Dual band/marine vhf antenna

[ctrout]

I will be setting up my Catalina 22 with a Ham radio station before the season begins for me this year. I'll be using one of my Yaesu FT-857Ds to save space. It IS a C22 after all. Anyway, I'll be exploring several options for an HF antenna but I want to get the dual bander right the first time so I don't have to raise and lower the mast multiple times. I'm not looking for a massive 9dbi antenna to achieve eme capable range, just a solid station that allows me to work some maritime mobile either simplex or through the local repeaters.

My big question though is, has anyone ever found a uhf/vhf ham antenna that can be tuned to achieve reasonable swr (<2:1) on all three bands (uhf, vhf, and marine)? I'm strongly leaning towards the Comet SSB-2 because it looks like a good balance between size (18") and power (2.15/3.8 dBi). Let me know what you all think.

73,
Chris
WA7ZAF

 

[Brian D]

Chris, welcome to the board and great question.

Dual band is fine if you are going to work two bands that are as far apart as London and Los Angeles. However, in the Marine and Ham VHF area they are too close to achieve the "dual band" concept. Now, if you still plan on using VHF/UHF, excellent as the 857D is a great radio for that. I too have an 857D which I use on HF/VHF (repeater and ISS) and UHF.

I have a home made VHF/UHF antenna here at the house. It is a vertical dipole, not a mast mount or mag mount or even a vertical. The 440 part works off of the 144 part, meaning, no filters or coils. SWR on both is acceptable.

Now, if you want to also work the Marine bands you will need to tune the antenna a little shorter to achieve a usable SWR in both the Marine and Ham portion of the band. Good VHF antennas have a forgiving bandwidth but some can be very narrow. The SWR I have on a repeater frequency is low (I would have to attach my meter to find the exact number) and the SWR on Channel 16 is also low. Probably in the <1.5:1. SWR on UHF is a little higher. If you need exact numbers I will hook up the NanoVNA and do a sweep for you.

Hope that helps.

 

[ctrout]

I found that the Comet CA-2x4SR is specifically designed for wide band coverage in the ham through the emergency services bands. They advertise it as having an SWR of less than 2 from 140 through 160 and 435 through 465. As a search and rescue member, I should have thought of this first, especially since I use this very same antenna on my truck to cover the ham bands as well as SAR/forestry service (151-172) and police/GMRS (451-465) and it does very well. I put my analyzer on the truck antenna last night and found that the Comet antenna is wide banded enough that if I tune the center frequency to 151.660 I'll see an SWR of 2.0 or less from 146.520 through 156.800 (channel 16, highest frequency I can legally transmit on). I'll try to remember to report back once I am able to raise the mast and put the analyzer on the new stick once it arrives.