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Over the years, I've read many accounts of people fighting moisture in their feed horns which connect directly to the LNB unit. But until a couple days ago, I had never personally witnessed the damage that can occur when that moisture gets into the LNB. I've posted some photos... http://www.rovinginternet.com/MoisturedamagedLNB.htm
-------------------- Terry Cannon HDTV Tripods and Internet Tripods Hughes and Starband parts and repairs. (303) 482-2547 http://www.rovinginternet.com Posts: 173 | From: Castle Rock, Colorado | Registered: Jul 2005
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posted
Good pictures. That seal can be either a good thing or a very bad thing. In the case of yours it was a very bad thing. The seal keeps moisture from traveling from the feedhorn to the LNB or vice versa. If the feedhorn front leaks then it is a good thing because it traps the moisture inside the feedhorn. If the O ring leaks it is a bad thing because you cannot see the moisture behind the feedhorn clear plastic thus warning you of the leak.
-------------------- Don Marr WWW.OREGONRV.NET 541-683-5361 See where I am Country Coach Concept 40' F1 - D3|7000s|99W|LinkSys wireless with 1000mw WiFi amp & Ext. antenna Posts: 3411 | From: Eugene, OR | Registered: Jun 2004
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I agree Don. In the past, there have been times that I've removed those seals, however I can see how it could save an LNB if a feed horn lens were leaking.
Obviously, this time, that seal saved the feed horn but since there was no moisture showing in the feed horn lens, the user apparently didn't notice or didn't know what to do about their gradual loss of signal strength over time.
I don't know the history of this particular unit other than it was bought used by someone who couldn't get it to work. Obviously, some installer somewhere made a slight error on assembling the unit.
-------------------- Terry Cannon HDTV Tripods and Internet Tripods Hughes and Starband parts and repairs. (303) 482-2547 http://www.rovinginternet.com Posts: 173 | From: Castle Rock, Colorado | Registered: Jul 2005
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posted
The pictures are typical of corrosion of the metal (aluminum most likely) surface and not a calcium build-up. Unfortunately, it is not repairable. Scraping away the corroded material changes the waveguide properties and deteriorates its performance.
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when i first installed my used datastorm, i had problems with moisture in the feedhorn assembly. I took it apart and dried it all out, then re-assembled it and put a thin film of silicon anywhere there were 2 surfaces mated together (not between the surfaces, but around the outside covering the joint), and put a film around the outer edge of the plastic cover on the horn. Never a problem since.
-------------------- 1977 MCI Bus Conversion
Real Men Love Jesus! A little about me...Faith Ministries At the moment, we are Here F1 Datastorm|D3|HN7000S|83W 1390|Linksys WRT54G w/DD-WRT Firmware|2 wireless laptops|Netgear SPH200W WiFi Skype Phone Posts: 494 | From: CONUS | Registered: Jun 2008
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We also put a ring of silicone around the three joints when we service the F1 TRIA assembly. Those Hughes rubber O rings are just not good enough.
-------------------- Don Marr WWW.OREGONRV.NET 541-683-5361 See where I am Country Coach Concept 40' F1 - D3|7000s|99W|LinkSys wireless with 1000mw WiFi amp & Ext. antenna Posts: 3411 | From: Eugene, OR | Registered: Jun 2004
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posted
On a recent TRIA assembly I bought from a reseller (shipped directly from Motosat)I noticed a dark painted on coating on the area around the joints.
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agkirk, thanks for the correction. I'll be re-writing the narrative on the pictures. My neighbor pointed out that rain and humidity don't leave calcium deposits. He thought it might be salt from a seaside location, but I know that people have experienced this far inland. Your simple explanation of corrosion makes the most sense and also answers the question of why it can't be repaired.
Everyone recommending an external sealant on those joints, I agree that's a great insurance policy.
On this particular unit, the two flat surfaces that were supposed to be mated seamlessly weren't because that O ring was pinched between them. I wonder if this unit ever performed the way it should have, given that mistake in assembly.
-------------------- Terry Cannon HDTV Tripods and Internet Tripods Hughes and Starband parts and repairs. (303) 482-2547 http://www.rovinginternet.com Posts: 173 | From: Castle Rock, Colorado | Registered: Jul 2005
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