Service Life Of Deployed Antennas

During some antenna maintenance this past weekend, two antennas that have been deployed for quite a while failed their functional checks, and were removed from service. The cause of failure on both antennas was due to degradation by weather and other environmental conditions.

The first antenna was an Alpha J-Pole Jr. originally installed in 2009 or 2010, and had been in service until this past weekend. After 10 or 11 years in service, moisture had finally penetrated the seal on the transformer unit. This issue caused a significant change in the normal SWR readings across the HF bands during transmit (100 watts power output). SWR readings via an Antenna Analyzer gave no indication of a problem. The antenna was retired after usable parts were salvaged. While unfortunately moisture had migrated through the SO-239 connector and into the coax, the zip cord used for the radiating element was still in serviceable condition, and 4:1 balun could be substituted for the original transformer, getting one on the air again with a J-pole, or as the OTs called it, and end-fed Zepp.

The second antenna was a Diamond Discone that was installed in 2001. This antenna had finally suffered the effects from UV degradation of the plastics insulating the top from the bottom elements. This issue was detected by the noticeable degradation in received signal strength of several transmitter stations used for RX check/reference purposes. This antenna had performed yeoman service dealing with the New England climate over the past 20 years.

Nothing lasts forever, but considering the varying weather conditions these antennas have had to deal with over the years, their longevity in service has left me suitably impressed.

ticom
Author: ticom

| December 14th, 2020 | Posted in Uncategorized |

2 Responses to “Service Life Of Deployed Antennas”

  1. Greg Brown Says:

    Finally found your newest writings. Lost track of you when you moved from the great western area back to the NE. Hope all is well and look forward to catching up on your writings.

  2. Saturday Night’s All Right For Scanning – Cyber-Tek Zine Says:

    […] reported two weeks ago about the loss of my primary VHF/UHF communications monitoring antenna after almost 20 years of yeoman service. Despite being a unity-gain, albeit wide-spectrum, antenna, the Diamond discone performed well, and […]

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