| Author |
Message |
    
Splbass17
Junior Member
Username: Splbass17
Post Number: 35
Registered: 9-2005
| | Posted on Tuesday, April 03, 2007 - 11:59 pm: | 
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I know this sounds stupid but I don't understand why some radios have FM.
I know FM is Frequency Modulation and AM is Amplitude Modulation but thats about all I understand. Isn't CB and all the Ham bands like,80,60,40,40,30,20,10,etc on AM ? If so, then what bands are on FM? And whats the reason for using FM if everyone is on AM ? Hopefully I dont sound like a dumb a** but I was always curious of this. Thanks guys |
Tech237
Moderator
Username: Tech237
Post Number: 739
Registered: 4-2004
| | Posted on Wednesday, April 04, 2007 - 10:14 am: |
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Lets see, 10m has an FM section and all hams bands above that run mostly on FM. Several other counties have CB services that use FM.
Simon
Tech237
KD7IEB
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Splbass17
Junior Member
Username: Splbass17
Post Number: 36
Registered: 9-2005
| | Posted on Wednesday, April 04, 2007 - 1:45 pm: |
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Interesting, thanks |
Bruce
Senior Member
Username: Bruce
Post Number: 4410
Registered: 9-2003
| | Posted on Wednesday, April 04, 2007 - 7:49 pm: |
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FM is widely used by land moble, MURS, GMRS and marine services. It has many advantages over AM and even sideband when used for this kind of services.
FM works well with tone squelch systems a must on most REPEATER systems.
It is LEAGAL on HAM radio above 29.500 mhz and HAMS are allowed the FULL leagal limit on this mode.
You can find it ABOVE 29.500 mhz with calling frequencies on 28.600, 52.525, 146.520, 223.500 and 446.000 mhz.
Due mainly to its bandwidth it is not allowed on cb in the US.
On 6 since 66
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Bruce
Senior Member
Username: Bruce
Post Number: 4411
Registered: 9-2003
| | Posted on Wednesday, April 04, 2007 - 9:40 pm: |
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oops 29.600
also 29.62, 64, 66 and 68 are repeater pairs
On 6 since 66
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