River Cleanup & A New Antenna

Today we (Duval County ARES) did another special event with the City of Jacksonville. It was the 2010 St Johns River Celebration Cleanup. There were about 20 sites around the city where volunteers gathered to collect trash and debris from the parks and waterways. It’s a fun event and gives our radio operators the chance to get out and about.

I was net control with a new operator assisting me. Things got off to sort of a rocky start. We weren’t sure where to setup first off. I’m usually at one of the cleanup sites and not net control. The event coordinator hadn’t communicate where I was to setup so I went with what the park foreman told me when I arrived. We set everything up and started doing initial checkins. Many people were still en route so I decided to wait about 15 minutes.

During the waiting period the event coordinator arrived and said I was in the wrong place. No big deal. I just announced to everyone on frequency that I’d be offline while we relocated. Since the event covers the entire city I decided to use two repeaters to give everyone the best chance of making contact. The secondary repeater was UHF. This posed a problem to me as most of our work is done on 2M and I didn’t have a dual-band antenna.

This wasn’t really a big deal as I was withing spitting distance of both and could’ve easily used my HT but I wanted to use my FT-8800 go-box since it’s more geared to net control usage. I’d been wanting to build a knock off of the Arrow Antennas j-pole but haven’t had time. The materials are in the garage but the opportunity hasn’t presented itself. Instead I took advantage of HRO’s close location and ordered one that arrived the next day. I assembled it last night but couldn’t check it out because my MFJ analyzer batteries were dead.

On location I put the new Arrow on the 14′ telescoping pool handle that serves as my portable mast I always keep it in the toolbox of my truck. I mounted it to a railing away from any metal and ran a 50′ section of RG-8 to the room we moved to. I couldn’t get the SWR below 3.5. I tried a different piece of coax (RG-8X) and it was worse. Keep in mind that I still hadn’t gotten back to the net checkins and time was wasting. Well, as it turns out our UHF repeater was offline. Now what? Well, I picked another VHF repeater and put out the word via my HT to use that.

The good news is that I had my standard deployment antenna, the EE-3, with me. I put that on the same mast, in the same location, with the same coax, and read 1.5! Once we were back on the air the event flowed very smoothly.

EE-3 Antenna

Over the course of the event the volunteers collected over 1200 bags of trash and all sorts of items that shouldn’t be disposed of around our lakes and parks such as couches, TVs, used motor oil, etc. After the event everyone was invited to Metro Park to enjoy a free lunch and entertainment.

Net Control Station

When I got home I decided to investigate the high SWR issue and was surprised with what I found. As I reviewed the assembly instructions again I noticed that the nylon washer that was supposed to be on top of the feedpoint connection was on the bottom.

Incorrect Washer Placement

I really didn’t see how how the location could matter. Top or bottom it seems to me that the measurements would still be the same. However, the SWR was definitely showing a problem. (Sorry for some of the blurry shots. The macro feature on my camera quit working for some reason.)

High SWR

I disassembled and reassembled per the instructions and was shocked.

Proper Washer Placement

That fixed the problem! I still can’t figure out why but I can’t argue with the meter.

Perfect SWR!

I guess I’ll just accept that the placement of the washer is critical and move on. Here’s a close-up of the antenna after the proper assembly.

Arrow J-Pole

And the total deployment on the bed of my truck.

J-Pole deployed in truck

All in all not a bad day. Had a great event and figured out the source of my problem. If only every day were like this one!

Leave a Reply

Your email address will not be published. Required fields are marked *


You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>