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THE N9AGT VERSION OF THE SLIM JIM ANTENNA 

 

This is the Slim Jim Antenna I made after reading KE5FXU, Richard's article on Hamuniverse.com. 

I used readily attainable parts to assemble it with.  It cleaned it up and made it real easy to look at...as well as functional!  In the pictures below you will see I used PVC tees (Pic # 2) with a 1 1/8" bushing cut from 1/2" PVC pipe.

The tees need to be reamed out with a 5/8" drill bit for a snug but sliding fit for placement. 

For the tuning stub (Pic # 3), I used 1/2" copper couplers that slide on the 1/2" copper tubing.  DO NOT use the couplers with dimples or grooves in them, these will not slide on the pipe! 
I soldered an SO-239 connector to the 1/4 WL pipe and then soldered a piece of solid wire between the 3/4 WL pipe and the center conductor on the SO- 239 connector.  You could solder the coax or ladder line directly to the sliding couplers.  I personally will use the SO 239 connector on this antenna. 

The pictures below will help show how it all went together.  Maybe this will give you some more ideas on how to construct your Slim Jim antenna!.


Pic #1 Full Length View


Pic #2 PVC "T"s


Pic #3 Sliding Couplers and tuning stub area at base

The pictures below show the final assembly with the SO-239 installed. 



Back view of SO-239 installed



Front view of SO-239 installed after final tuning.
(Antenna is upside down in view above)

I soldered the center conductor to the 'long' side of the antenna and the SO-239 base plate to the 'short' side.  
The gap spacing ended up being 1 1/4".  The distance from the bottom of the antenna to the center conductor on the SO-239 ended up being 3 1/4". 

I could have left the "tap" or feed points at Richard's (KE5FXU's project), measurement of 1 1/2" and 4" and would have been fine with a SWR of 1.5 to 1.  I got it down to 1.2 to 1 or less across the band! 

After tuning for lowest swr, I then soldered the bushing/couplings in place along with the end caps at the gap.   I love these 'one wave length or longer' antennae!   Actually, if you measure from gap end to gap end around the antenna, it is about 1 1/2 wave lengths long. The tuning stub takes up part of that so you could call it an end fed folded "long wire" or any other name you want to call it.

I think that with a little more tweaking I could have gotten the SWR down less than that!  I just don't like being perfect!  LOL.  

Some time back I also built the 2m Hentenna that was on the Hamuniverse.com antenna projects page.  I use that antenna at my home now and can't say enough good things about it. 

This Slim Jim performs on par with the Hentenna and I will use the Slim Jim at my QTH in Arizona when I get there in middle January for the rest of the winter! 
I have no doubts that at my location (Florence, AZ.) I will be able to make contacts in both the Tucson and the Phoenix areas which are nearly equal distance north and south. That will be a great test for this design!  Thanks for a great website for experimenting Hams! 
Having HAM fun,  N9AGT Roy.

 


 


  

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