Recommended VHF Antenna Length?

Kentucky: That is a good looking set up. I don't have (nor could I ever reach!) the rocket launchers. So I secure to outrigger base. The 8's used to leave a lot of antenna overhanging, unprotected. Now I believe the pool noodle absorbs a good portion of the vibration. I guess everyone's situation can be different. Not the best picture, but I've got a pair of VHFs, both with Digital 4's.



1651677109454.jpeg
 
Yep, I see the noodles up there. Beautiful boat by the way. Sailfish is one of my favorite boats,,,, along with my 228 of course. :cool:
 
  • Like
Reactions: wahoo33417
Here is my set-up for Primary and Secondary VHF:
The Primary is a 6dB Morad 156 MHz tuned antenna on top of a 2' Stanchion. That puts the top of the antenna whip at just under 8' over the mount (total +-$215 direct from Morad)
These are Top quality antenna, hand built in Washington, USA. Transmission is harder to test, but I receive communication from up to 70 miles away. This is a solid antenna system and does not have the fragility of fiberglass type antenna housings.
The secondary is a 3dB Gam SS-2 Whip antenna that is about 4' over the mount (+- $100 from Defender Marine)
The 3dB antenna won't have the absolute range as a 6dB or 9dB antenna, but is more forgiving in rough seas where the boat can be rolling a lot. Picture a 9dB transmission pattern like a frisbee coming off the top of the antenna. If the boat is tilted, the signal waves are heading to the water and the sky. A 3dB on the other hand is more like a donut.

If I'm 40 or 50 miles off-shore and have an emergency, I don't want to be saying "I can't reach anyone, but I sure am glad I save that $100 on my antenna". Communication and Fire suppression are two categories to get it right.

Antena.jpgAntena 2.jpg
 
Ky Grady said:
I secure my 8' antennas to the rocket launchers with a piece of foam pipe insulation and a couple of ball bungee's when I travel. No issues.

View attachment 25696View attachment 25697
Click to expand...
Hi KY Grady,
I'm getting ready to install the same antenna and bracket on my Seafarer and notice you have leveling blocks installed. Did you fabricate them yourself or where did you purchase them?
 
Seafarer_Bob said:
Hi KY Grady,
I'm getting ready to install the same antenna and bracket on my Seafarer and notice you have leveling blocks installed. Did you fabricate them yourself or where did you purchase them?
Click to expand...
I picked up a shim kit for them. West Marine has them.

Screenshot_20220609-110723_Chrome.jpgScreenshot_20220609-110749_Chrome.jpg
 
Also note that most 8' antennas have now been shortened to 93". If you see "RL" in the model number on the Shakespeare antenna line, you will know that's why.

The reason? UPS started charging oversize package fees. The slightly shorter ones can go through their systems without having to be manually handled.
 
For what it's worth, I have a 208 with the hardtop that had an 8' antenna - - ultimately broke off when I forgot to put it down after a long day on the water. I replaced it with a 4' and reception and transmitting seems comparable to the 8' antenna. I'm normally fishing within a few miles of shore (California coast) and picking up traffic from 15-20 miles away. My replacement antenna was the following:

Digital Antenna 528-VW White VHF Antenna, 4', 4.5db gain​

I had the same brand/same setup with the 8'. The key on these is that they are plug and play - - no need to add connectors which I believe improves the performance and reliability. The downside is when you replace the antenna, you have to swap out all the antenna wire as its fixed on the antenna. I agree with the advice in this post - - buy a quality antenna as it makes a difference. Taller is better, but at least now it's less likely that I will snap it off again and it fits nicely under my cover.
 
kees.barfield said:
Im not sure I understand the need for these shims especially since the mount KY is using has side to side and forward and back adjustment?
Click to expand...
Agreed. I just installed an 8' on the roof of my 228. I bought the shims but it stands straight without so I omitted them, very stable, great reception. Let me know if anyone wants a great deal on the shims. Also have a spare set of shims for my TACO outrigger bases I didn't use.
 
Depending on the year Seafarer you have, the tops will be different. The location can dictate needing shims also. The older ones have a near flat top. I think the change came between 2000/2001 to the more rounded, rolled off top. Believe me, if I didn't have to use them, I wouldn't. My OCD kicks in when I see antennas and outriggers leaning out instead of straight when looking at a boat from the bow or stern. Mine aren't perfectly straight, but closer than I could get with just the adjustment on the antenna mount.
 
Nothing wrong with a SS whip and the back up inflatable for coastal use.

  • Shakespeare INFL8-5 Galaxy-INFL8 VHF Inflatable Emergency Antenna
 
Ky Grady said:
Depending on the year Seafarer you have, the tops will be different. The location can dictate needing shims also. The older ones have a near flat top. I think the change came between 2000/2001 to the more rounded, rolled off top. Believe me, if I didn't have to use them, I wouldn't. My OCD kicks in when I see antennas and outriggers leaning out instead of straight when looking at a boat from the bow or stern. Mine aren't perfectly straight, but closer than I could get with just the adjustment on the antenna mount.
Click to expand...
I think his point was that your antenna mounts are adjustable in both directions so you could mount them to rise perfectly vertical without shims....OCD not withstanding...

Screen Shot 2022-08-07 at 9.59.27 AM.png
 
SkunkBoat said:
I think his point was that your antenna mounts are adjustable in both directions so you could mount them to rise perfectly vertical without shims....OCD not withstanding...

View attachment 26705
Click to expand...
Well aware of that. Where they are mounted, the adjustments still wouldn't allow for vertical orientation without a lean either out or in. The teeth on the ratchet just wouldn't hit where I needed them to. Probably could have moved the mount inboard some to make it work, but wanted the most separation I could get and still have all my mounting hardware hidden in the E-box. Not my first time rigging a boat out.
 
  • Like
Reactions: SkunkBoat
I just went through the same dilemma. One notch on the ratchet was leaning inboard and one notch the other way was leaning outboard. Kentucky Grady clued me into the shims. Made it easy.
 
  • Like
Reactions: Ky Grady
You must log in or register to reply here.