Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 15-03-2009, 17:39   #1
Registered User

Join Date: Dec 2006
Location: Orygun
Boat: Hunter 26
Posts: 64
Antenna choice

Antenna choice

Given the two antenna choices (I already own both), which would be better.
Both are Shakespeare and both are 3db gain:
The 5400-xt. A four foot rail mount (so rail height) with RG8x wire or,
The 5215. A 3 foot wire whip antenna (on the top of the mast) with RG58 wire.
THX in advance

Shakespeare Marine Antennas Specifications: Galaxy Little Giant™ 5400-XT VHF Marine Band

Shakespeare Marine Antennas Specifications: Shakespeare Squatty Body® 5215 VHF Marine Band
__________________

__________________
MABell is offline   Reply With Quote
Old 15-03-2009, 18:04   #2
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
Which boat?

The higher up antenna (either one) will outperform the lower one.

I'd lose the RG58 coax in favor of RG8X for a smallish boat with a short mast or RG213 for a tall mast.

Bill
__________________

__________________
btrayfors is offline   Reply With Quote
Old 15-03-2009, 18:09   #3
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
Best is the 5400-XT at the mast head. It is a true dipole so doesn't need a ground plane.

In order to fit it up there, you need to put a mount on top of the mast. Next, cut it's cable and put a connector on. Now you can connect the long cable with a coupler and put it in adhesive lined heatshrink. If your long cable is the 8x type, you can use a direct splice connector with less insertion loss.

We have the 5400-XT 64' up with RG-8U cable and it's truly amazing.

cheers,
Nick.
__________________
s/v Jedi is offline   Reply With Quote
Old 15-03-2009, 18:43   #4
Registered User

Join Date: May 2008
Posts: 1,965
My understanding is that better coax - as Bill suggests - helps a lot when masthead mounting. Maybe more important than the antenna choice.

Bill, I'm facing an upgrade myself and was thinking that RG213 would be a good choice for the coax but then noticed that LMR-400 is only 10% more expensive. Is this even better in the VHF frequencies?

Carl
__________________
CarlF is offline   Reply With Quote
Old 15-03-2009, 20:48   #5
Senior Cruiser

Cruisers Forum Supporter

Join Date: Jul 2006
Location: Chesapeake Region and Maine
Boat: 42' Bob Perry sloop
Posts: 4,038
Images: 4
Carl,

Yes, the LMR400 has lower attenuation at marine VHF frequencies (about 1.4db per 100 feet). But, it uses special connectors, usually crimp-on.

RG-213 has an attenuation of about 2.4db per 100ft, or about 1db more than LMR400. However, unless you have a very tall mast you're likely to use less than 100', so the attenuation difference would be less than 1db, i.e., not noticeable. And, RG-213 takes standard PL-259 connectors which, when properly fitted, make a very tight, water resistant connection.

So, I'd use RG213.

For interior use on SSBs, I like RG-214 which has a double-braid which helps to reduce RFI 2 ways (from the transmitter to other electronics on board, and to the receiver from other electronics on board).

Bill
__________________
btrayfors is offline   Reply With Quote
Old 15-03-2009, 21:55   #6
Registered User

Join Date: May 2008
Posts: 1,965
Thanks - good advice. Hadn't thought about connectors yet...

Carl
__________________
CarlF is offline   Reply With Quote
Old 16-03-2009, 01:50   #7
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Cruisers Forum Supporter

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: Van DeStat Super Dogger 31'
Posts: 7,331
FWIW, RG 393 is pretty hard to beat (except for the cost )
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is offline   Reply With Quote
Old 16-03-2009, 05:58   #8
Senior Cruiser
 
Talbot's Avatar

Cruisers Forum Supporter

Join Date: Jun 2004
Location: Brighton, UK
Boat: Privilege 37
Posts: 3,579
Images: 32
To give a straight answer without technicalities

the 4ft aerial should be a better aerial than the 3ft.

If they are located in the same position go with the 4ft.

If the 3ft is at mast head, and the 4ft on the rail, there is no question that the 3ft will seriously outperform the 4ft.
__________________
"Be wary of strong drink. It can make you shoot at tax collectors - and miss."
Robert A Heinlein
Talbot is offline   Reply With Quote
Old 16-03-2009, 10:30   #9
Registered User

Join Date: Dec 2006
Location: Orygun
Boat: Hunter 26
Posts: 64
Thank You Talbot!

And thank you Btrayfors and S/V Jedi
__________________

__________________
MABell is offline   Reply With Quote
Reply

Tags
antenna

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Still unsure on the best choice for heat... Amigo Liveaboard's Forum 21 05-11-2008 15:59
Insurance Company Choice? Moonchaser2304 Dollars & Cents 16 26-05-2008 16:04
Inverter choice caribnsol Electrical: Batteries, Generators & Solar 30 28-04-2008 14:47
Help with a choice 40North Monohull Sailboats 10 27-09-2007 07:35
more info for boat choice bob_deb Meets & Greets 6 08-03-2004 05:34



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 01:09.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.