Topic: Radio signals
What is the best way to boost your incar radio signal? we had problems this last race on the back end of the course.
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What is the best way to boost your incar radio signal? we had problems this last race on the back end of the course.
Be very very careful. Screwing with this stuff can land you in legal trouble.
disclaimer out of the way. Get a professional radio setup. look up nerdie racing or the rugged race radios that are sold on the Lemons store.
There are also tons and tons of cheap chinese radios all over amazon and ebay. They work great, but they very very easily let you get into frequencies that you should NOT be messing with. Do not play with these if you don't know what you're doing. Races have been shut down because someone was using an emergency band and interfering with local (and sometimes not even that local) fire/police/rescue.
You really should have a license for most radios. even the simple GMRS radios you can buy everywhere you are supposed to have a license for. Will someone ever check you? maybe unlikely, but you should at least know. Do not go trying to throw amplifiers on your existing radios. The FCC is not amused with someone trying to turn their handheld into a 50W transmitter.
You could just take apart your handheld radio and run an antenna wire to your roof, and mount a high antenna on your roof.
I heard it helps a lot....
I run the Samsons racing radios. To get good reception on longer race tracks I've found that the shark fin antennas are crap, better with the old school antenna. Making sure all your coms wiring is isolated from power and ignition wiring and NEVER coiling your antenna wire will improve range by cutting down on noise.
Bone head move on my part was also installing the in car radio in a spot where the drivers could reach it. Different ear buds and helmet speakers have widely different volume levels so it a good idea to have access. Some time when we run with teams we lie we share a channel or monitor each others channel so we can talk to each other as well.
I can't hurt to have your spotter in a place that's higher elevation and somewhat centrally located. Or if its an option have your spotter or crew hooked into a real antenna.
I like a 12 volt adaptor so you cant rum out of battery power also.
Greg
Yea go for a remote Antenna, but don't Efff around. Get your radio programmed correctly and be POSITIVE it's designed for the frequency you are using. Some folks like to run garbage outside its intended frequencies and it bleeds all over the spectrum and causes interference which makes everyone ELSES radios seem like they don't work right. (the interference is mostly under the Squelch threshold, but it still messes up your carrier.)
GMRS regs need to change. I can broadcast over 30W in the 120.00 MHz band in a plane with no FCC license for hundreds of miles, but ohh no not a 5 Watt up in the 400 MHz range on the ground. a whole half mile. oooooooh!
If you are talking about improving signal strength, there are a few things that you can do, even if you are using the simple "blister pack" FRS/GMRS handhelds that you get at the big box stores.
Even with the large holes (windows), the sheet metal of your car forms a Faraday cage that will highly attenuate the signals both received and transmitted by the radio. If your radio has a fixed antenna (which is the case for most FRS/GMRS radios), then placing it near a window opening should help. Don't keep it down low in the car, and make sure to keep the antenna oriented vertically. If you lay it down flat (horizontally), and your guy in the pits is holding his radio vertically, you will get significant polarization losses that will reduce your reception at both ends even further.
If your radio allows for it, running an external antenna on the roof of the car will provide the best bang for the buck. However, if you mod a radio that does not have a removable antenna, just running a "wire" to the roof-mounted antenna will likely make things worse (in addition to being illegal). The transmission path between the radio and antenna needs to be a specific impedance, usually either 50 or 75 ohms. If you don't provide the correct balanced-pair connection to/from the antenna (i.e., coaxial cable), you will degrade performance (best case) or damage the transmitter (worst case).
Obviously, the same goes for the pit radio. If you can use an external antenna, get it up as high as possible. I use a collapsible painters pole to get the pit antenna up around 15 feet or so.
I've seen some teams cut a hole in the roof of the car and mount their hand-held inside the car near the roof such that the antenna is poking out of the hole. That should probably help as well, but then you may have a hard time reaching the controls.
As others have mentioned, if you do use an external antenna, make sure that you do not coil the extra coax cable - run it in straight lines. You can "zig-zag" (s-shape) any excess as necessary. The coiling will essentially create an in-line inductor which will attenuate the signal going to/from your external antenna, counter acting the goodness that you added with the external antenna.
It seems many teams have problems by where they mount it and the radio antenna being buried in the car with too much interference. Do what you can so the antenna can have good line of site out of the car, so remote antenna, mount it so its antenna is popped up in the windows lines, I think I even have seen a car where they mount it to the roof and have a hole that the antenna sticks out the roof. This can help a lot of the radios and is totally legal so you don't accidentally get some upset, or the police closing down a race because someone is on their frequency.
We run the cheap Motorola walkabouts, MT352R. They do not have a removable antennae. If we did the "drill a hole in the roof" trick, would it matter if the antennae were actually touching the roof?
You should avoid it as best as you can. However, if the antenna is covered by a rubber/plastic coating (like most "rubber ducky" type antennas), touching the antenna to the car may degrade it a bit, but not too much (assuming that you are talking about the 'base' of the antenna). However, having any metal portion of the antenna touching the car is a no-no.
The radiation pattern of a rubby ducky antenna (technically called a normal-mode helix antenna) is essentially doughnut-shaped, with the bulk of the radiation coming from its center portion, so its important to get as much of the antenna outside the car as possible. Any portion of the antenna left inside the car will be attenuated by the metal of the car.
We run the cheap Motorola walkabouts, MT352R. They do not have a removable antennae. If we did the "drill a hole in the roof" trick, would it matter if the antennae were actually touching the roof?
We run pretty much the same radio, not sure on the exact model number off the top of my head. Our radio is pretty clear and usually work the full track. I think Road America we had one spot that it was iffy, and was out by the carousel which I'm sure would be a challenge for most systems. We never did anything fancy, its just when we were hooking things up we went the easiest route so on our dashbar we strapped the charging station that we connect to the cigerette lighter for power while running, and just plop a radio in the charging station. This makes it so the antenna is high enough that you can see it in the windsheild and out the windows and seems to always have a clear communication. We do sometimes feel we need to translate for other teams on our frequency who keep saying repeat.
As others have mentioned, if you do use an external antenna, make sure that you do not coil the extra coax cable - run it in straight lines. You can "zig-zag" (s-shape) any excess as necessary. The coiling will essentially create an in-line inductor which will attenuate the signal going to/from your external antenna, counter acting the goodness that you added with the external antenna.
It seems there are differing opinions on this or maybe it's just "fake news" LOL. Read post #8 here.
FWIW, we use an external antenna with the excess coax coiled, and have no reception problems.
We use this guy on the roof and it works well combined with a ducky antenna on the spotters radio.
https://www.amazon.com/gp/product/B016S … &psc=1
You could just take apart your handheld radio and run an antenna wire to your roof, and mount a high antenna on your roof.
I heard it helps a lot....
We did this. We removed the antenna from our Midland GMRS and installed a connector, then ran a cable to the roof and hooked it up to a generic antenna that was about the same size as the original. Works well. It also solved the problems we had with our video system. It took months to figure it out but radio comms messed up the video/audio sync.
We've always had communication issues. Partly because we are cheap and don't want to spend a ton of money on communication and partly because we just make mistakes or lose focus on that part of racing. This race we tried the Zello app along with a Bluetooth PTT button in the car. The only wires were from your phone to your ear, which I guess you could likely make Bluetooth as well. For those that used it it worked great. Fantastic sound, no wires in your car, and if everyone gets their own PTT button (about $30 each) they already have it synced to their phone. Another bonus is no one is ever on your channel. You don't have to listed to other teams endless chatter. Also, if you want anyone can add the app and join the channel with your permission so people can even listen in from home. Oh, and the app is free! Only cost is headphones with a microphone ($10) and the PTT ($30).
Downside would be if there is no cell service at the track, but NJMP does not have this issue.
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