Amateur Radio on a Bicycle
I am a bicyclist, and am interested in doing this. I am currently working on getting it set up.
My experience so far
I participated in the MCC Flatlander bicycle ride in September 2010. For that ride, I had my VX-7R in the back pocket of my jersey, with its standard rubber duck antenna. I had the earpiece with PTT button hooked up to it.
The ride didn't take me all that far from the repeater -- maybe 12 miles -- and it performed fine for receiving. Transmitting was impossible with it in that location. If I'd pull it out and hold it, it worked fine for transmitting as well. Conclusion: I need an external antenna for this.
I thought I'd try a mag mount antenna on my bike rack, but turns out the rack is made out of aluminum or some such material so that this won't work. It doesn't stick at all.
It generally seems that an antenna that is 1/2-wave on 2m is best. Such an antenna won't require a ground plane on that band.
People generally seem to make their own mount. Some attach it to the saddle post. Others to the bike rack. I think bike rack will be most suitable for me. One person suggested attaching an aluminum plate to the rack, and then use a NMO (non-magnetic option) mount on that. Another suggested an antenna with PL-259 connectors and an SO-239 bulkhead connector on such a plate.
HT mounting suggestions
Hose clamps, velcro...
A windscreen on the mic.
- I got a 2m/440 antenna that is half-wave at 2m. I used an automotive NMO mount to attach it to my bike rack, and caulked around the underside of it.
- The radio is a Yaesu VX-7R
I got a Pryme Radio SPM-400D series boom/mic headset suggested by the Riding the Air Waves article below. The SPM-442D is for the VX-7R, though that one may be getting discontinued.
To attach the radio, I got an Arkon SM327 universal mount
Other Bicycle Mobile Pages
- Uses a Larsen NMO-150HW half-wave. "I find the LArsen to be light and nimble, easily flexing around low tree branches and other obstacles in the woods. The coil is a great place to mount a flashing tail light, too."
- Used GOOP Household Adhesive to attach panel to rack.
- homebrew handlebar mount
Nice boom speaker/mic with detachable PTT button
- Suggests feedline that is odd multiples of 1/4 wavelengths. Not sure how much that matters.
- Larsen has GBR-1 (3/4 wavelengths) or GBR-2 (5/4 wavelengths), custom made for "bikemobes"
- Antenna Larsen NMO 150-C-HW
- Suggests feedline that is odd multiples of 1/4 wavelengths. Not sure how much that matters.
K5PA Bicycle Mobile - even does HF!
Tips from BMHA (needs organization)
- I love my Klein Electronics Ghost headset... it uses an in the ear bone conductive microphone so there is 0 (yes, ZERO) wind noise.
http://www.twacomm.com/catalog/model_GHOST-LITE.htm There is a Yaseu version... it's just not listed on that page.
You might try cutting a small block of foam packing from one of the ubiquitous pieces we all save from incoming shipments and poke a small hole in it just enough to fit over the microphone and see if it helps. My mike looks a lot like yours but has the foam sock on it, and I rarely get wind noise complaints any more. Here's a link to my favorite headset, and the mfr makes them for Yaesu as well: http://cgi.ebay.com/2-Pin-Motorcycle-Helmet-Headset-Kenwood-Radio-TH-D7-/220584814791?pt=2_Way_Radios_FRS&hash=item335be128c7 you didn't include a photo so I'm guessing you could elevate your "half-wave" antenna with a piece of PVC or fiberglass small diameter pipe/tubing so more of the radiation pattern would be above your back and hopefully your head. Height=gain. The tip of my homebrew J pole is about 8 feet in the air.... yes, it's a tree detector, but it does hit all kinds of repeaters and doesn't do too bad even on simplex. My J pole bends when it hits overhead branches; it helps if the antenna rod has some flexibility. Remember the basic laws of ham physics apply to bikes and cars as well as home stations: "If it stays up all year, it isn't big enough or high enough."
***It's often called a "wind sock" since it completely covers the mic, the only hole is the one you use to slide the "sock" over the tip of the mic. It does muffle the audio somewhat, but it SIGNIFICANTLY reduces the wind noise. I get no complaints on my audio even though the mike tube often splays 3 or more inches from the side of my mouth. All other mic setups I've used (several) result in complaints about wind noise even when I don't notice any wind. My foam "sock" surrounds the mic with at least a half inch of foam. Not sure an ear-bud foam cover would reduce the noise sufficiently but it's always worth a try..... BTW, I've tried all sorts of "throat mikes" and "bone-conduction ear-mikes" and while they work and have almost NO wind noise, the low and muffled audio complaints I always get convince me they're not worth the money, PARTICULARLY the MFJ "ear-mike" they sell. The Velcro-mounting handlebar PTT switch and wiring harness are probably almost worth the cost of the MFJ mike, but the mike itself absolutely SUCKS. Do NOT try one, you will regret it. I have some cheapo foam earbud covers that I'm thinking of cutting up and reusing for this.
No, the foam I'm recommending is the soft, gray, squeezable foam that often comes as packing with test equipment and other fragile parts shipments. Often it has "egg carton" ribs similar to the foam you can also buy to put on top of your mattress to increase sleeping comfort. (A small blob of that could be used too, but won't last too long in the outside world). You can cut it to any desired size and shape with scissors.
- ICOM IC02at is very rugged and nice
It's been a long time since I did bicycle mobile. I'm currently between setups. I don't think I ever did weatherproof mine. I don't recall if I got caught in the rain with it. But I'm sure I did since I had wrapped up my HT in a sandwich bag. If I were doing it again, I'd likely cut the thumb off a latex glove and put the PTT switch in there before mounting it to the handlebar. Yes, I kept it on the handlebar and would push the PTT with my thumb. The microphone held up to rain or sweat. The earpiece was sealed from the weather since it was in my ear. I had a problem with the wire getting pulled taught when I'd shift positions or something. It was a fine line between too much slack hanging toward my legs and it startling me when the slack was gone and the earpiece ripped out of my ear. I solved that by making a six-inch "drip loop" and using a rubber band as a "shock chord." I also put an alligator clip on the line to connect it to my helmet strap. With this, there was constant tension on the wire between my helmet and the handlebar. If all the slack was pulled out, then the shock would go to my helmet strap instead of directly to my ear. It was much better. Not sure if I've explained that well enough.
What happens is RF will travel back down the shield of the coax making your system less efficient. Just go down under or on top of you rack and where convient double back on the coax then continue toward the radio. I taped mine together before tie wrapping it to the rack. Don't let it kink, just nice clean set of 2... 180 degree turns. This way the RF stays where it belongs. The reason I said to try it with and without decoupling is sometimes metal objects close to the coax decouple it for you. I just check mine at the radio end of the coax. I do the same thing at home. I come down from the vertical antenna a foot or two, then take the coax back up a foot, tape it to the support mast then continue back down the pole to the radio. I only have homebrew 1/4 antennas on my roof for 2 meters, 220 and 440 and them must be doing ok because I can hit most repeaters with one watt. I have 2 separate VHF antenna one is a dual bander about 20 inches tall. The other is the Hustler Colinear which is just one big 80 inch tall antenna. I think the Hustler number is CG2. I had been using it on a vehicle until the bus coming up behind me got his mirror to close to my helmet. So I put up the big one and when I sway it back and forth the bus moves over and entire lane. How is the driver going to explain to his boss how his window got broke by a ham radio antenna.
I've done some bike mobile from my road bike (comms support for a century) and my commuter (Bianchi Castro valley, it's a steel cross style frame). I've posted a few time shere on my setup, and have photos of it (don't recall if the 2010 century mobile version is in there or not...nope, not yet!) Radio Mount - I've become a HUGE fan of the RAM mounts system. Check message #2332 (and the surrounding thread) - I'm using a Radio: RAM-HOL-BC1 RAM Mount Universal Belt Clip Bar Holder and Handlebar/Stem: RAP-274-1-BC1U RAM Mount Universal Belt Clip Bar Bike Mount with a VX8 and a VX5, liked it so much I bought a set for each bike. If you check the photos for my album (KS1G...), the very last picture shows the VX8 in the RAM mount on my commuter. Antenna - you've found that bigger is better already. I have the Larsen 2M 1/2 wave NMO on my road bike - I fashioned a mount I can bolt to the back of a behind the seat water bottle cage. The photo album shows the 2009 APRS-only version. For 2010, I had the APRS tracker on one side and the 2m whip for voice on the other (the tracker worked better than the VX8's internal APRS system). My other antenna of choice is a jpole on a fiberglass bike flag (see the 1st 2 photos in the album). 30 miles may simply be too far for 5W with a compromise antenna, or just lack of a ground plane, however. I have problems with either antenna at 5 w when I am much closer than 30 miles (terrain may be a factor for me, too). When you are in a car, can you hit the repeater reliably from 30 miles at 5W? You may have to accept the poorer S/N, or get one of the 25-30W "HT amps" and a small battery pack and run it only when you need it. I have gone through several Pryme mikes (400-series); the earpiece did not stay put, wind noise, or a wire got caught, ... For wired boom headsets, I found a cheaper one (and can't find the link now - might be in one of my older posts...yep, McKay C1LHS, see msg #2097) - looks like they make a version for the VX7: http://www.mckayproducts.com/store/Channel%20One%20Lightweight-Headsets.htm - C1LHS-V5 It's more rugged than the Pryme and cheaper. I zip-tie or clip the PTT to the handlebars near the right brifter for ease of access and safety. Just remember to take off the heaset when you dismount!