Hi Guys,
I believe some HF Yagi antennas receive more noise than others and I'm
wondering if any of you have noticed the same thing?
I've got two Tri-Banders located on different towers, in the same yard, at
aprx. the same height AGL, and one of them receives 3 S-units more noise, on
average, than the other when the antennas are pointed in the same direction
regardless of what direction they're aimed, though the received signals are
usually identical.
More specifics: both use the same model Force 12 Balun, both are fed with 1/2"
heliax, and both go to the same Stackmatch antenna switch. One antenna is a
Hy-Gain Tri-Bander which has grounded elements including the Driven Element
which is grounded at the boom through it's Beta Match, and this is the "quiet"
antenna. The other is a Bencher Skyhawk which has it's Driven element isolated
from ground. I'm wondering if the Hy-Gain may be quieter since the Driven
Element is grounded at the boom which the Skyhawk isn't?
By the way, I ran the test of disconnecting the shield of the PL-259 at the
shack end of the Skyhawks coax to see if the antenna got quieter or noisier to
determine if the addition of a "Noise Balun" would reduce noise on the Skyhawk.
The noise level increased with the shield disconnected, so I'm told a Noise
Balun like Palomar produces wouldn't help reduce noise on the Skyhawk.
I ask this question because the Skyhawk is too noisy for weak signal work and
I'm thinking of replacing it with another Tri-Bander that has a grounded Driven
Element if it's likely to receive less noise.
Thanks in advance for your thoughts.
73,
Dick- K9OM
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|