Just some further comments: I am talking about the GM4SLV-grabber
(http://www.gm4slv.org.uk/grabber.htm).
I used to have a measured 1.7 mW ERP with a more or less unknown antenna
current. Using some of the the recent observations of Jim, M0BMU and some
of Rik's (ON4YD) formulas I estimate that the radiation resistance of my 8 m
vertical with an 8 m horizontal top load radial to be in the 70 mOhm range.
I have increased the antenna current now to 1 Ampere which corresponds to an
ERP of about 70 mW. I will try to make some field measurments later to
confirm this. Anyhow, the powe is sufficient to be copied by John's grabber
from time to time.
Best 73
Geri, DK8KW / DI2BO
----- Original Message -----
From: "Holger 'Geri', DK8KW" <[email protected]>
To: <[email protected]>
Sent: Tuesday, December 25, 2007 9:56 AM
Subject: LF: Grabber
> Hello John,
>
> thanks for putting up your grabber on the internet.
>
> I am currently observing DI2BO's signal in comparison to other signals on
th
> air. It is intersting to see how big the QSB can be from one minute to the
> other. DI2AM seems to be stable throughout the day, DI2BO's signal with
much
> less ERP (my best guess is in the 100 mW range with a 1 Ampere antenna
> current) can only be seen from time to time, but sometimes it comes up
> almost as strong as DI2AM.
>
> The distance is around 1100 km.
>
> Again, thanks for providing this service. Best 73 and a Merry Christmas!
>
> Geri, DK8KW / DI2BO
>
>
>
|
