8200 mkII Marine Band Antenna

[glojo]

Hi folks,
I live right on the coast and in line of sight of both Lyme Bay and Tor Bay but with the standard antenna on my scanner I rarely pick up any marine band conversations.

Is there a better antenna I can fit to the 8200 or is the one fitted, the best one for the job?

I can hear our local coastguard and I can hear the lifeboat until it gets out of range but that's about it!!

Any advice would be greatly appreciated

John

 

[Fast1eddie]

John, consider installing a discone (wideband and extremely vesatile) or simply get a multi band scanner antenna and with a magnetic mount, slap it on a cookie sheet or filing cabinet or similar. You would be surprised at how well that would work! My personal choice is a discone for fixed station use, but they do have their limitations. Using one with my 8200, I enjoy surprisingly good reception and often monitor utility comms on HF. Took it mobile last night with it connected to my Austin Spectra and riding around Pittsburgh and the suburbs monitored HF aero traffic out of the Caribbean (Jet Blue) talking to New York.

Sometimes the gods of RF toss me a few crumbs......

Just setting my my (new to me) AOR 3000, got it cleaned up and thanks to several gentlemen who posted reference links, I am getting the hang of my (almost) birthday present to me.

Let me know how things work out for you and until then,

Good Signals!

 

[glojo]

Thank you very much indeed for that advice although I am really after an antenna I could actually fit to the scanner and still be mobile..

Thanks again though

John

 

[N8IAA]

Thank you very much indeed for that advice although I am really after an antenna I could actually fit to the scanner and still be mobile..

Thanks again though

John

Being that most CG frequencies are VHF, and in the 160MHz range, a mag mount, as previously posted would work when mobile with the scanner. Or, you could use a telescoping antenna on the scanner while in the vehicle, but won't work as well.
HTH,
Larry

 

[mmckenna]

Upgrading your antenna isn't necessarily going to solve the issue. The issue is likely more about antenna height rather than antenna gain.

VHF Marine radios only run 25 watts, which on it's own will work really well. The issue is the height of the two antennas. Even on the larger life boats, the antennas are only 5 meters off the water line. It doesn't take very far for that to be either too low on the horizon, or over the horizon. Once that happens, you are going to have very limited luck in picking up their signals. The other issue is that your hand held scanner is also low to the ground. That limits range, too.

Using a distance to horizon calculator, you can take a look at the numbers and see what I'm talking about: BoatSafe.com

At 5 meters off the water it's 4.7 nautical miles to the horizon. Once that antenna is over the horizon it's going to be harder to hear them.
Your hand held scanner with it's antenna is going to figure in, too. With the antenna 2 meter above sea level, it's 3 nautical miles to the horizon. Add that to the 4.7 nm above, and 7.7nm range isn't very much.

Now, of course there is some various propagation things that happen to extend that, but when it really comes down to it, the horizon is you biggest obstacle.

To over come that, you need to get the antennas higher up. Since you can't control the height of the antenna on the lifeboat, you need to increase your antenna height. This is how the Coast Guard does it. They put their shore side radios on tall towers, tops of buildings or mountain tops. This increases the distance to the horizon.

This is one of the reasons why SSB/HF band radios are used on ships. The issues with the higher frequencies is overcome by the signals bouncing over the horizon easier.
It's also why sail boats will almost always have their VHF antennas at the very top of the mast.

Antenna height is key to coverage. Increasing antenna gain won't solve everything. You need to find a way to get your antenna up higher.