Topband: Inverted L noise questions-DU9/N0NM

Jon Rudy Jon Rudy" <mccarpnc@yahoo.com
Sun, 13 Jan 2002 13:58:16 +0800


Top band buffs:

Another weak opening to EU, no US last night altho was calling all through
East C sunrise. Keep watching 1828.3 for my signal.

I have heard that the inverted L is a pretty noisy antenna on RX.  When I
run my IC-756 without the antenna tuner in line the noise is S-9+10 on 160.
Even with the 18DB att on its S-9 or so (I know the math doesn'tadd up). I
even measured about 2 v AC  on my VOM across the antenna connector.  Is this
dangerous to the radio? Is this normal for the L or do I have a problem?

I am probably 200 ft from the nearest power pole of any significance and 600
feet from the high tension lines on the main street.  My L is over the tin
roof of our house. I also do run my coax along a plasic house conduit
carrying our 220v but when I removed the coax and separated it by about 4
feet or more it the noise was still there.

When I kick in the antenna tuner the antenna is much quieter and its only
static crashes and an uneven noise floor to contend with but weak signals
make it through. I assume that the 756 uses the AT in RX so that is why the
noise drops.  I have been using my G5RV for RX and use the preamp 2
position.  The G5RV has some directivity on RX but I use it most of the
time.  When I use the L on RX I have to contend with far more noise but some
signals come up in strength.

Just checking if anyone has any thoughts to shed some light on this.

73...jon, DU9/N0NM