Reply
 
Thread Tools Display Modes
 
Old 12-10-2015, 11:16 PM   #21
Enigma
 
RT Firefly's Avatar
 
City: Slicker?
Country: Bumpkin?
Join Date: Oct 2007
Posts: 9,996
Greetings,
Mr. ES. Lots of good advice here. I'm the last person you should ask about electronics. I know a bit about paint, hence my advice to paint a fuzzy aerial.
__________________
Advertisement

__________________
RTF
RT Firefly is online now   Reply With Quote
Old 12-11-2015, 06:45 AM   #22
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,531
Just how much time do you spend off shore talking to other boats 50 miles away?

For most inshore apps the base loaded SS whip is fine.
__________________

FF is offline   Reply With Quote
Old 12-11-2015, 07:24 AM   #23
Guru
 
timjet's Avatar
 
Join Date: Apr 2009
Posts: 1,905
I sanded and painted my fuzzy AM/FM and VHF radio antenna with a one part epoxy 3 years ago. They still look new.
__________________
Tim
Tampa Bay
Carver 355 ACMY Twin Cummins Diesels Sold
timjet is offline   Reply With Quote
Old 12-11-2015, 07:56 AM   #24
TF Site Team
 
Larry M's Avatar
 
City: JAX, FL
Country: USA
Vessel Name: Hobo
Vessel Model: Krogen 42-120
Join Date: Nov 2008
Posts: 5,744
Quote:
Originally Posted by koliver View Post
... there will be a difference in signal strength between the two. The longer one will have a stronger signal.
The 36" antenna is 3 dB vs the 8' is 6 dB.

...An antennaís dB rating (or antenna gain) indicates the apparent increase in transmitting power due to its ability to focus energy...A gain increase of 3dB means a doubling of signal strength: 6dB is a fourfold increase, and 9dB is an eightfold increase. The actual watts transmitted doesnít increase; itís just that the power is concentrated, much like a reflector on a flashlight, in a more concentrated beam. Therefore, a radio with a 6dB antenna will sound like it has a larger transmitter than the same radio with a 3dB antenna...
Larry M is offline   Reply With Quote
Old 12-11-2015, 01:49 PM   #25
Guru
 
City: North Charleston, SC
Country: USA
Join Date: Sep 2010
Posts: 4,390
Quote:
Originally Posted by FF View Post
Just how much time do you spend off shore talking to other boats 50 miles away?.
For most of us, not much time, but there may be a time when it's very important to communicate to another station 50 miles away. I think it's important to think of our VHF transceivers as safety equipment, not entertainment. We should aim for the best we can practically accomplish.
rwidman is offline   Reply With Quote
Old 12-11-2015, 05:59 PM   #26
Senior Member
 
IntervaleII's Avatar
 
City: Tokyo, Japan / Tampa, Florida / Washington, Virginia
Country: Japan / United States
Vessel Name: Mondai Nai
Vessel Model: Nordhaven 55 - 45
Join Date: Mar 2013
Posts: 271
Send a message via Skype™ to IntervaleII
Digital antennas is also a option for a replacement if needed. They are wood epoxied and painted. Just wax a few times a year, always looks new and don't degrade. Very well made. They are located in Florida. I had 4 for over 10 years, looked great and looked like new the day I sold the boat.


Sent from my iPad using Trawler Forum
Capt. Don
IntervaleII is offline   Reply With Quote
Old 12-12-2015, 08:14 AM   #27
Guru
 
CaptTom's Avatar
 
City: Southern Maine
Country: USA
Vessel Name: Cygnus
Vessel Model: Prairie 36 Coastal Cruiser
Join Date: Dec 2012
Posts: 1,378
Quote:
Originally Posted by FF View Post
Just how much time do you spend off shore talking to other boats 50 miles away?
Hopefully, never. But that one time you need help, and it's 50 miles away, you'll probably be glad you didn't go cheap on the antenna.
CaptTom is offline   Reply With Quote
Old 12-14-2015, 07:10 AM   #28
Guru
 
SCOTTEDAVIS's Avatar
 
City: Vero Beach, FL.
Country: US
Vessel Name: FIREFLY
Vessel Model: Pilgrim 40
Join Date: Nov 2012
Posts: 913
I was wondering, how many of you only have one radio?

I have 4, two on 8' whips, one on the mast head "sailboat" antenna and of course a hand held with antenna adapter if needed to use in a pinch.

I do use 2 radios at a time in the wheel house, separate channels of course.

I have a back up near the helm but closer to the "first officer" in case the helmsman is too busy, bridge tenders respond nicer to a softer voice anyway.
SCOTTEDAVIS is offline   Reply With Quote
Old 12-14-2015, 08:39 AM   #29
Guru
 
City: North Charleston, SC
Country: USA
Join Date: Sep 2010
Posts: 4,390
Quote:
Originally Posted by IntervaleII View Post
Digital antennas is also a option for a replacement if needed. They are wood epoxied and painted. Just wax a few times a year, always looks new and don't degrade. Very well made. They are located in Florida. I had 4 for over 10 years, looked great and looked like new the day I sold the boat.


Sent from my iPad using Trawler Forum
Capt. Don
Just to be clear, "Digital" is a brand of antenna, not a type or technology. They are built the same as any other VHF antenna. They seem to be of high quality but the technology is the same. They won't work any better.
rwidman is offline   Reply With Quote
Old 12-14-2015, 08:41 AM   #30
Guru
 
City: North Charleston, SC
Country: USA
Join Date: Sep 2010
Posts: 4,390
Quote:
Originally Posted by SCOTTEDAVIS View Post
I was wondering, how many of you only have one radio?

I have 4, two on 8' whips, one on the mast head "sailboat" antenna and of course a hand held with antenna adapter if needed to use in a pinch.

I do use 2 radios at a time in the wheel house, separate channels of course.

I have a back up near the helm but closer to the "first officer" in case the helmsman is too busy, bridge tenders respond nicer to a softer voice anyway.
I have one fixed and one hand held. That's two.

Also two cell phones for calling marinas, etc.
rwidman is offline   Reply With Quote
Old 12-14-2015, 11:32 AM   #31
Guru
 
caltexflanc's Avatar
 
City: North Carolina for now
Country: USA
Vessel Name: Small Incentive
Vessel Model: Boston Whaler 130 Sport
Join Date: Aug 2011
Posts: 3,802
Quote:
Originally Posted by WesK View Post
Just to be clear, "Digital" is a brand of antenna, not a type or technology. They are built the same as any other VHF antenna. They seem to be of high quality but the technology is the same. They won't work any better.
1) the name derives from their roots making antennas for Motorola when the shift from analog to digital cellular was taking place.

2) No, they are not all made the same. I once witnessed an antenna dissection exercise when an offshore service company was bidding out a contract. The Digital had more robust internal parts and construction. Also, they tune each VHF antenna to be optimized and "centered" on 16. The Morads were the most rugged and the company went with a combination of them and the Digitals.
__________________
George

"There's the Right Way, the Wrong Way, and what some guy says he's gotten away with"
caltexflanc is online now   Reply With Quote
Old 12-14-2015, 12:46 PM   #32
TF Site Team
 
FlyWright's Avatar
 
City: California Delta and SF Bay
Country: Sacramento, CA, USA (boat in Vallejo)
Vessel Name: FlyWright
Vessel Model: Marshall Californian 34 LRC
Join Date: Apr 2008
Posts: 10,184
Quote:
Originally Posted by TDunn View Post
The sailboat antenna is also acceptable because it is up high. Since VHF is line of sight, higher means longer range. For example my antenna on my sailboat is 50' above the water at its base.
Quote:
Originally Posted by Larry M View Post
The 36" antenna is 3 dB vs the 8' is 6 dB.

...An antennaís dB rating (or antenna gain) indicates the apparent increase in transmitting power due to its ability to focus energy...A gain increase of 3dB means a doubling of signal strength: 6dB is a fourfold increase, and 9dB is an eightfold increase. The actual watts transmitted doesnít increase; itís just that the power is concentrated, much like a reflector on a flashlight, in a more concentrated beam. Therefore, a radio with a 6dB antenna will sound like it has a larger transmitter than the same radio with a 3dB antenna...
Great points.

Antenna quality, coax quality, connector quality, antenna length/efficiency and antenna height are all important factors in maximizing range of a given radio. Transmitter power also comes into play. Most marine radios are very capable and transmitters of 15W or above should perform well with a proper installation.

I had some old, itchy antennas that got replaced after I decided against painting. Nothing wrong with that approach if they're working well. A quality antenna is not that much more expensive than a cheapo. The expensive part can be shipping, so ship free to a local store for pickup if you have that option.
__________________
Al

Custom Google Trawler Forum Search
FlyWright is online now   Reply With Quote
Old 12-14-2015, 02:50 PM   #33
Guru
 
City: North Charleston, SC
Country: USA
Join Date: Sep 2010
Posts: 4,390
Quote:
Originally Posted by caltexflanc View Post
1) the name derives from their roots making antennas for Motorola when the shift from analog to digital cellular was taking place.

2) No, they are not all made the same. I once witnessed an antenna dissection exercise when an offshore service company was bidding out a contract. The Digital had more robust internal parts and construction. Also, they tune each VHF antenna to be optimized and "centered" on 16. The Morads were the most rugged and the company went with a combination of them and the Digitals.
The name "Digital" fools some people into thinking they are somehow a more advanced technology. They are not.

The technology is the same as any other VHF antenna. It's possible that some models are more "robust" than some models of other brands. I suspect dollar for dollar, they are all about the same. Performance is the same as well.
rwidman is offline   Reply With Quote
Old 12-14-2015, 05:17 PM   #34
Guru
 
caltexflanc's Avatar
 
City: North Carolina for now
Country: USA
Vessel Name: Small Incentive
Vessel Model: Boston Whaler 130 Sport
Join Date: Aug 2011
Posts: 3,802
Quote:
Originally Posted by WesK View Post
The name "Digital" fools some people into thinking they are somehow a more advanced technology. They are not.

The technology is the same as any other VHF antenna. It's possible that some models are more "robust" than some models of other brands. I suspect dollar for dollar, they are all about the same. Performance is the same as well.
They still make cell phone antennas, BTW. I suppose they could have changed their name after years in business to avoid angering you about "fooling" people.
You may suspect what you like, but I saw an actual test and unmasking what lay below the fiberglass (or aluminum in the case of the Morads). Probably had nothing to do with the tests I saw, but not long afterwards Shakespeare introduced a "premium" line of antennas.
__________________
George

"There's the Right Way, the Wrong Way, and what some guy says he's gotten away with"
caltexflanc is online now   Reply With Quote
Old 12-14-2015, 05:28 PM   #35
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,919
Wow...read up from manufacturer sites and independent info...too much borderline info here from my experience using and installing VHFs over 2 careers.

Power is way more important sometimes over height...especially with a lot of traffic or signal loss/interference.

Just my practical over theory experience talking.....
psneeld is online now   Reply With Quote
Old 12-14-2015, 05:59 PM   #36
TF Site Team
 
FlyWright's Avatar
 
City: California Delta and SF Bay
Country: Sacramento, CA, USA (boat in Vallejo)
Vessel Name: FlyWright
Vessel Model: Marshall Californian 34 LRC
Join Date: Apr 2008
Posts: 10,184
Quote:
Originally Posted by psneeld View Post
Power is way more important sometimes over height...especially with a lot of traffic or signal loss/interference.
Power only helps with half of the function of a VHF transceiver...the transmit side. Receiving VHF signals is passive but receiver sensitivity matters. Both functions, transmit and receive, require line of sight (with minor exceptions) and are affected the other factors I cited.

In my job, we did years of certification of transmitters and receivers for communication and navigation in the FAA. When the FAA went to the NextGen comm radios, there was great hesitation among the old timers with the reduced power consumption and transmitter power. I conducted many hours of real world in flight testing over flat land, mountains and water in a variety of weather conditions near Santa Barbara, CA and confirmed that the performance met or exceeded that of the older, more powerful radios. Even the old time controllers and airway facilities techs were impressed and pleased.
__________________
Al

Custom Google Trawler Forum Search
FlyWright is online now   Reply With Quote
Old 12-14-2015, 06:26 PM   #37
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,919
Quote:
Originally Posted by FlyWright View Post
Power only helps with half of the function of a VHF transceiver...the transmit side. Receiving VHF signals is passive but receiver sensitivity matters. Both functions, transmit and receive, require line of sight (with minor exceptions) and are affected the other factors I cited.

In my job, we did years of certification of transmitters and receivers for communication and navigation in the FAA. When the FAA went to the NextGen comm radios, there was great hesitation among the old timers with the reduced power consumption and transmitter power. I conducted many hours of real world in flight testing over flat land, mountains and water in a variety of weather conditions near Santa Barbara, CA and confirmed that the performance met or exceeded that of the older, more powerful radios. Even the old time controllers and airway facilities techs were impressed and pleased.
I should have been more clear...the higher gain antennas can mean the difference in decent comms or not...not the power of the radio itself.

With no antenna, the most powerful or sensitive radio is useless...sorta..
__________________

psneeld is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 01:26 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012