Hello,

I own the "Upgraded AURSINC NanoVNA-H4 V4.3 Vector Network Analyzer 10KHz-1.5GHz HF VHF UHF 4''" (purchase link is here https://www.amazon.com/gp/product/B083PQ4RXZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1). I am posting this link here to see if this si the correct group for my specific NanoVNA. I have been in Ham radio for many years but I am totally new to NanoVNA. I did just download the "Absolute Beginers Guide" and I will begin to read through that shortly.

I have a 10 meter DX Commander antenna (vertical multi-band antenna with about 6 vertical wires and a 32 wire ground plane) and I need to know to short out any static electricity that may be in the antenna before I connect it to the NanoVNA. I read in another post that simply touching the the end of trhe coax with a "moist" hand will do the trick.

Thank you in advance,

Peter,
N0PGM

The coax cable capacitance stores up a charge and if you short the ends of the coax together you discharge it. When shorted you can also touch the terminals to ground of you want to be really cautious.

Roger

On Fri, Aug 4, 2023 at 02:13 PM, Peter N0PGM wrote:

I need to know to short out any static electricity that may be in the antenna
before I connect it to the NanoVNA

This is good practice before connecting any cable to any instrument. I usually short the inner and outer conductors against the outer conductor of the connector to which it will be attached; I wouldn't use my hand, especially with an antenna feedline which may be quite long and hold a considerable charge which could pack a wallop.
73, Don N2VGU

Hi Don,

I agree – always a good practice to short center conductor and shield together before connecting to an instrument. Even better is to short them together and connect the shorted junction to an earth ground. I try to do that whenever possible. As you point out, coax has an inherent capacitance, and considerable breakdown voltage, so a long run of coax can store up a considerable charge, especially when terminated to a well insulated wire antenna.

However, just for the sake of argument and to exercise the neural muscles, is it necessary to do so if you have a balun or unun between the antenna and coax? I would think both would shunt any static charge to ground unless you had a true galvanic isolation configuration, with no electrical coupling between the primary and secondary of the coupling transformer. Not likely in a transmitting antenna, but who know.

Again, I’m not disputing your comment. I’m just trying to promote understanding, including mine, of antenna configurations. Regardless, it is still an invaluable practice to short center-to-shield before measuring, just to prevent any unforeseen failures on a known configuration.

Ken -- WBØOCV

From: Donald S Brant Jr
Sent: Friday, August 4, 2023 05:51 PM
To: nanovna-users@groups.io
Subject: Re: [nanovna-users] Static Energy and Is This the Correct Group? #newbie #beginners1 #general_vna

On Fri, Aug 4, 2023 at 02:13 PM, Peter N0PGM wrote:

I need to know to short out any static electricity that may be in the antenna
before I connect it to the NanoVNA

This is good practice before connecting any cable to any instrument. I usually short the inner and outer conductors against the outer conductor of the connector to which it will be attached; I wouldn't use my hand, especially with an antenna feedline which may be quite long and hold a considerable charge which could pack a wallop.
73, Don N2VGU

On Fri, Aug 4, 2023 at 06:34 PM, Ken Sejkora wrote:

is it necessary to do so if you have a balun or unun between the antenna and
coax?

Not if the transformer has continuity between inner and outer conductors, but it only takes a second, cultivates a good habit and will do no harm. 73, Don N2VGU

Thanks for all the great advise. I really appreciate it. I'm still in the process of ordering everthing I need to install my antenna. It involves drilling holes in exterior wall, installing interior and exterior boxes and ground cables and putting up the antenna.

I'll be able to ground the antenna cable with the ground I am bringing into the house.

Thanks again,

Peter