MURS Band FM Mobile Radios?

"Contraband radios nor old Cobra cases" will be necessary. Only a willingness to learn a new way of communicating. The radios are already on the market and are driving the Japanese Mfgs such as Icom, Yaesu, Kenwood & Alinco crazy!

The key word is your willingness to LEARN! And see Balakov100's comment on not interfering!

aimhigh

 

For reliable line-of-sight, truck-to-truck conversations, those inexpensive low-powered M.U.R.S., GMRS, and FRS handheld transceivers are perfectly adequate, and so is CB radio, of course.

The lack of skip noise interference on the FM-modulated VHF and UHF bands may be appealing, but the fact remains that Citizens Band can still be relied upon for reasonably-good local range, plus it remains the "waterhole" where drivers can meet and communicate during emergencies and monitor other drivers' traffic and roadwork reports and speed-trap warnings.

In fact, the recent reduced-usage and even abandonment of CB by some in the trucking industry was never a good idea to begin with, particularly since the current solar cycle 24 is winding down. This means that daytime skip noise will steadily decrease from 2015 onwards and not peak again for approximately another 11 years. In any event, there are currently still plenty of quiet CB channels to be found and used--not to forget the "freeband uppers and lowers".

As for the LAD channels (officially Logging Administration), these frequencies are designated by Industry Canada for use by the Canadian forestry industry in the western provinces as well as by some in the east.
Canadian truckers crossing the country must therefore always bear in mind that these LAD frequencies are also licensed to other services such as fire departments, school bus companies, taxis, as well as aircraft, and they are monitored by the RCMP, so it is strongly advised to listen before transmitting and to maintain strict radio silence if and when such licensed services are engaged in radio traffic.

See: https://www.radioreference.com/apps/db/?aid=7336

These Canadian LAD channels are NOT, however, assigned to the forestry service in the U.S. They are licensed to entirely different U.S. commercial businesses as well as to some emergency services, so it would be strongly advised that Canadian truckers not use them south of the border.

As for the tropospheric ducting phenomenon of sporadic, long-distance VHF-UHF communications, I will refer those interested to the following webpage:

http://www.kb6nu.com/tropospheric-propagation-extends-vhfuhf-signals/

Drive Safely!

 

When there is stable anticyclonic weather, temperature inversions exist (warm air higher, cold air lower) which cause variations in the index of refraction in specific layers of the atmosphere. In the same way a prism bends light the VHF EM wave is bent allowing it to travel for hundreds of miles to an area where it encounters air which is normally inverted (colder air higher in altitude) which bends the signal back toward the earth allowing stations in the area to receive the signal (or transmit along the return path). Whereas skip is the wave reflecting between the earth and ionized layers of the ionosphere. Obviously frequency matters in either scenario, HF is not going to be affected by varying index of refraction to any large degree (optical rotation of polarization does occur and slight path deviations may also exist) whereas VHF in a certain frequency range will. So a difference in the type of propagation does exist, skip is not tropospheric ducting. An analogy could be seen by comparing the use of prisms to alter a light path with the use of mirrors.

 

What I don't get is there are plenty of low band VHF freq. abandoned and available like the old 32 meg that was CD. If we could have that then we would have some decent communications.

And if not specifically 32 meg there's plenty more available up to 49 meg where they used to put baby monitors etc.

The US could easily have it's own LAD...plenty of room.

JMO

 

Chalupa, you raise a very good point: why aren't frequencies available to the U.S. trucking industry similar to Canada's LAD (Logging Administration) assignments?

Actually, you already DO: they are assigned within the Private Land Mobile Radio Service and licenses are required.

(Quote) The Private Land Mobile Radio Service (47CFR90, or Part 90 of the FCC Rules) was established in the US in 1927 [3] to permit commercial and public safety uses of two-way radio by commercial entities and non-Federal government agencies. Similar allocations are available in other countries. The available frequencies in the US have traditionally been separated into two pools. One is for industrial and business users, including some special categories such as petroleum, manufacturing and forestry, the other is for public safety.[4] including medical, police, fire and others. The industrial and business frequencies, sometimes also known as "business band radio" and the eligibility requirements are listed in 47CFR90.35.[1] Frequencies are licensed on a non-exclusive basis, although fixed stations and mobiles operating in a defined area are issued licenses only following frequency coordination [5] to assure equitable sharing of bandwidth. Anyone conducting commercial business or a number of other activities is eligible for a license.(Unquote)

...the preceding was taken from: http://en.wikipedia.org/wiki/Business_band

Up until 1987, U.S. truckers (among other commercial business) did have access to the frequencies alotted to the original Class A Citizens Service which eventually morphed into GMRS. However, due to congestion on all channels in metropolitan areas, this all changed.

(Quote) The predecessor to GMRS was named Class A Citizens Radio Service when it was rolled out in the 1960s. Tube type transceivers were used, and transmitter power was limited to 60 watts (plate input power to the final amplifier tube). The original service ran wideband FM with ±15 kHz transmitter deviation and 50 kHz channel spacing. At the time, this was the norm for all U.S. land mobile services. There was also a Class B Citizens Radio Service which used a different set of 461 MHz channels and was limited to 5 watts output. Business users were permitted to license in this radio service. Radios were built by consumer electronics firms and commercial two-way radio vendors.
In the 1960s, the UHF 450-470 MHz band was re-allocated to 25 kHz channels. This meant transmitter deviation was reduced to ±5 kHz. This doubled the number of channels available across the entire 450-470 MHz band. Class B Citizens Radio Service channels were re-allocated to other radio services.
In the 1970s, allowed power was again changed to 50 watts across the output terminals of the transmitter. In 1987, licensing of business users was discontinued and businesses were allowed to continue operating until their licenses expired. There was congestion on all channels in larger metropolitan statistical areas and moving businesses to Business Radio Service channels would provide some relief. The radio service was changed to its present name.(Unquote)

...the preceding was taken from: http://en.wikipedia.org/wiki/General_Mobile_Radio_Service

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Now, about low-band VHF: The 30-50 MHz range has traditionally been the playground of the government--including the Canadian and U.S. military where, for example, Fort Hood, Texas routinely conducts communications for their ordinance target practicing (and possibly still does).
At first glance there may seem to be "plenty of room" for a low-VHF CB-type trucking band, but I doubt that the FCC wants to open another can-of-worms which the original 27 MHz citizens band became for them due to similar overcrowding, skip interference, and bad operating practices. See:

http://forums.qrz.com/showthread.php?164074-VHF-Low-Band-30-50-Mhz

In Australia, the government did the right thing. In 1977 they set up a unique UHF Citizens Band with some of the channels designated to repeater access--a service which truckers (or "truckies" as they are called downunder) do take advantage of. Originally 40 channels, they recently expanded to 80.

 

Lots of wide commerical stuff availble cheep now that they futher reduced the bandwidth. Micors, Syntors, Spectras, even Sabers cheep now. Moto Radius.

 

Old Syntors being snapped up by hams...... dad had Motrac in the Cat car complete with "quick call" ....what a rig! Sounded like Rescue 51 station tone when it went off. Complete with "private line" and 4 frequency knob.

Irony was it wasn't much better than a cb. only had about a 30 mile range

 

And what about 32 meg ? It was civil defense....I travel a lot and keep it in the scanner....never heard a peep, not even a birdie.....

 

Government and some business radio licensees have been upgraded to higher frequencies and trunking networks. Equipment manufacturers even offer scrambling capability to deter eavesdropping.

Unfortunately, the real threat of computer hacking, industrial espionage, identity theft, and terrorism creates a sense of paranoia which has changed personal communications forever.