VHF Echoes

Warren Updike of Towson, Maryland, asks:"My Simrad RS8300 VHF has two full-function handsets. The VHF is a black-box type with a DSC class-C transceiver that is about 15 years old; it’s mounted behind a panel in the main saloon. The receiver is very sensitive and very easy to use. The transceiver interfaces with my Raymarine ST-50 GPS, which is mounted nearby. My AM/FM
Author:
Publish date:
Social count:
0

Warren Updike of Towson, Maryland, asks:

"My Simrad RS8300 VHF has two full-function handsets. The VHF is a black-box type with a DSC class-C transceiver that is about 15 years old; it’s mounted behind a panel in the main saloon. The receiver is very sensitive and very easy to use. The transceiver interfaces with my Raymarine ST-50 GPS, which is mounted nearby. My AM/FM stereo receiver is also located near the GPS and VHF transceiver, and the only FM antenna is a short wire that leads to a nearby fixed port.

I’ve been told that my transmissions frequently include background music and, occasionally, voices; at times the music is so loud that my voice transmission can’t be understood. The problem is intermittent, but it does seem to occur at particular locations on Chesapeake Bay, where I sail. The U.S. Naval Academy has large transmission towers, and an Air Force facility is not far away. Have you ever heard of this phenomenon? Is there a RF filter I can install? Would an FM antenna splitter let the VHF and FM share the signal?"

Gordon West replies:

First, your FM antenna wire has no effect on the music and voice problem. What I think is happening is that the strong radio signals ashore are being induced onto your VHF remote head cables. When you are on VHF receive, you may hear a faint signal coming out of the VHF speaker. When you transmit, those shoreside signals are getting into your mike cords and remote heads and are mixing with your own transmissions.

Putting a ferrite snap-on filter choke at both ends of each of your two remote-control head cables will minimize or eliminate these induced signals; now the cables are acting like a dipole antenna. You can get a pack of four ferrite filters at your local marine radio store for about $25. When the filters are installed at both ends of the two cables, your problem should disappear.

Related

TOTW_PromoSite

SAIL's Tip of the Week

Presented by Vetus-Maxwell.Got a tip? Send it to sailmail@sailmagazine.comImpeller Practice Engine raw-water pump impellers don’t last forever. Even if they are not destroyed by running the engine dry following a blockage, they still deteriorate with the years. If you’ve never ...read more

Waves1(1)

Know how: Weather 101, Basics

OverviewThe first thing to know is that “Weather 101, Basics” is a science course. Its goal is to prepare boaters for a second course launching later this year called “Weather 202, Advanced.” Taken together, these classes are designed to teach boaters to become their own weather ...read more

05-Close-reaching

Light-Air Sailing

Some of the best times aboard a cruising boat are in light airs—those quiet, relaxed sunny days with gentle sailing that just wouldn’t be the same if you were motoring. However, many cruising yachts are not set up to truly fullfill their potential in these kinds of conditions.One ...read more

VOR-BoatYard

Volvo Ocean Race: the Boatyard

The Volvo Ocean Race stopovers are a chance for sailors to rest between grueling legs of the race and for fans to enjoy seeing their favorite boats in person. Behind the scenes of the festivities, however, Nick Bice and his team of expert riggers, boatbuilders, sailmakers and ...read more

20160711_Klampe_Alu_013

Nomen: Folding Cleats

Springtime for CleatsIt’s not every day you see a new take on the humble cleat. There are two problems with these essential items: lines tend to get snagged in them when you least want them to and they attract bare toes with painful accuracy. German company Nomen, maker of the ...read more

WS-POD-600

Watt & Sea: Power Pod Hydrogenerators

Power PodHydrogenerators are an increasingly common addition to bluewater cruising boats, but for all their benefits many sailors don’t like to mount them on the transom, where they may interfere with self-steering gear or drop-down transom platforms. Instead, Watt & Sea’s new ...read more