Topband: 8 element antenna - Amplifier placement

[Gary Smith]

Hi Lee,

Thank you for those answers, that's what I 
need to do then and I should be good to go 
in a couple days after I remove all the 
foliage that will be around the elements.

I'm looking forward to working D6 on 160 
and know this will ]be a great help.

73,

Gary
KA1J

> 
>  Hello Gary,
>    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.
>   Lee  K7TJR
> 
> 
> 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 
> 
> doctorgary.net/Hi-Z-8-Pro-1.jpg
> doctorgary.net/Hi-Z-8-Pro-2.jpg
> 
> 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.
> 
> doctorgary.net/Hi-Z-8-Pro-3.jpg 
> 
> 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,
> 
> Gary
> KA1J
> 
> 
> 
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband
>