How get RF through a sealed window?
 

I gave a presentation on "How Ham Radio Can Help You in an Emergency"
to 70 Emergency Management types last week, and the windows in the
building which hosted the meeting were NOT open-able (so I "made do"
with an inside VHF antenna and didn't even try to demonstrate HF).

But in emergency/expedient situations, it would be really handy if one
could pass at HF, say, 100 watts of RF energy through a window (I
visualize some foil strips and an inductor or two to "tune out" the
capacitance) to an external antenna.

I've been told that the April, 1989, issue of Ham Radio magazine carried
an article "Easy antenna access for urban apartment dwellers" (for 15
meters) by Bryan Bergeron, NU1N, starting on page 18.

I'd sure like to read that article; can anyone send me a copy?
--
--Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

How get RF through a sealed window?
 

wrote in message ...
But in emergency/expedient situations, it would be really handy if one
could pass at HF, say, 100 watts of RF energy through a window (I
visualize some foil strips and an inductor or two to "tune out" the
capacitance) to an external antenna.

In an emergency I'd say... uh... just leave the window open? :-)

Over on eHam.net there's a recent article on building yourself a simple
rectangular wooden panel to stick in the frame of an (open) window. You then
just drive holes in the panel as needed to run cables, etc. I've even seen
people who didn't have, e.g., a drill or jigsaw do the same thing using a
thick-ish chunk of stiff foam (insulation material or even presentation poster
board) and an X-acto knife.

How get RF through a sealed window?
 

"Joel Kolstad" writes:
wrote in message ...
But in emergency/expedient situations, it would be really handy if one
could pass at HF, say, 100 watts of RF energy through a window (I
visualize some foil strips and an inductor or two to "tune out" the
capacitance) to an external antenna.

In an emergency I'd say... uh... just leave the window open? :-)

But be sure to bring a hefty brick along to create the opening in the first
place :)

The OP's dilema was that the window COULD NOT open, and therefore some
way to pass RF through glass would have been Useful.

-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
Lawrence Statton - m s/aba/c/g
Computer software consists of only two components: ones and
zeros, in roughly equal proportions. All that is required is to
sort them into the correct order.

How get RF through a sealed window?
 

wrote:
But in emergency/expedient situations, it would be really handy if one
could pass at HF, say, 100 watts of RF energy through a window (I
visualize some foil strips and an inductor or two to "tune out" the
capacitance) to an external antenna.

What I have done is plan ahead by drilling two small holes in the glass
and plugging them with nylon screws when not in use. That works best
on the first floor. :-)
--
73, Cecil, W5DXP

How get RF through a sealed window?
 

You'd have better luck with HF than VHF or UHF making it through any solid
object. I have used a homebrew mag loop in a hotel room on several
ocassions with some luck..on 20 and 40.

I have a 40m dipole in my attic, and I runn less than 5w HF most of the time
and I have WAS on several ocassions, I try to WAS every year.

73

--
=========================================
Radio Amateurs - Fill your junk box, from my junkbox!
http://www.hamradparts.com
73 de KB9BVN
=========================================


wrote in message ...
I gave a presentation on "How Ham Radio Can Help You in an Emergency"
to 70 Emergency Management types last week, and the windows in the
building which hosted the meeting were NOT open-able (so I "made do"
with an inside VHF antenna and didn't even try to demonstrate HF).

But in emergency/expedient situations, it would be really handy if one
could pass at HF, say, 100 watts of RF energy through a window (I
visualize some foil strips and an inductor or two to "tune out" the
capacitance) to an external antenna.

I've been told that the April, 1989, issue of Ham Radio magazine carried
an article "Easy antenna access for urban apartment dwellers" (for 15
meters) by Bryan Bergeron, NU1N, starting on page 18.

I'd sure like to read that article; can anyone send me a copy?
--
--Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and
cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785)
539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle,
Pistol)

How get RF through a sealed window?
 

In article -did-not-set--mail-host-address--so-shoot-me,
Lawrence Statton N1GAK/XE1 wrote:

But be sure to bring a hefty brick along to create the opening in the first
place :)

The OP's dilema was that the window COULD NOT open, and therefore some
way to pass RF through glass would have been Useful.

A lot of modern buildings have glass windows which not only cannot be
opened, but which have a "low-E" (low thermal emission) coating on the
glass. This is (I believe) a very thin layer of vapor-deposited
metal.

Its RF attenuation is considerable. Some years ago, we had our house
windows (1960s-era glass) replaced with new ones using a low-E-coated
glass. A previously-workable signal path for 802.11 signals, which
got to the back of the house from an access point in the garage by
going through the garage door and a couple of exterior windows,
suddently became quite unusable - I had to install an additional
access point to cover that part of the house.

The more obviously shaded or reflective the glass, the more of a
problem for RF transmission or coupling this stuff is likely to present.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

How get RF through a sealed window?
 

But in emergency/expedient situations, it would be really handy if one
could pass at HF, say, 100 watts of RF energy through a window ....

Over on eHam.net there's a recent article on building yourself a simple
rectangular wooden panel to stick in the frame of an (open) window. You then
just drive holes in the panel as needed to run cables, etc....

I can just see me now:
* Drive to the High-n-Mighty Hotel where I'm to provide communications
for the Red Cross (or Salvation Army) shelter
* Ask the desk clerk for someone to help me carry my sledgehammer and
other stuff in my grab-n-go kit to the shelter
* Walk into shelter where x-hundred shelterees are fast asleep
* Take sledgehammer and bash a hole through a window
* ....

Nope, that's just not gonna work!

--
--Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

How get RF through a sealed window?
 

You'd have better luck with HF than VHF or UHF making it through any solid
object. I have used a homebrew mag loop in a hotel room on several
ocassions with some luck..on 20 and 40.

Even in an emergency situation, I just don't think it would be a good idea
to string some kind of an antenna above the heads of shelterees and then
start soaking them with RF, especially depending on the HF frequency in
use. In fact, I suspect the FCC's RF-exposure regulations would frown on
one doing so!

--
--Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

How get RF through a sealed window?
 

"Lawrence Statton N1GAK/XE1" wrote in message
-did-not-set--mail-host-address--so-shoot-me...
The OP's dilema was that the window COULD NOT open, and therefore some
way to pass RF through glass would have been Useful.

Oops, sorry I missed that!

How get RF through a sealed window?