be either, 24 hour or 6 hours, but only all modes, and all bands. Multi operator stations are not permitted in the Home Category


[PART 4] 3 element 2 meter band Yagi conclusion

Well this is the conclusion after having bit of a play and a fiddle with this 3 element Yagi that I built based on VK5JST build notes. For a 3 element Yagi it is rather directional of about 45 degrees, and very deaf at the back which is a good thing for some setups. Overall it is a rather unusual design with characteristics of much larger Yagi’s for the same band. I have been able to get 1.2/1.3-1 SWR on my Yagi for 146Mhz which I am rather chuffed with and had a good QSO into the VK5RHO repeater from my place. I could probably get better SWR if had a network analyzer to see exactly what the Yagi is doing over 144-148Mhz 2M amateur band.

This Yagi was well worth the time it took to build.

[PART 3] 3 element 2 meter band Yagi construction finished

Well today I made the gamma section for my Yagi and mounted it and also added rubber bits for the ends of the elements and end caps for the boom. I have done a quick test of the Yagi with a 10pF capacitor and the SWR is ~1.5-1. I got a couple air variable capacitors I going to put on the Yagi to better tune it. As it was a lovely day most my work was done outside on the deck. 🙂

[PART 2] 3 element 2 meter band Yagi construction

Tonight this is the bracket I made for the SO238 socket all riveted and mounted to the boom of the Yagi. All that is left to do is make the bracket to hold the gamma matching and to fine tune the Yagi, all going well I should have it finished during the week 🙂

and yes working on the kitchen table again, hehe

3 element 2 meter band Yagi construction

This is a 3 element 2 meter band Yagi design by VK5JST that I am giving ago to make. The only difference is I am using 12mm OD round and 19mm OD square aluminum (as it what had around from another project) and I have used 3.2mm dia x 4.5mm long aluminum rivets to hold the elements to the the boom. All I have left to make is the bracket to hold the gamma rod and the bracket for the connector and drilling the holes for the v/u bolt assembly.

The pictures below are where have got thus far.

and yes that is the kitchen table I am working on, ssh don’t tell anyone. hehe