{"id":5260,"date":"2012-07-03T18:09:35","date_gmt":"2012-07-03T22:09:35","guid":{"rendered":"http:\/\/www.engineeringradio.us\/blog\/?p=5260"},"modified":"2023-04-29T08:33:00","modified_gmt":"2023-04-29T12:33:00","slug":"whatever-can-happen-will-happen","status":"publish","type":"post","link":"https:\/\/www.engineeringradio.us\/blog\/2012\/07\/whatever-can-happen-will-happen\/","title":{"rendered":"Whatever can happen, will happen"},"content":{"rendered":"\n

This is a universal truism that can also be expressed as “Murphy’s Law.”\u00a0 I don’t rightly know how Murphy received credit for this, however, I chalk it up to either the luck of the Irish or the gift of self-promotion.\u00a0 Either way, that principle was demonstrated again with a 950 MHz STL link between Mt. Beacon<\/a> and Peekskill, NY<\/a> for WHUD<\/a>.<\/p>\n\n\n\n

I noticed, while doing some transmitter maintenance, the receive signal strength of the STL had dropped from 300 \u00b5V to 30 \u00b5V. \u00a0 That is an alarming development.\u00a0 Therefore, we scheduled a tower crew for the next day, not wanting to go off the air over the coming holiday, which would be a sure bet otherwise.\u00a0 Upon arrival, the tower crew noticed a strange thing in the STL transmission line at the base of the tower, which looked like some type of a splice.\u00a0 Truth be told, I have been associated with this station since 1999 and had never noticed the splice before.\u00a0 This STL system was installed in 1998 when the station’s studio moved from Peekskill to Beacon. \u00a0 I can say, of all the things that have gone wrong over the years, this STL system was always very reliable.\u00a0 Regardless of that, I quick check with a spectrum analyzer showed a 3 dB return loss at 137 feet (41.75 m), exactly the distance from the transmitter room to the base of the tower.<\/p>\n\n\n\n

\"3<\/a>
3 dB return loss, distance to fault 137 feet<\/figcaption><\/figure>\n\n\n\n

A 3 dB return loss coincides exactly with the drop in received signal strength at the other end of the path.  Thus, the tower crew took apart the splice and water poured out of it.  I would estimate at least 4-6 ounces of water (180 ml), perhaps more.<\/p>\n\n\n\n

\"7\/8<\/a>
7\/8 coax cable splice connector, opened up<\/figcaption><\/figure>\n\n\n\n

We then began to take in the details:<\/p>\n\n\n\n