VHF/UHF radio and antenna questions

[KY_Ham_64]

Negligible impact.

As for your installation idea, sounds good to me. You want the actual mast grounded as well as the coax shield and the Polyphaser. Big wire gives it a nice low resistance/low impedance path to ground. Code is around human safety, and that's your goal. Yes, in a direct strike everything is going to fuse open but at that point, it really doesn't matter.

The copper grounding plate is a common way of mounting the Polyphasers and then running one large grounding conductor to the rod.

Is the coax shield grounded via the case of the Polyphaser to the ground plate?

 

[mmckenna]

Is the coax shield grounded via the case of the Polyphaser to the ground plate?

Yes. That would be sufficient for your application.

In the commercial world, the coax shield gets bonded to the tower leg near the antenna and at the bottom of the tower. Depending on height, it may get bonded one or more times as it comes down the tower.

Idea is you want to give that energy a better path to ground, and using the coax shield isn't it. Getting that onto the tower/mast and down to the ground rod with the straightest, most direct path is what you want.

For residential/hobby applications, almost no one goes that far.

 

[KY_Ham_64]

So is the lightning arrestor in these devices like a MOV? I'm somewhat familiar with those as I worked with power supplies and they would have them on the AC input side.

 

[AK9R]

So is the lightning arrestor in these devices like a MOV? I'm somewhat familiar with those as I worked with power supplies and they would have them on the AC input side.

The high level explanation is that a device such as a PolyPhaser Surge Protector provides a path from the center conductor of the coax to ground if the voltage on the center conductor exceeds a pre-determined limit, e.g. a lightning strike. The theory is that if the lightning energy has a easier path to ground through the PolyPhaser, the energy will go that way rather than follow the coax into a building and into an electronic device.

 

[KY_Ham_64]

Curious as to whether any of y'all use horizontally oriented antennas for 70cm and 2m? It seems most folks use vertically oriented types. Also what would the radiation pattern be for horizontal antennas and is there much gain compared to vertical?

 

[K6GBW]

The only real reason to use horizontal polarization would be when using a beam antenna for long range SSB type of contacts. For general use with simplex or repeaters vertical polarization is the standard.