136-175mhz? 400-520? or 800-940?
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136-175mhz? 400-520? or 800-940?
Hi I need to know whats the pro's and con's of 900mhz radios which is better all around 136-175mhz? 400-520? or 800-940? thanks
Which is better?
It all depends on what you are trying to do. Do you have mutual aid concerns? Be careful of 800 and 900 MHZ because nextel is actively putting systems on the air that may cause interference with anything you put there. Again, a very broad question, any more specifics? FatBoy.
......I understand what the package says sir, but you cannot talk 28 miles with 3 AA batteries.......
There are pros and cons to each of the bands which you have provided. Listed below are the pros and cons to each.
136-175 Mhz VHF HIGH
The VHF band tends to travel longer distances which can be very useful in coveing larger areas without the addition of more sites of course geographical considerations must be taken into consideration as well. the VHF band tends to have a much higher ambient noise level throughout the band which can cause problems as well.
400-520 Mhz UHF LOW
The UHF band is a preferred band amongst commercial users. UHF tends to be extreemly reliable in all types of geography. UHF has tends to penetrate buildings and nooks and crannies better that VHF. The ambient noise level on the UHF band throughout the lower end of the band 400-470 is genarally low, now from 470-520 is has much higher ambient noise levels due to Television Translators and High Power TV.
800-940 Mhz UHF HIGH
The UHF HIGH band is OK. It penetrates buildings better than any other frequency band, but does not propagate very well. Users on this band tend to need more sites to cover the same areas where the usual VHF HIGH / UHF LOW types of system cover. I would recommend not putting anythin on this band or even consider using this band due to the fact that NEXTEL is putting up sites everywhere and it is beginning to cause problems te co-existing systems. Stay away from this band if NEXTEL is in your area!!!
136-175 Mhz VHF HIGH
The VHF band tends to travel longer distances which can be very useful in coveing larger areas without the addition of more sites of course geographical considerations must be taken into consideration as well. the VHF band tends to have a much higher ambient noise level throughout the band which can cause problems as well.
400-520 Mhz UHF LOW
The UHF band is a preferred band amongst commercial users. UHF tends to be extreemly reliable in all types of geography. UHF has tends to penetrate buildings and nooks and crannies better that VHF. The ambient noise level on the UHF band throughout the lower end of the band 400-470 is genarally low, now from 470-520 is has much higher ambient noise levels due to Television Translators and High Power TV.
800-940 Mhz UHF HIGH
The UHF HIGH band is OK. It penetrates buildings better than any other frequency band, but does not propagate very well. Users on this band tend to need more sites to cover the same areas where the usual VHF HIGH / UHF LOW types of system cover. I would recommend not putting anythin on this band or even consider using this band due to the fact that NEXTEL is putting up sites everywhere and it is beginning to cause problems te co-existing systems. Stay away from this band if NEXTEL is in your area!!!
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larryepage
- Posts: 221
- Joined: Tue Jan 15, 2002 4:00 pm
Which Band?
I agree that 400-520 MHz is an optimum band for most purposes. Compared to VHF, an antenna of the same overall length will give you between 4 and 5 dB more gain. Offsetting this is that transmission losses will be somewhat greater, and the power amplifier will be a little less efficient (more battery drain required for the same power out).
As mentioned above...the shorter wavelength generates better propagation into buildings but isn't absorbed by trees, rain, and the like as bad as 800/900 MHz.
LP
As mentioned above...the shorter wavelength generates better propagation into buildings but isn't absorbed by trees, rain, and the like as bad as 800/900 MHz.
LP
I will go with uhf. I will be using the radio in the city.-
RadioSouth
- Batboard $upporter
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- Joined: Mon Sep 03, 2001 4:00 pm
This item might be of interest, radio range calculator with scales for different frequency bands. http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 1360641770