reasson for change to VHF for local marine comms??

[HBdigital1]

Hello! I recall, in high school, I built my first Knight Kit Star Roamer radio, and was able to get a lot of marine comms around the 2-3 Mhz area, and living in Gardena, Calif, was able to hear craft as far up the coast as Santa Barbara! Then I got busy, went to undergrad college, then spent a stint at UT in Galveston, and when I had some free time again, realized that all the local traffic had migrated to VHF.. Could anyone inform me, just for info, when this changeover occured, from HF to VHF, and was it due to, I believe, the great range of local HF radios which caused interference to other ship comms 100's of miles away which was no needed? I don't miss the days of analog tuning, but they hey, there is certainly a great fond memory of turning that dial and seeing where the dial indicator would land with another communication. thanks in advance!!

 

[SkipSanders]

There hasn't been any change. HF is used for NON-local communcations (over 25 miles or so, usually), while VHF is used for local communications.

The real difference is that, perhaps, fewer vessels carry HF gear, as they accomplish the 'long distance communications' needed via satellite phones, now, in many cases.

The Coast Guard, for instance, usually communicates with its aircraft on HF, and its cutters of any real size use HF as well, since they're often out of VHF range.

 

[OceanaRadio]

Commercial vessels still carry MF/HF equipment because of mandatory SOLAS (Safety of Life at Seas) regulations. The real change ocurred for pleasure craft around the early 1970's when the VHF Marine allocations were made. Once only cabin cruisers could have a radio at all, and they were big (boatanchor) AM/SSB xmtrs. When VHF hit the scene the recreational industry abandoned MF/HF like the plague and to this day only blue-water cruisers carry it and most of them are hams who want HF radio for ragchewing just like they do at home. The new and compact (for their day) VHF marine radios were waterproof or water resistant, and required only a fraction of the antenna size to accomodate line of sight marine communications. Large towers sprug up all over the Great Lakes and coastal areas of the country and the "Marine Operator" became the way to bring telephoine service into every sized craft. Before Mastercard you used to have to have an account with a Marine Operator agency, after credit cards hit the scene any boater could place a call to LL telephone systems via VHF radio. Cell phones spelled the death-knell for the marine operator system and today there is only WLO Mobile (Shipcom LLC, Mobile AL) who primarily serves the gas/oil and cruise industies in the Gulf and Caribbean for marine communication services. There are still a couple of SailMail stations that use PactorIII on HF to provide e-mail service to boaters who are too cheap to use SAT equipoment, but SAT has almost completely replaced all long range communications services afloat.

Jack

 

[marscan]

HF to VHF conversion

Just to add my two cents on the Marine conversion, I recall very well my marine listening in the mid sixties to mid 70's on the 2 MHz band, which technically is MF not HF. I listened from Vancouver Island to Canadian and American coastal traffic up and down the west coast from Alaska to California. Occasionally I heard coast stations and even ships from the Great Lakes, Gulf Coast, and Atlantic. In fact most of my radio listening was on 2182 and 2670. The big USCG coast stations came in well from all over the place. So it was not just recreational traffic using 2 MHz.... there were many many towboats and coastal freighters on there. VHF was around but it was not until at least the mid-70's that it really began to take over... and now of course 2 MHz is hardly used at all. I am not speaking here about the higher frequencies from 4 MHz and up, as they were around and common a lot longer until satellite pretty much took over, but coastal shipping didnt ever really use them much except maybe in the Arctic areas where coast stations were farther apart, or for private company communications between vessels and headquarters.

 

[CapnJon]

We used 2670 while on patrol in the Gulf of Mehico on the CG 82 footers in '87-'89.