Re: Topband: 160M Inverted-L Radial Question

[donovanf]

Hi Mark, 


The sloping radials you're proposing to use also have the affect 
of shortening the effective length of your vertical, just as if 
you had raised the feed point. 


73 
Frank 
W3LPL 

- Original Message -

From: "Mark K3MSB"  
To: "topBand List"  
Sent: Monday, September 26, 2016 2:33:54 AM 
Subject: Topband: 160M Inverted-L Radial Question 

I've been doing some reading on elevated radials for Inverted-L antennas. 
The existing literature seems to fall into two types; ground radials where 
the feed point is very close the ground, and systems were the feed point 
is elevated at the height of the radials. 

My Inverted-L is 50 feet high and has the feed point in a box at ground 
level. I'm considering using 2 elevated radials so as to reduce the 
radial field next to my new (hopefully) RX antenna (BOG). Since I 
don't want to raise my feed point by 5 feet and thereby decrease the 
vertical part of the Inverted L accordingly, I was considering using a 
pair of elevated radials (5 feet high -- don't know the exact height 
yet). I was planning on the radials sloping up 45 degrees from the base 
of the Inverted-L to my radial height. The radials will not be straight, 
but will have doglegs due to property constraints. 

I haven't found any literature that addresses this consideration. 

Comments? 

73 Mark K3MSB 
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Topband: 160M Inverted-L Radial Question

[Mark K3MSB]

I've been doing some reading on elevated radials for Inverted-L antennas.
The existing literature seems to fall into two types;  ground radials where
the feed point is very close the ground,  and systems were the feed point
is elevated at the height of the radials.

My Inverted-L is 50 feet high and has the feed point in a box at ground
level.   I'm considering using 2 elevated radials so as to reduce the
radial field next to my new (hopefully) RX antenna (BOG).  Since I
don't want to raise my feed point by 5 feet and thereby decrease the
vertical part of the Inverted L accordingly,   I was considering using a
pair of elevated radials (5 feet high -- don't know the exact height
yet).   I was planning on the radials sloping up 45 degrees from the base
of the Inverted-L to my radial height.  The radials will not be straight,
but will have doglegs due to property constraints.

I haven't found any literature that addresses this consideration.

Comments?

73 Mark K3MSB
_
Topband Reflector Archives - http://www.contesting.com/_topband

Re: Topband: Waterproofing a tupperware - drainage & advice

[Gene Smar]

Gary:

 The proper way to get a cable into an equipment box as you're proposing
is to install a conduit gland in the hole first, then feed the cable through
the rubber o-ring in the gland.  Here's a link to a photo:
http://tinyurl.com/z2pbynr .  Of course, the connectors cannot be put on the
cable ends until they're inside the box, past the glands. 

 I can't tell from your description whether the cables enter the
enclosure from the side or bottom.  If the bottom, you're ok.  If from the
side, then you ought to leave a drip loop of cable along side the enclosure
for each cable.  The downward direction of cables without drip loops just
makes for a path for water on the full length of the cable jackets to follow
directly into the box. 


73 de
Gene Smar  AD3F



-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary
Smith
Sent: Sunday, September 25, 2016 12:31 PM
To: topband@contesting.com
Subject: Topband: Waterproofing a tupperware - drainage & advice

Rather than invent a poorly designed
wheel, maybe someone here has already
successfully worked out a better solution to waterproofing.

I am using a Sterilite 25" x 18" x 8" 
container with secure snap on fasteners on each side of the lid to house the
outdoor electronics for the 8 circle array. The lid fits wonderfully and
there is a 1" rim that comes down from the lid to secure the contents from
exposure to rain.

I have drilled the holes for each coax (9 in all) and cut a slot for the
control wire. I'm planning on wrapping each coax & the control cable with
plastic from a plastic bag to make the coax snug to the hole and then
gorilla taping that to the side of the container on each side.

Any ideas to improve this?

Another option I've thought of to seal the openings is to use expansion foam
to seal the holes. My concern is that is that I've never used this foam
before and don't know how easy it is to remove it from the coax should I
ever need to. Seems like it would make a great seal.

Any caveats using the foam instead of the plastic bag & gorilla tape?

Another consideration is drainage; the
container will be placed on a large
boulder to keep it above rising salt
water, should there be any from a
storm/hurricane. 

I don't want to make access holes for
insects but I need to keep it dry inside.
Once the holes are sealed there isn't much access for water getting in.
Murphy being a McGuiver, should I drill a couple small holes in the bottom
for drainage or should I leave it as is and not provide for drainage?

73,

Gary
KA1J

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Re: Topband: Waterproofing a tupperware - drainage & advice

[HAROLD SMITH JR]

Gary, I would provide a drainage hole at the lowest point of the box. A one 
inch diameter hole covered with very fine screen wire. I would glue it in with 
silicon-rubber glue. If the box is sealed completely, you will have a buildup 
of condensation, been there and had it. I had a prop-pitch motor that was 
completely sealed. I always had water in it. It was condensation, I provided a 
drain hole at the lowest point and all was well. 73 es GL...Price W0RI

  From: Gary Smith 
   
Rather than invent a poorly designed 
wheel, maybe someone here has already 
successfully worked out a better solution 

I don't want to make access holes for 
insects but I need to keep it dry inside.
Once the holes are sealed there isn't much 
access for water getting in. Murphy being 
a McGuiver, should I drill a couple small 
holes in the bottom for drainage or should 
I leave it as is and not provide for 
drainage?

73,

Gary
KA1J

_
Topband Reflector Archives - http://www.contesting.com/_topband


   
_
Topband Reflector Archives - http://www.contesting.com/_topband

Topband: Waterproofing a tupperware - drainage & advice

[Gary Smith]

Rather than invent a poorly designed 
wheel, maybe someone here has already 
successfully worked out a better solution 
to waterproofing.

I am using a Sterilite 25" x 18" x 8" 
container with secure snap on fasteners on 
each side of the lid to house the outdoor 
electronics for the 8 circle array. The 
lid fits wonderfully and there is a 1" rim 
that comes down from the lid to secure the 
contents from exposure to rain.

I have drilled the holes for each coax (9 
in all) and cut a slot for the control 
wire. I'm planning on wrapping each coax & 
the control cable with plastic from a 
plastic bag to make the coax snug to the 
hole and then gorilla taping that to the 
side of the container on each side.

Any ideas to improve this?

Another option I've thought of to seal the 
openings is to use expansion foam to seal 
the holes. My concern is that is that I've 
never used this foam before and don't know 
how easy it is to remove it from the coax 
should I ever need to. Seems like it would 
make a great seal.

Any caveats using the foam instead of the 
plastic bag & gorilla tape?

Another consideration is drainage; the 
container will be placed on a large 
boulder to keep it above rising salt 
water, should there be any from a 
storm/hurricane. 

I don't want to make access holes for 
insects but I need to keep it dry inside.
Once the holes are sealed there isn't much 
access for water getting in. Murphy being 
a McGuiver, should I drill a couple small 
holes in the bottom for drainage or should 
I leave it as is and not provide for 
drainage?

73,

Gary
KA1J

_
Topband Reflector Archives - http://www.contesting.com/_topband

Re: Topband: 8 element antenna - Amplifier placement

[Les Kalmus]

Gary,

Sounds like a normal antenna raising day in the woods. Your antenna will 
probably work fine now. Don't ask me how I know that...


73, Les W2LK


On 9/25/2016 1:22 AM, Gary Smith wrote:

A little follow-up with my life in the
fast lane...

I move slowly, all considering, kind of
like Ahab with a pair of shoes. I've been
spending the better part of the last two
weeks putting up a HI-Z 4-8Pro array.

If it were open space with good soil, all
would have been done after the first 1-2
days. But no, I live in New England, the
place where the Glacier's Gall Stones came
to rest after it encountered Global
Warming.

The place I have to put the array in is
like a Louisiana Bayou minus the standing
water. It's a salt marsh and just a bit
above sea level. I don't have an option
where else to put it, this is it.

We're known for Lyme disease, Lyme, CT is
10 miles west of here so tick protection
is mandatory. Worse, this is Bambi's
frolic-land and deer sign is everywhere.
More, we're blessed to have West Nile  and
of course Zeka is getting all kinds of
press. So pyrethrin and DEET 40 is the
cologne de jour.

You can't imagine the scale of the rocks
here, it really boggles the imagination.
So much stone 5" below the surface and
muck on top of them. Some boulders above
ground are the size of Volkswagens and
most showing are like an iceberg with the
greater mass underneath.

This place has one other unusual issue in
that in a storm surge, at high tide, salt
water can get in there and will ruin
everything. So to outwit the tide, I moved
the amplifiers up inside the PVC tubes and
used a rubber cap to hold the amp high
enough that if the water rises, it won't
reach the electronics as there will be an
air pocket inside to keep everything out
of harm's way. I posted this pic earlier
of what I did:
doctorgary.net/Hi-Z-8-Pro-3.jpg
It will work just fine to keep the amps
safe..

Of course there are the briars, brambles
everywhere that are strong enough to stop
an Iron Man in his tracks, not to mention
the bittersweet vines that make walking in
a straight line impossible.

I staked out the proper placements for the
8 antennae, 4 times, before I found an
acceptable spot rock-wise but the trees
were unforgiving and ended up cutting down
7 rather large trees to make room.

Of course the Poison Ivy is everywhere and
the last spot I had to deal with branches
& rock-wise had a hairy 5" root of Poison
Ivy going up the tree with branches
hanging out right in the way of the
antenna. The Oak was too thick for my 20"
chain saw so I had to remove the tree
branches and the poison ivy.

I couldn't reach the branches 20' up and
my extendible saw/pruner could only reach
the poison ivy. Ended up slicking the vine
at knee level and leaving it die for a few
days. I tried a rope saw but it got stuck
1/2" in and was useless. Then I remembered
the extra elements I ordered from DXE and
connected the large ones & duct taped the
pruner to the aluminum and was able to
reach the branches. Between the tree
sawdust and the poison Ivy Sawdust, it was
a glorious time.

Finally , success! The local metal shop
cut my aluminum angle for the
ground/support rods, so today I hoped to
sink all the angles, using a Stainless
Steel angle as a probe to find what
worked. Great success, I get to the last
place I had marked out as correct, put the
knapsack with all my tools down, pull out
the SS angle and pound in the Aluminum and
there it was, the sound like small Harley
Davidsons on a mission from God, the
ground wasps that I had put my knapsack
down on their entrance were angry and knew
I was to blame.

Give me three good Honey Bee stings, one
yellow Jacket sting but nothing inch for
inch is more painful than these guys, they
are just mean. They stung me several times
and I proved Ahab can still run if the
prize is worth enough. I couldn't get my
tools, there were constantly 3-4 dozen of
these in the air swarming everything I had
laid down.

Some Hornet killer later and I could get
close enough with a stick to wrangle my
tools out but the damage was done
time-wise, I couldn't finish before dark.
So I finished assembling the antennas,
have them ready to connect to the
controller and tomorrow I get to connect
up all the coax, the terminals, everything
outside and I'm good to go.

My ear is the size of a Cauliflower but at
last count it was Wasps 5, Gary 100, that
wasp stuff really works... Looking forward
to hearing with this marvellous Antenna
system.

Oh, and I left out so much more of the
saga... ;)

73,

Gary
KA1J

  

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