Should contest rules allow and act upon 599K QRM reports?

Saturday, 5 January 2013

Innovantennas LFA2 3 element yagi for 10m

During the christmas break I ordered the above antenna. The plan was to build and errect it during the break weather permitting. Unfortunately for Justin at innovantennas, this meant dealing with an order at short notice just before christmas. Justin said he'd do his best to get it to me over the christmas holidays and sure enough a box arrived on the 27th by courier. Unfortunately there were no instructions in the box, but the LFA2 is so simple in construction I couldn't go wrong. The materials used are high quality and all the holes are pre-drilled and in perfect alignment. The antenna went together quickly, but it became obvious that there were 4 poles missing from the loop element. I e-mailed Justin as soon as I realised and luckily Justin was still working. Justin asked for a photo of the antenna so he could assertain which parts were missing and very quickly agreed the missing parts. 3 days passed and again the courier arrived with another box that completed the necessary parts.

I have to thank Justin for such excellent service as although the initial order was incomplete it was sorted out proffessionally and quickly and all this over christmas and new year holidays!
Whilst waiting for the missing parts I did 2 things:
1) Decided on a feeding arrangement and built a coaxial balanced feed out of 2 lengths of rg213 and a three way tee piece connector.
2) Profiled my original cushcraft ten-3 (3 ele 10m yagi) with a local ham 4 miles away.
The result from the original antenna:
Signal strengths to local station
towards, s8
180 degrees away, s2+
Noise towards the neighbours houses
towards, s4+
180 degrees away, s1+

I removed the Cushcraft ten-3 and mounted the LFA2 using the same pole and coax but with the addition of the coaxial balanced feed arrangement in-line.

The result from the LFA2 antenna:
Signal strengths to local station
towards, s8
180 degrees away, s2
Noise towards the neighbours houses
towards, s2+
180 degrees away, s0+

I'm not sure the noise figures with regards the neighbouring houses can be relied upon as this is dependant on what they are doing but the noise definately seemed down.

So all in all I'm happy:

pros : lower noise, good materials/construction
cons : the balance point for this antenna occurs at the driven element position meaning that when mounting it to a stub mast the weight has to be offset which can cause the end to droop or raise accordingly.