Two way radios
Joined: Jul 2003
Posts: 13,471
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From: Upstate NY
Radio Shack made a mobile one with an external antenna that runs off the car's power outlet. It is out of production, but they show up on eBay every so often. I picked one up, new in the box, for about $25 shipped.
Seems to work pretty well. I like not having to deal with batteries.
http://www.popularwireless.com/gmrsr...ack211850.html
Seems to work pretty well. I like not having to deal with batteries.
http://www.popularwireless.com/gmrsr...ack211850.html
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Joined: Feb 2001
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From: West Henrietta UPSTATE NY
Originally Posted by tomcatt,Oct 16 2004, 09:59 PM
I did find a motorcycle intercom system (Nady PMC-2X) that I think I can adapt to in-car use. It uses two headsets in full-duplex operation (like a telephone) with VOX for the noise-cancelling mics, and it has a jack for an external device like an FRS radio or cell phone. It runs on batteries or the vehicle's power, and lists for $80 although I found several websites that offer it for as low as $50.
Joined: Apr 2003
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From: Clifton, VA
Originally Posted by Elistan,Apr 6 2005, 10:26 AM
At our autocrosses, we use Cobra brand radios. Whenever somebody working a corner uses thier personal Motorola radio, I can barely understand them. But if they use our Cobra units, they come through perfectly clear. Previous Motorola radios I've owned have had clarity issues as well. Cobra is the way to go, IMO - although I only have experience with two different models, and one of those isn't made any more.
Perhaps we should cover this at the "drivers meeting" before the start of the drive. We have experienced these "unintelligeble" transmissions on past drives as well.
All most always, regardless of the brand of FMS radio it is caused by the user inducing "over modulation" by holding their radio's microphone too close to their mouth to (in their mind) compensate for having their top down.
For those of you have been on drive that we have participated in with our Motorola T5720's I do not believe that there has ever been a problem understanding either Plantpixie or myself due to this "over modulation". I humbly suggest that people have their VOX turned off (so wind noise does not key the microphone), and that you hold the radio no closer than two inches from your mouth closer the three inches is better. Unless you are so tall sitting in your S with the top down that it puts you into the airflow over the windshield in which case you may want to duck down a bit to get out of the turbulence before trying to transmitt.
For what it is worth, I have a bit of a back ground with RF, so that is why I throwing in my .02
Joined: Aug 2003
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From: Frederick, MD
That is absolutely right. In most cases, effectiveness really depends on the individual operator. Proper radio operating procedure must be followed to effectively communicate. Some people begin to talk as soon as they push the button which is the wrong thing to do. Push the talk button and wait about a second and then begin your transmission and when you are finished, make sure to let go of the push button about a second after you've finished talking. Using terms like "over" and "out" are basic radio operating protocol that everyone should agree on. Each person should have a call sign. But I am sure everyone knows.
Joined: Apr 2003
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From: Clifton, VA
Originally Posted by Honda 367,Apr 6 2005, 08:20 PM
That is absolutely right. In most cases, effectiveness really depends on the individual operator. Proper radio operating procedure must be followed to effectively communicate. Some people begin to talk as soon as they push the button which is the wrong thing to do. Push the talk button and wait about a second and then begin your transmission and when you are finished, make sure to let go of the push button about a second after you've finished talking. Using terms like "over" and "out" are basic radio operating protocol that everyone should agree on. Each person should have a call sign. But I am sure everyone knows.
^^^^ I guess that I should have mentioned that any radio of this type is Half Duplex that requires a Push To Talk (PTT) button. Unlike a regular POTS telephone that is Full Duplex which enables true two way communications. A half duplex radio requires ONE WAY communications at a time. As Honda367 has pointed out, most of the problems are user related (created) by a lack of understanding of how half duplex communications works. As he pointed out: That is where the words "over" came from. With the Motorola's the words over is replaced by a double beep tone to signal the end of the communication.But, at the risk of sounding redundant the biggest problem is "over modulation" caused by holding the microphone too close to one's mouth.
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Joined: Jan 2002
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From: Rochester
Actually, using "over" on an FM radio is "over"-kill. This procedure was developed for AM and single-sideband communications where you can't tell the other party has dropped carrier. That's not an issue with FM.
But the comments about waiting briefly after pressing the PTT and not being too quick to release it are right on. It also can be a good idea to make an initial transmission fairly simple to get the attention of the receiving party. Someone driving top down has a lot of noise to deal with an may not realize you're calling until you've already said what you wanted to say. Or maybe that's just me!
Tony
But the comments about waiting briefly after pressing the PTT and not being too quick to release it are right on. It also can be a good idea to make an initial transmission fairly simple to get the attention of the receiving party. Someone driving top down has a lot of noise to deal with an may not realize you're calling until you've already said what you wanted to say. Or maybe that's just me!
Tony
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