Handheld VHF Radio
#1
Posted 30 June 2012 - 06:28 AM
#2
Posted 30 June 2012 - 02:05 PM
#3
Posted 30 June 2012 - 02:18 PM
#4
Posted 01 July 2012 - 06:08 PM
#5
Posted 01 July 2012 - 09:49 PM
http://www.standardh...=3&isArchived=0
It's got GPS and a little strobe, so I figured it would be good to wear on the night watch.
If you fall overboard you can hit the DSC SOS button, which will transmit your position. You can also talk to your rescuers to guide them to you. Can't do that with a PLB.
#6
Posted 02 July 2012 - 12:51 AM
Icom M72. Get the attachable remote mic/speaker to carry around your neck.
+1.
Fantastic battery life (I had mine on for 70h straight for the Oregon Offshore) and its got a nice, solid feel to it.
#7
Posted 02 July 2012 - 04:50 AM
#8
Posted 02 July 2012 - 06:23 AM
I have the ICOM M72 for day racing as it's smaller than the Standard Horizon HX851 but use the HX851 for offshore because of its DSC feature.I paid about $200 for the Standard Horizon HX850S
http://www.standardh...=3&isArchived=0
It's got GPS and a little strobe, so I figured it would be good to wear on the night watch.
If you fall overboard you can hit the DSC SOS button, which will transmit your position. You can also talk to your rescuers to guide them to you. Can't do that with a PLB.
Both are good radios... horses for courses.
#9
Posted 02 July 2012 - 02:33 PM
#10
Posted 03 July 2012 - 01:56 AM
#11
Posted 03 July 2012 - 02:27 PM
$20 Mail-In Rebate on Standard Horizon HX280S, HX290 or GX1150 VHF Radios
#12
Posted 03 July 2012 - 02:34 PM
also through July 31st
$20 Mail-In Rebate on Standard Horizon HX280S, HX290 or GX1150 VHF Radios
I see that the HX280s ends up being $92 after rebate, which isn't much. I assume the HX751 is better but in what way? Is it just that it floats, glows in the dark, and has 1 watt more?
If I just want a radio to do radio stuff over short distances, are there usability issues with the cheaper radio? Is it a pita is some way? Being able to use a radio as a radio is more important to me than being able to use it as a strobe.
Allen
#13
Posted 04 July 2012 - 12:54 AM
#14
Posted 05 July 2012 - 08:07 PM
also through July 31st
$20 Mail-In Rebate on Standard Horizon HX280S, HX290 or GX1150 VHF Radios
I see that the HX280s ends up being $92 after rebate, which isn't much. I assume the HX751 is better but in what way? Is it just that it floats, glows in the dark, and has 1 watt more?
If I just want a radio to do radio stuff over short distances, are there usability issues with the cheaper radio? Is it a pita is some way? Being able to use a radio as a radio is more important to me than being able to use it as a strobe.
Allen
HX751=6W
HX280=5W
#15
Posted 10 July 2012 - 02:21 AM
Judge by the other factors; GPS for the purposes for the radio as stated is a bit unnecessary, but, that + DSC would be nice if used in more treacherous venues as well.
I have the earlier HX270, and if the 280 is similar, it'll do fine.
#16
Posted 11 July 2012 - 05:04 AM
1 watt difference is immeasurable in application. You have to double power output to appreciate a meaningful (3dB) increase on the receiving end, plus, we work in an environment where LOS is the determining factor.
Judge by the other factors; GPS for the purposes for the radio as stated is a bit unnecessary, but, that + DSC would be nice if used in more treacherous venues as well.
I have the earlier HX270, and if the 280 is similar, it'll do fine.
Exactly. 2.5W, 5W, 6W, whatever W makes fuck all of a difference in performance - but higher power will drain the battery more quickly.
#17
Posted 11 July 2012 - 05:33 AM
I got into a long discussion on the benefits of a mast head mounted 1/2 wave antenna vs a stern mounted one. Turns out the mast head mounted antenna is not that much better and a stern mounted antenna is way better if you lose your mast. The numbers were done for a 25 watt radio talking to a USCG station (150 ft antenna). Masthead was 48 miles, stern mounted was 44 miles. Put a 5/8 antenna on the stern and I think it was about the same as the 1/2 wave on the masthead. A note, this was done for 3 foot long antennas. If you put one of the shorter 18 inch antennas on the masthead, it will only be good for talking to the moon. It radiates straight up. I have a 18 inch antenna on my stern pulpit with a 18 inch grounded rod below it for a total of 3 feet. It works great. And if I lose my mast, it will continue to do so.
Allen
#18
Posted 13 July 2012 - 02:13 AM
They are, for all practical purposes, the same antenna setup simply mounted at different heights... And look how well your moon-talker works! I have to believe the same setup 25' higher up will do better to surface-based users i.e. other boats, though, if you're chiefly interested in working people with tall towers, it should be fine.
Here's a simple range calculator - http://www.qsl.net/k...i/distance.html
This one lets one play with more variables - http://www.cepd.com/...propagation.htm
#19
Posted 13 July 2012 - 02:45 AM
#20
Posted 13 July 2012 - 03:20 AM
OK, so it looks as if you believe that a 1/4-wave stick on top of a 30' counterpoise will only be good for talking to the moon, but swear by a 1/4-wave a yard above the ocean with a 18" coumterpoise.
They are, for all practical purposes, the same antenna setup simply mounted at different heights... And look how well your moon-talker works! I have to believe the same setup 25' higher up will do better to surface-based users i.e. other boats, though, if you're chiefly interested in working people with tall towers, it should be fine.
Here's a simple range calculator - http://www.qsl.net/k...i/distance.html
This one lets one play with more variables - http://www.cepd.com/...propagation.htm
The problem is that the pattern changes when the counterpoise changes length. When the counterpoise is the same length as the radiator, the pattern goes out equal distance between them (straight toward horizon). When the counterpoise is long as in the length of your mast, the pattern goes straight up (toward the moon). A 1/2 wave antenna will be driven just before the end and there will be some kind of isolation so that the mast does not become part of the antenna.
So, if you put an antenna on top of your mast and let the mast be ground for the antenna, it is not at all the same thing as having the same antenna sitting on top of a 1/4 wave counterpoise at your stern. That is not to say that being higher is not better. But having shorter cable going to the antenna is also better and clearly having an antenna at the stern involves shorter cable. So the net is that an antenna on top of the mast is a little bit better, not as much as what you would see in the range calculator.
In addition, your range calculator is for land. Water vapor over the ocean forms a duct that will allow the waves travel further. You need to look for the Navy for details on that. I got my data from someone with access to the AREPS program.
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