VHF antennas height vs DB

[psneeld]

I will trust my expeience when it comes to important comms.

I have both so I hope everyone else uses 3db antennas so I can step all over them.

 

[rslifkin]

Thinking about it, this has to be somewhat of a local concern. Around here, VHF is usually pretty quiet. So height likely matters more than db for range, as being heard vs stepped on isn't much of a concern. But go to somewhere with lots of chatter and people getting stepped on and the answer will almost certainly change.

 

[backinblue]

Same where I am. Most channels are pretty quiet. Also the USCG is pretty good about policing ch 16 and keeping people off it except in emergencies.

 

[ofer]

Same where I am. Most channels are pretty quiet. Also the USCG is pretty good about policing ch 16 and keeping people off it except in emergencies.

i boat in So Cal and Homer Alaska. I am surprised how different the coast guard
responds to communications on 16 in both areas.

in So Cal most radio checks on 16 are followed by CC warning etc.

in Alaska heard many radio checks on 16 and not one warning yet.

 

[rslifkin]

i boat in So Cal and Homer Alaska. I am surprised how different the coast guard
responds to communications on 16 in both areas.

in So Cal most radio checks on 16 are followed by CC warning etc.

in Alaska heard many radio checks on 16 and not one warning yet.

Around here it seems to vary. If it's just one radio check with 1 or 2 quick responses and 16 is otherwise very quiet, they tend to ignore it. If it's 2 or 3 boats in succession or if 16 has been busier, they typically give the warning.

 

[Bud]

Blackinblue's link shows a good illustration.
Here is a good comparison showing all three antenna gains. I apoligize for the sideways pic.

 

[diver dave]

..
Will say I’ve never asked nor been asked to”state intentions “.

I did hear that one once. On a nite swordfishing trip, and my spot apparently was also a light cruiser "spot". I should have had the presence of mind to send that same quote to the USCG one time, as they were crossing paths, intentionally.

 

[backinblue]

Blackinblue's link shows a good illustration.
Here is a good comparison showing all three antenna gains. I apoligize for the sideways pic.

I have seen that one too and it is also a good illustration. I guess a lot of it matters on where you boat and what kind of boating you do.

 

[psneeld]

With all the arguments on TF over the best way to join 2 wires together....etc...etc..., and the relatively low cost of 2 radios and 2 different antennas capable of superior performance for situations that can directly relate to safety....I just shake my head.


So often is trawler forum described as any kind of boat is welcome as it describes a similar "style boating"....


I can't imagine cruising anywhere in the US without 2 fixed radios (1 - 9db ant/ 1 - 6 or 3 db antenna) and a backup handheld for last resort, ditch bag, dingy use and what I use if I have to lay my big antennas down. Because I know when you need to talk to someone...you need good comms as poor ones can jeopardize any rescue or assistance cases.


So I am really glad someone is willing to spend top dollar on tinned wire and top level butt connectors but then the what I see as misunderstood debate over what many consider safety gear.


Plus...as a follow on....those simplistic representations of transmission lobes for REAL antennas (not theoretical) are just that.

 

[backinblue]

With all the arguments on TF over the best way to join 2 wires together....etc...etc..., and the relatively low cost of 2 radios and 2 different antennas capable of superior performance for situations that can directly relate to safety....I just shake my head.

Nothing against anything you have stated and I respect that you have more real-world experience than most of us. However, you should also realize that some of us are not in a position to have multiple radios and multiple antennas, so if you can only choose 1, there is a compromise to make, one way or the other.

I actually do have multiple radios. My fixed unit with a 6db antenna, and a floatable handheld as backup or for situations where a handheld is best, dinghy rides, etc.

 

[psneeld]

All but a very few here could have multiple radios and antennas.

And as I pointed out, few here ever argue cost....usually the first is me posting balancing the cost/benefit balance.


I get the resistance to do it, just hope you never wish you had a higher gain antenna.

 

[ofer]

this is a wrong assumption.

ill end up with four fixed radios and 3,2x6 and a 9 db antennas. just trying to figure out where and how to place and which would be better to use in different conditions.

With all the arguments on TF over the best way to join 2 wires together....etc...etc..., and the relatively low cost of 2 radios and 2 different antennas capable of superior performance for situations that can directly relate to safety....I just shake my head.


So often is trawler forum described as any kind of boat is welcome as it describes a similar "style boating"....


I can't imagine cruising anywhere in the US without 2 fixed radios (1 - 9db ant/ 1 - 6 or 3 db antenna) and a backup handheld for last resort, ditch bag, dingy use and what I use if I have to lay my big antennas down. Because I know when you need to talk to someone...you need good comms as poor ones can jeopardize any rescue or assistance cases.


So I am really glad someone is willing to spend top dollar on tinned wire and top level butt connectors but then the what I see as misunderstood debate over what many consider safety gear.


Plus...as a follow on....those simplistic representations of transmission lobes for REAL antennas (not theoretical) are just that.

 

[backinblue]

All but a very few here could have multiple radios and antennas.


Please don't insult my intelligence.


And as I pointed out, few here ever argue cost....usually the first is me posting balancing the cost/benefit balance.

No insult intended. I am speaking mostly from personal experience. I have a single helm and really no room or need for multiple units and antennas, so my opinions are based on my experience. I didn't mean that it's right for everyone.

 

[Bud]

For safety I would recommend a satelite comm for back up to VHF. Spot X, Epirb. sat phone ect... There are a lot of reasons a vhf fails to communicate and not all are eliminated by using or having a backup VHF radio.

Bud

 

[backinblue]

For safety I would recommend a satelite comm for back up to VHF. Spot X, Epirb. sat phone ect... There are a lot of reasons a vhf fails to communicate and not all are eliminated by using or having a backup VHF radio.

Bud

Again, it depends a lot on where and how you boat. For some, a cell phone is an acceptable backup.

 

[psneeld]

1. No you don't need 4 radios. 95% of the time most boaters can be at either helm to use the best radio in an emergency. If a true emergency, hit the distress button on a DSC radio and it will keep transmitting (even if rolling cuts out high gain antenna) till acknowledged by a SAR unit (at least the way I understand it).


2. VHF is used for the vast majority of SAR and assistance, EPIRBs and such are usually for emergencies when totally out of VHF range (and are only an alert, not valuable comms) or when abandoning ship.


3. Cel is a different tool, not a substitute all the time for VHF and usually has a range of only 5-10 miles offshore.

 

[Bud]

True on the cell phone. I figured that was a given. The spot X works good down here in the Florida Keys. We go to the Bahamas and the Dry Tortugas often and the VHF has very limited use in these areas. The spot X we can text or email anybody anytime and it is low cost.

Bud

 

[psneeld]

True on the cell phone. I figured that was a given. The spot X works good down here in the Florida Keys. We go to the Bahamas and the Dry Tortugas often and the VHF has very limited use in these areas. The spot X we can text or email anybody anytime and it is low cost.

Bud

I get all the great stuff we have on our boats these days..... but the real worth of but a few good tools we have are lost until one needs them and all the other gizmos are useless. I was on the other end of that need for nearly 35 years.



How well does spot X work with communicating with another boat, a USCG boat or a USCG helo coming to your assistance?

 

[Bud]

IMO The DSC system on the vhf is poorly implemented and not well understood/used by boaters. Ends up adding to radio congestion and taking up dispacher time.

Bud

 

[diver dave]

In my world of cruising, its used as a telephone.
Cruiser shows up to a large anchorage or mooring field. He or she fires off a bunch of targeted dsc calls to buddy boats. Those in range answer back and drinking commences. Its a wonderful social tool.
Most cruisers these days include their MMSI nos. on their boat card.

Dispatcher [emoji484]

 

[Bud]

I get all the great stuff we have on our boats these days..... but the real worth of but a few good tools we have are lost until one needs them and all the other gizmos are useless. I was on the other end of that need for nearly 35 years.



How well does spot X work with communicating with another boat, a USCG boat or a USCG helo coming to your assistance?

The most important communication is the SOS and the location which are both in the spot X transmission.

Bud

 

[rslifkin]

I do have 2 VHFs at my helm (both with remote mics in the cabin) plus a handheld. Both fixed units currently have 6db antennas on them, however. Partly because I don't have a good way to secure an upper mount for a taller antenna due to no flybridge, hardtop, arch, etc.

At some point when I have a good way to mount bigger units, I'll plan to go for it. And probably keep smaller ones with a way to switch to the smaller units when the big ones are lowered for bridges. Or use antennas with a connector rather than built in cable allowing me to physically switch them out for shorter ones when in areas where bridge clearance is a concern.

 

[Bud]

In my world of cruising, its used as a telephone.
Cruiser shows up to a large anchorage or mooring field. He or she fires off a bunch of targeted dsc calls to buddy boats. Those in range answer back and drinking commences. Its a wonderful social tool.
Most cruisers these days include their MMSI nos. on their boat card.

Dispatcher [emoji484]

I am Glad to hear that. I like the tecnology and intention of it. We been using it in the two way radio industry for years.

Bud

 

[psneeld]

The most important communication is the SOS and the location which are both in the spot X transmission.

Bud

I totally disagree....the vast majority of rescue cases and assistance calls involve a lot of communications, sure once the primary SAR/assistance resource is on scene a small handheld is all that's needed.


DSC emergency is as simple as pushing a button and holding it a given number of seconds as long as you have it with a MMSI and GPS input.



The trick is to have the RIGHT resource show up.


I don't know where most people get their concept of rescue/assistance...but I guess I should know as how poorly many SAR/assistance cases go badly.


For the interested, tall antenna bracing can be fabricated for almost any boat and usually aren't all that complex or costly.

 

[psneeld]

I do have 2 VHFs at my helm (both with remote mics in the cabin) plus a handheld. Both fixed units currently have 6db antennas on them, however. Partly because I don't have a good way to secure an upper mount for a taller antenna due to no flybridge, hardtop, arch, etc.

At some point when I have a good way to mount bigger units, I'll plan to go for it. And probably keep smaller ones with a way to switch to the smaller units when the big ones are lowered for bridges. Or use antennas with a connector rather than built in cable allowing me to physically switch them out for shorter ones when in areas where bridge clearance is a concern.

I believe this is a 381 with either 9db antennas or 6db on masts...so it can be done 9f you really want to.

 

[Bud]

For safety I would recommend a satelite comm for back up to VHF. Spot X, sat phone ect... There are a lot of reasons a vhf fails to communicate and not all are eliminated by using or having a backup VHF radio. The spot X works good down here in the Florida Keys. We go to the Bahamas and the Dry Tortugas often and the VHF has very limited use in these areas. The spot X we can text or email anybody anytime and it is low cost.

 

[rslifkin]

I believe this is a 381 with either 9db antennas or 6db on masts...so it can be done 9f you really want to.

It's definitely possible. I just haven't come up with a suitable upper mount yet. But a hardtop is in the plans at some point, so that would make it easy if I don't come up with something else first.

 

[psneeld]

For safety I would recommend a satelite comm for back up to VHF. Spot X, sat phone ect... There are a lot of reasons a vhf fails to communicate and not all are eliminated by using or having a backup VHF radio. The spot X works good down here in the Florida Keys. We go to the Bahamas and the Dry Tortugas often and the VHF has very limited use in these areas. The spot X we can text or email anybody anytime and it is low cost.

You are obviously missing my point...... so be it.

 

[psneeld]

It's definitely possible. I just haven't come up with a suitable upper mount yet. But a hardtop is in the plans at some point, so that would make it easy if I don't come up with something else first.

The upper mount doesn't have to be much and mine are only about 1/2 the recommended distance from the upper....no problems in 20,000 miles.


I have seen htem attached to bimini frames, but I have no idea if it works well, but I think if it's a sturdy frame it would work well enough.

 

[diver dave]

I am Glad to hear that. I like the tecnology and intention of it. We been using it in the two way radio industry for years.



Bud

Selective call. [emoji106]. At least at Mot.

And then P25 paging and call.