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Wow http://www.interceptradio.com/bbs/viewtopic.php?f=8&t=9098 |
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Author: | mw [ Mon Dec 03, 2018 6:26 pm ] |
Post subject: | Wow |
http://nwbroadcasters.com/clay12-18.html |
Author: | Wilrobnson [ Mon Dec 03, 2018 8:02 pm ] |
Post subject: | Re: Wow |
I thought Sean's ADHD was rough... |
Author: | Craig H [ Tue Dec 04, 2018 11:45 am ] |
Post subject: | Re: Wow |
Hmmmm ? After a bit of a dry spell on Intercept NW, here's a new subject matter for some further research. So here's an eccentric hypothesis / working theory - but to validate this speculation one would need to actually reproduce the experiment and observe the results. Alas, I don't have that kind of RF power available at my disposal. Wikipedia claims "Dielectric Heating" involves the heating of electrically insulating materials by dielectric loss. Rotating molecules push, pull, and collide with other molecules (through electrical forces), distributing the energy to adjacent molecules and atoms in the material. The process of energy transfer from the source to the sample is a form of radiative heating. Frequencies in the range of 10–100 MHz are necessary to cause, . . . lower frequency electrical fields penetrate non-conductive materials far more deeply than do microwaves, heating pockets of water and organisms deep inside, . . . ( weather cracked / damaged / chipped radome, dust ?, pollen ?, or maybe long term moss build up on the radomes ? ). ABS ignites at 416 F, but will begin to deform much sooner than that. I hereby pass the shoe. |
Author: | N7QOR [ Tue Dec 04, 2018 6:29 pm ] |
Post subject: | Re: Wow |
And here I thought the Fisher Plaza Bus Duct failure was impressive. https://www.datacenterknowledge.com/arc ... plaza-fire |
Author: | chpalmer [ Tue Dec 04, 2018 9:10 pm ] |
Post subject: | Re: Wow |
Craig H wrote: Hmmmm ? Wikipedia claims "Dielectric Heating" involves the heating of electrically insulating materials by dielectric loss. Rotating molecules push, pull, and collide with other molecules (through electrical forces), distributing the energy to adjacent molecules and atoms in the material. The process of energy transfer from the source to the sample is a form of radiative heating. Frequencies in the range of 10–100 MHz are necessary to cause, . . . lower frequency electrical fields penetrate non-conductive materials far more deeply than do microwaves, heating pockets of water and organisms deep inside, . . . ( weather cracked / damaged / chipped radome, dust ?, pollen ?, or maybe long term moss build up on the radomes ? ). ABS ignites at 416 F, but will begin to deform much sooner than that. I hereby pass the shoe. We had a failure of a brand new transmitter (5kw) due to the location of a pre-drilled hole that they used for the dialectic spacers ending up at the connector "finger" that was used for the feed line. Once any arching starts its a short ride to failure at their kind of power. According to the linked information from the manufacturer "Power Ratings up to 280 Kilowatts." Id love to know exactly how much was entering the antenna at the time. And what the actual bandwidth of that antenna was. 92.5 to 106.1 is a big spread for these antennas.. edit- From the front page http://nwbroadcasters.com/ "2/03/18 - Further info has been made available following the West Tiger-1 tower fire on November 8. These stations are operating from standby transmitters without HD: KSWD-FM 94.1, KJAQ-FM 96.5, KZOK-FM 102.5 and KBKS 106.1. KQMV-FM 92.5 and KNUC-FM 98.9 were also on the burned tower, but their ownership (Hubbard) ordered new backup transmitters some weeks before the blaze, and those are equipped with HD capability. A listener reports weaker signals in the northern and southern suburbs for 92.5, 94.1, 96.5, 98.9 and 102.5, which are now operating from Cougar Mountain. In a report by ERI after inspecting the antenna, it was noted that one of the brass bolts welded to one of the radiating elements had broken due to storm or vibration and fallen inside the fiberglass insulator. Arcing grew larger and caused a fire to ignite in the plastic radome. The fire then grew further, melting the ends of the element and the other radomes." |
Author: | dste [ Mon Jan 21, 2019 3:28 pm ] |
Post subject: | Re: Wow |
They're Baaaaack! I just noticed the HiDef stuff are broadcasting today. |
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