Richard Clark wrote:
On Sat, 10 Feb 2007 12:06:06 -0600, "David G. Nagel"
wrote:

I hope it helps the student with his science project.

Hi Dave,

That is of infinite improbability. How many times do we have to tell
adult amateur radio enthusiasts the necessity of matching (a warning
already offered from the shadows of this thread)?

So, shall we consider the merit of a total length of 3 meters in the
AM band? If this discussion is so studiously avoided by those who
weep away about the dearth of information, what chance does a naive
student have to rummage up the details?

The Rr summons up to roughly 20mOhms. Are any of the scolds going to
offer the implications of this value? Are there any suggestions of
using commercial tower sections to cut down on Ohmic loss? Any
matching details for the massive SWR? Any hints on how to load the
structure? Details for a top hat? Would the top hat consume part of
that 3 meter restriction?

Richard, I dare say that the 3 meter limit, and the horrible mismatch
achieved with such an antenna just might be part of the whole idea of
part 15 transmission. The user isn't supposed to put much of a signal on
the air. It's supposed to be a technically poor setup.

Of course, assuming that the science fair is taking place in a school
building, the student could operate as a campus transmitter. Lots of
extra steps and paperwork there though.


Would a loop perform better? What dimensions? How to build the
capacitors? Talk about underwhelming help....

Seems like a good way to go for the kid would be to buy a kit or
better, build a radio from scratch, keeping within the legal limits.

Asking for help in here can be confusing enough for a new Ham, let
alone a young schoolkid.




the dark side of the net had to have it's way with the subject.

I have these visions of you making Darth Vader sounds, and saying
"I...am your father T."...... 8^)


- 73 de Mike KB3EIA -