How to Build the Best VHF RADIO [Capable Cruising Guides]

Comments · 772

• LA

  @larryb5914 · 2 years ago

  The stories take time ...and while initially seem like unnecessary,  are in fact reminders that some items on the boat are critical for survival,  if not your own, someone else...there is nothing more depressing than to be aware of a distress situation and the feeling of helplessness if you are not able to help...while being able to help makes for a better life and my belief that good Karma will be returned many times more than expected,  so thank you Clark for the stories,  they fill out the purpose of a life well lived...congrats!

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• JI

  @jimpiper5297 · 3 years ago (edited)

  Full disclosure: I was trained in the Navy to repair comm equipment (though not to OPERATE it ;-) , I hold a Extra Class Amateur Radio license and have operated VHF for most of the time I’ve been a ham (since 1993).<br><br>Kudos on a great video, especially for the less electronics-technically inclined sailor.<br><br>Would really enjoy a video on your ham gear &amp; setup, experiences with it, if you use Pactor for email while at sea (Winlink or Seamail?), etc.<br><br>General and, hopefully, kibbitzing &nbsp;comments:<br>1. DC power connection to radio – clean, solid connections through properly sized wire is an absolute imperative. Recommend using a wire voltage drop table to properly size the wire between the battery and the radio to ensure that the radio gets 12 volts and above. Use the current that the radio is spec’d to draw on TRANSMIT. Radios tend to get very cranky when the supply voltage drops below 12Vdc.<br><br>Note re supply power: As marine VHF radios use FM (frequency modulation), for a given power setting modulation (one’s voice into the microphone) has no effect on output RF power. Simply keying the radio is enough to measure the voltage at &nbsp;the radio dc power terminals/connections<br><br>2. Coax: Agree 100%: RG-58 SUCKS for VHF. Loss over a short length ( a few feet isn’t enough to lose any sleep over, but from the nav station to the antenna, LMR-400 ULTAFLX (Times Microwave) is an excellent choice. Recommend the ULTRAFLX over standard LMR-400 as the former has a stranded center conductor to give the cable flexibility vs, the solid center conductor of the latter that makes for some pretty stiff cable. For some reason, West Marine doesn’t offer LMR-400 ULTRAFLX but it is readily available from amateur radio equipment suppliers.<br><br>3. RF connections: ESPECIALLY in salt water environments, use self-fusing rubber electrical tape (e.g., Scotch Tape 70 or 3Mself-amalgamating tape) to wrap the connection from the connector toward and down the cable. Add a second wrap of electrical tape over the first to protect it from UV and salt-air. If wrapping a PL259-SO239 barrel-PL259, start several inches from one of the PL259.<br><br>4. RF cable water intrusion from experience (30 min point in the video): for my money where my life might depend on my radio, if any water invades coax, esp where one end of the cable is up in the air, I would not depend on it. I strongly recommend replacing the entire length. Compared to the cost of lots of boater stuff, at about $2.30/ft, replacing a length is cheap insurance.<br><br>5. Antenna height: height = range. Open air (no obstructions) NOMINAL range in miles can be calculated as 1.42 x square root H1 + H2 where H is the heights of the station antennas in feet. &gt;However&lt;, certain atmospheric conditions can and occasionally do affect range, the more common is “ducting”. With this phenomena, the signal can bounce between moisture layers in the atmosphere for many miles. For example, at a certain time of year a particular VHF (ham) repeater at 300 feet can communicate loudly and clearly with a ham repeater on top of the volcano (Mauna Loa?) on the Big Island, Hawaii.<br><br>6. Troubleshooting no output, you might try these:<br>Caution: don’t use high power without troubleshooting at low power FIRST. If a short exists in the coaxial cable, you risk “blowing” the final amplifier in the radio, and then you’ll have nothing.<br> A. If you have a hand-held/portable/handy-talky (HT)/”walkie-talkie”, set the problem radio to low power and key up, listening for it on the hand-held. <br><br> B. A subjective go/no-go test of coax cable (what you’re calling “wire”) is to use a hand-held in place of the fixed radio. Will need an adapter to convert from SO-239 to BNC to connect the antenna cable to the radio. &nbsp;<br><br>6. SWR meter, note the one in the video: it’s designed for the VHF band. An el- cheapo Power/SWR meter for the CB band won’t do the job.<br><br>-- Jim n6med

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• SA

  @saenole66 · 5 years ago

  Really good information clearly told. In the late 70’s and early 80’s our fishing club used CB radios in addition to our VHF radios on our skiffs. One of my friends blew an outdrive about a mile east of Bimini. He tried to call for help on his CB and go a response from someone who said where’s Bimini. My friend said it’s 55 miles east of Miami. The other person said he was just outside of Knoxville, TN and could not help. My friend said his 21’ skiff back to Florida using his Bimini top as a sail.

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• CH

  @chrisscott1547 · 1 year ago

  I&apos;m a retired radio engineer. &nbsp;You&apos;re spot on with everything! &nbsp;A decent antenna on top of a sailboat mast wins. &nbsp;Height is everything. &nbsp;A 4 foot antenna there will work very well. &nbsp;Also, if your cable run is more than 50 feet, use the RG-213 / RG8-u. &nbsp;One last thing: the handheld radios are great for keeping in touch with the boat when ashore, but don&apos;t expect much range - and no it is not the reduced power so much as the very poor rubber whip antenna. &nbsp;It&apos;s a good idea to get an adapter cable to connect from the handheld to the mast-mounted antenna - in a pinch it will work almost as well as the main radio.

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• SE

  @semersion · 6 months ago

  ‘Mayday Relay’ is something we were taught in our vhf marine radio course.<br>Even the best vhf radio still has limited range.

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• AR

  @artfulalias3984 · 5 years ago (edited)

  Excellent coverage of a much misunderstood topic. &nbsp;Also coax looses more power if it gets deformed, pinched, flattened, bent too tight, looped excessively. &nbsp;Technical stuff: &nbsp;Some antennas work with a ground plane like the 3db quarter wave whip. &nbsp;Their pattern suffers without a good ground plane, which is another piece of the system not always addressed on boats. &nbsp;Some antennas work without a ground plane, like the 6db design you prefer. &nbsp;For people who want deeper understanding, buy the ARRL Antenna handbook as a place to start.

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• DA

  @danielcorcoran7132 · 5 years ago

  Very good. Missing is at least a mention of installing a dedicated cheap GPS antenna powered by the same circuit, a $30 part, that when combined with obtaining and programming an MMSI number gives your vhf radio the ability in the USA to send your gps location to authorized after pressing distress button. So many people fail to set this up, mentioning the importance in your video would contribute to awareness. The coast guard can better respond when they are convinced you know exactly where you are, and it helps novice boaters better succeed with the radio when the skipper is incapacitated. In addition products like the MOB1 can be setup to work with your vhf radio to alert crew if you fall out of boat. &nbsp;See if you can edit and include early on when you describe the install process involves antenna and power wire. Dan, marine electronics writer, practical sailor magazine.

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• 73

  @73Kaarn · 4 years ago

  I served in the australian navy as a comms operator and found this explanation and advice excellent for general sailors. by the way for cable connections we covered them in impregnated cotton wrap which would last for years preventing water penetration. very difficult to remove though.

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• LI

  @LiveFreeOz · 2 weeks ago

  Thankyou from sunny Oz. Such a clear description.

• TE

  @terrybest3036 · 5 years ago

  Nice one Clark! Very informative. Love you guys! One thing I would have touched on and is generally overlooked is the twisting/shielding and routing of the power wires. A large percentage of you will say it doesn&apos;t matter because its DC, however I would have to disagree based on experience. Remember that day when you were so proud of your new car stereo install and it sounded so good ….until you started your car. There was a terrible whine that was proportional to the rpm of the engine...You had to fix this using an EMI filter. &nbsp;I am a design engineer in aerospace and defense (specifically designing automated test systems for electronic...&quot;things that are critical to your survival&quot;). Collective data would support twisting of the power wires as the default go-to if cost and weight do not prohibit its use. When in doubt twist them and shield them. Two reasons....1. Reduced susceptibility to noise from other magnetic fields. 2. Reduced magnetic radiation from loads that are switching. Additionally, the routing of these wires is even more critical. Its generally a bad idea to run power wires to your radio in parallel with wires going to your bilge pumps, transducers, stereo speaker wires, shore power lines, etc. I&apos;m guessing there is a filter circuit on the power input side of a quality radio, but to cut costs in a Chinese radio I wouldn&apos;t be surprised if it didn&apos;t exist at all. Scenario: Your sinking and the bilge pumps are now running full bore, and an inductive interference is now coupled to your radio when your calling for Mayday. All they hear at the other end is a whining bilge pump with some guy garbled underneath all the noise. Greetings from Clearwater!

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• NO

  @NotaFlea · 5 years ago

  Great video, I am a ham and the info in this video is spot on. Good equipment, good connections, &nbsp;water,proofing to keep corrosion down. Understanding db, antenna placement. Good stuff for the layman to adhere to.

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• MA

  @MarcoYolo420 · 4 years ago

  Love your stories!<br>As a beginner sailor, I started to get some nice stories to tell too, until now, mainly what goes wrong. <br>I&apos;ll check my VHF cables and antenna, thanx so much for sharing your expertise.

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