Wednesday, August 15, 2007

Some antenna tests during the summer (ALA100) at the King´s Village QTH

I made some tests using the ALA100 during July. The first attempt was to make a
round loop of spiral wounding using the ALA100, the circumference was about 6 meters and the antenna was rotatable using some rods (supports of a tent) and a fishing rod, The antenna was mounted at about 5 meters. In the picture it is waiting to be erected up.
However it seemed that either the small diameter or sprial wounding made this set up not as good as a bigger normal square loop. It had approx. 10 dB lower gain than the sprial one.
I changed eventually the type to a square "<> - shape" loop of large aperture (ALA100) using about 24 meters of wire. The antenna was also constructed using one center mast (of 10 meter fishing rod) with the highest point at about 8 meters (<> - shape).
It seems this is a very low noise antenna indeed at least at rural QTH with noise floor at SDR-IQ (0 dB preamp.) at about -125 dB. The antenna is at least as good as my longwire of 150 meters but with lower noise level (approx 5 dB) , so the better S/N. However, it seems to be more effective to high angle signals - so the BOG or a good beverage could be better - that will be tested later on this Autumn.
73 TK

1 comment:

Bjarne Mjelde said...

I agree that the ALA100 is better for higher-angeled signals. It does not match a 175-metre beverage, especially not on or after sunrise. Good SW antenna though. Mine is 8m horisontal/4m vertical.