[TowerTalk] Static Drain Resistor in Arrestor

[Jack Brindle]

Here in Louisiana we get a lot of rain and thunderstorms. Operating during rain used to be a huge issue caused by rain static. As the rain drops fall, they pick up a static charge. When the hit the antenna that is transferred to the antenna, and is heard on the receiver as an increasing buzz. Eventually the charge builds up to the point where it exceeds the level where the receiver protection kicks in, we get a quick “bzzzzt” then the noise is gone until it builds up again. This is the static that Wes correctly refers to. I first experienced this in the Clearwater, FL area many years ago, and before the arrestors I experienced it here regularly.

I have done two things to solve this. The first, on a ladder-line fed 80 meter dipole, it the use of a 4:1 balun, with ground connection. The second is the use of WX0B (derived from Morgan) arrestors. This has completely eliminated the problem of rain static, and allows me to operate normally during rain. If there is a lightning storm in the area, I simply shut things down and disconnect the antennas (they are still grounded).
Unfortunately WX0B closed shop and the arrestors are no longer available. They contain not just the resistor, but also a hefty RF Choke that very effectively bleeds off any static to ground. It’s my understanding that the RF Choke is a standard component in the Morgan devices.

One other thing - these devices, especially the ones for use at VHF and above, contain components to make the device somewhat transparent to RF. This simply matches the device to the line in an attempt to eliminate the impedance bump the device will otherwise add to the transmission line.

By the way, the order of the components in these devices - starting from the radio end it has a hefty blocking capacitor in series with the transmission line, followed by a GDT, matching capacitor, high value resistor and RF Choke, all connected in parallel to the device chassis. It the connects to the SO239 Going to the antenna. I have my devices bolted to a heavy aluminum panel that is very well connected into my extensive ground system. I now sleep well at night during thunderstorms.

73, Jack, W6FB


> On Dec 16, 2025, at 11:24 AM, Wes <wes_n7ws at triconet.org> wrote:
> 
> I think you confuse static (not moving) charge with QRN, natural and/or man made.  The drain resistor is not a noise blanker.
> 
> Wes  N7WS
> 
> 
> On 12/16/2025 10:07 AM, RVZ via TowerTalk wrote:
>> I love the idea of a "Static Drain Resistor" in an arrestor if it actually reduces "static" QRN on receive.  I've installed about a dozen ICE/Morgan arrestors on Verticals and Yagi's here in Florida during the past 25 years, where we receive a great deal of "static", but when doing unscientific A/B tests when listening by ear, I haven't noticed the ICE/Morgan arrestor to be quieter than a Polyphasor.  I realize that's a poor way to judge performance, so I've always wondered if anyone actually measured and confirmed that the "static drain resistor" in the ICE/Morgan was effective at reducing QRN.  Would anyone know of test results confirming the effectiveness of a static drain resistor in an arrestor?     73, Dick- K9OM
>> The ICE, now Morgan arrestors work superb. They use a static drain resistor, then a DC blocking cap, then the shunt inductor, then the GDT.
>> _______________________________________________
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