[GreenKeys] Questions on troubleshooting an antenna

[hunybuny at eskimo.com]

Hello Wayne;

Thanx for the information.

My antenna is similar to what the picture shows except that my
coil is 12" long wound on a 4" diameter / 4' PVC pipe, and I
have about 20' of magnet wire running up to the roof.

I got an MFJ-207 SWR Analyzer and hooked it up to the antenna.

I played around with the taps and ran into something really
interesting:

Again, the coil is 12" long.

About 5" from the beginning (bottom) of the coil I find
the 1.7MHz tap. That's the lowest frequency that the SWR Analyzer
will go. As I continue up the coil, to about 8" from the bottom,
I finally reach 2.3Mhz. The next inch, no matter where I tap it,
I have an infinite SWR from 1.7 - 33MHz.

Now the really weird thing happens: once I pass the infinit-SWR zone,
as I tap the coil, higher and higher, the frequence of resonance drops:
at 3" from the top, it resonates at 11MHz, and drops in frequency with
each winding I tap until I reach the end of the coil and it resonates
at 8.4Mhz.

No - I checked the continuity of the coil and there are no breaks.

I'm thinking about sending it in to ARRL tech. support...  :-)

Just kidding.

I'm going to wrap a coil like the one in the article and see what happens.

Anybody got any ideas as to what is happening, well, I'd like to hear them.

UE
W6ESE - tony
NNNNZCZC

hwhall at compuserve.com wrote:
> Hi,
> Attached is a cleaned up scan of the pages from the Bill Orr Radion 
> Handbook and the antenna design that I think may help you with your 
> project.  
> 
> 73,
> Wayne
> WB4OGM


-- 
Tony J. Podrasky | Back in my day we didn't have virtual reality or
                  | video games. If an axe-wielding one-eyed razorback
                  | barbarian warrior was chasing after you, you just
                  | had to hope you could outrun him.