RFI Adventures in April

April’s park outing of the Ocotillo Hams was a little smaller than usual as the HOA garage sale spring season kicked in for Don. Three of our rotating number turned up to the Veteran’s Oasis Park in Chandler on April 9th bright and early to the Curved-Bill Thrasher Ramada.

John (AI7AQ) and Norm (K7NWF) both brought different Mag-Loop antennas, while Lisa (me, KJ7DJR) turned up with a Wolf river coil mini-bullet on a MFJ tripod with custom measuring tape radials.

Setup was a breeze for the mag-loop posse, and only slightly more complicated for me. We were all setup by 9am, tuned up at different times for 10, 12, 15, 17 and 20m bands.

As usual, there was at least one technical issue to work through. This time Norm was the lucky target of the radio gremlins, filling in for Don and I. =)

Norm was encountering an audio problem with his setup, which turned out to be a case of RFI on the USB cables between his SignaLink and radio. One of the symptoms is that the SignaLink will flutter on and off, or the USB interface will just stop, and need to be disconnected and reconnected or the laptop rebooted.

This is a problem I’ve had more than a few times at home on different bands. I ended up resolving it by attaching some good size ferrites that I got over at to the USB cables. I usually wrap it around the ferrite about 5 times and then snap it closed.

Giant Snap on Ferrite wrapped with USB cable multiple times.

Don’t bother with those tiny piddling little snap-on’s the size of a thumb though. They don’t do the job!

John’s RFI solution on HIS cables is a little more aggressive.. he has a toroid the size of an elephant’s bracelet wound with his cables. =) He giggles delightedly about it every time we meet at the park.

Lol. You want to see someone’s eyes light up like it’s Christmas, just ask John to show you his toroid.

Norm usually hasn’t had a problem with RFI in the park, so it may have been the different antenna, or a bad cable. John had a spare TripLite USB cable to loan, which seemed to get Norm up and running.

We made plenty of contacts, including Cuba, Ecuador, Canada, and a plethora of stateside QSO’s.

The weather was beautifully mild, the park was not as busy as the March outing, but we still got plenty of visitors dropping in to ask what we were doing, talk about ham radio and admire our antennas.

We wrapped up with lunch at Village Inn, and headed home, happy little hams for another month.