I like your design, I have made a similar arrangement, including the #31 cores
but am not that satisfied with my
scheme. I let the RF choke hang below unsupported. If you can do a picture
that would be great.
Do you know what type of plastic the white cutting boards are ? They sure
look like teflon although I'm sure they are not, hihi.
I am thinking of getting one and trying it for a dipole center support panel
like we are discussing. I guess the first thing to do is to see if they
are immune to RF. Putting one in the microwave for a little bit to see it gets
warm might be a good test. The ones I have seen are about 1/2" thick,
and they sure look like they are begging to be used on antennas, hihi
On Apr 21, 2012, at 5:18 PM, K8RI wrote:
> On 4/21/2012 6:17 PM, Dick wrote:
>> I just got a rope over a tree after 4 years of trying. I need a dipole
>> center insulator that has strain relief for the coax. To clear the branches,
>> the coax will be pulling against the center support rope. All the center
>> insulators I've seen have an SO-239, it doesn't seem like putting that
>> strain on a PL-259 is a good idea... Do any have a strain relief??
> I make my own out of 1/2" Plexiglass, or two 1/4" sheets laminated
> together with epoxy. I drill a hole in the center slightly larger than
> the coax and round the edges. Typically I make a RF Choke of 5 or 6 2.4"
> # 31 cores with 5 or 6 turns of BuryFlex(TM) coax. I typically make the
> choke part of the feed line so no PL-259s are under tension. It takes
> very little (relatively speaking) to pull the coax out of one even if
> it's thoroughly soldered. I will often put a connector on the antenna
> side of the choke and run a coax pigtail from it to aid in water
> proofing. To take up the antenna strain I use a 4 or 6" ceramic
> insulator TieWraped to the Plexiglass. I drill holes just large enough
> for the tiewraps. Remember that nylon does not stand up well to UV or
> out in the elements nor do cheap cable ties.
> So I end up with the coax going through the Plexiglass, then the choke
> on the other side and finally to the antenna ends at the ends of the
> ceramic insulator. In some cases I epoxy the coax in the hole through
> the Plexiglass. I have some of these supporting about a 100' of
> BuryFlex(TM) back to the tower while the antenna may be under between
> 100 and 200# of tension such as the 75 meter fan dipole.
> I hope to have a photo up yet this evening.
> Roger (K8RI)
>> Dick NY1E
>> TowerTalk mailing list
> TowerTalk mailing list
TowerTalk mailing list