New antenna info for Sirio 2016

Hi all,just purchased a Sirio 2016 5/8 vertical and need some info on grounding it.It says that it is DC grounded but do I still need to ground it for the small chance of a lightening strike?
I’ve also seen on YouTube people having a few turns of coax at the base of the antenna as some sort of choke,is this necessary ?
Many thanks Jerry.

You don't have to have a lightening ground for the antenna to function.  Further, most antennas used for CB will not survive a direct strike, or even a near miss.  I've seen strikes over 100 meters away vaporize antennas.  That being said lightening protection will minimize to eliminate other issues, such as the strike making it to other equipment in the house.

About the choke.  You may or may not need one.  The way to find out is to add three feed of coax and retest SWR.  If it changes noticeably, then you need a choke.  If you do need to make a choke, make sure you get your dimensions and number of windings right.  More is not better, and in fact can make a problem that requires a choke worse.  You can also buy snap on toroid beads as well, this is by far the easiest option, and unlike making an air choke, in this case more snap on beads is better.


The DB

Add three feet of coax ???????.

"......and retest SWR. If it changes noticeably, then you need a choke."

Simplest test to see if your coax has become part of the antenna by changing it's resonant length and therefore the standing wave.

Might I add that the position of the antenna will require around 60ft of coax,I’m going to be using Formula Zero which is a low loss coax similar to RG213

Victor wrote:

"......and retest SWR. If it changes noticeably, then you need a choke."

Simplest test to see if your coax has become part of the antenna by changing it's resonant length and therefore the standing wave.

Penny has just dropped lol derrrrrr.

Thanks for the reply,I’ll try it with some toroids if needed and see how it goes.

JerryAlfaBrera wrote:

I’ve also seen on YouTube people having a few turns of coax at the base of the antenna as some sort of choke,is this necessary ?
Many thanks Jerry.

Yes. It's necessary to use a RF choke on all end fed verticals except ones like the Gainmaster which is actually a centre fed one.

Ideally you'd use a ferrite cored RF choke but if you make one from coax it's 5 turns of diameter 110mm/4.25". Waste pipe, the brown stuff you can buy from builders merchants, is the perfect size to wrap around.

Thanks for the reply ,do you mean centre fed as on the gainmaster the feeder is inside the fibreglass outer?