Gonios
- Thread starter alberto
- Start date
The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
Steve
Guru
Until today I had never heard that word, I imagine they are some sort of RDF(radio direction finder) used mostly before loran and GPS. I guess the Coast Guard may use something similar to locate distress calls from non DSC radios.
RickB
Guru
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- CHB 48 Zodiac YL 4.2
Are you interested in how VHF DF works or just if anyone is using it on their boat?
A good treatise on how different systems work is available here:
http://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1938&context=theses
I had one of this type antenna on my tug, it allowed me to find a "null" or no signal point but did not discriminate which of the 180 degree points it came from, that took a little maneuvering to work out.
A good treatise on how different systems work is available here:
http://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1938&context=theses
I had one of this type antenna on my tug, it allowed me to find a "null" or no signal point but did not discriminate which of the 180 degree points it came from, that took a little maneuvering to work out.
Attachments
I used to use a portable transistor radio as a direction finder to orient TV antennas on roofs of buildings. It shows a null in two directions so you have to have a general idea which direction the signal is coming from to start with.
I have no idea why a private boater would care what direction a VHF signal came from. Also, VHF transmissions are normally too short to use a simple direction finder antenna.
I have no idea why a private boater would care what direction a VHF signal came from. Also, VHF transmissions are normally too short to use a simple direction finder antenna.
psneeld
Guru
Some of our assistance towboats have VHF ADF...they work pretty well even with short transmissions...especially when you get close and check to see if you passed them yet..just a couple words or a keyed mike for a few seconds will give a usable indication.
I can remember when the offshore billfishermen were all hot on the Standard Horizon ADFs and installing them to see if they could home in on each other's "hot bite".
Here's the company who make the ones we use now...
Direction Finder?Products?TAIYO MUSEN CO., LTD.
I can remember when the offshore billfishermen were all hot on the Standard Horizon ADFs and installing them to see if they could home in on each other's "hot bite".
Here's the company who make the ones we use now...
Direction Finder?Products?TAIYO MUSEN CO., LTD.
OP
OP
alberto
Veteran Member
It is just curiosity.
Sometimes for knowing when fishing, and also when silly conversations are blocking the number 9 channel in Europe...
It is important to identify these cases
Thanks
Sometimes for knowing when fishing, and also when silly conversations are blocking the number 9 channel in Europe...
It is important to identify these cases
Thanks
Don Souza
Veteran Member
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- 42-ft. Camano Offshore
Polaris VHF was a rdf and was made in the 60's and 70's around $1200 worked well.
The one I had on my old willard worked good,probably still does. nice to who how is answering and safety.
Don Souza
The one I had on my old willard worked good,probably still does. nice to who how is answering and safety.
Don Souza
In the very old days, when Loran A was just coming in, we used an RDF on our charter fishing boat out of Wrightsville Bch, NC. Used it to return to fishing spots offshore and to find other boats that were on a hot spot. We would tune in a known station, vector it on the chart, find another and, voila, we were at the intersection! I didn't know they were even still around. It worked right beside our chart recorder with the graph paper on a roll and the squiggly needle!
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