Mark;
The increase in frequency is due to mutual coupling.
This is the very reason we state in our 27 page Instruction Manual for
4-Square customers to tune 1/4 wave verticals approximately 75-100 KHz
l-o-w-e-r than the desired resonant frequency. When all 4 are connected
to the Comtek Hybrid Phasing Coupler, the array shifts up to the desired
operating frequency.
So lengthen the loops accordingly and let us know results.
Good luck.
73,
Jim Miller, K4SQR
http://www.comteksystems.com
4-Square Experts, Stack Yagi
& Remote Antenna Switching Systems
On Fri, 29 Mar 2002 07:38:10 EST K8fu@aol.com writes:
> Hi Y'ALL..............
> Here is an antenna conundrum I wish to pose for your edification,
> rumination
> and reflection............
> I have erected 2 full size Delta Loops for 40m. I am feeding them
> with 1/4
> wave 75 ohm transformer lines that I cut to resonant lenght here in
> the shack
> with my analyzer. Then went out to the site and tuned each loop by
> trimming
> the loops and reading the result at the end of each transformer
> line. Each
> loop is tuned to the resonant freq I wish to achieve. But when each
> loop is
> connected to a tee the combined output reads 200 mhz higher than the
> resonant
> freq of each loop. What am I missing here ??? In hopes that the
> great
> "Antenna Guru in the Sky" subscribes to to TT, I look forward to
> your
> enlightened responses.........Mark K8FU
>
>
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Jim Miller, K4SQR
http://www.comteksystems.com
4-Square Experts, Stack Yagi
& Remote Antenna Switching Systems
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