Help getting RF out of AL. box

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

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

-- Peter Bennett, VE7CEI peterbb4 (at) interchange.ubc.ca new newsgroup users info :

GPS and NMEA info: Vancouver Power Squadron:

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

Jim

The picture has been sent to your email address.

Mike

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

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
"Winners never quit, quitters never win", Jack Bradley Budnik ~1956

the

Yea, I think that is because the base transmits to the handheld on 915Mhz and the handheld transmits to the base on 5.8Ghz.

the

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.

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

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.

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

Regards, Joerg

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

Hello Jim,

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.

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

[snip]

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.

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

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
"Winners never quit, quitters never win", Jack Bradley Budnik ~1956

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

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. ;-)

--
  Keith

--
Now there\'s a visual I\'d been just as happy not to have read... Ugh!

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

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
"Winners never quit, quitters never win", Jack Bradley Budnik ~1956

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

Slu-u-u-u-urp ;-)

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | |

| 1962 | "Winners never quit, quitters never win", Jack Bradley Budnik ~1956