ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  
Pages: 1 2 [All]   Go Down

Author Topic: Walkie-Talkie...CB..what else??  (Read 5790 times)

Kurt Rivers

  • Full Member
  • ***
  • Offline Offline
  • Posts: 193
Walkie-Talkie...CB..what else??
« on: May 20, 2004, 09:51:35 pm »

I need some type of radio system that I can contact a person about 1 mile up a hill which is a jungle between where I will be and the person on top. What would be the best radio type system to use and what kind? I dont want to spend anything crazy but what a good solid connection if you know what I mean. I would also like it if their was a ear piece and a small lavre kinda mic to talk with. Anything will help here.
Logged

Craig Leerman

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1389
    • http://www.techworksvegas.com
Re: Walkie-Talkie...CB..what else??
« Reply #1 on: May 21, 2004, 05:25:16 am »

There are three bands of service that would work well for you. FRS, GRMS, and MURS. Other services and bands are available, but will require expensive licenses, and expensive equipment.


For uses up to about 1 mile, a good solution is the FRS band of radios. FRS stands for Family Radio Service. This is a band
of radio service that does not need a license for use. FRS radios have a maximum output of 1/2 watt (500 milliwatts).  Cheap radios can be had for less than $50 bucks per pair. Better radios will cost almost $100 bucks per unit.  Radio Shack, Wall Mart, K Mart, Sporting Goods Stores, Best Buy, etc.. and elsewhere sell these type of radios


The channels available are

Channel 1: 462.5625mhz
Channel 2: 462.5875mhz
Channel 3: 462.6125mhz
Channel 4: 462.6375mhz
Channel 5: 462.6635mhz
Channel 6: 462.6875mhz
Channel 7: 462.7152mhz
Channel 8: 467.5625mhz
Channel 9: 467.5875mhz
Channel 10: 467.6125mhz
Channel 11: 467.6375mhz
Channel 12: 467.6625mhz
Channel 13: 467.6875mhz
Channel 14: 467.7125mhz

The most common radios for FRS are the  Motorola Talkabout radios. Many other manufacturers make them also, and they are all compatible.  Low cost radios offer one or more channels. Better units offer all 14 channels, and even privacy codes so you don't hear or interfere with others using the same channel.  Many road shows use this service and these radios. I keep a few in all my road boxes as well as a pair in my own tool kit!  1 mile is pushing it for the range though!

 http://commerce.motorola.com/consumer/QWhtml/2way_family.htm l


For longer ranges, and higher power output, there is a band called GMRS or General Mobile Radio Service. GMRS radios are available in higher output that FRS radios (1-5 watts) and transmitt for longer ranges (up to about 5 miles). GMRS radio operators are required to get a GMRS radio license from the FCC. A license costs less that $100 for the first year, and a few bucks per year renewal.  Inexpensive GMRS radios cost around $100 and better models can top out over $300.

The available GMRS channels are:

1 GMRS/FRS 462.5625
2 GMRS/FRS 462.5875
3 GMRS/FRS 462.6125
4 GMRS/FRS 462.6375
5 GMRS/FRS 462.6625
6 GMRS/FRS 462.6875
7 GMRS/FRS 462.7125
8 GMRS 462.5750
9 GMRS 462.6250
10 GMRS 462.6750
11 GMRS 462.5500
12 GMRS 462.6000
13 GMRS 462.6500
14 GMRS 462.7000
15 GMRS 462.7250


There are also radios that will work on both services. They are marked as "FRS/GMRS" or "dual-service radios" and are available from many manufacturers. The pair in my toolkit are dual-service.
You can get GMRS radios from places like Graingers, Sporting Goods Shops,  and of course from radio companies like Motorolla and Kenwood (among others)


The last service of radio that would work well for your use is called MURS or Multi- Use Radio Service.  Murs is sometimes called the VHF CB Radio. Radios are restricted to 2 watts of power and handheld units can expect ranges of 1/2 mile to a few miles. Mobile units with car mounted antennas usually work up to ten miles, and base stations with large fixed antennas can have a range of 20 miles or more!  I have never used MURS, but I understand that the radios are not that expensive with models available starting at about $100.



Chan: 95.632 MHz
Chan: 151.820 MHz
Chan: 151.880 MHz
Chan: 151.940 MHz
Chan: 154.570 MHz
Chan: 154.600 MHz

Out of all the available options, I would go with dual service FRS/GRMS radios from either Kenwood, Icom, or Motorolla. These radios will work well for your application, and can also be used with all the other FRS radios.

Craig
Logged
I'm so old, when I was doing FOH for Tommy Dorsey, to balance out the horn section I would slide their chairs downstage and upstage to mix!


Kurt Rivers

  • Full Member
  • ***
  • Offline Offline
  • Posts: 193
Re: Walkie-Talkie...CB..what else??
« Reply #2 on: May 22, 2004, 05:11:39 pm »

Thank You, I'll look into the FRS/GRMS radios.
Logged

Alex_C

  • Full Member
  • ***
  • Offline Offline
  • Posts: 162
Re: Walkie-Talkie...CB..what else??
« Reply #3 on: May 22, 2004, 05:25:37 pm »

I'd go for a dual-service FRS/GMRS set as well. Good range, and are great for comms at work as well. We used to (when I was in the USA) plug one into the sound desk ("Push-to-talk / PFL-to-listen") and give them to all the crew. Only bad thing was when the FOH guy routed his radio to the mix buss Laughing
Logged

Kurt Rivers

  • Full Member
  • ***
  • Offline Offline
  • Posts: 193
Re: Walkie-Talkie...CB..what else??
« Reply #4 on: May 22, 2004, 09:58:07 pm »

So lets see if this would work. Can I make some attenna to connect to a murs or FRS radio from the station at the bottom of the hill(because it will be staionary). So if the radio w/o the super attenna only has a short range but the stationary radio will send and receive all the signals from the normal one correct? If theirs a normal radio at one end then another somewhere else could the super attenna from the stationary extend their range? I doubt it but I don't know much about radio signals.


Would this help at all w/ these kind of signals?
http://www.oreillynet.com/cs/weblog/view/wlg/448
Logged

Craig Leerman

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1389
    • http://www.techworksvegas.com
Re: Walkie-Talkie...CB..what else??
« Reply #5 on: May 22, 2004, 11:46:17 pm »

Quote:

    Can I make some attenna to connect to a murs or FRS radio from the station at the bottom of the hill(because it will be staionary). So if the radio w/o the super attenna only has a short range but the stationary radio will send and receive all the signals from the normal one correct? If theirs a normal radio at one end then another somewhere else could the super attenna from the stationary extend their range?      


Antennas come in 2 basic varieties, OMNI and DIRECTIONAL. An OMNI antenna is one that works in all directions. A whip antenna is a good example of an OMNI antenna. Directional antennas are antennas that pickup or transmit in one direction better than others. The old TV antennas on many roofs are good examples of DIRECTIONAL antennas. The other things important about antennas are the WAVELENGTH of the radiator, and the GAIN in any direction.

The WAVELENGTH refers to the length of the radiator . Since this is an audio site, I'll use an sound example, and talk about a wireless mic receiver antenna. Most of us have seen a Shure L4 or LX wireless system. These come with 1/4 wave antennas. That means that the antenna is 1/4 as long as the wavelength it operates on. These Shure systems operate in the VHF range of 169 - 209 MHz and their 1/4 wave antennas are about 18" long.  A 1/2 wave antenna for the same system would be about 36" long, and a full wave antenna would be about 72" long. 1/4 wave antenna work OK (as long as they are 1/4 of the actual band wave) but only really pick up about 1/4th of the signal. A full wave antenna picks up the entire signal, and therefor suffer from less dropouts, and has a hotter signal to send to the receiver.

Transmission works the same way. You can transmit over a shorter wavelength antenna, but you will send out more signal over a longer wavelength antenna.

GAIN refers to the signal strength of the antenna, as well as signal strength in any direction. A  1/2 wavelength antenna will have more GAIN than a 1/4 wavelength antenna (in all directions). For a directional antenna, the antenna may have 10 or 20 dB more GAIN in one direction than all others. Directional antennas work better because of two things. One, they keep out stray signals (to a degree) from entering the receiver. Two, they increase the gain of the signal in one (or more) directions, so you can "aim" the antenna.  There are different types of directional antennas. The common TV antenna is called a Log-Periodic Dipole Array or LPDA, the common satellite dish is called a Paraboloid Reflector. Other common types are Yagi, Screen and Corner reflectors, and Dipoles.

For your short (1 mile) needs, simply using longer whip antennas, or using a set of basic directional antennas would be a good idea.

MURS radios are set up to take remote antennas. Like a CB or HAM  Radio, MURS radios have an antenna connector that allows you to use different ant types depending on your needs. Unfortunately,  FRS/GMRS radios (at least all the handheld ones that I have seen) all seem to use built in antennas with no provision for using an external one. There may be GRMS radios out there that have external antenna capabilities, I just have not seen them.


Actually, after thinking about what you want to do, I was also thinking a CB Radio system (26.965-27.405 MHz) would do the job for you as well. You could get 2 inexpensive mobile CB radios, a pair of 120 to 12 volt adapters and some good whip or directional antennas all from a place like Radio Shack for way under $200 bucks and just pick a CB channel (other than channel 9 which is used only for emergencies) that is clear and use them. No license required, and they will surely transmit more than a mile!  If you go the CB route, make sure you use mobile CBs (like for use in a car, or base station CBs and not the Walki Talkie styles, as the handheld Walki Talkies won't have the available power as the mobile or base station units.  Other than truckers, and the odd amatuer radio buff trying to skip CB signal around the globe, you should find the CB Band pretty clear these days! Also, there are many companies who sell CB radio amplifiers (AKA Linears) that will increase the transmit power of the units. These devises will be illegal if they boost the transmit power over of what is allowed by the FCC (5 watts) but they are out there, and available if people want to use them.

In fact, the more I think about this, CB is probably the way to go for this! That way you would be able to use large whips or directional antennas, and also use any other hand held or mobile CB to also communicate to your system.

Craig
Logged
I'm so old, when I was doing FOH for Tommy Dorsey, to balance out the horn section I would slide their chairs downstage and upstage to mix!


Michael Prasuhn

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 673
Re: Walkie-Talkie...CB..what else??
« Reply #6 on: May 23, 2004, 12:26:17 am »

Craig Leerman wrote on Sat, 22 May 2004 21:46


[snip]

Other than truckers, and the odd amatuer radio buff trying to skip CB signal around the globe, you should find the CB Band pretty clear these days! Also, there are many companies who sell CB radio amplifiers (AKA Linears) that will increase the transmit power of the units. These devises will be illegal if they boost the transmit power over of what is allowed by the FCC (5 watts) but they are out there, and available if people want to use them.

[snip]




EXCUSE ME? I think you would have to look long and hard to find an amateur messing around in non amateur bands. Hams are exceptionally noted for doing an excellent job self policing themselves. Not to mention that there would be no reason for a ham to use those frequencies, as they wouldn't find anyone there that they could talk to, except for other hams breaking the law as well.

And as far as I am informed, there are no legal linear amplifiers  for use on the citizens band radio. Most that you will find are home made, and also tend to be of rather poor design, and produce large amounts of spurious emissions.

Not to start a flame war, but I just feel the need to defend often misunderstood amateur operators.

-Mikey P (KC8JHS)
Logged
Michael D. Prasuhn
Freelance audio engineer and technical director/IT
http://mikeyp.net

Craig Leerman

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1389
    • http://www.techworksvegas.com
Re: Walkie-Talkie...CB..what else??
« Reply #7 on: May 23, 2004, 09:39:50 am »

Quote:



EXCUSE ME? I think you would have to look long and hard to find an amateur messing around in non amateur bands. Hams are exceptionally noted for doing an excellent job self policing themselves. Not to mention that there would be no reason for a ham to use those frequencies, as they wouldn't find anyone there that they could talk to, except for other hams breaking the law as well.

And as far as I am informed, there are no legal linear amplifiers for use on the citizens band radio. Most that you will find are home made, and also tend to be of rather poor design, and produce large amounts of spurious emissions.

Not to start a flame war, but I just feel the need to defend often misunderstood amateur operators.

-Mikey P (KC8JHS)




I love how some folks get their panties in a bunch for no reason.


If you actually read what I said, I said the "odd amateur radio buff",  NOT a HAM radio or licensed radio operator!  My neighbor, a retired defense electronics guru, spends his time skipping CB radio signals around. His longest distance so far is  from Southwestern AZ, to Central America.  YES, its legal to skip signals off the atmosphere, and NO I didn't imply that HAMS were invading the CB band. According to my neighbor, the CB bands are very active with "skippers". Its a big trend in low income nations who cant afford high priced radio equipment.  

If you also read all my posts, you will see that I pointed out where licenses were and were not required. I do not advocate anybody operating radios in the wrong bands and without licenses. Of course, FRS, CB, and MURS need no licenses to operate.


Also, LINEARS amplifiers ARE legal if they are under the allowed wattage. You will also note that I mentioned that they "will be illegal if they boost the transmit power over 5 watts"  Do a little searching and you will find many manufacturers like Cobra, Golden Eagle, Messenger, and Galaxy make these LEGAL amplifiers.   Truckers like to use them because many mobile radios do not actually put out the legal wattage limit. I have a CB in my large truck. On the test bench it barely gets out 3 watts, though it says it does 5. Enough for my local trucking needs, but probably not powerful enough for the over the road truckers, who still rely on CB radios daily.  


Craig
Logged
I'm so old, when I was doing FOH for Tommy Dorsey, to balance out the horn section I would slide their chairs downstage and upstage to mix!


Scott Raymond

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1628
Re: Walkie-Talkie...CB..what else??
« Reply #8 on: May 23, 2004, 12:03:22 pm »

[quote title=Craig Leerman wrote on Sat, 22 May 2004 22:46]
Quote:

    Can I make some attenna to connect to a murs or FRS radio from the station at the bottom of the hill(because it will be staionary). So if the radio w/o the super attenna only has a short range but the stationary radio will send and receive all the signals from the normal one correct? If theirs a normal radio at one end then another somewhere else could the super attenna from the stationary extend their range?      


Unfortunately,  FRS/GMRS radios (at least all the handheld ones that I have seen) all seem to use built in antennas with no provision for using an external one. There may be GRMS radios out there that have external antenna capabilities, I just have not seen them.


Craig,

They are available!  I have an Audiovox set that have "unscrewable" rubber ducky antenna's.  To look at them you wouldn't realize they are removable. They use what's called an SMA connector.  A quick search turned up mobile magnetic mount antennas for GMRS.  The antenna's seem to use BNC connections so they have SMA to BNC adapters available for that purpose.  A 5 db gain antenna ran about 40$ and a mag mount car antenna ran about 25$. I haven't gone this route yet but it may be interesting to try.

Scott

Some info I found.
Logged

Kurt Rivers

  • Full Member
  • ***
  • Offline Offline
  • Posts: 193
Re: Walkie-Talkie...CB..what else??
« Reply #9 on: May 23, 2004, 01:09:53 pm »

From what I'm getting I see that with CB radios have can really loose strength with objects in their way. I was thinking of getting a good base sation like CB pretty strong and then get some handhelds. I'm not sure if the jungle full of trees and brush would really cut down the signal for CB.

I was thinking of maybe this   http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4 0055&item=5700684142&rd=1
or this   http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=57007 12216

One at least needs to have jacks for mic/speaker because I'm thinking of getting the bone mic on one.
Logged

Michael Prasuhn

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 673
Re: Walkie-Talkie...CB..what else??
« Reply #10 on: May 23, 2004, 09:29:41 pm »

Thanks Craig, after re-reading your post I realize that you weren't quite saying the exact things I thought you were.

The CB band is quite versatile, there is no reason that given optimal band conditions, a person couldn't talk to anyone anywhere in the world, operating a good CB with good antenna at 5 watts. A few field days ago, my friends and I had a 10-meter (just a few megahertz higher than CBs...if that) station setup operating off of a shortened CB vertical. The rig was putting out less that 5 watts, but was well tuned. The moment of the day was working San Joaquin Valley from our measly station hidden in the Ohio valley.

-Mikey P
Logged
Michael D. Prasuhn
Freelance audio engineer and technical director/IT
http://mikeyp.net

Andy Peters

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 9104
    • http://www.latke.net/
Re: Walkie-Talkie...CB..what else??
« Reply #11 on: May 23, 2004, 11:56:59 pm »

Scott R wrote on Sun, 23 May 2004 09:03

To look at them you wouldn't realize they are removable. They use what's called an SMA connector.


SMA connectors are commonly used for microwave applications.  They do a gas-tight seal and have excellent signal-transfer characteristics.  Somewhere in a tool box, I have the proper torque wrench one should use when tightening these connectors.

-a
Logged
"This isn't some upside down inverted Socratic method where you throw out your best guess answers and I correct your work." -- JR


"On the Internet, nobody can hear you mix a band."

Scott Raymond

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1628
Re: Walkie-Talkie...CB..what else??
« Reply #12 on: May 24, 2004, 09:45:10 am »

Kurt,

Here's something I ran across in my quick search.  Just something else to throw into the mix.  If the base station is able to use an external antenna, it might be worth a look.  Unless it's changed, GMRS license's are 85$ for 5 years.

GMRS set
General Info on GMRS

Scott
Logged

Scott Raymond

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1628
Re: Walkie-Talkie...CB..what else??
« Reply #13 on: May 24, 2004, 10:20:48 am »

Andy Peters wrote on Sun, 23 May 2004 22:56

SMA connectors are commonly used for microwave applications.  They do a gas-tight seal and have excellent signal-transfer characteristics.  Somewhere in a tool box, I have the proper torque wrench one should use when tightening these connectors.

-a


Thanks Andy,

If we covered these back when I was in school I'd forgotten them.  I do remember some of the "quirky" things about microwave properties related to waveguides etc., but that was early 70's and I'd imagine the applications have changed a bit. Smile  They're a neat little connector and work well in these compact radios.

These little radios use a "finger" wrench Laughing to tighten as the connectors are built into the radio and antenna with nothing to get a hold of.

Scott
Logged

Kevin Maxwell AKA TheMAXX

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 935
Re: Walkie-Talkie...CB..what else??
« Reply #14 on: May 25, 2004, 10:35:16 pm »

Craig Leerman wrote on Fri, 21 May 2004 05:25


Better units offer all 14 channels, and even privacy codes so you don't hear or interfere with others using the same channel.


Just to clarify something, Craig your write up was very detailed and I know it is hard to cover everything, but the above quote is not 100 percent accurate. In simplified terms, the privacy codes generally will not let the radio hear the transmissions from someone that is on the same channel but is not using the same privacy code. But since you are both on the same channel it will affect transmission and reception. Radios using this type of system usually have an indicator light that blinks when the channel is in use and you are supposed to check if the light is blinking before transmitting. Technically I think you are supposed to open the squelch and confirm that there is no traffic on your frequency before you transmit.

I have used a variety of radio systems in a lot of different places and personally I hate the FSR radios. But if you are trying to do it cheap its hard to beat them.
Logged
Kevin Maxwell
Freelance Audio Eng. QBE
Pages: 1 2 [All]   Go Up
 

Page created in 0.05 seconds with 20 queries.