The Wisconsin Ham Radio Campout started out as a lark. Joe, Travis, and I have been getting together for a weekend in the fall for some ham radio. Three years ago I had the idea that maybe we should open this up to the ham radio community. Not knowing the what the acceptance would be, we picked a park in Northern Wisconsin and the results totally blew my mind. Almost 30 people showed up with only the six weeks I had to plan and publicize the event. Needless to say hit on something good.
This year is our third annual event and we almost totally filled Buckhorn State Park in central Wisconsin. Over 50 hams showed up and had such a great time that the event stretched out, unofficially, over 5 five days. This week’s video: The Wisconsin Ham Radio Campout SURPRISES Everyone! is the result of the core weekend portion of the event. You can watch it here: https://youtu.be/Rs0q-J6CPi4
Thank you to our sponsors:
Flatlander’s Mirrors Antennas: https://www.etsy.com/shop/FlatlandersMirrors
KB9VBR J-Pole Antennas: https://www.jpole-antenna.com
Learn about the 2026 Ham Radio Campout: https://groups.io/g/WI-Hamradio-Campout
Keeping the noise out
When you get a bunch of hams together and on the air, you are bound to get interference from the adjacent transmitters. There are a few methods that can mitigate things, like running QRP or spacing your antenna systems out far enough to not interfere, but those are not guarantees to solving the problem. Dave, KZ9V, and I run multi transmitter for the Wisconsin and Minnesota QSO parties, and after a fair amount of trial and error, we’ve come up with a few ways to coexist without stepping on each other.
First off is to think of antennas and placement. At the campout this year, all my neighbors were running wire antennas, like end fed half waves and dipoles. Knowing that signal polarization can make a difference, I deployed a vertical antenna at my site. Polarization mismatch can attenuate a signal up to 20 dB in the near field, so that can knock out a big chunk of the noise.
But that won’t eliminate all the noise, so the next item most hams gravitate towards are band pass filters. These are tuned circuits that greatly reduce signals outside their frequency specifications. A typical band pass filter can achieve 30 dB or more attenuation, depending on its complexity. That’s a good way to filter out the noise if you are on the 20 meter band and your neighbor is running 15 or 40 meters. But a band pass filter won’t eliminate the in-band interference, like if another ham is running CW or phone on the same band as you. For that I have a different trick up my sleeve.
Did you know that your coax can act as an antenna? We commonly will use the outer braid of our coax cable as a counterpoise for some types of antennas. An in other cases we will put a common mode choke at the feed point to help prevent the RF energy from traveling down the outer braid of the coax. But past that point your coax braid can act like a big antenna, and it will receive any wide band signal, be it noise or close by station transmitting, and funnel it into your receiver. Adding a second common mode choke at the transmitter output eliminates that.
And after a bunch of trial and error, that’s the secret ingredient that makes Dave’s and my multi operator station a success. I’m currently using the common mode choke by KF8ASEHamRadioSupply. Brian sent me a sample choke for evaluation. I am certainly impressed by the quality and durability of these chokes. Constructed out of low loss cable and Messi and Paoloni connectors, these chokes are rated for up to 300 watts sideband and 100 watts digital. He also has a smaller QRP choke and larger QRO chokes with integrated heat sinks.
This three step approach to reducing interference works. The next time you operate with other stations, be it Field Day, contest, or at our campout, consider adding a pair of common mode chokes as part of your noise reduction kit. It will certainly make a difference.
Finishing Up
Camping season is coming to an end with only two more planned outings. First up is this weekend when I head to Governor Thompson State Park in northeast Wisconsin. I’ve been to Governor Thompson many times and it is a favorite place of mine, but what I haven’t done yet is to explore the Menominee River State Recreation Area. The Menominee River forms the border between much of Wisconsin and UP of Michigan and the 17 mile stretch that makes up the State Recreation Area is riddled with deep gorges and waterfalls. It also features three seldom activated POTA entities and my goal is to get all of them on the air this Saturday. Watch for me, depending on cell signal I may or may not be spotted. I’d love to make the contact.
I hope to get you in the log soon
Michael
KB9VBR
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