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Old January 24th 04, 09:09 PM
The Eternal Squire
 
Posts: n/a
Default upside down vertical?

Hi all,

My wife wants to put up a birdfeeder and I want to put up a hidden antenna.
My landlords allow
only the former but seem to be winking at the latter as long as I can assure
them that it is absolutely
visible, temporary, and a hazard to no one. I also have friendly neighbors
with patios on either
side of my patio, and I have thier permission to mount the far side of a
wire on thier balconies.
The balconies are spaced about 20-30 feet apart.

I also have access to the ground outside so that I can mount a discreet
dowel row from the dirt to perhaps a few feet above my balcony, using a
clamp on the balcony to keep it steady on the top side.

My intention is to put the birdfeeder on a dowel rod which I have wound with
#30 white wire and spraypainted with white paint. The dowel rod would be
15-20 feet tall, so a helical for 10-80
meters might make a lot of sense.

Here's the big question: how badly would it hurt the helical's performance
to install it "upside down"? I would have a far easier time putting the
capacity hat on the dirt side and hiding the hat with sand, and then
mounting a 5-15 foot counter poise between balconies.

Thanks in advance,

The Eternal Squire


---
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Old January 25th 04, 10:57 PM
Mikey
 
Posts: n/a
Default

Proximity to earth is going to present some interesting tuning problems for
you, but if you're feeding with a tuner anyway, you should be able to get
past them.

Still, if I had my druthers, I'd prefer to see the capacity hat well above
the physical ground.

73,
Mike KI6PR
El Rancho R.F., CA

"The Eternal Squire" wrote
Hi all,

My wife wants to put up a birdfeeder and I want to put up a hidden

antenna.
My landlords allow
only the former but seem to be winking at the latter as long as I can

assure
them that it is absolutely
visible, temporary, and a hazard to no one. I also have friendly

neighbors
with patios on either
side of my patio, and I have thier permission to mount the far side of a
wire on thier balconies.
The balconies are spaced about 20-30 feet apart.

I also have access to the ground outside so that I can mount a discreet
dowel row from the dirt to perhaps a few feet above my balcony, using a
clamp on the balcony to keep it steady on the top side.

My intention is to put the birdfeeder on a dowel rod which I have wound

with
#30 white wire and spraypainted with white paint. The dowel rod would

be
15-20 feet tall, so a helical for 10-80
meters might make a lot of sense.

Here's the big question: how badly would it hurt the helical's

performance
to install it "upside down"? I would have a far easier time putting the
capacity hat on the dirt side and hiding the hat with sand, and then
mounting a 5-15 foot counter poise between balconies.

Thanks in advance,

The Eternal Squire


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.564 / Virus Database: 356 - Release Date: 1/19/04




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Old January 26th 04, 09:05 PM
Steve Nosko
 
Posts: n/a
Default

Sumptin's wrong wi dis picture, Sir Squire.



If the capacity hat is at the bottom, what will then be at the top? The
counterpoise??



What were you intending to put at the bottom of the "non-inverted" version?
Radials, or just a ground rod?



Is the intended design a ground-plane type vertical (1/4 wave -or rather a
shortened 1/4 wave), or a di-pole (1/2 wave or rather a shortened 1/2 wave -
center or end fed) type?



It would seem to me that the bird house could be a pretty good "capacity
hat" as it would have quite a bit of capacitance to the universe, being a
pretty good volume of conductive material (since you would make sure it is
conductive, that is). Also, I can easily see a "squirrel baffle" right
below the bird house which, being made of metal, makes a pretty good
addition to the "Bird hat".

...Now, the question is, how much de-tuning will the bigger birds have ??....
Stand-by fellas. I have to go out and chase the owl off my antenna to get
the antenna tuned back to the top of the band.


--
Steve N, K,9;d, c. i My email has no u's.



"The Eternal Squire" wrote in message
...
Hi all,

My wife wants to put up a birdfeeder and I want to put up a hidden

antenna.
[...snip...]

My intention is to put the birdfeeder on a dowel rod which I have wound

with
#30 white wire and spraypainted with white paint. The dowel rod would

be
15-20 feet tall, so a helical for 10-80 meters might make a lot of sense.

Here's the big question: how badly would it hurt the helical's

performance
to install it "upside down"? ....
The Eternal Squire



  #4   Report Post  
Old January 27th 04, 08:50 AM
The Eternal Squire
 
Posts: n/a
Default

If the capacity hat is at the bottom, what will then be at the top? The
counterpoise??


Yup.

What were you intending to put at the bottom of the "non-inverted"

version?
Radials, or just a ground rod?


Ground is lousy in Tucson whe
1) There is sand all over the place.
2) I'm on the second floor so my ground wire would radiate anyway.
3) I can't be sure of building grounds.
4) I can't bury my radials. Best to hide them in plain sight as innocent
SWL wires of #30 Kynar, invisible beyond 5 feet.

Therefore, a counterpoise makes better sense for me. Basically:

___
/ \ Birdhouse hides
feedpoint.
| o |
---------------=====--------------- 1/4 Lambda radials disguised as
invisible dipole.
O
O
O Helical wound
around 15 foot "support pole"
O for birdhouse.
O
O
O
-------- Capacity hat buried
in the sand.

Is the intended design a ground-plane type vertical (1/4 wave -or rather a
shortened 1/4 wave), or a di-pole (1/2 wave or rather a shortened 1/2

wave -
center or end fed) type?


The former.


It would seem to me that the bird house could be a pretty good "capacity
hat" as it would have quite a bit of capacitance to the universe, being a
pretty good volume of conductive material (since you would make sure it is
conductive, that is). Also, I can easily see a "squirrel baffle" right
below the bird house which, being made of metal, makes a pretty good
addition to the "Bird hat".


I understand. Fortunately, no squirrels, just pigeons.


..Now, the question is, how much de-tuning will the bigger birds have

??....
Stand-by fellas. I have to go out and chase the owl off my antenna to get
the antenna tuned back to the top of the band.


I doubt for QRP it is going to matter much

I'm more interested in how my radiation pattern is going to be affected
by inverting the vertical, assuming that there would be effectively no
conductive ground below the capacity hat.

The Eternal Squire



--
Steve N, K,9;d, c. i My email has no u's.



"The Eternal Squire" wrote in message
...
Hi all,

My wife wants to put up a birdfeeder and I want to put up a hidden

antenna.
[...snip...]

My intention is to put the birdfeeder on a dowel rod which I have wound

with
#30 white wire and spraypainted with white paint. The dowel rod would

be
15-20 feet tall, so a helical for 10-80 meters might make a lot of

sense.

Here's the big question: how badly would it hurt the helical's

performance
to install it "upside down"? ....
The Eternal Squire





---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.564 / Virus Database: 356 - Release Date: 1/19/04


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Old January 27th 04, 06:28 PM
Steve Nosko
 
Posts: n/a
Default

With great puzzlement Steve attempts a reply ...



"The Eternal Squire" wrote in message
...

If the capacity hat is at the bottom, what will then be at the top? The
counterpoise??


Yup.


But...but. Isn't that BIGGER than the capacity hat? Therefore a BIGGER
problem to hide from the neighbors...?


What were you intending to put at the bottom of the "non-inverted"
version? Radials, or just a ground rod?


Ground is lousy in Tucson whe
1) There is sand all over the place.


OK, now were getting a better picture of your constraints.


2) I'm on the second floor so my ground wire would radiate anyway.


Won't touch the radiating ground wire here.



OK... Second floor out of how many? If you're at the top, can you
put some ("invisibly hidden") wires up over the roof? Along the outside
walls?


3) I can't be sure of building grounds.


That's irrelevant. A building ground is never an antenna ground (except
for special cases). People seem to think there is something special about
the "real ground", but that's another complete subject.

Getting back to the problem @ hand, you need to construct a self contained
antenna (both halves).


4) I can't bury my radials. Best to hide them in plain sight as innocent.


Yea. With some of that invisible paint. Sorry, couldn't help
myself, just being silly.


SWL wires of #30 Kynar, invisible beyond 5 feet.
Therefore, a counterpoise makes better sense for me. Basically:

___
/ \ Birdhouse

hides feedpoint.
| o |
---------------=====--------------- 1/4 Lambda radials disguised as
invisible dipole.
O
O
O Helical wound around 15 foot "support

pole"
O for birdhouse.
O
O
O
-------- Capacity hat

buried in the sand.

Yup. That's the picture I was getting.



But whoa! Hold on there partner. You really seem to be upside down in
your thinking or I been smoking bad stuff... "Buried capacity hat" ...
Yikes! You said above that you can't bury the radials! This is confusing.
You say that you can "bury" a "capacity hat" (relatively small) yet "show" a
radial system (relatively large). I still say you can make the capacity
hat = "disguised as invisible dipole" and put the radials in the sand.
Septin' you said you are on the second floor... Am I bitin' on something I
shouldn't be bitin' on here fellas?



IF "SWL wires of #30 Kynar" are invisible, then how about an "SWL dipole".


It would seem to me that the bird house could be a pretty good "capacity
hat" ......



I understand. Fortunately, no squirrels, just pigeons.




Be creative. Bigger house.... Hey! I just realized you were saying
"bird house" and I was thinking "Bird feeder". Add a Bird house/feeder
combo with a "seed catching tray" for all the "seeds that get knocked off
the feeder". I have birds that intentionally knock seeds to the ground up
here in glacial deposit country (Illinois)!


..Now, the question is, how much de-tuning will the bigger birds have

??....
Stand-by fellas. I have to go out and chase the owl off my antenna to

get
the antenna tuned back to the top of the band.


I doubt for QRP it is going to matter much


The very same amount as with QRO, friend.



How about a nice 9/11 honoring, patriotic "flag pole". Wink, wink, nudge,
nudge.



Whew!...You got more constraints than Carter had pills... Collecting
match book covers is a nice hobby. I have quite a collection I'd be willing
to donate to get you started (and distracted).

Then there's IRLP / EchoLink?

73, Steve
--
Steve N, K,9;d, c. i My email has no u's.. and my brain hurts.




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Old January 28th 04, 01:28 AM
Stephen Cowell
 
Posts: n/a
Default


"Steve Nosko" wrote in message
...
With great puzzlement Steve attempts a reply ...


....

But whoa! Hold on there partner. You really seem to be upside down in
your thinking or I been smoking bad stuff... "Buried capacity hat" ...
Yikes! You said above that you can't bury the radials! This is

confusing.
You say that you can "bury" a "capacity hat" (relatively small) yet "show"

a
radial system (relatively large). I still say you can make the capacity
hat = "disguised as invisible dipole" and put the radials in the sand.
Septin' you said you are on the second floor... Am I bitin' on something

I
shouldn't be bitin' on here fellas?


You can't put the voltage end of an antenna
in the dirt... you're working into a short. It
*has* to be the normal way, since we are talking
about ground here.

Just do the cap hat in wire-wrap wire
like you were going to do the counterpoise...
I see no need to invert the thing.

Not to mention the difficulty in lowering
the antenna every time you add food...
what about the hazard of invisible wires
to birds? Sounds like you're creating
a bird-mangling device.

A pox on all deed restrictions regarding
antennas!
__
Steve
KI5YG
..



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