Replace Heliax?

[taco6513]

Yesterday morning my hour was struck by lighting. My antenna I just put up took the strike. My antenna and radio are toast.

No I didn't ground like I should have. Was on my "to do" list.

My question is should I replace the run of LMR400 going from my antenna to the radio?

Yes I will ground this pole before anything else is done. This is a mess.

Thanks

WRCW870

[kidphc]

Anything in the path and near path should be replaced. Near field strikes can cause huge emp surges.

Highly recommend checking appliances and such. They could of been damaged. Not sure if homeowners insurance will help when gear isn't properly grounded, AKA antennas.

On a note to try and help you feel better. Even if you had properly grounded it, it wouldn't have mattered for a direct strike. Grounding the equipment is to bleed of static buildup ( could have been the cause of the strike) and for near lightning strike damage. Hence, why hams rush to disconnect equipment as soon as a bad microcell enters the area.

Keep in mind the damage may have been minimized if grounded properly commercial repeaters get hit all the time. Although the antennas are usually obliterated from direct strikes.

Even in a car accident you should have insurance replace your gmrs/ham/cb radio circuit boards can develop micro cracks and such. Which develop into erratic behavior.

It isn't the massive amount of voltage doing all the damage. The gigantic rise is what really destroys everything. Inside of cables and such that do survive can have parts of it vaporized internally.

Sent from my SM-G975U using Tapatalk

[mbrun]

Yesterday morning my hour was struck by lighting. My antenna I just put up took the strike. My antenna and radio are toast.
No I didn't ground like I should have. Was on my "to do" list.
My question is should I replace the run of LMR400 going from my antenna to the radio?
Yes I will ground this pole before anything else is done. This is a mess.
Thanks
WRCW870

Sorry to hear about your bad luck. I feel for you.

Yes, I would lean towards replacement of the cable also. The high-voltage arching that would likely have occurred inside the cable would have damaged the internal dielectric and altered the performance of the feed-line.

A funny/memorable experience from years past. A nearby lighting strike occurred at a former residence. Many electronics toast, including phone, garage door opener and many more. I thought it was cool when I opened up some of the electronics to see if I could repair them when I observed several chips (ICs) that where literally blown out right in their centers. It was like a little explosive charge had been set off right in the middle.


Michael
WRHS965
KE8PLM

[JohnE]

Yes, absolutely change the cable. 400 is not capable of handling a strike. If it were 1/2" or 7/8" hard line I would say give it a go.

ground the pipe and get yourself a poly phaser to at least give you some protection.

https://www.polyphaser.com/search?Rfpssp99app=LMR%2FVHF&Rfpssp99con1gender=Female&Rfpssp99con1series=N&Rfpssp99con2gender=Female&Rfpssp99con2series=N&sort=y&Category=RF+Surge+Protectors&Rfpssp99minfreq=125&initial_sort=Sortsku:ASC&res_per_page=48&view_type=grid

just my thoughts

[OldRadioGuy]

Here's a way to test your coax.

Use a low power source that will not be damaged by high SWR or pad the source (radio output) with an appropriate power rated 6dB pad so it will not see the bad SWR.

First put a dummy load at at the antenna end and look for a good low SWR - maybe 1.1 or better.

If this passes this test leave the end open and look for a very high SWR.

Then short the end and look for also a bad SWR.

The short is more reliable than the open so put more weight on that test.

 

You can figure out how bad your SWR should be with the short and open as follows.  

Look up the loss of your line for the length you have and double it.  This should be your return loss.

Find a table to translate return loss to SWR.

 

Vince

[OldRadioGuy]

Another simple test that does not have the complications of high reflected power is to simply measure the loss of the coax by putting the meter at the antenna end and directly on the radio and comparing.  No worries about your radio seen a high SWR this way.

Vince

[taco6513]

I an going to replace the coax. I have grounded the pipe with a run of #2 THHN to a ground rod. I have Times Microwave lightning protector ordered for my 

radio will ground to another ground rod.

Do you think this is enough to ground the pipe?

Thanks

WRCW870

[kidphc]

Nec wants you to bond to the house ground. Remeber, even it is grounded to the rod the max potential might be higher then the the other ground. Path of least resistance, guess where it going to want to go.

Secondary, you can cause a ground loop although not bad at uhf/vhf. Try avoiding it.

I think spacing between 8' rods is 16 feet.

Sent from my SM-G975U using Tapatalk

[mbrun]

I an going to replace the coax. I have grounded the pipe with a run of #2 THHN to a ground rod. I have Times Microwave lightning protector ordered for my 
radio will ground to another ground rod.
Do you think this is enough to ground the pipe?
Thanks
WRCW870

Ideally you would tie your mast to the ground rod. Install your lighting arrestor immediately outside your home and connect it to the ground rod. And I second the recommendation that the ground rod for your antenna system be bonded to the main electrical ground rod. This helps to ensure that the electrical potential of the coaxial shield remains consistent with the potential of the electrical grounding conductors in the home during a nearby strike occurs.

As I recall, NEC requires that the bonding conductors between ground rods be least equal to the size required between the electrical panel and ground rod. So if #6 copper is required panel to rod at your place, then anything #6 copper or larger for bonding is acceptable.


Michael
WRHS965
KE8PLM