Slim Jim mounting

[tracker1962]

I read there is to be free-space when mounting the antenna to a mast.
The construction of the antenna would be 1/2 copper pipe.
Does this apply to PVC or ABS pipe or metal only?
Would like to build one for travel.
Thanks, tracker.

 

[wavrider]

Interesting, where did you read that at?

I guess you are talking about where the boom of the antenna meets the mast pipe?

 

[mackmobile43]

SLIM JIM ANTENNA PROJECT

Clearly show PVC being used as an insulator.

 

[BOOTY MONSTER]

"It is estimated that the Slim Jim appears to have about 6dB gain over a 5/8 wave antenna due to the extreme low angle of radiation."

hmmm........... so on 11 meters it would be 25 ft 9 3/8 inches tall . only a few feet taller than a 5/8 or .64 . it looks like a taller j-pole with the top folded/bent back down .

 

[tracker1962]

mackmobile43,the first few lines in the construction details section of the link you attached, this is what I'm asking about.
I would presume that a PVC or ABS mast would be ok but asking for member confirmation because nowhere on that site did I see that, that material is ok and not affect SWR and radiation pattern.
Thanks tracker.

 

[BOOTY MONSTER]

ive used PVC from lowes before on a antenna projects . i put a few pieces in the microwave to see if they would get hot or warm from metal content . they felt the same after 30 seconds on high . not the most scientific method , but it worked for me . i wouldn't us it for a long term or permanent project/antenna , but for proof of concept or just to see if something will work it does pretty good . going much past 20 feet unsupported gets tricky quick with any wind or strong breeze though . that military fiberglass mast stuff might be a better option , but i dont know what kind of weight it will support .

 

[W5LZ]

The illustration shows a length of PVC at the bottom of the antenna, and the text says no part of the antenna should be grounded. That leads me to believe that there's some PVC separating the antenna and a metal mast. How much 'separation'? Beats me, try about 6" to start with.

"It is estimated that the Slim Jim appears to have about 6dB gain over a 5/8 wave antenna..."
I thing the two key words in that statement are "estimated" and "appears". I didn't read the rest of the article so have no idea what evidence there is to support that 'estimate' and make it 'appear' to be what was said. You suit your self, but I'm afraid I'd have to see it proven.
- 'Doc

 

[HomerBB]

The only real challenge I see to this antenna is the distance from the mounting mast part. Effectively holding it out 9 feet for 11 meters is a lot over overhang.

If you have two high enough mounting points for suspending it from, you could use the city tenement style clothesline pulleys and rope and make it of wire, suspend it from the endless clothesline, and rotate the line out from the tie-off structure to where you got clearance as needed. Hang something non-conductive from the bottom (run it through PVC pipe at top and bottom) of it to keep the wire from curling up antenna vertical.

Similar to this:

 

[Robb]

Wow Homer - you sure have some heavy-duty power lines near your setup!
Just had to say...

 

[HomerBB]

I just borrowed the photo.

There are power lines here about 200 feet away, but are underground coming into my side of the street.

 

[tracker1962]

The illustration shows a length of PVC at the bottom of the antenna, and the text says no part of the antenna should be grounded. That leads me to believe that there's some PVC separating the antenna and a metal mast. How much 'separation'? Beats me, try about 6" to start with.

"It is estimated that the Slim Jim appears to have about 6dB gain over a 5/8 wave antenna..."
I thing the two key words in that statement are "estimated" and "appears". I didn't read the rest of the article so have no idea what evidence there is to support that 'estimate' and make it 'appear' to be what was said. You suit your self, but I'm afraid I'd have to see it proven.
- 'Doc

Your quite right Doc, I missed that "illustration on the right shown mounted on a PVC pipe"
My answer was there all the time!!
At the time of my post I was looking at another site that didn't make mention of that.
Thanks to all for your replies.
tracker.