Marine SSB

[New Cruiser]

Last summer I was fortunate enough to join a friend on a cruise from San Francisco to Los Angeles. While on watch I noticed what appeared to be two HF (I assume marine SSB) Radios in the pilot house. I am a recently licensed Ham radio operator interested in purchasing an ICOM 718.

My questions are: Is marine SSB the same as HF ham operation? Will I be able to communicate with boats equipped with a marine SSB radio if I am using an ICOM 718?

[Paul Elliott]

The marine SSB bands are different than the ham bands. They both use several bands in the HF range, but there is no overlap.

If you have a marine SSB radio you may be able to "open it up" and operate it on the ham bands. This is perfectly legal, and I do this occasionally. The opposite is not the case, however. Ham radios are not FCC-authorized (in the U.S.A) for operation on the marine bands -- I believe that the spurious output spec is not stringent enough for marine use.

In an emergency, you can use any radio you've got. Some people open up their ham radio and use it on the marine bands for everyday use. I'm not going to recommend that.

[goboatingnow]

most ham units dont have the oscillator stabilty to maintain the tight marine SSB band requirements.

Dave

[Sheriff]

also amateur radios are locked to transmit on amateur bands alone!

[goboatingnow]

also amateur radios are locked to transmit on amateur bands alone!
__________________

Naw not really.

[S/V Illusion]

Originally Posted by goboatingnow

most ham units dont have the oscillator stabilty to maintain the tight marine SSB band requirements.

Dave

It is a function of spurious emission rather than freq stability that differentiates the "type acceptance" of marine radios. I find the whole distinction somewhat silly given the excellent suppression characteristics of most ham transceivers and have used both marine and ham radios interchangeably for decades with no adverse emissions but it is always good to be on the right side of the law particularly when entering foreign ports.

[roverhi]

The ICOM 718 can be 'opened up' to broadcast on any HF frequency by disabling a couple of electronic thingamabobs. Takes longer to open the case to expose the thingamabobs than it does to to do the modification. Google it and you can get a wiring diagram and instructions.

Ham and Marine HF both operate in the same wavelengths just slightly different frequencies. Seems that Marine HF uses lower HF frequencies more than Ham which is primarily 20 and 40 meters. There is a bit of contention about the suitability of Ham radios to operate on the the HF frequencies. Have heard ham radios have crappy freq and noise control while others, who seem to know what they are talking about, claim the newer ham radios are just as good as the Marine Radios. In any case, it's okay to use a radio on any frequency in an emergency. Almost all the action is on the Ham frequencies with the MM nets on 14300 around the world and many regular and impromptu and local nets in various areas. Don't really see a need for a Marine HF radio except to contact Race Committees if you are doing long distance races.

I've got an opened up 718 running through an SGC 230 tuner to my backstay. It works a charm after some initial problems with a malfunction in the tuning circuit in the radio. I bought the radio used and it wouldn't give the ICOM tuner the proper signal to tune. Didn't have time to get the radio fixed before I left so bought the SGC tuner. The SGC tuner doesn't need anything but RF output from the radio to tune and has worked very well with my slightly malfunctioning radio. Used the 718 to communicate with the Pacific Maritime Mobile net on last summers sail to Kona and to do Email and GRIBS through a Pactor Modem. The radio worked fine on the 20 and 40 meters but haven't tried on any of the Marine frequencies.

[SoonerSailor]

I don't know myself how good modern Ham rigs are at suppressing spurious energy. Some or nearly all may be well within FCC requirements for type acceptance, but the manufacturers aren't going to spend the money to have them formally type accepted when the market for having it done is so small.

Most ham radios are also flexible enough that if you don't know what you are doing or are careless you can make their transmissions pretty dirty through their various adjustable parameters - adjustments which are typically not available on marine type SSBs.

[Auspicious]

Originally Posted by S/V Illusion

... have used both marine and ham radios interchangeably for decades with no adverse emissions

How do you know? Have you tested with a calibrated service monitor or spectrum analyzer?

It isn't a coincidence that most of the ham bands are harmonically related.

There are some great ham radios out there that are clean and stable enough to meet the marine type acceptance requirements that simply haven't been certified. Those radios cost as much or more than a marine radio.

I don't think you'll get that kind of performance from an IC706, IC718, or TS50.

Don't agree? Let's measure. There is no substitute for real data.

[fairbank56]

Well, consider this. The Icom M802 advertises "more talk power" with their DSP speech compression when in fact, this feature is not even enabled because with it enabled, it no longer meets FCC specs for spurious emissions. I'm a tech and have done side by side comparisons between the M710 and M802. The M710 has significantly more average power than the M802 but with the M802's compression enabled, it then has significantly more than the M710. Even the "great" Gorden West advocates breaking the rules and having this compression enabled due to the pitiful average power of the M802 as it is shipped. Icom won't do it, and neither should we. Ham radio's are not required to meet the specs that a marine SSB does and are not certified to operate in the marine services, plain and simple.

Eric

[S/V Illusion]

Originally Posted by Auspicious

How do you know? Have you tested with a calibrated service monitor or spectrum analyzer?

Yes....

[fairbank56]

I doubt that. I currently use an IFR 2945 communications service monitor for most of my troubleshooting/maintenance work on marine VHF/HF transceivers. These run around $10-$12K and have spectrum analyzer capabilities but are not sufficient for verifying compliance with regards to spurious emissions. I have access to and have used the Agilent Technologies ESA series spectrum analyzers which are sufficient for these measurements, meaning you can actually see the spurious emissions, not neccessarily that they are good enough for compliance testing. These are 2-3 times the cost of the 2945 depending on specific model. The various companies that do compliance testing for Icom and others use very high dollar sophisticated test equipment for doing so. There's a reason for all the rules and regs and requirements for compliance testing. My guess is that when Icom built the M802, their "low dollar" test equipment didn't show spurious emissions with their speech compression but did show up during third party compliance testing so they either had to re-design, or just disable it. They chose to disable it.

Eric

[S/V Illusion]

I don't think you want to go there - comparing the equipment Icom uses at their Belvedere, Wa manufacturing and testing facility at which I have access and use. It's also pretty evident from the limited testing ARRL does at their lab in Connecticut.

Do you really have ANY data to contradict my findings?

[fairbank56]

New Cruiser

As you can see, this is a touchy subject. Bottom line is: To operate on the marine MF/HF channels legally, you must be using a part 80 FCC certified marine transceiver and you must have an FCC station license and restricted operator permit. Some don't care about the law and interference they may be causing to others, most do. It's your decision. It is perfectly legal BTW to operate on the ham bands with a certified marine radio.

Eric

[Auspicious]

Originally Posted by S/V Illusion

Yes....

Okey dokey. I'd like to see the data, including the test equipment specs and the calibration certs.

This stuff is tough to do right. That's why so many people don't understand why opening up ham gear to marine frequencies isn't okay for routine comms.