First time doing a "radio check" and it didn't go so good!

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Island Dreamer

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I took the fam out today and one of the first things I did at the launch ramp was do a radio check with the harbor patrol on channel 16. The first call out was received but they said it was weak with static. The second try was a little bit better. They were about 1/2 mile away from me when they got the call. 10 miles from shore and 20 miles from shore I couldnt hail anyone for a radio check I now I'm questioning this old VHF. The LCD says 25w and I dont know if that is strong or weak compared to modern VHF's? The unit is likely from around the time of the boat being built in 1997. Also, the antenna was up!
 

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I would be willing to wager you have a corrosion issue at the connection from the antenna to the VHF ( or somewhere along the circuit).
1.) Has the coaxial cable been spliced at any time? If so, this is a suspect area.
2.) Has the VHF and antenna worked successfully up to this point and all of a sudden it won't transmit?
3.) Can you receive without disruption?

These are all important questions to isolate the problem area.
Also, as an FYI, the USCG frowns upon using 16 for radio checks. BoatUS use to offer a 27 channel radio check, but they have stopped that. I usually use channel 72 as that is our local fishing channel.

Thoughts?
 
My mistake, I called harbor patrol on channel 12! This was my first time ever using it. Im going to try and inspect any connections for corrosion.
 
1997 is a very long time in the world of electronics. May be time for a fresh system, A-Z. But, I would check for cuts, corrosion, etc as mentioned above. That said, my 1976 Stamas still has the original radio, as far as I know. Been thru a bunch of antennas due to breakage.
 
I took the fam out today and one of the first things I did at the launch ramp was do a radio check with the harbor patrol on channel 16. The first call out was received but they said it was weak with static. The second try was a little bit better. They were about 1/2 mile away from me when they got the call. 10 miles from shore and 20 miles from shore I couldnt hail anyone for a radio check I now I'm questioning this old VHF. The LCD says 25w and I dont know if that is strong or weak compared to modern VHF's? The unit is likely from around the time of the boat being built in 1997. Also, the antenna was up!
My bet is the IC-MC502 is still working fine. I 'second' what syndgoose suggested about the antenna; it is often (usually?) an antenna issue and/or a connection to the antenna. I have a 1983 Apelco VHF that still operates today, although the microphone was replaced in the late 1990's....I haven't used it on a boat since the 1990's but did use on a base-station until I gave it to friend last year.... Back in the 1970's-80's it was common for boaters to call the Coast Guard for a radio check, but now they not only 'frown' on getting such calls, it is illegal to call the Coast Guard for a radio check. (Although I've never heard of anyone getting arrested over it! )
 
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The antenne connections at the radio and antenne should be inspected and cleaned. The coaxialcable should be replaced or at least replace the ends before replacing the antenne.
 
I took the fam out today and one of the first things I did at the launch ramp was do a radio check with the harbor patrol on channel 16. The first call out was received but they said it was weak with static. The second try was a little bit better. They were about 1/2 mile away from me when they got the call. 10 miles from shore and 20 miles from shore I couldnt hail anyone for a radio check I now I'm questioning this old VHF. The LCD says 25w and I dont know if that is strong or weak compared to modern VHF's? The unit is likely from around the time of the boat being built in 1997. Also, the antenna was up!
Most Sea Tow and TowBoat/US encourage folks to call them for radio checks. I guess in some ways, it's free over- the- air advertising... I meant to add the following about the VHF Channels; (you likely are aware of this, but in case you were not 'getting out' because you could have been on a different channel).. The following channels automatically switch the radio to 1 Watt and of course would not transmit as far. Channel-13 (Bridge to Bridge). Channel 15 (Commercial). Channel 17 (SAR). Channel-67 (Bridge to Bridge). Channel 75, Channel 76 Channel 77 (Port Operations)....
Recreation boats can use 68, 69, 71, 72 and 78a. This used to include Channel 9 and 70, but Channel 9 is now an additional Hailing and Distress Frequency like Channel 16, and Channel 70 is for (Digital Selective Calling DSC/ MMSI)....
 
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Make sure the antenna is as close to vertical as possible. VHF transmission is perpendicular to the transmitter, so the field is more like a frisbee than a ball. Tilting the antenna greatly reduces your range in the half of the field it is tilted towards.
 
Buy a new unit and 8 ft antenna . Look at Digital brand antenna

This.....Do This! Why a Digital?

Because of their cable connector......No splicing.

These antennas comes with a baby connector on the coax.....It's the size of the coax in diameter. Then there is a adapter that screws on to the coax and the back of the radio....All factory sealed....Also down the road....If you break the antenna...and people do by leaving them up and going down the road on the trailer. It's twice as easy to replace the antenna....It's the only antennas I'll use.

PS. Do Not coil your excess coax. hank it by going back and forth.
 
Cut back the coax and solder in new pl-259 connectors at both ends and check your work with an ohm meter. Clean the mating connectors at the radio and antenne making sure you clean inside the center receiving hole. Do Not use crimp or scew on style, they might work for a while but not in a marine enviorment.
 
The ICOM M502 was discontinued in 2006. The earliest date I find in the operation manual literature is copyrighted 2000. I guest it could be from 1997, but I would not jump to that conclusion. Take a look at the back and you may find a date. Either way, let's start by recognizing it was a $500 radio when it was new. It's probably worth a little investigation.

First step is really two parts. Yes, as mentioned above, you should unscrew the antenna connection and inspect it. Look at the radio side and the coax side. Look for corrosion, exposed wires, or a lose fitting. If the coax side of the connector looks wonky, they can be replaced. There are a couple of different approaches to antenna connectors. Some are multipart assemblies that push on and then screw down and make contact with the coaxial cable. Others are soldered. I understand the screw-on is preferred, but whatever you have check to make sure it is clean and tight. It isn't a bad idea to examine the entire length of the cable for any damage or splices that need attention or replacement. I have a spare antenna that I keep in the house that I can connect to my radio to see if that improves or cures the problem. This lets me know the trouble is on the antenna side.

The second part often goes overlooked and can cost you hundreds of dollars in new equipment that was unnecessary. Check the power line to the radio. Make sure the power is coming in at 13.8 volts + or - 15%. This comes directly from the manual:
  • Power supply requirement:
    13.8 V DC ±15%

Too often people think the power supply is fine because the unit powers up. They are wrong. Electronic equipment will power up with less than the required voltage, but won't work properly without the full requirement. And yes, oh yes, on a boat power can and is reduced through bad connections, incorrect wiring, and resistance across fuses that have corrosion. Get a multimeter and measure the voltage coming to the radio. If it is not coming in at 12 volts or better, you need to run a new wire. Always check the values at the source of the power if you are taking it from a fusebox or buss bar. You can run a new wire from a poor source and still have a low value because you were not connecting to 12V in the first place.

Try these things first and maybe, for an out of pocket expense of $5.00 to $35.00 (depending on if you need to buy a multimeter and a coax connector) your radio will be as clear as a bell without spending a single dollar on antennas, coax cables, or a new radio. It is well worth the time and effort to take these steps before you buy a lot of new parts and equipment.

Good luck.
 
How was your reception of them returning the radio check? If 4.0 then your antenna and connections are probably good, though I'd still check and clean. My experience with VHF radios is that their transmission tends to fail while they receive fine. Some go a long time, others only a few years.
 
Ditto on getting a good antenna if it is the issue.

I still have an original '96 Standard Horizon going fine. I added a second VHF a couple years ago.

I have an average antenna and a very good one, I can tell the difference in reception.

Dana
 
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