GPS Chart Plotters VHF Radios

[hellosailor]

Yes, there is test equipment but you won't want to spend what it costs for one-time personal use.

You can do some gross testing with a multimeter, to see if there are continuity problems, and then use an SWR meter with the radio to test the whole system. That's the most effective way to test it. An SWR (standing wave ratio) meter probably will run $100 at the Best Marine store but you can use one that is sold for "two meter ham radio" from ham radio stores for half of that. Or buy one sold for two-meter ham radio on eBay for $25, just as good.

Two-meter ham radio is a VHF band right next to marine VHF (approx. 144 MHz versus 165MHz) and the SWR meters have enough range to cover both with no problem. As opposed to meters for HF or CB radio, which usually can't do VHF at all.

[RhythmDoctor]

Thanks, I'll look into the ham radio equipment on ebay.

Sorry to sound naive, but I do not want to assume anything. What constitutes a continuity problem with an antenna? If it has continuity a good thing, or a sign of water intrusion in the antenna or connectors? Or is lack of continuity a bad thing, or a sign of a cracked copper in the core? Is there a general resistivity or impedance spec?

[hellosailor]

A continuity problem would be either a dead short in the coax, or a break in it. Depending on what's in the antenna (coil, etc.) I'm not sure what resistance you might find with the antenna connected, but measuring actual impedance would need the expensive test equipment.

[bandaidmd]

I didn't read all the replies so forgive me if this was mentioned. If you have one of the so called smartphones, navionics has a app that turns it into a chartplotter. Ithink its like 30 bucks