lundi 24 octobre 2016

Communication Complete Newbie- where to start?

Basic Comms

There are several legal choices available to the civilian to handle two way communications needs.

FRS: handheld radios only, fixed antenna, 0.5 watt fixed power, no repeaters, no license required (UHF band)

GMRS: handheld, mobile, and base radios, variable power okay, repeaters okay, external antennas okay, license for the family is required (UHF band)

MURS: handheld, mobile, and base radios, up to 2 watts, no repeaters, external antennas okay, no license required (VHF Band)

CB AM: handheld, mobile, and base radios, up to 4 watts, no repeaters, external antennas okay, no license required (Upper end of HF band, near the bottom of Low VHF band)

CB AM/SSB: mobile and base radios, up to 4 watts AM/12watts SSB, no repeaters, external antennas okay, no license required (Upper end of HF band, near the bottom of Low VHF band)

Amateur Radios: handheld, mobile, base radios, power depends on band, up to 1,500 watts in some HF bands, repeaters on some bands okay, external antennas okay, license for each operator required (HF, Low VHF, VHF, UHF plus some others that don’t really apply to general communications needs)(Personal only, no business)

Land Mobile Business Band: handheld, mobile, base radios, power depends on band and operating location, must always use minimum power required, repeaters on some bands okay, external antennas okay, Frequency selection fees & license fees are fairly expensive. (There are limited frequencies in HF, Low VHF, VHF, UHF bands.)(Business only, no personal)

FRS/GMRS/MURS/CB AM/ CB AMSSB are all set up with channel numbers on specific bands.

Amateur radios, for the most part, can tune various frequencies within the bands, with some standardization of frequency use on VHF and UHF bands for repeater and various other uses. Equipment is from cheap to very expensive.

Land Mobile Business band users, for the most part, are assigned specific frequencies within specific narrow band limits, but there are no channel numbers. Equipment is from somewhat expensive to very expensive.

Handheld to Handheld ranges:

Short Range (Less than 1 mile): FRS, GMRS (in and around urban areas, UHF Land mobile business band, UHF Amateur band)

Medium Range (Up to 5 miles): GMRS, MURS, CB AM, (there are no legal handheld CB AM/SSB radios I know of), UHF Land mobile Business Band, UHF Amateur

Medium Range (Up to 10 miles) Low VHF Land Mobile business band, high power VHF Land Mobile Business band, high power VHF Amateur

Longer Range (Up to 25 miles) As Medium range, but using repeater systems. Using linked repeater systems can extend the range, mostly just Amateur, well above the 25 miles.

Long Range (Over 25 miles): There are no 25 mile or 50 mile or 100 mile hand held to hand held options of which I am aware other than using linked repeaters. The closest one can come are man-pack HF radios for Amateur or Land Mobile Business band use, which are compact (relatively speaking), medium power, fairly large batteries, and long, awkward antennas. I simply don't consider these handhelds. The operation parameters are the same as regular Amateur and Land Mobile Business band HF set-ups, with limited antennas, unless stationary and larger antennas are deployed. Use on the move is somewhat limited.

For vehicle mobile to mobile ranges:

Short range (Less than 10 miles): FRS, GMRS, MURS, CB AM, VHF/UHF Land mobile Business Band, Amateur VHF/UHF (2 meter & 70 centimeter)

Medium range (up to 20 miles in really good circumstances: CB AM/SSB, GMRS with repeater use, VHF Land Mobile Business Band, Amateur VHF

Longer range (Up to 50 miles in really good circumstances): Low VHF Business band, VHF Business Band with repeater use, Amateur VHF with repeater use

Long range (Anything over about 50 miles): HF Land Mobile Business Band, HF Amateur

The ranges are extended very slightly from handheld range when talking to mobiles or base stations.

The ranges are extended somewhat from mobile range when talking to base stations.

All options can get longer ranges, except FRS, MURS, CB AM, & CB AM/SSB, and some Business band sections, with additional power amplification over the basic radios, very good omnidirectional antennas (all around coverage), and directional antennas.

Terrain plays a huge part in effective distances. Mountainous terrain (unless you are talking mountain top to mountain top) reduces the range of just about all frequency bands, with the lower HF frequencies the least. Heavily wooded and urban terrain reduce range. Heavy usage on a given band reduces range.

The cheapest options simply don’t have much range. The medium priced options can have a bit more range, if high quality equipment is used. The higher priced options will get you just about anywhere you want, though not necessarily on any given day at any given time, though by learning propagation effects, and the ability to use different frequencies as needed, one can often carry on scheduled comms if the right band and time is matched to the propagation at the time. Propagation is rather complex, and one needs to be fairly radio literate to start trying to make reliable communications based on it.

It basically boils down to having limited range communications, up to about 5 miles handheld to handheld, and 25 miles mobile to mobile reliably, for a decent price, and going Amateur for distances over that. Getting Land Mobile Business band systems are complicated and expensive, though they can do essentially the same thing the Amateurs can do. One is personal comms, and the other business comms.

This is my opinion of the very basics of civilian radio communications options. If you want additional information or have questions, feel free to ask.

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Communication Complete Newbie- where to start?

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