Discone or marine vhf antenna

[tcg]

Hi,

I set up a scanner (Radio Shack PRO-2030) a few years ago using a discone antenna. It does really well picking up stuff from up to 50 miles away.

I now use the setup to broadcast a live feed of the marine channels to a local boating forum.

The boaters would like to get away from monitoring the local police/fire/ems. I tend to like those extra channels to fill the dead air when listening.

I live on Lake St Clair so I have little obstructions.

Would I get better reception of the marine channels using a marine VHF antenna mounted outside at the peak of my 2 story house?

Matt

[OceanaRadio]

Matt,

You might do better with some marine antennas, but here's why that's not assured:

1. The RS discone is a known performer, not the best, but has good results.
2. Marine antennas come in all grades, from great to junk. The lower end of marine antennas may not even equal the discone performance, and would certainly not be a noticeable improvement

If you are willing to spend the money for at least 6dbi gain or better marine antenna, you can probably beat the discone. The gain claims of marine antennas are exaggerated and may require at least 6dbi "claimed" gain before you notice an improvement in reception, if at all.

However for about $45, you could own an I.C.E. active VHF 4-port multi-coupler, and from your single discone feed two or more scanners, one for marine only, and others for general/public safety monitoring. That would be my suggestion for your requirements.

R/
Jack

[tcg]

Thanks

I'm going to talk to the wife and see what's in our budget.

I may end up with 2 scanners. Most police in my area have gone digital. All I have left is fire/ems and marine with some spotty police channels. I would love to listen to more police and dedicate the old scanner just to marine.

Living on Lake St Clair in Michigan the lake gets pretty exciting on the weekends. Last year we listened to several search and rescue missions. Unfortunately to many deaths last year.

The boaters are always saying to much other stuff. Marine channels on the right channel and police/fire on the left would be great.

I just rebuilt the broadcast computer when I get all the bugs worked out I'll post the link to the feed. Am I allowed to post that in these forums?

Matt

Originally Posted by OceanaRadio

Matt,

You might do better with some marine antennas, but here's why that's not assured:

1. The RS discone is a known performer, not the best, but has good results.
2. Marine antennas come in all grades, from great to junk. The lower end of marine antennas may not even equal the discone performance, and would certainly not be a noticeable improvement

If you are willing to spend the money for at least 6dbi gain or better marine antenna, you can probably beat the discone. The gain claims of marine antennas are exaggerated and may require at least 6dbi "claimed" gain before you notice an improvement in reception, if at all.

However for about $45, you could own an I.C.E. active VHF 4-port multi-coupler, and from your single discone feed two or more scanners, one for marine only, and others for general/public safety monitoring. That would be my suggestion for your requirements.

R/
Jack

[DDan]

You can buy a 12-15' whip made for offshore boats. A good one will have 9db gain and they really work. I had a compromise 9' 9db gain antenna on a boat and would occasionally shock guys when I gave them a signal report. 30 miles across water was possible. It would have been even better with a real 9db antenna.

[mags71]

Not sure if you can get these, but some thing like Mobile Ones 5/8 wave are great , remember most vhf marine antennas are made for fibreglass boats ( mounting ) the one here is for standard metal mounting, as in standard cb mount. http://www.mobileone.com.au/antennas/ftp/M144-3.png

[prcguy]

This is what an earlier post was pointing out, there are no 9dB gain omni antennas for VHF marine, the marketing people have blown the gain ratings way out of proportion. A 21ft tall 4-bay dipole array is about the highest gain you can find for VHF (thats what the coast guard will use) and it has 9dB gain when configured for about 120deg pattern, otherwise its 6dB gain when configured for omni. A 21ft fiberglass collinear array like the largest Shakespeare or Cellwave antennas are rated around 5dBD gain. A 6ft marine whip is probably around 0 to 1dBD gain.

However, a 6 or 8ft long VHF marine antenna should outperform a Discone within the VHF marine band.
prcguy

Originally Posted by DDan

You can buy a 12-15' whip made for offshore boats. A good one will have 9db gain and they really work. I had a compromise 9' 9db gain antenna on a boat and would occasionally shock guys when I gave them a signal report. 30 miles across water was possible. It would have been even better with a real 9db antenna.

[DDan]

Thanks. I assumed that there was some inflation of the numbers but didn't know it was that bad.