2 Meter Slim Jim
This antenna is specifically
built to resonate within the 2 meter amateur radio band
Slim Jim Plan that we
Among the items used to construct the
antenna are :
Aluminium tubeing, 8mm diameter, sold in 10 feet (can be obtained from hardware store, 10 feet, RM10)
U PVC Pipe (15mm-20mm) for holding with T junction, RM4
SO-239 connector (for mobile rig), RM10
Coax Cable (either RG-8 RM7/m or RG-58 RM2/m, quality varies
Tools that we used are (included with cost if you want to buy them):
Bosch hand drill for drilling pipes and aluminium tube ( RM100)
Rivet / Riveter for attaching coax cable to antenna (RM 20)
Bender (RM 30)
Hack saw for cutting pipes and aluminum (RM 3)
and oh yes, we *dont use* any torch welder for this one
As you already might guess, the cost for constructing the antenna alone cost slightly less than RM30 (~USD 10, except cable and tool cost), the Slim Jim is mounted on the roof of my house with ordinary TV antenna bracket, with the height of close to 40 feet from the ground.
Why build your own antenna? It is a way for me to better understand about radio wave resonance and to learn more about how to build a radio antenna to tune in to specific frequency, something that commercial antenna lacks, because it is built to tune to a wider range of frequency due to market demand.
This antenna is said to have a gain of 3.2dBi, though I dont have confirmation about this information.
Heres the reading I've obtained from Diamond SX-200 SWR meter, using 20 watt output power :
The reading is kinda bit off from the center of frequency 146Mhz, I know. this is due to my poor handling with aluminium bender. I've made it almost an inch longer, so that kinda explains the SWR reading is kinda centered on the lower frequency.
However this is way cheaper than buying a commercial antenna which cost me a lot of bucks, and I surely have more fun!
What can be improved?
If you want the antenna to resonate better, you could replace aluminum tubing with copper or brass tube and replace RG-58 coax cable with a low loss cable such as RG-213 or RG-8 which was used in this experiment.
ANOTHER PLEASED BUILDER
REPORTS HIS GOOD LUCK!
I needed an antenna for the VHF Marine Band. I decided to build a Slim Jim according to your article on Hamuniverse.com. I cut the antenna for a center frequency of 156.8MHz (Marine Channel 16) and find the SWR to be virtually 1.1:1 across the band.
The antenna is
mounted to a 6ft piece of PVC. I also used the nut and bolt gap adjuster
shown elsewhere on your site. And used the sliding SWR adjuster of
KE5FXU's design. Works
great. See photo
And now....part of..... "The rest of the
I am very pleased with the results of the antenna. Thanks for a great resource, 73, Robert Carr KD8FQM
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