WSHL413

There's a Youtube video where the presenter discusses the optimal number of ferrite beads for common mode current attenuation. If I recall, 5 good, 7 best, after that diminishing returns as you state. Interesting demonstration...beyond a certain point more is not always better for this purpose! Following this advice I added five beads at the feed point of my two roof-mounted dipoles. I think that does the job.

Definitely a factor here in So Cal suburbia. My neighbor a few houses down the street is a ham. He experiences RFI as high as S9 on HF 10m and 20m. He turned off the mains to the house and ran the rig on battery power. RFI persisted, so it's an external source, either the power lines in the back yard, neighbor's solar installation and/or their air conditioners. He's doing more investigation to locate the cause. I am fortunate - RFI around S1 during the day except in very hot weather when people run their air conditioners. RFI goes up to S5/S6 then.

Good to know and I appreciate the info. If this was a more permanent installation (mobile and home) I would use dedicated antennas for both services for maximum performance. That's a goal for my new home station - GMRS, HF and UHF/VHF. For the cross-country road trip the temporary magmount 2m/70cm antenna should suffice. Hope to make a decent number of contacts along the way.

Had a few minutes and performed a quick SWR test using a NanoVNA with the magmount antenna in place on the vehicle roof. 2m band SWR ranged from 1.5 to 1.4; 70cm band SWR ranged from 1.9 to 1.1; GMRS frequency measurement range set to 462 MHz to 468 MHz and the SWR varied from 1.5 to 1.4. Better than I expected! I should note the magmount is also manufactured by SignalStuff.

Steve, this is great information and thank you. Definitely want to learn more about DMR. I'll digest this and do some research - lots of good info on the interweb and Youtube. I have a few commitments that are pulling me away from radio for a bit, but you've got me off to a great start when I have more time to pursue.

Appreciate the offer. The route is briefly north on I-15 to I-40, then eastward to I-44 and I-70 into Wheeling, WV. One-way trip as that will be my new QTH (big change but nice place to retire and close to family). Not to stray too far off-topic...For 2m and 70cm I'm using an Anytone AT-D868UV programmed with analog repeater info from Repeaterbook. Similar to how I compiled the set of GMRS repeaters using this site's map function for my UV-5G, I searched for ham repeaters along the interstates that appeared to be available for travellers. The D868UV also supports DMR. I don't yet have experience with code plugs or that digital mode. Are code plugs only used for DMR? It would be great to see a real-world example. Glad to talk further offline or create a new thread under the Amateur Radio section. You got my curiosity piqued so some web searching is in order as well.

I know what you mean. There are places on the HF bands where certain people congregate and may not necessarily follow the rules for courteous operation.

Steve, got a question. On my road trip I plan to use the Signal Stuff dual-band (2m/70cm) antenna on a roof mag mount with an HT inside the car. I remember seeing something on their web site saying the dual-band antenna should work for GMRS. That would be nice so I don't have to mount a second antenna on the roof. Would you agree or should I invest in a second magmount and antenna specifically designed for GMRS? I'm not looking for maximum efficiency - just casual use of HTs while on the road.

Glad it worked! Appreciate the compliment although it was more of an educated guess. If I ever had any genius brain cells, they burned out decades ago! LOL

Happy so far with a pair of UV-5Gs. I plan to use them soon for a cross-country drive with two vehicles to keep in touch. Interestingly they ID as "Radioddity UV-5G" which works fine with Chirp. I programmed as many open GMRS repeaters as I could find between CA and WV into the higher numbered memory channels. We'll see how they perform on the road.

@TNFrank Due to skip on 10M, states including AZ and NV are generally unreachable from my home in So Cal. In a few months I am moving to West Virginia, so perhaps we can try to make contact then?

Looks like 10M has opened up again and we're mostly back in business. HF bands ranked "fair" instead of "poor". Hunted a half-dozen POTA stations today including stations from WI, MI, FL, AL and TX. Not bad! Anyone else make contacts on 10M?

Way to go! 10M here in So Cal is crackly but I'm hearing other stations.

Roger that. Making these chokes out of a toroid and coax is easy-peasy and they do the job. I use hamstick dipoles too, a 10M and 20M on a chimney roof mast (pic on my QRZ profile under call sign KO6IOJ). The mounts are Opek brand. It's a rental house so the antenna has to be removable and non-intrusive. (We are moving in April so it will come down soon.) Can you tell me more about your station setup? What bands for the hamstick dipole, and what do you think about the POTA Performer antenna?

Good points. My understanding is a dipole should have a 1:1 balun at the feed point to choke common-mode current. One can purchase a commercial choke or make one with 12 to 14 turns of RG8X coax wrapped around a FT240-43 toroid. That's what I use. Measured with a NanoVNA, the attenuation is -25dB and greater across the entire 3 to 30 MHz spectrum. I've read this is generally sufficient for this type of choke. With a wire dipole, the 468/f is a general guide. I usually cut the wire 12 inches longer, then cut some of the excess length when testing in place. Some excess is wrapped back at each end insulator for fine-tuning in the field. My 20M wire dipole shows an SWR of 1.5:1 or less across the band, with the sweet spot (is that a technical term? LOL) less than 1.1:1 around 14.230 MHz since I operate SSB. During yesterday's POTA activation I measured the sweet spot at 1.04:1. Pretty good. Antennas are really fun to work with and I've only scratched the surface with the various kinds. Have yet to explore verticals and antennas for VHF/UHF. Always something new to learn in this hobby!