Handheld Radio Channels
I recently bought myself a VHF Marine band portable walkie talkie radio. It was going cheap and I couldn’t resist a bargain.
What I need it for is to use it as an FRS radio. I plan on usingit when I’m out hiking and for stuff like that.
Are the VHF Marine band channels the same as the FRS radio channels, and if not, can I reprogram them for the Family Radio Service?
The handheld marine transceiver I bought was made by Midland.
A marine radio is for use over water *only* (yes, you might get in trouble for attempting to use it for land to land contacts). It is VHF (30 MHz to 300 MHz) and will not communicate with FRS units, which are UHF (300 MHz to 3GH).
Most handheld units, whether FRS, VHF, or UHF (and it doesn’t matter if they are ham units or FRS) will generally not be usable for more than about 3 to 5 miles between handhelds over flat terrain. This is due to the curvature of the earth and there exists a formula which can give you a pretty good "guestimate" as to their range. That formula is to take the height (in feet) of the antennas and double that number. In the case of handhelds, 5 or 6 feet is about right. Now take that number and double it. Let’s use 5.5 feet doubled, which is 11. The square root of that number is the distance in miles to your radio horizon. The square root of 11 is between 3 and 4 (closer to 3). So long as your radio horizon intersects with another station’s radio horizon, you can communicate. In this case, another handheld would have a radio horizon of 3 to 4 miles. You may well be able to communicate with another handheld for 6 miles.
Getting a higher antenna (standing on top of a hill, for instance) will improve the situation considerable. Although my handheld antenna is but 5 or 6 feet off the ground, the repeaters I communicate with are often hundreds of feet off the ground. If a repeater is located atop a hill and has a tower that puts the antenna at 200 feet above average terrain, doubling 200 yields 400 and the square root of 400 is 20. 20 miles to the repeater horizon plus my 6 miles would indicate that I can use the repeater some 26 miles away. When I was atop a 23 story building, I could communicate with repeaters over 100 miles away. The building was on ground 600 feet above local terrain plus the 23 stories plus the height of other repeaters. I chatted with another handheld over 100 miles away.
27 MHz CB is different as F layer (or sporadic E layer) propogation can come into play. Then openings can occur over thousands of miles (although the are not legal in the United States).
For what it is worth, power is not as important as some think. It is the antenna and (at VHF and above) elevation. 2 amateurs succeeded in communicating via moonbounce (bouncing signals off the moon) using under 100 watts. The moon is some quarter of a million miles away and the signal has to complete the round trip of half a million miles. 85 watts. Go figure.
You might consider MURS, a VHF offering that is license free and offers very little interference (unlike 27 MHz CB). You could get your 6 miles between handhelds or perhaps 20 miles between a mobil and a base unit.
For longer distances on a consistant basis, about your only legal alternative would be an amateur radio license (no more Morse code!!!). I have included a URL.
You can do a search of Yahoo groups to find a number of amateur radio groups, some devoted to helping swls, cbers, and others in obtaining their first license as well as others in upgrading their license. For me, six double a batteries has been sufficient (with the aid of one repeater) for a nice chat (all rf path, no internet involved) with Australia. On FM.
Hope this helps
Best regards,
Jim
Sorry chum, you bought the wrong handheld radio for your needs. You purchased a VHF radio that is factory programmed for the VHF Marine band. It isn’t built to convert into anything else and especially not into an FRS radio. Why? Because the Family Radio Service (FRS) is way up in the UHF band! Totally incompatible…
Get rid of the marine VHF radio to someone who can use it on their boat or whatever, and buy a proper FRS radio instead.
Incidentally, the FRS radio service is license-free (in the USA) because the radios are built to FCC specifications for that service. If you bought a non-FRS radio and had it converted, it would not be type-approved, and therefore it would be against FCC regulations.