From btippett at alum.mit.edu Thu Mar 8 14:57:06 2012 From: btippett at alum.mit.edu (Bill Tippett) Date: Thu, 8 Mar 2012 14:57:06 -0500 Subject: [Hi-zreceivingarraydiscussions] Preamp Installation in high humidity environments Message-ID: I recently repaired one of my ~30 month old RX 4SQ preamps. When I folded the board back I noticed some aquamarine colored corrosion around the inside insulator area of the connector. However the cable side of the connector looked clean. After thinking about this I believe the following is happening: 1. In NC summers we often have high humidity (90-95% RH) and high temperatures (>90). 2. At night temperatures cool which probably causes condensation inside the preamp case. 3. My preamps are mounted connector side down so condensation collects around the connector causing corrosion. My preamp and cable entry is covered by an inverted plastic bucket to prevent critters from chewing. The problem with this is that the cover also prevents the sun from warming the black preamp case which would otherwise help dissipate the moisture. I'm going to try mounting my preamps so that a metal side corner faces down. Hopefully this will allow condensation to weep out around the metal cover instead of collecting around the connector. For those of you in similar environments, you might want to consider this. I don't know if it will work but it surely cannot hurt! 73 & GL! Bill W4ZV From n1rj at roadrunner.com Thu Mar 8 16:46:54 2012 From: n1rj at roadrunner.com (Roger D Johnson) Date: Thu, 08 Mar 2012 16:46:54 -0500 Subject: [Hi-zreceivingarraydiscussions] Preamp Installation in high humidity environments In-Reply-To: References: Message-ID: <4F5928CE.2060103@roadrunner.com> How about a good slathering of silicone grease on the preamp side of the connector? I didn't have that problem because I took the boards out of the cases and mounted them in some wx proof boxes I had laying around. Also, a very small weep hole drilled at the lowest part of the box might help. Congrats on 3C0! I'm still trying. 73, Roger On 3/8/2012 2:57 PM, Bill Tippett wrote: > I recently repaired one of my ~30 month old RX 4SQ preamps. When I folded > the board back I noticed some aquamarine colored corrosion around the > inside insulator area of the connector. However the cable side of the > connector looked clean. After thinking about this I believe the following > is happening: > > 1. In NC summers we often have high humidity (90-95% RH) and high > temperatures (>90). > 2. At night temperatures cool which probably causes condensation inside > the preamp case. > 3. My preamps are mounted connector side down so condensation collects > around the connector causing corrosion. > > My preamp and cable entry is covered by an inverted plastic bucket to > prevent critters from chewing. The problem with this is that the cover > also prevents the sun from warming the black preamp case which would > otherwise help dissipate the moisture. > > I'm going to try mounting my preamps so that a metal side corner faces > down. Hopefully this will allow condensation to weep out around the metal > cover instead of collecting around the connector. For those of you in > similar environments, you might want to consider this. I don't know if it > will work but it surely cannot hurt! > > 73& GL! > > Bill W4ZV > _______________________________________________ > Hi-zreceivingarraydiscussions mailing list > Hi-zreceivingarraydiscussions at hizantennas.com > http://mail.hizantennas.com/mailman/listinfo/hi-zreceivingarraydiscussions_hizantennas.com > -- Remember the Liberty (AGTR-5) http://www.usslibertyveterans.org/ http://www.gtr5.com/ From n1rj at roadrunner.com Thu Mar 8 17:10:14 2012 From: n1rj at roadrunner.com (Roger D Johnson) Date: Thu, 08 Mar 2012 17:10:14 -0500 Subject: [Hi-zreceivingarraydiscussions] Preamp Installation in high humidity environments In-Reply-To: <4F5928CE.2060103@roadrunner.com> References: <4F5928CE.2060103@roadrunner.com> Message-ID: <4F592E46.5010309@roadrunner.com> Sorry! Meant this to got to Bill On 3/8/2012 4:46 PM, Roger D Johnson wrote: > How about a good slathering of silicone grease on the preamp side of > the connector? I didn't have that problem because I took the boards out > of the cases and mounted them in some wx proof boxes I had laying > around. Also, a very small weep hole drilled at the lowest part of the box > might help. Congrats on 3C0! I'm still trying. > > 73, Roger > > > On 3/8/2012 2:57 PM, Bill Tippett wrote: >> I recently repaired one of my ~30 month old RX 4SQ preamps. When I folded >> the board back I noticed some aquamarine colored corrosion around the >> inside insulator area of the connector. However the cable side of the >> connector looked clean. After thinking about this I believe the following >> is happening: >> >> 1. In NC summers we often have high humidity (90-95% RH) and high >> temperatures (>90). >> 2. At night temperatures cool which probably causes condensation inside >> the preamp case. >> 3. My preamps are mounted connector side down so condensation collects >> around the connector causing corrosion. >> >> My preamp and cable entry is covered by an inverted plastic bucket to >> prevent critters from chewing. The problem with this is that the cover >> also prevents the sun from warming the black preamp case which would >> otherwise help dissipate the moisture. >> >> I'm going to try mounting my preamps so that a metal side corner faces >> down. Hopefully this will allow condensation to weep out around the metal >> cover instead of collecting around the connector. For those of you in >> similar environments, you might want to consider this. I don't know if it >> will work but it surely cannot hurt! >> >> 73& GL! >> >> Bill W4ZV >> _______________________________________________ >> Hi-zreceivingarraydiscussions mailing list >> Hi-zreceivingarraydiscussions at hizantennas.com >> http://mail.hizantennas.com/mailman/listinfo/hi-zreceivingarraydiscussions_hizantennas.com >> >> > -- Remember the Liberty (AGTR-5) http://www.usslibertyveterans.org/ http://www.gtr5.com/ From btippett at alum.mit.edu Fri Mar 16 12:58:29 2012 From: btippett at alum.mit.edu (Bill Tippett) Date: Fri, 16 Mar 2012 12:58:29 -0400 Subject: [Hi-zreceivingarraydiscussions] Preamp Installation in high humidity environments Message-ID: <68.C9.21063.B31736F4@pacmmta53> Just a follow-up on this. I removed all preamps for the season as a precaution for lightning and inspected them for corrosion. The other 3 plus my spare were all very clean. I'm guessing it was simply bad luck that the corroded one was mounted vertical so condensation collected around the the RG6 connector. When I reinstall I'll be careful to slightly tilt each so any condensation will drain out one of the corners. 73, Bill W4ZV From gysgt at peak.org Sat Mar 17 13:11:52 2012 From: gysgt at peak.org (gysgt) Date: Sat, 17 Mar 2012 10:11:52 -0700 Subject: [Hi-zreceivingarraydiscussions] Preamp Installation in high humidity environments In-Reply-To: <68.C9.21063.B31736F4@pacmmta53> References: <68.C9.21063.B31736F4@pacmmta53> Message-ID: <4F64C5D8.4000006@peak.org> Hi Bill et al, That can happen. The PLUS 6 amps are more immune to such issues. The standard Hi-Z Amps do take a bit of consideration in the way they are mounted, in particular the way they are weatherproofed. Very 73 / Cheers Dick KO7N On 3/16/2012 9:58 AM, Bill Tippett wrote: > Just a follow-up on this. I removed all preamps for the season as > a precaution for lightning and inspected them for corrosion. The > other 3 plus my spare were all very clean. I'm guessing it was simply > bad luck that the corroded one was mounted vertical so condensation > collected around the the RG6 connector. When I reinstall I'll be > careful to slightly tilt each so any condensation will drain out one > of the corners. > > 73, Bill W4ZV > > > _______________________________________________ > Hi-zreceivingarraydiscussions mailing list > Hi-zreceivingarraydiscussions at hizantennas.com > http://mail.hizantennas.com/mailman/listinfo/hi-zreceivingarraydiscussions_hizantennas.com > > > From thorntonash at comcast.net Sat Mar 17 13:19:35 2012 From: thorntonash at comcast.net (thornton ash) Date: Sat, 17 Mar 2012 13:19:35 -0400 Subject: [Hi-zreceivingarraydiscussions] Preamp Installation in high humidity environments In-Reply-To: <4F64C5D8.4000006@peak.org> References: <68.C9.21063.B31736F4@pacmmta53> <4F64C5D8.4000006@peak.org> Message-ID: <96518266-EE48-48D9-9313-ED92A05E6303@comcast.net> I mounted my amps in a plastic box with a hole drilled in the bottom and then mounted them on a stake 3-4" above thee ground. I sealed the entry for the RG6 and antenna/ground connections. If any water or moisture gets in then it will drain out. Thornton On Mar 17, 2012, at 1:11 PM, gysgt wrote: > Hi Bill et al, > > That can happen. The PLUS 6 amps are more immune to such issues. > > The standard Hi-Z Amps do take a bit of consideration in the way they are mounted, in particular the way they are weatherproofed. > > Very 73 / Cheers Dick KO7N > > On 3/16/2012 9:58 AM, Bill Tippett wrote: >> Just a follow-up on this. I removed all preamps for the season as a precaution for lightning and inspected them for corrosion. The other 3 plus my spare were all very clean. I'm guessing it was simply bad luck that the corroded one was mounted vertical so condensation collected around the the RG6 connector. When I reinstall I'll be careful to slightly tilt each so any condensation will drain out one of the corners. >> >> 73, Bill W4ZV >> >> >> _______________________________________________ >> Hi-zreceivingarraydiscussions mailing list >> Hi-zreceivingarraydiscussions at hizantennas.com >> http://mail.hizantennas.com/mailman/listinfo/hi-zreceivingarraydiscussions_hizantennas.com >> >> > > > _______________________________________________ > Hi-zreceivingarraydiscussions mailing list > Hi-zreceivingarraydiscussions at hizantennas.com > http://mail.hizantennas.com/mailman/listinfo/hi-zreceivingarraydiscussions_hizantennas.com From Paul at PaulFerguson.us Sat Mar 17 13:52:40 2012 From: Paul at PaulFerguson.us (Paul Ferguson) Date: Sat, 17 Mar 2012 13:52:40 -0400 Subject: [Hi-zreceivingarraydiscussions] Advantages of the PLUS-6 Preamps? Message-ID: <4F64CF68.9311.106F3CB@Paul.PaulFerguson.us> I have a Hi-Z 3-element array with the original preamps. I see the newer PLUS-6 preamps are in weatherproof boxes and offer 6 db more gain. I wonder if the newer preamps would make any difference in hearing weak signals. I see a testimonial by W0FLS on the Hi-Z site, but the comparison is between a 4-square TX array and an 8-circle Hi-Z RX array. Has anyone done any comparisons of the original preamps versus the PLUS-6 preamps by changing only the preamps on a Hi-Z array? 73, Paul K5ESW From k7tjr at msn.com Sat Mar 17 15:52:05 2012 From: k7tjr at msn.com (Lee K7TJR) Date: Sat, 17 Mar 2012 12:52:05 -0700 Subject: [Hi-zreceivingarraydiscussions] Advantages of the PLUS-6 Preamps? Message-ID: >I have a Hi-Z 3-element array with the original preamps. I see the newer >PLUS-6 >preamps are in weatherproof boxes and offer 6 db more gain. I wonder if the >newer preamps would make any difference in hearing weak signals. Hello Paul, It is my belief that you would not see any better signal to noise ratio with the Plus-6 amps when used on a three element array. Just more gain. The combining losses in the three element array are substantially lower which keeps the noise figure of the array a lot better than the more lossy 4 and 8 element controllers. The 8 element controllers are significantly improved in SNIF (Signal to Noise Improvement Factor) with the exchange of the Plus-6 amps whereas the 4-square is improved, but less. I would judge this as a minor improvement to the 4-square noticeable only in the quietest times. Likely no improvement at all to a three element. Lee K7TJR From mikewate at gmail.com Sat Mar 17 19:42:58 2012 From: mikewate at gmail.com (Mike Waters) Date: Sat, 17 Mar 2012 18:42:58 -0500 Subject: [Hi-zreceivingarraydiscussions] Preamp Installation in high humidity environments In-Reply-To: <96518266-EE48-48D9-9313-ED92A05E6303@comcast.net> References: <68.C9.21063.B31736F4@pacmmta53> <4F64C5D8.4000006@peak.org> <96518266-EE48-48D9-9313-ED92A05E6303@comcast.net> Message-ID: Silicone dielectric compound is your friend. I fill all my outdoor connectors with it, and haven't had a water or corrosion problem in over 30 years. You can get it at auto parts stores sold as Permatex "Dielectric Tune-up Grease". I now buy it in 3.3 oz. pressurized dispenser cans made by CRC, P/N 05105. *NOT* to be confused with silicone RTV rubber, which hardens. 73, Mike www.w0btu.com