Solved: VHF Radio Problems

[mattkab]

I'm actually quite embarrassed. Not that I solved this problem, but embarrassed by the root cause. I wanted to share because someone else may benefit from it.

I received a new VHF radio for Christmas, a Standard Horizon GX2200. It's a really nice VHF radio with integrated GPS and AIS receivers, as well as NMEA output so that I can connect it to my OpenCPN chart plotter and get position reports of both my boat as well as AIS transmitting vessels. I programmed my MMSI, and my dinghy's MMSI into it, so DSC works well too. Almost everything worked perfectly out of the box.

The problem is that I couldn't get it to transmit voice. I would key the mic, and I could see the TX light on the display. I could sometimes hear transmissions if we were right next to the boat, but sending my daughter with a handheld to the marina parking lot a few hundred yards away proved that the signal wasn't strong at all. Reception was perfect though.

Thinking it may have been the antenna, coax cables, or connectors, I purchased a basic SWR meter from Amazon, watched a few youtube videos on how to use it, and proved that my antenna signal strength was pretty close to ideal. After a few phone calls with Standard Horizon's tech support to no avail, and with no other options, I sent the radio back to Standard Horizon to get checked out. They looked into it, found one small loose diode, but otherwise the radio was set to spec, and they have sent it back.

<Spoiler alert, solution below>

This weekend we went on our first trip of the year, and in preparation I was cleaning the flybrige when I noticed something.... I had lowered all of our antennas at the end of the season last year to protect them from the winter storms, and I hadn't raised them back up again! I found an image on offshoreblue.com that shows the radiation pattern from a standard VHF antenna, and you can see why all the symptoms happen -- close to the boat, you are within the "donut", but the signal wouldn't transmit to shore (straight astern) from our slip. I would bet that had we walked a half-mile directly port or starboard we would have been able to receive just fine. I called back Standard Horizon and told them what happened, and after a decent laugh by both of us, they have added this check to their support list.

So... lesson learned... unless you are trying to communicate with the moon or with the fishes, raise your antenna.

 

[bridaus]

I really appreciate when people take the time to document a solution, even when a tiny bit of pride has to be swallowed. It's so helpful. Cheers to you! I'll do my best to give back when I can too.

 

[menzies]

Thanks for sharing. I have quite a few of those stories, including taking my tender into the shop to have the outboard fully serviced because it was cranking strong but would not start. I had spent some time with the cowling off trying to resolve it. They called me back and told me that the fuel hose from the tank was not connected to the engine. When they pushed it is the engine ran fine.

Two similar things with my big AB RIB. I had it in for a service. Went around to pick it up at their dock. Couldn't get the motor to trim down. Went into the office and said "you must have done something to the trim motor, it won't go down." He came out and showed me the support plates. I never knew I had them!

Same boat and engine. The PO said he could get it to run about 34-35 with just him in it. I could never get it above 27. I checked the WOT RPM ratings and saw that it was ~5300. I could never get it above 4500-4600. Called the shop again and asked what I could check. He asked me if I was trimming the motor up once I was running. Huh? He explained that concept to me as well - Duh!

 

[psneeld]

All those boaters who have their antennas raked back to look cool with the rest of the boat looks...well, take a guess...

 

[Bkay]

...uh...I think I need to go check my antenna...

 

[Larry M]

I really appreciate when people take the time to document a solution, even when a tiny bit of pride has to be swallowed. It's so helpful. Cheers to you! I'll do my best to give back when I can too.

What he said.

 

[High Wire]

But the SWR meter showed a good match with the antenna laying down? That does not compute!

 

[mattkab]

I'm no expert, clearly, in antennae theory. Nor do I really know how to use the meter other than watching YouTube videos.

Here's the pic I sent to Standard Horizon.

 

[Xsbank]

The antenna is absorbing the signal just fine, it was transmitting it straight up, which is good for birds, flying fish and airplanes. Not so good for other boats...

The swr meter doesn’t care where the antenna points.

 

[diver dave]

good radio. thinking of getting same. I really like the gps built in; no cables needed for full DSC and a redundant nav system that has zero space and wiring rqmt!

 

[FF]

Folks that do many locks or bridges , where the antenna may be lowered might contemplate purchasing a hand held.


The locks and bridges channel is only 5W output and add the lay down effect , and you can shout as far .

 

[jleonard]

Similar thing happened to me also, but with my wifi antenna.
It was on my trip into the Erie canal. My antenna was mounted on my mast and was working fine, until I lowered the mast(40 degrees) to clear the 19 ft bridges. (It stays at "half mast until I clear the canals)
I was right in front of the building at Waterford and could not get their wifi.
Another boater pointed out my tilted antenna and said I'd never receive anything that way.
Put the antenna straight up and bingo.

 

[diver dave]

Look at that 30db null overhead. That means 1000:1 power density reduction.

 

[sledge]

All those boaters who have their antennas raked back to look cool with the rest of the boat looks...well, take a guess...

psneeld; you're absolutely right. All of our VHF antennas are vertically polarized; meaning the more vertical they are, the better range you will appreciate.
A VHF pattern is like a flattened donut. I've seen boats, most often those big fast sport fishers with what appears to be antennas slanting back for looks. Either those are just for looks, or they're getting pretty bad long range performance. I don't know, maybe they have a shorter vertical VHF antenna hidden along the halibut chair that they actually connect to their radios....

 

[Alaskan Sea-Duction]

To add. If you have multiple antennas, make sure they have at least a 4 feet separation

 

[ProMaritime]

I would never have admitted to that but my wife would tell everyone anyway.

 

[FlyWright]

All those boaters who have their antennas raked back to look cool with the rest of the boat looks...well, take a guess...

psneeld; you're absolutely right. All of our VHF antennas are vertically polarized; meaning the more vertical they are, the better range you will appreciate.
A VHF pattern is like a flattened donut. I've seen boats, most often those big fast sport fishers with what appears to be antennas slanting back for looks. Either those are just for looks, or they're getting pretty bad long range performance. I don't know, maybe they have a shorter vertical VHF antenna hidden along the halibut chair that they actually connect to their radios....

Since I have a covered slip with insufficient clearance for the antennae in vertical position, I used to lay them down before entering the slip, then stand 'em up when departing. It gave me max range AND protected the antennae.
This worked fine until I forgot to lay them down a couple times and I discovered that the noise is atrocious! Scared the living daylights out of me! Even got the USCG attention since they are docked right behind me. How embarrassing!

Now I set them in a raked position, knowing that this will limit the range until they're stood up. I live with this compromise for my normal local jaunts and fishing trips unless I'm travelling longer distances in the Bay or Delta. If I feel I might need the extra VHF range, I'll stand them up vertically.

 

[jimisbell]

Folks that do many locks or bridges , where the antenna may be lowered might contemplate purchasing a hand held.


The locks and bridges channel is only 5W output and add the lay down effect , and you can shout as far .

On my sailboat I didnt lay the antennas to transit....I asked the bridge tender to raise his bridge. Worked EVERY time and I always had a good signal.....LOL

 

[denverd0n]

Kudos to you for being brave enough to step up and admit your error. There are a whole lot of people out there who's ego would not have allowed them to do that.

 

[BuoyOBuoy]

Been there. Done that. Should have the T shirt.
After leaving the Erie Canal at Oswego and concerned about crossing Lake Ontario to Toronto, I decided to call Rochester YC by cell phone to request a berth for the night. They claimed they monitor CH 68 but never heard my calls.
Next morning while doing my pre-voyage check something didn't look right. The antenna was lying in it's cradle sleeping peacefully. After standing it back up and calling for a radio check it worked perfect !
I was embarrassed but I learned something.
I could fill a book with dumb-ass stories over the last 30 years.
Maybe I should !

 

[GFC]

My roof clearance over the boat to get into our slip is about 1'. I have to lay the antennas down flat to get in and out. It got to be a PITA always raising and lowering them so I bought a good handheld VHF. Now, if we're just going out for the day that's what I use.