Hi Mark:
The problem with the BC-611 is that the antenna (1 meter) is very
short compared to a 1/4 wavelength (20 meters) so it's very
inefficient.
When the operator is standing on the Earth (ground) there's some
coupling from the radio metal box to the operator to the ground
acting as a counterpoise.
But when the BC-611 is used from a parachute (without a wire
counterpoise) the radiation efficiency will be extremely low. This
may explain the lack of contacts.
https://prc68.com/I/BC611.shtml
--
Have Fun,
Brooke Clarke, N6GCE, MSEE
https://www.PRC68.com
axioms:
1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
2. Everybody, with no exceptions, holds false beliefs.
-------- Original Message --------
Date: Wed, 2 Oct 2024 20:36:27 -0700
From: [email protected]
To: Facility 406 <[email protected]>
Cc: List Milsurplus <[email protected]>
Subject: Re: [Milsurplus] BC-611 Operational Question
Message-ID:
<CAFZq+Ez4mb0vXw0hmxiX8SQV36tztto9jJ3NeUr_x3FY41HMFw@mail.gmail.com>
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I?m an EE and agree with your theoretical analysis but I tried many
different antenna orientations during descent hoping to contact my friend
on the DZ. No joy until I was about half a mile from him vertically.
Mark
AF6IM