Tuesday, 4 February 2014

Antenna up ready for UKAC 144MHz

The antenna this morning
Back in 2011 my brother won a Innovantennas 4-element LFA at the National Hamfest, he couldn't make us of it back then so I adopted it. I have used it for reception but until now not for transmission.

I should say my brother has took his foundation exam and has the callsign M6GTD, so am expecting him to ask for his antenna back at some stage! ;-)

This evening is this months 144MHz UKAC contest and I spent yesterday evening getting the antenna set up properly so I could take part. Unfortunately the antenna was damaged just before Christmas and I have now replaced the boom insulators and straightened the bent director element.

It took a while to get the antenna VSWR down to a satisfactory level, not due to any fault but simply I had the adjustable sections of the active element loop too far out. They are now almost fully in, but at 144MHz the VSWR is a little over 1:1 and across the entire 144-146MHz the maximum is around 1.3:1 so I am hoping it preforms reasonably well, even with 10m of RG-58.

As suggested I have a 'ugly' rf-choke inline, which you can see on the photo. The antenna is clamped just under the vertical collinear, and hopefully this won't affect its performance.

I can put the pole up to around 5m, but the top section isn't that substantial and has a reasonable loading with the yagi and the collinear on it, but the pole it is securely guyed so for temporary use should be okay. Well that is what I thought till I saw the weather forecast

The wind speed and gusts look a little worrying, peaking at around 40mph between 21:00 - 00:00!

The only saving grace is that I will be manually rotating the antenna I will be out checking on it regularly during the contest!

Best of luck everyone taking part...

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