[TowerTalk] Static Drain Resistor in Arrestor

Tue Dec 16 23:22:19 EST 2025

Most of the precipitation static discussion, including those from W8JI and K1TTT and the ARRL Antenna Book, involve towers with stacked beams. This has been analyzed extensively, and the conclusions are all similar. The problem, they state, comes from corona discharge in pointed elements at height. I won’t dispute this, this is what they experienced and recorded.

The situation I describe is not in this case. As I previously described, the antenna is not an aluminum yagi. It is not way up high. Quite simply, it is a wire dipole, 120 feet in length, constructed from #14 THHN with white insulation. I bought the wire at the Home Depot in Campbell, CA about 15 or 20 years ago. The insulators are ceramic, the feedline down to the balun is plastic-coated ladder line. A big oak tree holds up the center insulator at a height of 35 feet. The ends of the antenna attach, through egg insulators and Dacron rope, to 20 foot tall TV antenna supports, bought at Fry’s in Campbell. There are no pointy structures in the area. The closest would be atop a 5-story hospital building located about 1/2 mile or so away.

I constructed the balun using #14 gauge enameled wire, with teflon tubing. There are two wires wrapped on a pair of T-200-2 toroids. This essentially forms a multi-turn coil that is center-tapped. The center tap is connected to the SO-239 ground tab and a #10 brass screw with wing nuts on the outside of the electrical junction box. The outer ends of each wire connects to a leg of the ladder line, while one of those also connects to the SO-239 center connector. Again, I use about 40 or so feet of RG-213 coax to connect the balun to the transceiver, an Elecraft K3. Originally the shell of the SO-239 was not attached to ground in any way other than through the coax. Everything was fine until it started raining, and what I then heard was exactly what I had previously experienced and was told was rain static. This has been described in other places and I am sure there are recordings on the internet. Note that this static was not accompanied by lightning, although all rain drops collect charge as they fall through the atmosphere. Also note that the rain drops did not directly strike the copper wire of the dipole. It was, and still is, insulated. Nevertheless, the static did build up over a relatively short time, ending in an arc-over in some component in the system, quite possibly the GDT in the front end of the K3. At the time I was experiencing this, I had no lightning arresters in the system. That has changed also, although the particular dipole does not yet connect to an arrester due to the nature of its use with an antenna tuner, which results in high reflected power over the feedline.  Th tree that holds the center insulator is probably 50 or more feet high, so it protects the antenna, except when high winds cause branches to break and fall on the antenna. That has happened twice since original installation.

After experiencing the problem, I did extensive research on the subject and decided to try attaching the Balun’s ground lug to a ground rod. The problem has not recurred since, a period of about 3 years. Since that time I have added a short tower and C3S-JK beam, and an extensive ground system. I have a very low noise floor, and the only static I hear comes from thunderstorms, usually distant. When one is in the vicinity, the antennas are disconnected (although still connected to ground) and the radios protected and off. I have seen way too much destruction from lightning hits in my career. 

Now, after explaining all this, what would you call what I heard? If it talks, walks and acts like a duck, it must be a duck. As I noted above, a lot of study has been given to tall towers with stacked antennas. I have done extensive research, and have found virtually none about fairly low dipoles. Yet the phenomenon is real, and has been described by many. Perhaps it may be time for more research to finally note that precipitation static has forms that are not that well understood in the industry.

73,
Jack, W6FB

> On Dec 16, 2025, at 9:18 PM, john at kk9a.com wrote:
> 
> I did not think that a static drain would help precipitation static but I was curious what experiences others have had. It would be nice if it  really was that simple. Below is what w8JI wrote on the subject:
> 
> "Despite having grounded antennas and the same rain or precipitation striking physically identical antennas, the highest antennas are always noisy and the lowest antennas are always the quietest. This occurs on a variety of antennas and in a variety of systems. Antennas with grounded elements and antennas with insulated elements all behave in similar ways. Antennas near the top of towers, especially those without taller towers nearby, all have severe p-static in storms. Lower antennas show very little noise under the same conditions, even though they are being struck by the same particles.
> 
> The cause of noise most commonly called p-static or precipitation static is obviously not from charged particles striking the antenna. While some of this might occur under some conditions, the overwhelming cause appears to be corona discharge from protruding points into space around the antennas or antenna structures. On dark nights with closing storms, I can look at my upper 40-meter Yagi with binoculars and see a faint http://en.wikipedia.org/wiki/St._Elmo's_fire from the element tips.   This is similar to what I saw on the VHF antenna that noised-up during foul weather. Sailors have seen it on salt-water soaked wooden masts, and we are plagued by it also. We just have not paid enough attention to the evidence and have missed the real root cause. We consider it particles striking the antenna was nearly all cases appear to be the simple phenomena known as St. Elmo's fire.
> 
> We can't cure precipitation static, but it can be reduced through the following steps:
> • Having something else much taller than the receiving antenna close to the receiving antenna or lowering antenna height.
> • Avoiding sharp points on or near the antenna. Sharp points increase voltage gradient and increase corona.
> • Avoiding protruding elements. Protruding elements increase corona.
> 
> As a general rule the following makes little difference:
> • Grounded elements
> • DC shunt elements on feed lines
> • Improving ground systems or grounding"
> 
> 
> John KK9A
> 
> 
> From: ve6wz at shaw.ca <mailto:ve6wz at shaw.ca> <ve6wz at shaw.ca <mailto:ve6wz at shaw.ca>> 
> Sent: Tuesday, December 16, 2025 8:58 PM
> To: john at kk9a.com <mailto:john at kk9a.com>; Jack Brindle <jackbrindle at me.com <mailto:jackbrindle at me.com>>
> Cc: towertalk at contesting.com <mailto:towertalk at contesting.com>
> Subject: Re: [TowerTalk] Static Drain Resistor in Arrestor
> 
> Jack,
> "P-Static" (precipitation static) is a different phenomena that "wind static".
> A grounded antenna will NOT prevent P-Static. W8JI is correct.
> 
> Wind static can build incredible voltages (I've seen it) and will discharge to ground. Grounding the element through a choke or high value resistor will eliminate this. All my antennas must have this.
> 
> Precipitation static is a different thing. This is that screeching, buzzing, even whistling sound that will crescendo and sputter out, only to start again.
> Its the noise that when happening will shut you down from operating.
> It happens when a storm is approaching or in effect. I hear it all the time during rainstorms and even snowstorms.
> Grounding the elements on your Yagi or verticals make NO difference at all to this type of static.
> 
> I really don't think precipitation static is well understood regarding how it develops and the exact mechanism that triggers it, but a google search might give you some background.
> 
> Either way, a static drain choke or resistor will NOT eliminate this type of noise when it happens.
> 
> Steve ve6wz
> ________________________________________
> From: TowerTalk <mailto:towertalk-bounces at contesting.com> on behalf of Jack Brindle via TowerTalk <mailto:towertalk at contesting.com>
> Sent: Tuesday, December 16, 2025 4:06 PM
> To: mailto:john at kk9a.com <mailto:john at kk9a.com>
> Cc: mailto:towertalk at contesting.com <mailto:towertalk at contesting.com>
> Subject: Re: [TowerTalk] Static Drain Resistor in Arrestor 
> 
> Yes, it definitely helps with rain static. If W8JI actually stated that grounding the elements doesn’t help, he was wrong. 
> It is important to bring both sides to ground, and together, usually through a large value resistor or RF Choke that will handle the power. Tieing both sides of a dipole through this to ground provides a path to bleed off the static charge, thus eliminating rain static (and snow static, etc). As Wes stated, adding a fairly large resistor across the dipole insulator really helps. Then timing that to ground through the arrestor finished the job.
> 
> 73,
> Jack, W6FB
> 
> 
>> On Dec 16, 2025, at 5:48 PM, mailto:john at kk9a.com wrote:
>> 
>> Does the Morgan coaxal arrestor help with precipitation static or just the
>> arc noise?  Rain static can be brutal when contesting.  I thought mine might
>> be related to using OWA designs with insulated elements but W8JI has stated
>> that grounded elements make little difference.
>> 
>> John KK9A
>> 
>> Ron WV4P wrote;
>> 
>> My fullsize 4el 40 with cool dry air wil arc several inches from coax tip
>> to ground from static. With the Morgan M303 inline... Nothing. This was
>> also very apparent on the SDR (Flex) screen from what looked like lightning
>> static crashes to.. Nothing. In that respect, they did exactly what they
>> claimed.
>> 
>> Ron, WV4P
>> 
>> 
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