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Help getting RF out of AL. box

A

amdx

Jan 1, 1970
0
Hi,
I have recently put a cordless phone on my boat. The boat is docked
and I would like the handheld to ring when I'm on the marina.The boat
is all aluminum and limits the distance the phone base will transmit
to the handheld. The distance is down to about 1/3. If it was only
limited to 2/3 of it's normal range I wouldn't have any problem!
I would like to put an antenna outside the boat to get the range up.
Any suggestions on how to couple the signal to an external antenna?
I have a picture on abse with the subjuct "915 Mhz antenna" See the
antenna with the coil, (ignore the short one, the is a 5.8Ghz antenna)
Any chance the antenna is 50ohm and I could remove it, attach a coax
and put the antenna back on the other end? :-/

Mike
 
R

RST Engineering \(jw\)

Jan 1, 1970
0
I'd like to see a picture of an all aluminum boat. I've never seen one
before, other than a rowboat.

Jim
 
J

John Larkin

Jan 1, 1970
0
Hi,
I have recently put a cordless phone on my boat. The boat is docked
and I would like the handheld to ring when I'm on the marina.The boat
is all aluminum and limits the distance the phone base will transmit
to the handheld. The distance is down to about 1/3. If it was only
limited to 2/3 of it's normal range I wouldn't have any problem!
I would like to put an antenna outside the boat to get the range up.
Any suggestions on how to couple the signal to an external antenna?
I have a picture on abse with the subjuct "915 Mhz antenna" See the
antenna with the coil, (ignore the short one, the is a 5.8Ghz antenna)
Any chance the antenna is 50ohm and I could remove it, attach a coax
and put the antenna back on the other end? :-/

Mike

It's common to put an antenna outside an enclosure, run a coax through
the wall, and put another antenna inside, coupling the inside of the
box to the outside world.

So take a hunk of coax and strip back both ends to expose the inner
conductor about a quarter wavelength or so, 10 inches or so maybe.
Hang one end outside and one inside near where you park the telephone.
Grounding the shields might help? That's easy to try, might work,
might well *increase* the range.

In San Francisco we have the Broadway Tunnel. There's a simple
longwire antenna the runs along the ceiling on insulators, then
outside on poles on both ends for a block maybe. It collects RF
outside and re-radiates it inside so radios keep working. You might
even get by with just a piece of solid wire, 20-30 inches long, half
inside and half outside.

John
 
A

amdx

Jan 1, 1970
0
I'd like to see a picture of an all aluminum boat. I've never seen one
before, other than a rowboat.

Jim

The picture has been sent to your email address.

Mike
 
R

RST Engineering \(jw\)

Jan 1, 1970
0
OK, so looking at the picture, why don't you put the phone on a hook on the
window facing the transmitter?

Jim
 
J

Joerg

Jan 1, 1970
0
Hello Jim,
OK, so looking at the picture, why don't you put the phone on a hook on the
window facing the transmitter?

Tried that near our garage. It rang all right but when I turned around
after picking it up, beep, beep, out of range.

Thing is, connecting anything to it would most likely void FCC compliance.

Regards, Joerg
 
A

amdx

Jan 1, 1970
0
Joerg said:
Hello Jim,


Tried that near our garage. It rang all right but when I turned around
after picking it up, beep, beep, out of range.
Yea, I think that is because the base transmits to the handheld on 915Mhz
and the handheld transmits to the base on 5.8Ghz.
 
A

amdx

Jan 1, 1970
0
RST Engineering (jw) said:
OK, so looking at the picture, why don't you put the phone on a hook on the
window facing the transmitter?

Jim
Hi Jim,
Did you even get the pic I sent? I got it bounced back to me!
Anyway, I had the phone right next to the window when I
did the distance test.
I'll try one of John Larkins ideas tommorrow.
 
J

Joerg

Jan 1, 1970
0
Hello Mike,
Yea, I think that is because the base transmits to the handheld on 915Mhz
and the handheld transmits to the base on 5.8Ghz.

Ours transmit spread spectrum on 2.4GHz, set and base. The first one
from Cincinnati Microwave was the best but it also would cut out.

Some houses around here behave like your boat from an RF point of view.
The insulation in the walls is aluminum foil backed and tacked on in an
overlapping fashion.

Regards, Joerg
 
J

Jim Thompson

Jan 1, 1970
0
Hello Mike,


Ours transmit spread spectrum on 2.4GHz, set and base. The first one
from Cincinnati Microwave was the best but it also would cut out.

Some houses around here behave like your boat from an RF point of view.
The insulation in the walls is aluminum foil backed and tacked on in an
overlapping fashion.

Regards, Joerg

My house additionally has wire mesh to hold the stucco. My wireless
pool remote won't work from inside :-(

The antenna inside, coax-thru-wall, antenna outside sounds promising
to me as a passive repeater. I may try that on my garage doors...
with metal doors I presently do better if I remember to press the
button 3-4 houses down the hill from my place.

...Jim Thompson
 
J

Joerg

Jan 1, 1970
0
Hello Jim,
My house additionally has wire mesh to hold the stucco. My wireless
pool remote won't work from inside :-(

If you can hold it so a window is in between instead of a wall it might
work. Directional receiving antennas can also work wonders.

The antenna inside, coax-thru-wall, antenna outside sounds promising
to me as a passive repeater. I may try that on my garage doors...
with metal doors I presently do better if I remember to press the
button 3-4 houses down the hill from my place.

Those often operate at low frequencies, 27MHz or 40 something MHz. The
receiving 'antenna' on our openers is pathetic, a snippet of wire
dangling around. You should be able to route that outside, maybe tack it
onto the header beam above the door.

Regards, Joerg
 
J

John Larkin

Jan 1, 1970
0
My house additionally has wire mesh to hold the stucco. My wireless
pool remote won't work from inside :-(

Stucco is probably OK in your climate. Around here, unless it's modern
stuff with a nice sheet of Tyvek over the wood, it basically
guarantees dry rot underneath.

But, uh, why does a pool need a remote? To prevent it from
accidentally causing exercize?


John
 
K

Keith Williams

Jan 1, 1970
0
Stucco is probably OK in your climate. Around here, unless it's modern
stuff with a nice sheet of Tyvek over the wood, it basically
guarantees dry rot underneath.

But, uh, why does a pool need a remote? To prevent it from
accidentally causing exercize?
When I lived in NY my pool pump was on an X10 system so I didn't
have to crawl under the back porch to turn it on/off. I also had
it set up to cycle automatically to control temperature (daytime if
it was too cold and night time if too warm). Of course, it was
easier to turn it on when it rained all day. Remotes have some
uses. ;-)
 
J

Jim Thompson

Jan 1, 1970
0
On Mon, 26 Dec 2005 19:00:28 -0700, Jim Thompson
[snip]
My house additionally has wire mesh to hold the stucco. My wireless
pool remote won't work from inside :-(

Stucco is probably OK in your climate. Around here, unless it's modern
stuff with a nice sheet of Tyvek over the wood, it basically
guarantees dry rot underneath.

I don't know whether it's "Tyvek" or what, but from stud outwards...
1" fiberboard of some kind, 2" of poly something or other, wire mesh,
then 1/2" stucco. Then insulation batts between studs.

This is the best insulated house I've owned. Larger (+20%) than the
previous one, but with about half the electricity cost.
But, uh, why does a pool need a remote? To prevent it from
accidentally causing exercize?


John

To turn on and warm-up the spa before I dash out the bedroom door nude
and jump in ;-) Once in the spa, to turn the lights up or down, or
adjust the bubbles.

...Jim Thompson
 
J

John Fields

Jan 1, 1970
0
On Mon, 26 Dec 2005 19:32:58 -0800, John Larkin


To turn on and warm-up the spa before I dash out the bedroom door nude
and jump in ;-) Once in the spa, to turn the lights up or down, or
adjust the bubbles.
 
R

RST Engineering \(jw\)

Jan 1, 1970
0
That's all right, Jim. Let's synchronize watches and all jump nude into our
hot tubs at the same time. I go in at 0715 Pacific every morning. Anybody
for a mass nude-in every morning?

Jim
 
J

Jim Thompson

Jan 1, 1970
0
That's all right, Jim. Let's synchronize watches and all jump nude into our
hot tubs at the same time. I go in at 0715 Pacific every morning. Anybody
for a mass nude-in every morning?

Jim

I'm too desert acclimated... it's "cold" in the morning over here ;-)

So I go into the spa about 10 at night.
[snip JF]

...Jim Thompson
 
J

John Larkin

Jan 1, 1970
0
That's all right, Jim. Let's synchronize watches and all jump nude into our
hot tubs at the same time. I go in at 0715 Pacific every morning. Anybody
for a mass nude-in every morning?

Jim

I have one (with a view!) but haven't used it in years. I'm very lazy,
so push most of my serious problems into background, where my loyal,
hard-working subconscious can do the grunt work. The answers are
almost always delivered in the morningshower, so I can't afford to
soak.

John
 
J

Joerg

Jan 1, 1970
0
Hello Spehro,
I find I can adjust the bubbles from a sitting position with no
problem.

But that would be the bubbles in the champagne, wouldn't they?

Regards, Joerg
 
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