> BTW -- if you read my piece on Antennas For Limited Space, you'll
> find a reference to a piece in QST roughly 6 years ago on exactly
> this sort of design. Written by a Frenchman, if I recall.
There is also a piece in one of the ARRL Antenna Compendiums or
"Wire Antenna" books that comes from QST some 30 years or more
ago.
There are two possible designs ... one in which the Xl is high
enough on the upper frequency to "divorce" the ends similar to
a conventional trap and the other in which the Xl and position
are selected to resonate the antenna as a half wave on the lower
frequency and as 3/2 wave on the higher frequency. The two
frequencies need not be harmonically related ... for example,
one could use the same technique for either 80/40 or 40/30
meter antennas.
73,
... Joe, W4TV
On 12/15/2010 4:09 PM, Jim Brown wrote:
> On 12/15/2010 6:15 AM, Jim Thomson wrote:
>> This just amounts to a midpoint placement of a loading coil
>> in each leg.
>
> No, it's not. Re-read my description. It's also not new -- these designs
> have been around in one form or another for years, but most hams, me
> included, are lazy about doing the engineering to build them ourselves,
> so we buy another guy's work. Now that I'm retired, I AM doing more of
> my own design work, rather than buying another guy's work. BTW -- if
> you read my piece on Antennas For Limited Space, you'll find a reference
> to a piece in QST roughly 6 years ago on exactly this sort of design.
> Written by a Frenchman, if I recall.
>
> 73, Jim K9YC
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