Topband: 8 element antenna - Amplifier placement
k7tjr at msn.com
Mon Sep 19 14:33:54 EDT 2016
Spray painting the elements is no problem. As far as mounting the amps to the elements I would not recommend that. It likely could compromise performance. It would be much better if you could take a steel post like a piece of rebar and provide a second place for the amps to mount with just the wires reaching the element and ground. If you have to lengthen the leads to the amp do not lengthen the ground lead any more than absolutely necessary. Lengthening the element wires will have to be done exactly the same length and dressed as closely the same way as possible on each element/amp.
Subject: Topband: 8 element antenna - Amplifier placement
I'm so close to being done with putting this together. I have all 8 antennas made @ 23' each the tip section is .5" and the base is .850" I'm using a 3/4" fiberglass rod as an insulator
I am having a conundrum with the placement of the enclosure for the preamp mounted at each antenna and need some advice. The problem is I am at sea level and the antennas will be mounted in a location that will possibly get a storm surge during a Hurricane, it ruined my remote coax switch during Sandy from this very reason. The preamp does have a silicone gasket but if the amp gets submerged in salt water, I'm sure it will get past the terminals and ruin the amp. I have no alternate choice, this is the location where I have to put the array.
Seeing the photo of the end cap on the PVC tubing with the zip tie holding the amp in place (to protect from rain & Snow), gave me an idea for the solution; At the top of the PVC tube, make two opposing holes, run a loose loop of thin wire through and twist together. Run the coax up & over the wire to hold the amp elevated inside the tube, all the way to the top. Use a rubber cap with radiator clamp to secure the top and make it truly airtight. Now if the tide water from a storm surge encroaches, there will be a pocket of air inside and will be unable to push high enough to reach the amplifier. I tried this with a Mason jar and the water did not get very high in the upside down jar.
So here's the dilemma: As a further hedge against water damage assuming there are strong winds making waves (they would not be breakers, just waves in the marsh) at this time, I'd like to raise the placement of the amplifier so it would be another foot higher than standard placement which is on the base below the insulator. This would require me to clamp the PVC on the antenna instead of the base. Can anyone see how this might be a problem with operation?
Also, I'd like to spray camo paint on the elements so they don't stand out. When the leaves come down, I'd prefer the neighbors not see the elements, they're nosy enough as it is. I think I remember reading a layer of paint on the element shouldn't cause a problem, is this correct?
Thanks & 73,
More information about the Topband