Cordless Phone Linear

This is the place for any magazine-related discussions that don't fit in any of the column discussion boards below.
JdOwNj
Posts: 95
Joined: Thu Dec 06, 2001 1:01 am
Location: Garland, Maine
Contact:

Re: Cordless Phone Linear

Post by JdOwNj » Wed Jan 16, 2002 4:51 am

I suppose you could work on the antennas at both ends... the fcc doesnt say ANYTHING about how good a reciever can be... i dont know about five miles but i dont see why one mile would be a prob... If you go ahead with any project make sure it is properly filtered... neighbors call fcc when their tv picks up your phone convo... mebbe somebody here can help you make a better antenna/reciever amp... a better antenna that will transmit farther with the same power shouldnt be hard to build

Dean Huster
Posts: 1263
Joined: Wed Dec 05, 2001 1:01 am
Location: Harviell, MO (Poplar Bluff area)
Contact:

Re: Cordless Phone Linear

Post by Dean Huster » Wed Jan 16, 2002 8:59 am

Locating the base unit as high in the house as you can will help coverage, especially if you have a multi-story house, wood frame vs. metal, etc. If you have a charger separate from the base unit so that you can put the base unit in the attic, so much the better. You'll just have to momentarily replace the handset to the base if you ever let the battery die or you get a power hit so that the phone and base can "reintroduce" themselves to each other.<p>Although the phones are frequency agile, the problem with kicking up power is that your tranmitter may cause all-band interference and overloading to nearby phones, putting them out of business. When you start disrupting communications, the neighbors get hacked off and the FCC gets interested.<p>You MIGHT have worked some CB skip on 5 watts in favorable conditions, but in general, a ham radio operator with a little 15-watt transceiver on the adjacent 10 meter band can routinely make contact between Singapore and Oklahoma while the CBer with his full illegal keg can barely make it across some state lines. And it all has to do with that magic signal-to-noise ratio.
Dean Huster, Electronics Curmudgeon
Contributing Editor emeritus, "Q & A", of the former "Poptronics" magazine (formerly "Popular Electronics" and "Electronics Now" magazines).

R.I.P.

User avatar
Chris Smith
Posts: 4325
Joined: Tue Dec 04, 2001 1:01 am
Location: Bieber Ca.

Re: Cordless Phone Linear

Post by Chris Smith » Wed Jan 16, 2002 1:59 pm

You cant, and Terra Htz? I think you mean Gig. A couple of watts is what sets the white vans running. They dont wait for complaints, and like Afganistan, They monitor everything. Hit and Run and you'll get away with it. They still wait on over passes and pick off the clone phones, every day of the year. Big brother has grown, Real Big. The best you could hope for is to TOY with them.

toejam
Posts: 253
Joined: Wed Dec 05, 2001 1:01 am
Location: n.c.
Contact:

Re: Cordless Phone Linear

Post by toejam » Wed Jan 16, 2002 7:38 pm

to legaly do that you must first examine and analyze all the fcc regulations pertaining to the alloted power and frequency deviation in the particular frequency band you wish to operate in.After you have determined the parameters you wish to operate in spend enough time educating yourself on how to design filter networks and rf amplifers.I doubt you will recieve much help from anyone here but you might take some of the thirty grand you made and hire an engineer compitent in that field you might get a few weeks of his time.

HomeBrew
Posts: 41
Joined: Fri Jan 18, 2002 1:01 am
Location: Tenn.
Contact:

Re: Cordless Phone Linear

Post by HomeBrew » Fri Jan 18, 2002 1:09 am

As far as CB is concerned, I've been in the business for 30 years and you can easily make contacts at distances of hundreds of miles with only three watts,which was all that was legal back in the 60's when I first used CB. We didn,t use skip, it was just ground wave communication when the skip was out. Aside from that, I don't think it would be worth your while to try to beef up a cordless phone because of the expense of components and problems you would have trying to drive it with the flea power most phones have. Have you looked into the "spread spec." phones ? Some of them claim to have a range of at least five miles !!

HomeBrew
Posts: 41
Joined: Fri Jan 18, 2002 1:01 am
Location: Tenn.
Contact:

Re: Cordless Phone Linear

Post by HomeBrew » Fri Jan 18, 2002 1:15 am

Just noticed you said you were using a DSS phone. There are linear amps for sale surplus for cell phone use that might cover your frequency requirments. I have seen some of them listed in N&V from time to time. Still, you may not have the drive required to get full output.

User avatar
frhrwa
Posts: 897
Joined: Mon Feb 04, 2002 1:01 am
Location: Eastern Washington (state) and N. Las Vegas (winter)
Contact:

Re: Cordless Phone Linear

Post by frhrwa » Mon Feb 04, 2002 3:54 pm

yes they will notice the slight modification to your power output.. not because your getting your 5 miles of service without paying for it, but because you'll be walking all over someone elses legal signal... and that will eventually lead to a complaint, which WILL bring the FCC cruising down your street... ever do anything legal?
JESUS”…… don’t leave EARTH without HIM!

IHateTTL
Posts: 1
Joined: Tue Mar 12, 2002 1:01 am
Contact:

Re: Cordless Phone Linear

Post by IHateTTL » Tue Mar 12, 2002 11:42 pm

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by keymaker:
Here's a question without answer. How can I LEGALLY make my cordless phone go 5 miles?<hr></blockquote><p>Launch it from a cannon.

unknown_entity
Posts: 98
Joined: Thu Dec 06, 2001 1:01 am
Location: ohio
Contact:

Re: Cordless Phone Linear

Post by unknown_entity » Wed Mar 13, 2002 4:06 pm

actually in this months magazine there is an ad for just such a thing, I think it said the range was 5 miles. it's towards the bottom of pg33 www.futurehorizons.netis their website<p>[ March 13, 2002: Message edited by: unknown_entity ]</p>

unknown_entity
Posts: 98
Joined: Thu Dec 06, 2001 1:01 am
Location: ohio
Contact:

Re: Cordless Phone Linear

Post by unknown_entity » Wed Mar 13, 2002 4:20 pm

I really don't know much about radios but the FCC trying to bust people for CB power boosters and and cordless boosters they sound like radio nazis or something. But i have heard of people getting some pretty big fines and their equipment taken for destructive interference like tesla coils and stuff like that.

Vince
Posts: 2
Joined: Tue Mar 19, 2002 1:01 am
Contact:

Re: Cordless Phone Linear

Post by Vince » Tue Mar 19, 2002 8:43 pm

This isn't simply a question of what's legal (can't use more than default in the band the phone is designed for) or how many watts or what kind of distance. Let's ignore the legalities and plunge ahead.<p>RF signal propogation is dependant on frequency and strength of signal. Some frequency bands (>300mHz) will simply penetrate ionospheric layers in most cases and will not bounce off of them. I, too, had excellent contacts with 100mW (.1W) on 11m with ranges upwards to 40 miles. Did a few thousand on 5W. These kind of rules won't work well >300mHz.<p>49 mHz is a different animal. It will bounce off of ionospheric layers depending on the time of day, etc. However, if you get a bounce, you will also be skipping over ground coverage and will experience a blackout area of sorts.<p>You would need to boost the signal in both directions. While I'm not overly familiar with the nature of cordless phones, I do believe they duplex the signal. Base station is out on one freq and the handset is out on the other freq. Ergo, you'd have to boost the signal in both directions... unless you are only travelling in one direction away from home then a directional antenna such as a yagi could work without boosting.<p>Bon apetit.

keymaker
Posts: 214
Joined: Mon Jan 14, 2002 1:01 am
Contact:

Re: Cordless Phone Linear

Post by keymaker » Thu Apr 18, 2002 2:22 am

Wow
Yea
Duplex
In the back of my mind I always said to myself, How in the hell will it work if the handset aint modified<p>I don't want that much power by my head...<p>I would go with an antenna up on the car<p>
The ionisphere... Is that the thing in space that we can only use for 10 years, then it aint there 10 years, then we can use it 10 more years???<p>How can I easily use my landline 5-10 miles from my house, without getting busted or buying $1000 worth of wire and a spool?<p> :D :D

Post Reply

Who is online

Users browsing this forum: No registered users and 12 guests