VHF w/GPS install/Is Fiberglass transparent to GPS signal?

[justason]

Thread Hijack, sorry - What you have there looks awesome for your antenna. I tried to do something similar but couldn't find anything that would match the thread layout for a tower clamp, so I used a drill press and grinder and made one that is very similar to what you have (mine looks less sleek, I think).

/threadhijack


As it relates to the OP's question, as long as you mount the GPS antenna to a fixed location, you're probably perfectly fine. That said, I would try to make sure you don't put it next to any wiring or near any of the grab rails/cleats/etc as they for certain will interfere. I have a GPS antenna installed in my truck for a nav unit and there is only a thin layer of plastic above where it originally was, but it always took a while to get signal and lock a location... I moved it 2" over (still hidden under the plastic) away from the frame and it made the world of difference.

http://www.amazon.com/gp/product/B00CA5UEE0/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
I bought this unit, came with 2 rubber sleeves to hit the diameter needed...I was pleased with it.

 

[ArmyChief]

Another thing about the spare coax. Some antenna companies put no PL259 end on their cable and leave it to the installer. You want at least 3' of coax and the antenna should be NO CLOSER to VHF radio than 3'. After that, you want the coax to be short as possible (keeping 3'). Any excess coax should not typically be tightly rolled and wired tied together. The tight looping MAY create an electrical coil and effect SWR.

BTW, I will be bringing my VHF SWR meter to Bimini trip if anyone wants to test their setup

 

[Bruce]

I like what you did @ArmyChief @sysinu . It was important to me to be able to detach the antenna as a whole and leave the mount behind.

I believe that if you power up the radio without an antenna attached you will burn up the transmitter.

 

[ArmyChief]

I believe that if you power up the radio without an antenna attached you will burn up the transmitter.

Powering up, "No", transmitting (pushing the key to talk button on mike)...possible.

 

[Bruce]

Powering up, "No", transmitting (pushing the key to talk button on mike)...possible.

Remember we have DSC in our radios. I am concerned that they transmit on their own. I have not reviewed the DSC protocol to know when it transmits but it certainly transmits without any user input.

I worked at Radio Shack when I was in high school. I remember repairing CBs that transmitted without an antenna attached. Our VHF radios are similar.

 

[ArmyChief]

Lol..I started at Radi Shack in 1977. I also repaired and "tweaked" CB's.

More research into DSC is needed I guess. You could use a 50 ohm load with SWR to see if a VHF transmits when not keyed.

 

[justason]

I put my Lowrance here: Tied to my Lowrance GPS. no interference at all.

O damn this thing fits like a champ there @kthrash And clean as hell !!! Now to stare at it for a year before i cut fiberglass (like my power port)

 

[ArmyChief]

Remember we have DSC in our radios. I am concerned that they transmit on their own. I have not reviewed the DSC protocol to know when it transmits but it certainly transmits without any user input.
.

Well, I've researched online and called ICOM & Standard Horizon tech support. Unless the user has setup and initiated DSC polling (the feature I want us to utilize during our Bahama trip..hence the thread to post your MMSI), the radios WILL NOT transmit without pushing the talk button.