G7 - 144 Interest--- I've had a G7-144 on top of a hospital here for more years than I can figure and all was good until it went bad a few years ago. Corrosion was the problem evidenced by severe desense. On transmit, the corrosion was rectifying and producing wide band noise enough that the repeater receiver saw it as a desensing signal. The interesting thing was that input signals were desensed without additional noise being apparent in the repeater receiver audio.
Anyway---The fix I used was to clean and severely scratch up all the metal to metal joints in the antenna and reassemble using liberal amounts of the corrosion preventive goop sold for aluminum electrical connections---Home Depoe and the like all sell it. Then, I ran self tapping screws through all of the aluminum slip joints rather than use the original hose clamps and then I put a couple of layers of high grade heat shrink tubing over all the joints. Oh, and I put sharp burr washers between all of the threaded together pieces too. This was 5 or 6 years ago and the antenna continues to work fine. Scott, N6NXI ----- Original Message ----- From: John Poindexter To: Repeater-Builder@yahoogroups.com Sent: Tuesday, June 02, 2009 9:11 AM Subject: [Repeater-Builder] Re: 2 meter repeater Thanks for the tip on screwing the sections together. I am not a real fan of the clamps on an antenna myself. When I out up the HF tri-band, I used the clamps and not regretting it. 73 John, W3ML ------------------------------------------------------------------------------ No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.339 / Virus Database: 270.12.50/2150 - Release Date: 06/02/09 06:47:00
