Marine VHF

[GreggInFL]

For those of you remotely interested in why a cell phone may not be enough when on the water:

https://www.bostonwhaler.com/navigator-blog/fishing/vhf-cell-phone.html?utm_content=&emid=$emid&mkt_tok=MTYyLUtVRi01MjkAAAGafbxL2QyGoJPbJBjrLcJ-lbHanNwDmjZT6SoK0grQSvstFrCTqPzXllh_ap9aNedhZReMJcOrEMsdI4P_voDV8RNoOJSC3lpPcxIkS3oKBJHUcA

[Socalgmrs]

That’s the same reasons why cell phones are not enough on land.  

[WRUE951]

3 hours ago, GreggInFL said:

For those of you remotely interested in why a cell phone may not be enough when on the water:

https://www.bostonwhaler.com/navigator-blog/fishing/vhf-cell-phone.html?utm_content=&emid=$emid&mkt_tok=MTYyLUtVRi01MjkAAAGafbxL2QyGoJPbJBjrLcJ-lbHanNwDmjZT6SoK0grQSvstFrCTqPzXllh_ap9aNedhZReMJcOrEMsdI4P_voDV8RNoOJSC3lpPcxIkS3oKBJHUcA

remember the days when we watched TV off Antennas..  One could easly pick up VHF signals 100's mile away and it didn't always requrie line of site..  The same broadcast and from the same site in UHF never faired as well.  UHF reception always required line of site and distance was drastically cut short.  Marnie Radio is VHF, where cell is UHF..   VHF signals tend to work bounce back and forth between the earth and the ionosphere where UHF signals don't under most conditions making VHF a lot more reliable in the water   

[GreggInFL]

24 minutes ago, WRUE951 said:

remember the days when we watched TV off Antennas..  One could easly pick up VHF signals 100's mile away and it didn't always requrie line of site..  The same broadcast and from the same site in UHF never faired as well.  UHF reception always required line of site and distance was drastically cut short.  Marnie Radio is VHF, where cell is UHF..   VHF signals tend to work bounce back and forth between the earth and the ionosphere where UHF signals don't under most conditions making VHF a lot more reliable in the water   

A fixed-mount marine radio with a big antenna mounted on the top (third?) deck at max power (25W IIRC) transmits many farz when the only obstacle is the earth's curvature.

Another good reference for those new to the subject: https://www.boatingworld.com/articles/boating/vhf-radio-your-ultimate-guide/

[WRUU653]

 I was aware that you are required to monitor 16 while out on the water and why. The info of recommended channels for “chatting” was new to me. My dad had a commercial fishing boat. Sadly I get pretty sea sick so I’ve kept my boating to the bay, lakes and streams. Still I liked the info.

[Lscott]

There is movement, international so far, to go digital voice on the VHF marine band. Then it will likely happen here sooner or later.

 

Implementation of digital voice radio telephony in the VHF maritime mobile band.pdf

[GreggInFL]

16 hours ago, WRUU653 said:

 I was aware that you are required to monitor 16 while out on the water and why. The info of recommended channels for “chatting” was new to me. My dad had a commercial fishing boat. Sadly I get pretty sea sick so I’ve kept my boating to the bay, lakes and streams. Still I liked the info.

Here is the USCG page for channel/freq assignments: https://www.navcen.uscg.gov/us-vhf-channel-information. Even though I'm just a recreational boater, it's still fun to monitor some of these channels, especially when overseas.

[WRCZ387]

19 hours ago, WRUE951 said:

Remember the days when we watched TV off Antennas? One could easily pick up VHF signals 100's of miles away and it didn't always require line of sight. The same broadcast and from the same site in UHF never fared as well. UHF reception always required line of sight and distance was drastically cut short. VHF signals tend to work bounce back and forth between the earth and the ionosphere where UHF signals don't under most conditions making VHF a lot more reliable

That explains why I could pick up VHF stations from Buffalo [2, 4, sometimes 7] & Syracuse [3, 5, never 9] when I lived in Rochester, NY, I couldn't get any UHF from Syracuse [24. 68] at all, & only once from Buffalo [29, never could get 17], & I think that was because of a band opening

I probably would have needed a very tall tower to improve my reception chances

There was a house just outside the city limits on the NW side that had vertically stacked TV antennas, I'm sorry that I never knocked on the door to ask what they were able to pick up

[marcspaz]

Something I always found interesting is most VHF stations were using about 3kw ERP.  Some UHF stations were 150kw ERP, but high-power stations were 500kw ERP.  Between the higher power and shorter wavelengths, UHF always had better image quality compared to VHF.

 

I remember dang near every house had a massive TV beam antenna on the roof and a rotator controller on top of the TV. We had a list of what direction to point the antenna to watch specific channels, and we would kind of fiddle with it to get it just right. But the best was if you had a set of TV top 'rabbit ears' and loop. I remember (before we got a beam) we weren't allowed to move around the living room while mom and dad were watching TV and we all had specific spots to sit when we watched TV, because our bodies would impact how well the TV signal were received. Or we would stand there touching the rabbit ears so grandpa could watch the news. LoL

[AdmiralCochrane]

WMPT is cranking a meg these days.  If I recall correctly, they had a temporary experimental licensed increase to 2 for a few months.

 

My father bought a beam/yagi so far back I don't remember not having it. Probably on advice from my godfather who was a navy radio tech in the very early 1960's.

[WRKC935]

On 5/17/2025 at 6:32 PM, WRUE951 said:

remember the days when we watched TV off Antennas..  One could easly pick up VHF signals 100's mile away and it didn't always requrie line of site..  The same broadcast and from the same site in UHF never faired as well.  UHF reception always required line of site and distance was drastically cut short.  Marnie Radio is VHF, where cell is UHF..   VHF signals tend to work bounce back and forth between the earth and the ionosphere where UHF signals don't under most conditions making VHF a lot more reliable in the water   

Not sure that's right. 

Part of analog VHF TV was below 100Mhz, but went as high as 210 Mhz.

https://en.wikipedia.org/wiki/Television_channel_frequencies

But, satellite communications are done, at least with ham radio, at 145Mhz.  Now, there isn't much satellite happening below that, and the reason is the reflection.  But low powered handheld radios with modest gain antenna's are used with great success at 145Mhz.  So there isn't much 'skip' happening on the upper portions of VHF. 

TV signals are NOT a good measure of coverage distance, reason being is thousand foot towers and 100KW plus ERP's.  You can't sit and have a discussion of GMRS or ANY type of non-broadcast radio and compare it to TV or even AM /FM radio.  The antenna heights and power levels are so much greater with commercial radio and TV stations that it's not even apples and oranges.  Its apples and steak, or beer, NOTHING is similar when it comes to coverage. 

And broadcast anything is just that, broadcast.  It's all one way.  Now if you operate simplex (without a repeater) it's at least one way at a time RF, unlike a repeater that's listening to something and transmitting it somewhere else. 

 

[WRUE951]

8 hours ago, WRKC935 said:

Not sure that's right. 

Part of analog VHF TV was below 100Mhz, but went as high as 210 Mhz.

https://en.wikipedia.org/wiki/Television_channel_frequencies

But, satellite communications are done, at least with ham radio, at 145Mhz.  Now, there isn't much satellite happening below that, and the reason is the reflection.  But low powered handheld radios with modest gain antenna's are used with great success at 145Mhz.  So there isn't much 'skip' happening on the upper portions of VHF. 

TV signals are NOT a good measure of coverage distance, reason being is thousand foot towers and 100KW plus ERP's.  You can't sit and have a discussion of GMRS or ANY type of non-broadcast radio and compare it to TV or even AM /FM radio.  The antenna heights and power levels are so much greater with commercial radio and TV stations that it's not even apples and oranges.  Its apples and steak, or beer, NOTHING is similar when it comes to coverage. 

And broadcast anything is just that, broadcast.  It's all one way.  Now if you operate simplex (without a repeater) it's at least one way at a time RF, unlike a repeater that's listening to something and transmitting it somewhere else. 

 

what the hell are you saying there?  sounds like 'Bud' talking.   99.9% of us would not argue that broadcast TV is oneway transmission and no way compares to a GMRS signal. We know that, why do you bring that up.   Sorry, but  i cant wrap my head around your comment.  'Bud' will do that sometimes.  

[SteveShannon]

43 minutes ago, WRUE951 said:

what the hell are you saying there?  sounds like 'Bud' talking.   99.9% of us would not argue that broadcast TV is oneway transmission and no way compares to a GMRS signal. We know that, why do you bring that up.   Sorry, but  i cant wrap my head around your comment.  'Bud' will do that sometimes.  

He didn’t initially bring broadcast TV up; you did.  All he did was reply to your comment from Saturday:

On 5/17/2025 at 4:32 PM, WRUE951 said:

remember the days when we watched TV off Antennas..  One could easly pick up VHF signals 100's mile away and it didn't always requrie line of site..  The same broadcast and from the same site in UHF never faired as well.  UHF reception always required line of site and distance was drastically cut short.  Marnie Radio is VHF, where cell is UHF..   VHF signals tend to work bounce back and forth between the earth and the ionosphere where UHF signals don't under most conditions making VHF a lot more reliable in the water   

 

 

[WRUE951]

33 minutes ago, SteveShannon said:

He didn’t initially bring broadcast TV up; you did.  All he did was reply to your comment from Saturday:

 

 

I get that..  I brought up 'Broadcast TV' in my comment as a reference to Marine VHF because Broadcast TV is VHF.   Most of us know VHF Broadcast TV reacts to skip off the ionosphere like VHF Marine radio and UHF TV does not, so it was a reference.   His first line comment  'Not Sure Thats Right'  and the rambling after was a bit boggling.. Thats all.  

[WRKC935]

OK, Marine VHF is at 160Mhz.  I said that hams use 145 Mhz which talks right through the Ionosphere to satellites.  No reflection.  Try to be nice,

Nope.  Ain't your BUD, so here it is straight.

  Anything ABOVE 100 Mhz for certain and most anything above 30 Mhz will NOT reflect off the Ionosphere.  Which is what you said, which is incorrect.

SO VHF TV on any of the upper channels and mostly on the lower VHF channels doesn't skip, reflect, DX or whatever you were referencing.

Marine VHF also doesn't do that.  Hence the reason that HF comms were required on ships over a certain tonnage by maritime regulation.  And the reason that we had MORSE CODE requirements in ham radio for the amount of tie we did.

Now that GPS and satellite systems are in place and required on ships, the HF radio requirement is gone. 

And BTW.  When TV went digital, it quit being VHF all together.  There are no VHF (below 300Mhz) TV channel allocations any more.

https://www.antennasdirect.com/hdtv-station-list.html

Look at the list and it will show the station channels are NOT where the claim to be and instead have moved to the UHF band and only claim to be on the original analog channel position.

Bud

[WRUE951]

15 minutes ago, WRKC935 said:

OK, Marine VHF is at 160Mhz.  I said that hams use 145 Mhz which talks right through the Ionosphere to satellites.  No reflection.  Try to be nice,

Nope.  Ain't your BUD, so here it is straight.

  Anything ABOVE 100 Mhz for certain and most anything above 30 Mhz will NOT reflect off the Ionosphere.  Which is what you said, which is incorrect.

SO VHF TV on any of the upper channels and mostly on the lower VHF channels doesn't skip, reflect, DX or whatever you were referencing.

Marine VHF also doesn't do that.  Hence the reason that HF comms were required on ships over a certain tonnage by maritime regulation.  And the reason that we had MORSE CODE requirements in ham radio for the amount of tie we did.

Now that GPS and satellite systems are in place and required on ships, the HF radio requirement is gone. 

And BTW.  When TV went digital, it quit being VHF all together.  There are no VHF (below 300Mhz) TV channel allocations any more.

https://www.antennasdirect.com/hdtv-station-list.html

Look at the list and it will show the station channels are NOT where the claim to be and instead have moved to the UHF band and only claim to be on the original analog channel position.

Bud

You should spend a little time and google this topic and possibly re-read my comment.  Yes VHF marine radio is significantly affected byt the inoosphere, is it common, No but yes it does happen just as it does with Broadcast TV.  Is it common at UHF NO..  You may want to go back and retract your statement, "30 Mhz will NOT reflect off the ionosphere".   That my friend is defiantly incorrect.  BTW,  i wasn't calling you Bud.  I was more currious if you were drinking BUD.     Meanwhile  here is a little bit you may find on a Google Search:

How the Ionosphere Affects Marine Radio:

• High Frequency (HF) Radio:

  Marine radio communication often uses HF bands, which are susceptible to ionospheric effects. The ionosphere can reflect HF radio waves, allowing them to travel long distances, sometimes even around the world. 

   
• Ionospheric Disturbances:

  Solar activity, such as solar flares and coronal mass ejections, can disrupt the ionosphere, leading to reduced or even blackouts of HF radio signals. 

   
• Absorption and Refraction:

  The ionosphere can absorb radio signals, especially during periods of increased ionization density, and it can also refract (bend) radio waves, altering their path. 

   
• Long-Range Communication:

  The ionosphere's ability to reflect HF radio waves is crucial for long-range communication, as it allows signals to be transmitted over distances beyond the line of sight. 

   
• Daytime vs. Nighttime:

  The ionosphere's characteristics vary during the day and night. At night, the ionosphere can be thinner, allowing for more efficient reflection of radio waves, which can enhance long-distance communication. 

   
• VHF and Higher Frequencies:

  While HF radio is strongly influenced by the ionosphere, VHF and higher frequencies usually penetrate the ionosphere and are more commonly used for ground-to-space communications. However, there can be exceptions, such as Sporadic E (E-skip) propagation, where VHF signals can be reflected by the ionosphere during certain seasons. 

[FishinGary]

17 hours ago, marcspaz said:

I remember (before we got a beam) we weren't allowed to move around the living room while mom and dad were watching TV and we all had specific spots to sit when we watched TV, because our bodies would impact how well the TV signal were received. Or we would stand there touching the rabbit ears so grandpa could watch the news. LoL

Inductive coupling! It's fascinating, but also frustrating when you're trying to tune a mag loop, you get it "perfect", then move your hand away and your SWR shoots up. 

[marcspaz]

For what its worth, with both VHF and UHF, you can greatly extend communications well beyond the traditional LOS on the regular bases with the two stations involved being a bit 'over the top' for a typical Amateur or GMRS user.  For example, if you have a 9 element or 11 element high-gain yagi on a 50' tower at both stations, you can reliably communicate 100+ miles with a 50w radio on VHF, and 60+ miles with a 50w radio on UHF / GMRS.  If you happen to have your antenna somewhere comfortably above the average terrain, your station can talk even further.

 

This is because the additional height above ground extends the LOS range a bit, but the magic is in the yagi antenna.  Not only is the high-gain antenna able to pull more scattered energy out of the sky with greater efficiency, the fact that the beam is focused in a specific direction reduces the amount of random noise it pulls from the atmosphere.  This allows the antenna to perform significantly better compared to a vertical antenna with the same gain as the yagi, for example.  By reducing the total number of photons the antenna reacts to, you essentially improve the Part Per Million ratio in favor of the signal you are receiving.

 

My radio club used this principle in combination with a propagation method called Sporadic-E (reflecting a signal off the E Layer) to talk over 1,500 miles on VHF, from Virginia to Texas.  Our club had a stacked beam array and a 1,500w amplifier located on a mountain ridge in VA at 4,400+ feet and the Texas station had a similar setup in the western part of Texas, on a ridge line at about 6,000 feet.  We were also running a UHF station with a similar configuration that same week. We contacted a station over 450 miles away.  Though I don't remember the specifics of where the other station was for the UHF contact.

 

Anyway, I guess the moral of the story is, while refraction off the ionosphere isn't an option for mid to upper VHF or UHF... if we get creative with location, antenna and available forecasts of atmospheric conditions, we can bend or even break the commonly accepted LOS rules with our base stations, control stations and fixed stations.  We just need to leverage physics a little better.