Your post was clear and concise. The point got through to me, and that's not always easy!
Increasing handheld range
- Thread starter flynhi4u
- Start date
Here you go:
http://wireless.fcc.gov/commoperators/index.htm?job=wncol
and actually the antenna and transmission line are technically part of the radio.
I suspect it would take a pretty good attorney to argue the point. In actual practice many people do disregard the rules. To work in the field I suspect most employers would ask to see your FCC license (Yes I've had one since 1974).
Ken
My ham license says i can modify certified marine gear to operate on ham bands?? Where is that stated.
I know this is off-topic now (actually, we went off-topic some time ago), modifying an antenna that is designed specifically for a type of signal, such as satellites, is a major no-no. Most satellite antennas are type-approved and cannot be modified for any reason. To do so would change the characteristics of the signal leaving the antenna and could cause willful/harmful interference to its neighbor. What we called Adjacent Channel Interference. So even modifying a HF antenna on a ship could cause interference with other navigational systems.
https://apps.fcc.gov/edocs_public/attachmatch/DA-11-970A1.pdf
"What Happens if Users Do Not Comply with the FCC’s Rules?
Interference to a maritime distress and safety frequency, including VHF Marine Channel 16, is a violation of the most critical nature, with potential impact upon safety of life and property. Harmful interference can be caused not only by intentional operation, but also by stuck microphones on Channel 16, and inadvertent activation of EPIRBs. Harmful interference disrupts vital safety frequencies, and can obscure genuine distress transmissions. Tracking down such interference also places a strain on valuable resources of the safety and rescue agencies. Be aware that the Enforcement Bureau intends to strictly enforce the Rules related to marine radio operations.
Violators may be subject to the penalties authorized by the Communications Act, including first offense fines as high as $16,000 for each violation or imprisonment for up to one year. Your radio equipment can also be seized and forfeited to the U.S. Government. In addition, the Coast Guard can recover the costs of its rescue efforts when the initiating distress call is determined to be false; these rescue-related costs can be as much as $5,000 per hour."
The handheld antenna can be replaced with similar one but cannot be modified or extended to get more range or power as it may cause interference and then the above are the consequences... the handheld was certified and issued the FCC certificate and the antenna is part of that certification... any modifications voids the certification.
"What Happens if Users Do Not Comply with the FCC’s Rules?
Interference to a maritime distress and safety frequency, including VHF Marine Channel 16, is a violation of the most critical nature, with potential impact upon safety of life and property. Harmful interference can be caused not only by intentional operation, but also by stuck microphones on Channel 16, and inadvertent activation of EPIRBs. Harmful interference disrupts vital safety frequencies, and can obscure genuine distress transmissions. Tracking down such interference also places a strain on valuable resources of the safety and rescue agencies. Be aware that the Enforcement Bureau intends to strictly enforce the Rules related to marine radio operations.
Violators may be subject to the penalties authorized by the Communications Act, including first offense fines as high as $16,000 for each violation or imprisonment for up to one year. Your radio equipment can also be seized and forfeited to the U.S. Government. In addition, the Coast Guard can recover the costs of its rescue efforts when the initiating distress call is determined to be false; these rescue-related costs can be as much as $5,000 per hour."
The handheld antenna can be replaced with similar one but cannot be modified or extended to get more range or power as it may cause interference and then the above are the consequences... the handheld was certified and issued the FCC certificate and the antenna is part of that certification... any modifications voids the certification.
Nick. I respectfully submit this paragraph is not correct. The FCC does not care what kind of antenna you put on your radio as long as it does not cause harmful interference to other users or cause a violation of the FCC rules pertaining to Effective Radiated Power (ERP). Since the FCC stopped requiring licenses for marine radios I do not believe an ERP limit has been set for VHF marine radio but I know for a fact that a portable radio output will not exceed the 25 watt input power of the ship's radio. There is absolutely nothing illegal about attaching your properly functioning HH to your properly functioning mast mounted antenna system. You will not violate the FCC type acceptance of your radio by doing that.
Brian D you are right here. One of the problems with changing antennas is if it creates spurious radiation or harmonics (Which on some radios is really hard to avoid and if you ever look at it on a spectrum analyzer you will be impressed. ) you will be transmitting off band and most likely not know it. The way to find out is using a screen room and spectrum analyzer. Most of us don't have those $$$$$ facilities. Our transceivers are FM and aren't subject to over modulation off band radiation, but if the antenna happens to cause the radio to clip the carrier, you are right back in the same condition. Some engineers spend a lifetime studying and creating antennas exclusively and few of us are in that position. Antenna theory isn't simple no matter how simple an antenna looks.
One of the main reasons the FCC requires a license is to make sure off band radiation is reduced due to people who don't have enough understanding to prevent this from happening. An FCC license doesn't make you a designer, but should reduce the risk by limiting who messes with this stuff.
Ken
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Bawlmer, I have done quite a bit of work with the FCC and their Labs on getting systems certified in the past. If I tell you modifying a product certified with the antenna as part of it's certification the antenna cannot be modified or enhanced to achieve more ERP or cause interference outside it's 'type' design. This would be a violation of the FCC rules and they are quite adamant in finding and prosecuting offenders.
One way to find out is to add the elongated antenna to the handheld (mast mount antenna) and call the FCC agent to come visit and see if your installation is right or if you incur the wrath of the FCC. It is OK to use the mast antenna with the cabin mounted radio as designed... the mast antenna is not designed for a handheld and as others have mentioned would cause spurious unwanted radiation that could cause interference.
couple of points
"if you modify a product certified with the antenna as part....." So there are type certs that include the antenna and certs that do not. Your main boat radio did not even come with an antenna so you can put any type you want on it an not be in violation of the rules. In general if the radio has a standard antenna connector fitting you can attach any antenna to it. If the radio has an antenna that you ask yourself "how do I get that thing off" there is probably a reason for that ie the type cert includes the antenna (always found on cheaper radios BTW)
Also antennas do not contribuit to spurious signals. They simply radiate what the radio transmitter gives them. The transmitter is the culprit if you have spurious signal. Another way to look at this is antennas are passive and cannot radiate something that is not there. Conversly they radiate what is given to them so if you have spurious signal it will radiate that also. The trick is the antenna may have such a narrow band width that the attenuation of the spurious signal, which is always out of band, helps the radio-antenna set meet the type cert...... and those are the radios with antennas you can't take off. FWIW
"if you modify a product certified with the antenna as part....." So there are type certs that include the antenna and certs that do not. Your main boat radio did not even come with an antenna so you can put any type you want on it an not be in violation of the rules. In general if the radio has a standard antenna connector fitting you can attach any antenna to it. If the radio has an antenna that you ask yourself "how do I get that thing off" there is probably a reason for that ie the type cert includes the antenna (always found on cheaper radios BTW)
Also antennas do not contribuit to spurious signals. They simply radiate what the radio transmitter gives them. The transmitter is the culprit if you have spurious signal. Another way to look at this is antennas are passive and cannot radiate something that is not there. Conversly they radiate what is given to them so if you have spurious signal it will radiate that also. The trick is the antenna may have such a narrow band width that the attenuation of the spurious signal, which is always out of band, helps the radio-antenna set meet the type cert...... and those are the radios with antennas you can't take off. FWIW
Bill, an antenna that is designed to suppress sidelobes (even if the radio is transmitting properly and no spurious signals are present) should not be modified. Any modification could cause those sidelobes to exceed the design requirements and cause willful interference. Not saying you are wrong, just saying that antennas are an integral part of a well designed system. Some systems cannot work (legally, not physically) without the properly designed antenna.
The only way an antenna or coax can cause spectrum issues is if it or the transmission line is not the same impedance as the transmitter. Radio output impedance is 50 ohms. Characteristic impedance of coax is 50 ohms. The characteristic impedance of the antenna is 50 ohms at marine VHF freqs. As long as the transmitter is designed correctly there are no "spurious" problems. Put a CB antenna on it and there will be issues cuz its not tuned to marine VHF freqs. Theres a lot of theorey here that we wont get into....The rubber duck antenna for hand helds employ designs for a short antenna to have a 50 ohm impedance. Any 50 ohm coax and proper antenna will work on a handheld or other radio. Icoms manual specifically states that other Icom approved antennas can be used (verified)..You're not going to find a list of those cuz there's "a million of them" that could work. The type approval is not going to include any specific antenna or the antenna would be such that it could not be removed. I would think the type approval would state something to the effect of using a proper transmission line/antenna. The other issue is personnel radiation limits. If you put a large gain antenna on a handheld, those limits could be compromised assuming the connector is not broken. Type acceptances are public info. Should be able to find one and see what it says.
So much for a simple question LOL
How about I just make up the adapter and tuck it away in the boat. If in worst case scenario I have no other option I will look all around for a FCC inspector before I hook it up, but this will only be in a an emergency.
Sam
How about I just make up the adapter and tuck it away in the boat. If in worst case scenario I have no other option I will look all around for a FCC inspector before I hook it up, but this will only be in a an emergency.
Sam
I don't think anyone would object to use of a 52 ohm antenna designed for the VHF marine radio.
The real problems come up when someone tries to make something that fails (as an example causing 1/2 of the final amp to fail, which could vary well cause the radio to output all kinds of junk.) Most properly designed equipment can handle certain expected failures such as corroded coax for example. It's just the folks who know enough to make bad design flaws (such as trying a CB antenna on a handheld) that end up causing us all to go out and take license tests and big fines for those who get caught.
In 1975 The Renton Municipal Airport in Washington had several near misses (All Cessna airplanes with Cessna radios installed.) The pilots couldn't hear the tower warning them of other airplanes on their flight path due to radio interference. They eventually had to change the tower frequency (I think it originally was on 118.9MHZ which isn't too far away from our marine frequencies.) They never actually identified the source but it clearly could have cost people's lives. This and other events like it are the real reason for such strict regulations.
Sorry guys, but this is why it's also important to me. I wasn't in one of those near miss airplanes but I was one of those trying to fix the problem. I've also been in several Boeing airplanes also chasing interference issues and it's never easy to locate the problem when coming from somewhere outside. Fortunately the FCC is getting better at tracking these things down and the equipment is getting WAY better..
Ken
The real problems come up when someone tries to make something that fails (as an example causing 1/2 of the final amp to fail, which could vary well cause the radio to output all kinds of junk.) Most properly designed equipment can handle certain expected failures such as corroded coax for example. It's just the folks who know enough to make bad design flaws (such as trying a CB antenna on a handheld) that end up causing us all to go out and take license tests and big fines for those who get caught.
In 1975 The Renton Municipal Airport in Washington had several near misses (All Cessna airplanes with Cessna radios installed.) The pilots couldn't hear the tower warning them of other airplanes on their flight path due to radio interference. They eventually had to change the tower frequency (I think it originally was on 118.9MHZ which isn't too far away from our marine frequencies.) They never actually identified the source but it clearly could have cost people's lives. This and other events like it are the real reason for such strict regulations.
Sorry guys, but this is why it's also important to me. I wasn't in one of those near miss airplanes but I was one of those trying to fix the problem. I've also been in several Boeing airplanes also chasing interference issues and it's never easy to locate the problem when coming from somewhere outside. Fortunately the FCC is getting better at tracking these things down and the equipment is getting WAY better..
Ken
Why? In case my hard mount radio fails or I lose battery power. I have my plane set up so I can connect my hand held aircraft radio to the one of the plane's com antennas and have had to do so twice in 23 years.
Sam
I guess pedantic is a disease affliction for some of the northerners during this time of year.Man...you guys need spring to come ASAP. OP needs to buy a used fixed mount VHF on ebay and call it a day.
Academic arguments aside, There is absolutely nothing wrong with putting an extendable antenna on a handheld as long as it won't break the antenna connector by excessive stress.
The FCC won't surround your house or lob tear gas. Like isn't TV.
Just read an interesting article on West Marine .com. http://www.westmarine.com/WestAdvisor/Selecting-a-VHF-Handheld-Radio
Scroll down to the section that says Does the radio have especially useful accessories. They seem to promote the use of the masthead antenna with an adapter.
Thanks for all the info. I will just get the adapter and have it on board should the need ever arise.
Sam
Scroll down to the section that says Does the radio have especially useful accessories. They seem to promote the use of the masthead antenna with an adapter.
Thanks for all the info. I will just get the adapter and have it on board should the need ever arise.
Sam
Nick. I guess we are in the weeds now. I will not bore everyone with my qualifications. The sole purpose of my response was let the OP know what he is trying to do is not illegal. There are a lot of things you can do to your radio that are illegal, that is not one of them. There is a lot of information on this post that is correct, as well as your response, that is not directly related to the OP's question. I think the interpretation that can be taken from your last paragraph leads the OP to believe what he is specifically trying to do is illegal. It is not.