vhf cable

[Apex]

Since I am working on the masthead, I am looking to replace the old antenna. It is currently bent with a jog to avoid the windex....so Davis makes a combination antenna and windex that I may be going to. My questions are this:

the current antenna is a Shakespeare 5215squat body. I read that they don't last forever, do the bodies go "bad"? If so, I will replace now.

the Shakespeare site mentions ais compatibility for the 5215 squat. Are other bodies from Shakespeare as well? what special considerations on the antenna end is necessary. Certainly the electronics are important,but what of the VHF antenna?

the 5445 Shakespeare is the combined unit, and it also comes with new VHF cable, RG-58. What are the types of cables, and what should be used? We sail the great lakes (day cruising mainly.) if that makes any difference.

I did see MainSails connectors thread on his site.

Thanks all for the answers...the thought is
1) replace the bent antenna, it wiggles wildly with the bends and likely doesn't do any service to capability to receive and transmit.
2) combine the windex and antenna to simplify the masthead top. Plus that gives the all around anchor light less posts to shine around
3) replace the cable and antenna body would be additional preventive maintenance, and all can be had for a hundred bucks....

 

[Brian D]

Just my opinion, others may agree or disagree.

RG-58 is "ok", but there is better. For about the same size (diameter) LMR-240 would be a better choice. I believe LMR-240 beats out RG-8X in attenuation levels at VHF frequencies.

When it comes to radio communications, we want as much of our RF energy to reach the antenna. RF deals in decibels (dB) and a 3 dB loss due to cable is half of our power. So if our cable has a 3 dB loss @ 25 watts, only 12.5 watts is making it to the antenna. The rest is dissipated as heat. There there is the issue of VSWR at the antenna, that will also reduce our RF output.

So when it comes time to replace the cable, look for the smallest diameter, lightest, and less attenuation at 150 MHz. It might cost a little more but at least most of your RF energy will make it to the antenna.

 

[woodster]

while you are looking look at the Metz vhf antenna that is what the coasties use