VHF Radio FAQ's
Q: Can I use my Icom mounted VHF radio, or a SSB radio on a vessel with a 24 Volt electrical system?
A: ONLY if you purchase a separate power converter that will convert 24
Volt DC into 12 Volt DC. All Icom mounted VHF and SSB marine radios are
designed to operate with 12 V power systems. Connecting them to 24 Volts
will result in immediate failure of the radio due to over voltage. It may
even damage the radios beyond repair.
Q: My mounted VHF radio, or a SSB radio seems to have a problem. The display lights dim when I transmit. The radio even shuts down by itself sometimes. I'm not getting full TX output power either.
A: This behavior is caused by an insufficient power supply, or bad electrical connection somewhere between the battery (or a power supply) and the transceiver. Check your electrical connections and the battery. Pay special attention to the in-line fuse holders and power cord terminals on the battery side.
Q: Are your waterproof marine radios really waterproof?!
A: Absolutely! But, only to a point. For example, the IC-M15 can withstand being submerged in one meter of water (about 3 feet) for thirty minutes with no water intrusion. If the radio ever goes overboard, you should retrieve it as soon as possible. Remember, even submarines will get crushed if they submerge beyond certain depth. We make quality radios, but we cannot change the laws of physics!
Q: I'm using your optional hailer horn with my Icom marine radio, and all I get is feedback!
A: This is caused by close proximity of the hailer horn to the location of the radio. The hailer horn is VERY loud, and it should be mounted a safe distance away from the operating location.
Q: I have an Icom VHF marine radio, and I'm attempting to contact another VHF operator. But, even though we are very close, we can't seem to be able to communicate. Stranger still, some channels seem to be working, and others do not!
A: Most marine channels can be used for direct ship-to-ship communication. They are called simplex channels. Some marine channels are duplex, and can only be used for ship-to-shore communications. Duplex means that the receive and transmit frequencies are different for one given channel. You can read more about the marine radio service at the US Coast Guard marine radio communication information source written in everyday English.
UNIDEN FAQ's
Shakespeare FAQ's
VHF Antennas
- Which antenna is right for me? This is a big question, and there's no easy answer. It has an answer file all its own. See also Shakespeare's Audio Fact Books web page for digitized sound samples that you can download.
- Can I cut the coax on my VHF antenna? Yes, if you need to. However, you should leave at least three feet of coax. Note that this is not true for all antennas. CB antennas' coax should not be cut.
- How can I check the antenna to make sure it is working? You should transmit to a friend's receiver, and have the friend assess your transmission for quality from a variety of known distances. Note than the US Coast Guard frowns on radio test calls made to them. To help you measure the efficiency of your antenna/radio system more scientifically, Shakespeare makes an antenna / radio tester. The ART-2 will test the output power of your transceiver, as well as the VSWR of the antenna.
- How do you install the PL-259 connector? An instruction sheet for installing the PL-259 connector is included with the antenna. Follow the instructions and consult the diagrams. Shakespeare's new PL-259 connector includes special washers and spacers to reduce the complexity of the installation. For true ease of installation without soldering, check out Shakespeare's innovative Centerpin® PL-259-CP and PL-258-CP connectors.
- Will metal or other objects that are close to the antenna affect it? Yes they will. It is best to locate the antenna at least three feet from any metal objects or other antennas.
- Can I mount the antenna beside the radio? No, it must be at least three feet away from the radio, so transmission will not interfere with the radios reception (usually resulting in a squeal in the speaker).
- Do I need a ground plane for the antenna? No, Shakespeare VHF marine antennas are designed with independent ground planes built in.
- What is the antenna's wavelength? It can range from 1/4 wave to 5/8 wave, depending on the length and style of antenna. Please see the antenna specifications section for information on your particular antenna.
- How high must the antenna be? There is no particular height requirement, but remember, the higher the antenna, the better the reception.
- What range can I expect from the antenna? Here is the formula to determine range:
- What is the receiving zone for my antenna? On all Shakespeare VHF Marine antennas the receiving zone is 360 degrees - or omni-directional.
- What is the half power beam width for my antenna? On all Shakespeare VHF Marine antennas the beam width is between 24 and 26 degrees.
- What is the difference among the many styles of antennas? Basically, the price, type and size of its elements, plus the way the antenna's fiberglass is wrapped, and the coax that is used determine the basic cost factors of an antenna. To this, add the relative cost of the finish applied to the antenna.
- How much power can I put into the antenna? Power input varies with the antenna. Please see the antenna specifications section.
- Do I lose anything by using a Combination antenna? Yes, usually - depending on the type of combination antenna. Usually reception performance in the VHF side is somewhat sacrificed. Shakespeare recommends using separate antennas if space is available for them.
- Is it better to use a dedicated AM/FM antenna or a band separator? Shakespeare recommends using a separate antenna for this purpose. Band separators were designed for people who don't have room for two antennas.
- What is gain, and how is it measured? Gain is an increase (or decrease) in "effective radiated power" from an antenna, usually stated in + or - dB (deciBels). As a rule of thumb, you can add 4 times the radio's output power for 6dB antennas and 8 times the radios output power for 9dB antennas. Shakespeare's Audio Fact book web page has digitized sound samples and streaming audio files of off-air broadcasts for you to compare 3, 6, and 9 dB gain systems.
- Can I paint the antenna, and with what? Shakespeare's antennas can be painted any color you wish. But, make sure not to use any paint containing metallic chips or lead bases.
- Can I repair the antenna if the fiberglass becomes frayed? Yes. Simply wash the antenna with soap and water first, and allow it to dry completely. Next, paint the antenna with polyurethane or a lead free, non-metallic paint. Then lightly sand the surface with 400-grit sandpaper. Additional coats of paint may be added, but are usually not really necessary.
- What is the transmission line loss for coax? This depends on the amount, as well as the type of coax used. On the average, 50 feet of RG-58 coax will have about 3dB loss, 50 feet of RG-8X coax will have about 2dB loss, and 50 feet of RG-213 (RG-8U) will have about 1dB loss.
NEW! Downloadable PDF Instruction Sheets for PL-259 Connectors: RG-8/X - RG-58
Calculation for Range of an Antenna:
Square Root of Height (in feet) above water x 1.42 = Range in miles Remember to perform the calculation for BOTH vessels, and then add the results for the range between two vessels.
Square Root of Height (in feet) above water x 1.42 = Range in miles Remember to perform the calculation for BOTH vessels, and then add the results for the range between two vessels.
CB Antennas
- Can I cut the coax on my CB antenna? Generally NO! On most Shakespeare CB antennas the coax is part of an electronically "tuned" system, and should NOT be cut or altered. Shakespeare only has two CB antennas on which it's okay to trim the coax: Styles 5223 and 5207. Note that this applies to CB antennas - VHF antenna coax is not part of a tuned system, and can be trimmed.
- Can I take the PL-259 connector off to feed the coax through a hole? No, this will change the tuning of the antenna - and also voids the warranty. If coax needs to be passed through a bulkhead, be sure to add additional coax which can be cut or altered.
- Can I tune the antenna? Most Shakespeare antennas are pretuned at the factory and do not need any additional tuning. Shakespeare Styles 5223 and the 5207 can be retuned after the coax has been cut. Instructions for doing so are packed with the antennas.
- Why does my antenna system have a high SWR? There can be quite a number of reasons for this. The most usual reasons are coax having been cut or altered, coax running through conduit, antennas located near metal objects, or people standing too close to the antenna while SWR readings are being taken.
- Do I need a ground plane for my CB antenna? No, all Shakespeare Marine CB antennas have independent ground planes built into them.
- Which way should the radials for the Style 318-GBT Pogo Stick point? The radials can point either up or down. Neither direction will affect the performance of the antenna.
- Do I need to cut the coax in wavelengths? No. Shakespeare's CB antennas do not require this type of tuning.
- Can I add coax to the antenna? Yes. Shakespeare suggests that if adding more than 25 feet, use RG-8X or RG-213 (RG-8U) coax. See Tips for Installing Shakespeare Antennas, too.
Cellular Antennas
- What type of connector is used on the Motorola bag phone? This connector is known as a Mini PL-259 connector or Mini UHF connector. This connector is only available for RG-58 coax presently.
- How many feet of coax can I use with the antenna? There is no set limit, except practicality. However, remember that at the frequency of Cellular communication, great line loss will be encountered with long coax runs. For best performance, be sure the coax is short and is the best grade possible.
- How can I check the antenna to make sure it is good? Unfortunately, there is no sure test. The best suggestion is: if the signal strength meter on the phone is low or shows no signal, there could be a problem.
- Why do I get better reception with my pigtail antenna? It might be the location of the antenna. Try mounting the antenna as high as possible or shortening the coax.
- Will other objects close to the antenna affect its performance? Yes they will. It is best to locate the antenna at least three feet away from any metal objects or other antennas.
TV Antennas
- How can I tell whether my antenna is affected by the 2002 USCG Safey Alert? Only units of Style 2040 and 2050 which were manufactured in 2000 are affected. Style 2030 was originally listed erroneously by the USCG. A corrected Alert removed the 2030 from the list. For complete information, click here.
- How can I check the antenna to make sure it is working? Check the voltage from the power supply for 17 vAC on AC operation and 12 vDC on DC operation. Also, try moving out of the slip to see if interference from other boats might be causing your reception problems. VHF TV transmission is line-of-sight, so at sea level, you're quite possibly out of "view" of the TV signal.
- Why can I pick up some channels but not others? Poor reception can be caused by location, height (for example, is your boat at sea level?), atmospheric conditions, and power. Marine TV antennas have the same limitations as the ones that install on top of your home.
- Can I mount the antenna upside down or sideways? Yes. However, be sure to seal the coax connector located on the underside of the antenna.
- Can I mount the antenna in my spreaders? No, spreaders will interfere with the antenna's reception. It is better to mount the antenna above or below the spreaders.
- Can I mount the antenna in an enclosed area? No, signal bounces off of flat, reflective surfaces which effectively shield the antenna from the TV signals.
- Can I use the Style 2020-G or Style 2030-G for my house? Yes. In fact, the reception can be excellent, depending on where you are. For best results, mount the antenna in a clear area, away from obstructions.
- Why does the power supply's red light stay on when I run the unit in AC mode? This modification was made by Shakespeare to show that power is getting to the antenna. This is only true if the power supply on your unit is black in color.
- Why can I get better reception on my boat with a pair of rabbit ears? Your Shakespeare Marine TV Antenna is doing its job too well. It's delivering too much signal, overloading the TV's Automatic Gain Control circuitry. Use an in-line attenuator (available at most Radio Shack stores, for example) to reduce the antenna's signal to a usable level. Shakespeare's SeaWatch® 2025 Marine TV Antenna System uses dual amplifiers to permit boosting or attenuating the signal as needed. The control panel for the 2025 is available as an upgrade for other Shakespeare antennas as SeaWatch® Style 2025-CP
- Can I run two or more TV's off of the same antenna? Yes, two TV's will work with one antenna, as long as the total coax run is kept relatively short.
- How long is the warranty for the TV antennas? SeaWatch® Marine TV Antennas carry a Shakespeare Limited Warranty for 1 Year from the date of purchase.
- Will a booster help me get more signal? No, a booster just amplifies the signal that is being received. Boosters are used for increasing signal strength for multiple TV installations with long runs of coax.
- Can I replace the preamp myself? No, this is not a stock item from Shakespeare. The antenna head has to be returned to Shakespeare for repair.
- What is the difference between Shakespeare units having the gray power supply and those with the black power supply? In units having the black power supply, the RED light stays on in AC and DC operation, and a thermal fuse has been added.
- What is the difference between the 2020-G and the 2030-G TV antennas? The Style 2030-G is larger (21" diameter, instead of 14"), and also heavier (11 lbs., instead of 3 lbs.). The Style 2030-G is designed for maximum omni-directional performance in the marine environment. The 2020-G is the ideal smaller marine TV antenna where styling and size are the predominant factors. It's perfect for close-in, or stronger signal areas.
General Issues
- What antenna should I use with what radio? It depends on your needs and the amount of space that is available to mount the antenna. Some considerations are: the height at which you can mount the antenna; whether you have to raise and lower it to fit under drawbridges or other obstructions; and how far you need to reach with the transmitted signal. Always purchase the best antenna you can afford, since the antenna is the most important part of any VHF installation. The longer the antenna, the better coverage you can expect, generally speaking. This question has an answer file all its own.