VHF Power

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
rwidman said:
More marinas than I would like simply don't answer the VHF regardless of what channel you call on. My current one does, but the one I was at for ten years did not. In fact, they unhooked the VHF to move stuff around and never reconnected it. I learned to call them on the phone if I wanted docking help.

We recently returned from a nearly three month cruise and were unable to reach marinas for docking instructions several times.
Click to expand...

It must vary by region. I have never visited a marina that did not prefer to communicate on VHF when approaching. In fact, many will ask that you call their working channel if you need anything during your stay after you've docked, like ice delivery, etc.
 
VHF: Marine coast stations are limited to 50Watts. Including Rescue 21 installs.
Marine utility stations are limited to 10Watts. These are defined as handheld.
Shipboard is 25W max. , with ability to reduce to <1W.

Much different rules for HF apply.

I'm still thinking about the VHF comm band as "obsolete". Certainly, there are issues, but I think the biggest one is the lack of proper DSC usage. Exasperated by difficult to use VHF radio menus. ie: how do YOU call collision traffic, by DSC or Voice? When you look at the MMSI on the AIS screen, what steps are needed in YOUR system to load that number in the VHF? How long does it take, and who on board is trained??
 
Last edited:
Re 1W vs 25W, remember radiation propagates at the inverse square of distance. That is, the 25W transmitter is really only 5x more effective than the 1W, not 25x. Anything less than 25W would not make much difference.
 
gsholz said:
Re 1W vs 25W, remember radiation propagates at the inverse square of distance. That is, the 25W transmitter is really only 5x more effective than the 1W, not 25x. Anything less than 25W would not make much difference.
Click to expand...

True; unless you are in a competitive environment with the receiver. Also, locally generated noise. The closer answer is a certain Signal to Noise ratio. Working with just the numerator may give you wildly optimistic values. :thumb:
 
In the past before cell phones travel in winter on the AICW heading south in Jan or Feb was very difficult .

The bridge tenders would have the squelch turned up on their channel and also 16 .

An air horn was usually required to overpower the squelch and TV .
 
One other point on handheld radios that is overlooked.
If the antenna is not vertical the effective range is reduced.
Not always easy to remember to hold the antenna vertical.
Ask me how I know.
 
I agree with the several comments that if 1W doesn't work for you out to some reasonable distance -- say two or three miles -- that you should look at (or have an expert look at) your antenna and its cable. Being over 65', Fintry is required to have channel 13 on all the time while underway and in Boston Harbor we use it frequently. I've never had a problem communicating on 13. Fintry's channel 13 antenna is on the railing above the wheelhouse -- not one of the two high on the spreaders - so it's about 25' above the water.


Jim
 
The antenna or "rubber ducky" as it is frequently called has no gain.
The 8 ft long fiberglass antennas have a gain of 6 db.
Every 3 db of gain doubles the apparent power.
So 6 db effectively gives you 4 times the apparent power.
1 watt on the fixed radio feeding a 6 db gain antenna is effectively 4 watts.
Antenna height will also allow longer range.
 
Apologies for any duplication; I'm preparing for a passage and can't read more than the first dozen or so...

It also can bleed onto other channels; when I do morning nets, I tell folks to turn up to high power so that everyone can hear, but then when you go to a private-chat channel (not private but not on the net frequency), to go to low power if you can, as that can bleed back.

Particularly 68 (typical hailing channel) and 72 (common net channel if 68 is usually a busy one) are one such pair/problem...
 
Definitely check out your equipment: radio, antenna, and cabling. I've been hit by lightning and radio worked close by so I thought it worked but at distance, not at all. After testing and replacement, new equipment was working great and realized our ineffective old equipment. Corrosion on connections will hurt you too.
 
I'm tired of saying this but there is nothing wrong with my radio. I was only questioining where the 1W limit came from. Thanks for everyone's responses, all good discussion regardless.
 
You did post this as your 3rd sentence in the OP.....


"I think something like 5W/25W makes more sense. I rarely use 1W because I often don't get an answer even when fairly close to a marina I am hailing."
 
psneeld said:
You did post this as your 3rd sentence in the OP.....


"I think something like 5W/25W makes more sense. I rarely use 1W because I often don't get an answer even when fairly close to a marina I am hailing."
Click to expand...

And I still stand by that statement. I can do 1W radio checks with no problem. The marina issue I blame on the kids manning the the docks with handhelds. Also, when I say fairly close to a marina, I could be entering a channel or harbor and the marina is close but not within sight yet. I'd rather not broadcast my slip request to everyone within 20 miles, but sometimes have no choice.
 
True, but you know how drift can take over if you introduce ideas even if they have nothing to do with your question.


If you didn't then, you know now.
 
psneeld said:
True, but you know how drift can take over if you introduce ideas even if they have nothing to do with your question.


If you didn't then, you know now.
Click to expand...

LOL. Lesson learned, thanks!
 
Yep; definitely should head for a radio bench.
Tx power on hi/low; Tx deviation; Tx hum and noise; Tx frequency error; Tx audio distortion; Tx harmonics to the 10th; Tx spurs; Rx 20 db quieting, 12 dB sinad, squelch blocking, squelch threshold, squelch tight; Antenna horiz pattern;
Antenna vertical pattern; Tx ERP on and off the body; Rx 3rd order IMd; Rx distortion; Rx adjacent channel selectivity; Rx rated audio power; Rx alternate channel selectivity; Rx image rejection; and a full spur sweep on Rx; and then redo at +60 deg and -30 deg C; sorry I forgot some....:flowers:
 
Last edited:
diver dave said:
Yep; definitely should head for a radio bench.
Tx power on hi/low; Tx deviation; Tx hum and noise; Tx frequency error; Tx audio distortion; Tx harmonics to the 10th; Tx spurs; Rx 20 db quieting, 12 dB sinad, squelch blocking, squelch threshold, squelch tight; Antenna horiz pattern;
Antenna vertical pattern; Tx ERP on and off the body; Rx 3rd order IMd; Rx distortion; Rx adjacent channel selectivity; Rx rated audio power; Rx alternate channel selectivity; Rx image rejection; and a full spur sweep on Rx; and then redo at +60 deg and -30 deg C; sorry I forgot some....:flowers:
Click to expand...

Sorry, not impressed. I know everyone is very concerned and losing sleep about my radio health. So to put everyone at ease, today I did a 1W radio check. I was not on the open water but up a river. The response I got was from another harbor about 5 miles away OVER THE LAND! So everyone take a deep breath and relax. Me and my radio are in fine health. In fact, my radio is probably in better shape than I am.
 
Hey, what channel # is the auto repeat, to check the radio?
 
My thoughts:
Channel 16 for hailing then, pick a working channel. GET OFF channel 16.
If I dont get a response on 16 at 25watts, I am too far away or their squelch is set wrong.
I was taught, adjust the squelch until you get static and then, adjust the squelch so where the static goes away aka, just a little tiny bit. I could be wrong but, I dont think so.
 
https://boatbeat.org/boatbeat-alerts/sea-tow-automated-radio-check-system-no-longer-available/

For several years, Sea Tow operated an Automated Radio Check System, which was available on VHF Channels 24 to 28 for the benefit of mariners in over 130 locations. However, on October 2nd, 2020 that service was discontinued. The Coast Guard Inspections and Compliance Directorate has issued MSIB 20-20 to inform mariners of the proper procedure for performing a VHF radio check.
 
OldDan1943 said:
My thoughts:
Channel 16 for hailing then, pick a working channel. GET OFF channel 16.
If I dont get a response on 16 at 25watts, I am too far away or their squelch is set wrong.
I was taught, adjust the squelch until you get static and then, adjust the squelch so where the static goes away aka, just a little tiny bit. I could be wrong but, I dont think so.
Click to expand...


That's my procedure for setting squelch as well. Just enough to avoid constant background static.
 
psneeld said:
https://boatbeat.org/boatbeat-alerts/sea-tow-automated-radio-check-system-no-longer-available/

For several years, Sea Tow operated an Automated Radio Check System, which was available on VHF Channels 24 to 28 for the benefit of mariners in over 130 locations. However, on October 2nd, 2020 that service was discontinued. The Coast Guard Inspections and Compliance Directorate has issued MSIB 20-20 to inform mariners of the proper procedure for performing a VHF radio check.
Click to expand...

Yes 5 more working channels!
 
I guess I am back to hailing on 16 for a radio check. SHRUG
 
You must log in or register to reply here.

Similar threads

Pete Meisinger
You (Us) old guys have lots of options
2
Replies
40
Views
5K
Sailor of Fortune
Sailor of Fortune
wkearney99
New Peplink gear
Replies
8
Views
1K
wkearney99
wkearney99
PNW
Seattle, new to trawling, excited to learn all the diesel things
Replies
19
Views
1K
Bacchus
Bacchus
D
Holding Tank Fittings Help w/ discharge
Replies
9
Views
1K
Barking Sands
Barking Sands
Sabre602
37' Diesel Trawler, Former Commercial Fisher - Bellingham, Washington
Replies
4
Views
3K
delirious duo
D

Latest posts

Back
Top Bottom