price%marlin@nosc.ARPA (James N. Price) (12/16/85)
------- Gentlemen--in a hellacious wind here in San Diego last week, my HyGain TH3JRS tri-bander sustained some damage that I'm having trouble sleuthing out. There is no obvious physical damage to the beam (I haven't lowered it yet, but between my Mk 1 eyeball and looking thru binoculars everything looks OK). However it behaves as if it weren't an antenna any longer. To wit--in its previous state, the beam had a normal SWR curve, dipping to near 1:1 in the CW portion of 20 and 15, and around 28.5 on 10. Post wind damage, the SWR is greater than 2.5:1 over the whole frequency range of each band, and gets as high as 5:1 in places. What's the most likely failure mode? Has one side of the coax come loose from the balun? (I do have the HyGain balun). Has a trap shorted out (or opened up) on the driven element or any element for that matter? This is my first beam so I literally don't know where to start in fixing it. Taking it down, as with all beams, is a big production, so I'd like to have a game plan before I lower it. Any help will be much appreciated. 73rds--Jim Price, K6ZH, PRICE@NOSC.ARPA -------