VHF not hearing long distance

[Xavierp]

Originally Posted by lifeofreilly57

Theres no magic bullet here.
Basically, if the radio itself is not suspect then it's somewhere in the cabling or remote mic, try it and see if there's an improvement.
Oh, I also have had an antenna base fail from corrosion. There's not much to them but like all things on boats they caan corrode and cause issues too.

Thank you so much!!!!

[S/V Illusion]

Originally Posted by Xavierp

I think people are genuinely trying to help by throwing ideas. And I really appreciate that

What do you think I could do?

Certainly but sending you off on multiple wrong directions serves no one well.

You need to verify the proper output power of the radio and use any of a number of antenna analyzers, any of which will confirm whether or not the antenna and feed line is working properly. Absent that or “operator error” but having the squelch set too high, questing generally isn’t helpful.

[ScottRhodes13]

An earlier post mentioned your AIS splitter. You should check that. If it's not an 'active' splitter it will impact your reception and your transmission.
However, since you mentioned that your squelch was turned all the way up, I expect that was the real problem.

[Xavierp]

Originally Posted by ScottRhodes13

An earlier post mentioned your AIS splitter. You should check that. If it's not an 'active' splitter it will impact your reception and your transmission.
However, since you mentioned that your squelch was turned all the way up, I expect that was the real problem.

The squelch level didn't help.
Yesterday I was able to swap the coax connectors with new ones (from the mast cable to the cabin)
Because of the weather we haven't moved from the marina and not able to test yet.

Thx for your contribution

[TheOffice]

Had a similar problem. Cable was frayed where it exited the top of the mast. The wire tested OK with a meter.

[donradcliffe]

Learn how to use your squelch knob. You can check out if your receiver is working by listening to the Noaa weather channels.

[Stewie12]

A SWR meter is you best idea. Do remember that VHF is line of sight. If your antenna can see it, you can talk to it.

[Captain Graham]

In this thread I posted a youtube video about getting better range from your VHF radio
Some very good advice and explained well

https://www.cruisersforum.com/forums...ce-286652.html

[abarrow]

Check antenna, feedline, etc. Measuring SWR is a good first step - it'll show feedline issues and antenna issues. You didn't say if it worked before (at least I didn't see it). Most people don't have them, but a good quality resistive dummy load is a great tool for determining if your feedline has issues - but of course someone will have to go to the top of the mast and put it on the end of the feedline so you can test SWR again. Good SWR with a dummy load replacing the antenna? You have an antenna problem. SWR still bad? You have a feedline problem.

Another thing to try is turning EVERYTHING off except your VHF. Poor quality LED controllers can overwhelm the receive circuits in a VHF radio and the result is much reduced sensitivity.

[dreuge]

Originally Posted by S/V Illusion

The symptoms of bad or poor connection or bad coax would manifest more during transmit than receive. Either would cause reduced power and therefore reduced range while a problematic feed line would still receive albeit not as well.

The actual cause of what you describe can’t be ascertained with the limited info you mentioned although that apparently doesn’t prevent some people from making wild guesses.

Simply “looking at the connectors” won’t reveal a poor solder connection, moisture in the braid, etc…

I would say that it is likely a bad or poor connection or bad coax. A bad cable/connection could easily degrade a signal by 95%. This would still allow a 25W transmit as an effective 1.25W would go out which is plenty for a good receiving station. But on receiving a signal, which is small to begin, a 95% degradation would greatly reduce the incoming reception to below the squelch level or receiver's capabilities.

Also, a bad or poor connection or bad coax is common problem with Marine and Amateur Radio stations.

S/V Johanna Rose

[zstine]

I had a very similar problem with weak signal strength. I could receive ok, ais about 10-15miles, (Link-8 radio had ais built-in) but transmission was poor.

my problem turned out to be the antenna. But the troubleshooting was done like this...
I bought a pre-connecterized VHF cable (PL259 ends on it) and connected it to the antenna and straight, outside the mast, down the companion way to the radio. It did not fix the problem and since that took all connections and cables out of the system, it had to be the antenna or the radio itself. I installed a new antenna and returned the cable to Amazon. problem fixed.

had the cable fixed it, I would have cut the lower end off and pulled it down the mast with the old cable, then reconnectorized the end. and plug in to radio

[John Williams]

Not being an expert I am not sure why I am posting this.

But if you can be heard but you can't hear a reply I wonder why people think it is the antenna or connections. If the radio transmits and is heard, I make the assumption that the antenna is working the way it should. The squelch could be the issue. Otherwise it seems a mystery.

[S/V Illusion]

Originally Posted by dreuge

I would say that it is likely a bad or poor connection or bad coax. A bad cable/connection could easily degrade a signal by 95%. This would still allow a 25W transmit as an effective 1.25W would go out which is plenty for a good receiving station. But on receiving a signal, which is small to begin, a 95% degradation would greatly reduce the incoming reception to below the squelch level or receiver's capabilities.

Also, a bad or poor connection or bad coax is common problem with Marine and Amateur Radio stations.

S/V Johanna Rose

The effect of feed line problems isn’t always reciprocal. While it might degrade receive performance somewhat, the effect on transmit ERP is much more significant and pronounced. Regardless, absent proper testing, this is a guessing game

[continuouswave]

Another possible cause for poor receiver performance is locally generated noise.

This matches your description of being able to transmit but not receive well.

If something near the VHF radio antenna is producing radio-frequency-interference (RFI), the effective sensitivity of your receiver will be reduced, as only signals that arrive at a level above the noise floor will be able to be received.

You can test for this situation quite easily: turn off everything on your boat that runs from electrical power except the VHF Marine Band radio.

Tune in a weak NOAA weather radio station. Find a station for this test that is just on the margin of being received. You need a weak signal because you want to easily detect by ear if the signal is degraded by noise interference.

Then restore power to the other electrical devices, and see if the NOAA weak signal is degraded.

If this occurs, shut all the electrical device off, and then power them on, one at a time. You should be able to determine what device is creating the noise.

A typical source of noise can be a computer display or a television set, that is, a receiver actually receiving television broadcast signals.

ASIDE: I have observed this in several instances. For example, I have a VHF Marine Band radio at my cottage, which I use to listen to NOAA and also the local boat traffic at the nearby marina. The VHF transceiver is connected to a 3-element Yagi vertically polarized Loop-Fed antenna in the attic. (The loop fed design is intended to reduce noise pickup, and it is fed with balun.)

If I have my desktop computer running and the monitor is displaying the computer screen (not in sleep mode with a black screen), the VHF reception is noticeably degraded by noise from the computer monitor that is a foot or two from the radio, but the antenna is 15-feet above in the attic.


I also have a SONY Bravia TV set that is connected to an another antenna in the attic, a UHF-only, horizontally polarized, long Yagi (needed because the TV tower is 42-miles away) . There is no preamplifier on the TV antenna. As soon as the TV set is turned on, the VHF Marine Band receiver sensitivity is degraded due to noise from the TV set. In this case I think it is noise emitted by the TV receiver through its antenna.

At my home, I also have a similar situation in which a computer monitor obliterates TV reception on a weaker VHF station. In order to get an actual picture on the weaker HDTV station, I have to shut off the computer monitor.

Another source of interference can be from Ethernet unshielded cables.

[continuouswave]

Originally Posted by S/V Illusion

The effect of feed line problems isn’t always reciprocal. While it might degrade receive performance somewhat, the effect on transmit ERP is much more significant and pronounced. Regardless, absent proper testing, this is a guessing game

I believe that the effect is reciprocal, but the reason that the influence on reception is not as notable as on transmission is because of the ability of the receiver to add a lot of gain. During transmission, the effective radiated power is limited by the transmitter power delivered to the antenna, and the transmitter power is fixed at 25-Watts or less due to line loss and mismatch.

But on receive, the receiver has enormous reserve gain available to amplify the received signal, perhaps as much as 40 dB reserve gain, or a factor 10,000:1, which may be enough increase to make a signal readable even though the antenna efficiency is much reduced.

But, yes, typically with an antenna problem, you can receive better than you can transmit.

In this discussion we have the opposite situation: transmits but cannot receive.

The most reasonable inferences are:

--the receiver is badly damaged and has lost most of its sensitivity, or

--the receiver is working normally, but the presence of local noise or RFI is masking all but the strongest signals from being received.