| Home |
| Search |
| Today's Posts |
|
|
|
#1
April 23rd 17, 06:22 PM
posted to rec.radio.amateur.antenna
|
|||
|
|||
Antenna for Marine VHF
rickman wrote:
On 4/23/2017 10:17 AM, Ralph Mowery wrote: In article , says... On Sat, 22 Apr 2017 12:43:39 -0400, rickman wrote: I've also considered the possibility of a higher powered unit built into the boat with a small remote control. A higher power transmitter will help the Coast Guard hear you but will do nothing for you hearing the Coast Guard. More antenna gain, and a higher antenna are better solutions. Going from 5 to 25 watts of FM will gain almost nothing. Raising the antenna several feet from the sitting down position will gain a lot. Are you saying that a hand held 5 watt transceiver with a rubber ducky antenna will reach all receivers because of the line of sight limitation? Is that true even for contacting a land station with a 200 foot high antenna? A 3 foot high antenna and a 200 foot high antenna give nearly 20 statute miles of range. Will 5 watts be heard that far away? Radio amateurs have launched satellites which usually have about 1 to 5 W of power on VHF and UHF. Those can be clearly heard on a portable with a very small antenna even when 2000-3000km away. The loss of signal on line of sight is easy to overcome with narrow band modulation and this kind of power. It is the "beyond line of sight" attennuation that is the problem. Everything you can do to remove that will help a lot more than power. Today I was working at the repeater in our local radio/tv tower. We were at 220m above ground level and it was easy to work over a repeater about 80km away from us using only a handy with 1W of output. Only because at that height this is (almost) line of sight. |
| Reply |
| Thread Tools | Search this Thread |
| Display Modes | |
|
|
Similar Threads
|
||||
| Thread | Forum | |||
| Marine antenna ?? | Antenna | |||
| Marine 2m Antenna wanted | Antenna | |||
| help with a marine antenna | Antenna | |||
| FA: CB ANTENNA M'CYLE-MARINE-BOAT>ANTENNA SPECIALIST MR306 | CB | |||
| Is it a CB or VHF marine antenna? | Antenna | |||
![Rob[_8_] is offline](https://www.radiobanter.com/images/SultanThemeVB3R/statusicon/user_offline.gif)
Hybrid Mode
