My First Whack at a Homebrew Jungle Antenna

This afternoon I made a VHF jungle antenna for the first time. 

The jungle antenna is a field expedient ground plane antenna that can be made with limited supplies and tools, under austere conditions, though I built on my dining room table (the XYL is out of town).

This antenna design is featured in military manuals, survivalist videos on YouTube, and @NCScout has a great blog post on them on his site Brushbeater and in his book, The Guerilla's Guide to the Baofeng Radio.

Materials Used:

• 18 AWG wire
• #36 bank line
• A BNC F-to-binding post adapter from Amazon
• Bamboo stakes garden stakes from Lowes, to spread out the ground plane radials.

The only tool I used for the initial build was a SOG PowerAccess multitool, leftmost in the above picture. It is 4.5" long, which I used to measure the wire and bamboo for cuts.

I first cut thee 22" long pieces of bamboo for the spreaders. These were tied into a triangle with bank line.

Three radials were cut to ~20" and one wire for the vertical radiator was cut to 18".

I attached a bank line hang loop to the end of the vertical with a sheet bend. The other end of the vertical was stripped and put into the red binding post. The three radiators were stripped on one end, combined, and attached to the black binding post. The other ends have a small overhand knot tied in them and then were tied to the corners of the triangle.

Unfortunately, SWR (Standing Wave Ratio) came out high on both VHF and UHF, measured with my NanoVNA. On 2M VHF, SWR was 2.29 at 146.5 MHz. On 70cm UHF it was a bit better, 1.86 at 450.2 MHz.

After dinner I made a couple changes. First, I replaced the 18" vertical element with one cut to 19.2", with an overhand knot tied at the top end, with my bank line hang loop tied under that with a couple half hitches.

I have it suspended from an uncut bamboo stake in my second floor home office. Yes, it's a bit cluttered.

I also improved the ground plane part by replacing the bank line securing the ends of the radials and bamboo pieces with a cable tie at each junction. This made the structure much stronger.

After reworking it I remeasured SWR with 29.5 feet of RG-174 coaxial feed line. It's much improved now.

On the 2M calling frequency of 146.52 MHz SWR is now at 1.36, and on the 446 MHz 70cm calling freq it's at 1.06.

Note that SWR will probably change some with the antenna hanging in free space but I cannot test that today because it's been raining off and on outside.

Reception of a couple local repeaters has been very good but I haven't transmitted with it yet.