nolan@helios.unl.edu (Michael Nolan) (01/28/91)
ho@hoss.unl.edu (Tiny Bubbles...) writes: >1. Are flexible antennas any good? They sell them for ten bucks or > so at the local discount store (genuine AT&T), but they're pretty > short compared to the "whip" that comes with it. Do they work as > well as the whip? (Too bad they can't retract.) I personally prefer the flexible antennas, as opposed to the three foot extendible/breakable monsters. Part of this is using them in places like lying down in bed, when the antenna kinda gets in the way, and the fact that I've replaced two or three of the others because my younger son busted them by bending them too fast. Can't say I've noticed much difference in signal strength between the two thpes, either. >2. Without divulging anything nasty, how secure is the security code? > Are voice transmissions scrambled by the key, or is it just the > dialing codes? I ask because recent rulings say that monitoring > a radio broadcast from a cordless phone is not a "wiretap," and I > wonder if my phone is safe. That's a big consideration for me, and > it's one of the reasons I buy AT&T cordless phones. My understanding is that the 'security code' only affects the recognition of a 'ring' signal, so that someone calling your phone doesn't ring your neighbor, even if they are on the same channel. It does NOT scramble your phone call in any way. This is based on a fairly thorough perusing of the manuals and the fact that scrambling/descrambling chips are still a little pricey for phones in the under $200 range. The cheapest cordless phone I've seen that offered scrambling was something like $500. (Don't remember where I saw it, somewhere like Sharper Image.) BTW, I've had several cordless phones, and have had VERY good luck with the higher priced Panasonic phones, especially the ten channel model. (I missed the original posting, but get the impression it slammed Panasonic.) I've not had much good luck with Sony cordless phones, though. Michael Nolan
rborow@bcm1a09.attmail.com (01/29/91)
Michael Ho had queried about flexible antennas for cordless
phones. I, too, have seen them. My father has one on his Panasonic
two-line cordless, and let me tell you that phone has way too many
static problems! I don't know if it's the antenna or the phone itself
(methinks it's the combination of both); nevertheless, the clarity
leaves much to be desired.
Basically, the question of flexible antennas is a matter of
personal preference. I am not a technician, nor do I admit to having
much knowledge of this realm of telecommunications; however, most of
the people whom I know prefer the regular, metal, retractable
antennas.
Re: AT&T's security code for its cordless phones: the higher
model numbers (5300, 5400, 5500 series, etc.) have many more security
channels available. From what I know, these models scramble a security
code every time you put the phone in its base or hang up. I have never
been the victim of mysterious calls (even when I had AT&T's atrocious
4000 series cordless phones), nor have I ever known anyone who
experienced this problem. Anyone out there ever been the victim, or
know someone who has been a victim, of such? I'm curious to know.
BTW, one unrelated item of interest: several issues ago, our
esteemed Moderator explained about Illinois Bell's accomplishments
(first in....., etc.). I would just like to give credit where credit
is due. We all, including myself, too often complain about telcos:
their reps, policies, etc. While I sometimes wish Illinois Bell would
do this or that differently, I commend their people with whom I have
dealt. I continue to be amazed at their technological advancements,
accomplishments, nifty little telecommunications toys (Caller ID, auto
ringback, call screening, etc.). One problem, though: I wish in my
home area all this stuff was available. It seems like in Pat's it
already is up and running. So far, all we have of the new stuff is
distinctive ringing. I can't wait for the Caller ID, ringback, and
screening. My harassing calls are getting more than annoying.
Randy Borow
Rolling Meadows, IL.
[Moderator's Note: Several years ago I knew someone whose idea of a
good time on Saturday night was to take a cordless handset and go out
'cruising for dial tone'. He'd drive around in his car and whenever
dial tone was heard he'd stop and make a call or two. Real upstanding
character. Regards CLASS in 708/312: It was just about two months ago
that we were able to order *some* features. I have Call Screening and
for all I know may still be the only subscriber or one of the few in
the Chicago-Rogers Park office to have it. The business office is
still not actively marketing it. About 70-80 percent of 312 is now
equipped, and a somewhat smaller percentage of 708. Just keep asking
for it. :) PAT]barefoot@hobbes.ncsu.edu (Heath Roberts) (01/29/91)
In article <16478@accuvax.nwu.edu> ho@hoss.unl.edu (Tiny Bubbles...) writes: >1. Are flexible antennas any good? They sell them for ten bucks or > so at the local discount store (genuine AT&T), but they're pretty > short compared to the "whip" that comes with it. Do they work as > well as the whip? (Too bad they can't retract.) They have less range than the telescoping antennas, but still work very well. I have one and only notice a difference at the edges of reception. Sound quality is still excellent. >2. Without divulging anything nasty, how secure is the security code? > Are voice transmissions scrambled by the key, or is it just the > dialing codes? I ask because recent rulings say that monitoring > a radio broadcast from a cordless phone is not a "wiretap," and I > wonder if my phone is safe. That's a big consideration for me, and > it's one of the reasons I buy AT&T cordless phones. If you want encrypted audio, start looking for digital transmission. You could maybe get a couple of Motorola walkie-talkies with their DES scrambling module (this'd work great for cordless telephone -- good sound, three or four mile range w/o a repeater....) but that'll run you about $1K per radio, plus the security modules. I don't think you'll find any consumer telephone on the market that actually has secure communications. AT&T's security simply sets a key number in the base and handset each time they're mated, which prevents someone sitting outside your house from using your telephone line with another handset. Cordless conversations are definitely legal to receive (cellular too, but law enforcement can't use information from cell telephones without a warrant). Heath Roberts NCSU Computer and Technologies Theme Program barefoot@catt.ncsu.edu
jlangri@relay.nswc.navy.mil (01/29/91)
Keep in mind that flexible antennas are a "compromise". You have to give a little to get a lot. Replacing whip rod antennas can get expensive ... but I keep one for fringe areas.
schwartz@uunet.uu.net (S. H. Schwartz) (01/30/91)
In article <16490@accuvax.nwu.edu> is written: >My understanding is that the 'security code' only affects the >recognition of a 'ring' signal, so that someone calling your phone >doesn't ring your neighbor, even if they are on the same channel. I thought the security code affected call-OUT, i.e. prevent someone with a portable handset from calling out through your base unit and your paying for his calls. S. H. Schwartz schwartz@nynexst.com Expert Systems Laboratory 914-683-2960 NYNEX Science and Technology Center White Plains NY 10604
jta@hydra.jpl.nasa.gov (Jon T. Adams) (01/30/91)
Somebody named "Tiny Bubbles" queries: > 1. Are flexible antennas any good? They sell them for ten bucks or > so at the local discount store (genuine AT&T), but they're pretty > short compared to the "whip" that comes with it. Do they work as > well as the whip? (Too bad they can't retract.) For the most part, the current rash of portable phones that use the 46MHz/ 49MHz spectrum will not work quite as well using a rubber duck. Capture area is what generally makes an antenna and using a physically smaller antenna does reduce the capture area. However, since you are dealing with a hand-held radio which is a decidedly non-optimal environment for RF propagation especially at around 50MHz, you will be happier choosing personal convenience rather than efficiency. In other words, if I was regularly breaking the metal whip antennas (or had an urchin that did) I would opt for the flexible antenna. Also consider moving the base unit to a better location, higher up (get it off the floor), etc. > 2. Without divulging anything nasty, how secure is the security code? > Are voice transmissions scrambled by the key, or is it just the > dialing codes? I ask because recent rulings say that monitoring > a radio broadcast from a cordless phone is not a "wiretap," and I > wonder if my phone is safe. That's a big consideration for me, and > it's one of the reasons I buy AT&T cordless phones. The security codes vary in their sophistication; but all concern themselves only with protection from some other person using your phone line and/or your handset ringing when someone else locally receives a call. None do any kind of voice encryption. Nothing you say on a portable telephone (different only by politics from a "cellular" telephone) is legally protected from eavesdropping. In fact, anyone with a 46 to 49MHz radio receiver / scanner (available at Radio Shack and anywhere else) can pick up your conversations. The police can enter anything heard there as evidence in court. But it's fairly boring eavesdropping, at least in MY neighborhood... Eventually, if enough people complain that their "rights" are being violated by this loophole, well maybe Congress'll just pass another law, forbidding anyone from listening, just like up in the cellular telephone spectrum. Or, with the same likelihood of a snowball lasting fifteen minutes in Hell, maybe some smart manufacturer will come out with a great new phone and some reasonable encryption system using spread-spectrum stuff and will make this fact pointedly known through worldwide advertising. There's still room for entreprenuers. But they are darned handy things to have. Plantronics makes one (or more likely, MADE one, since DAK now sells it for 59.95) that clips on your belt, has a tone pad for dialout, and a featherlight earphone/mic that just fits in your ear. Great for when you're working around the house. Have fun! jon
Jim.Redelfs@iugate.unomaha.edu (Jim Redelfs) (02/10/91)
On 30-JAN-91, Robert Savery wrote: > All the security code does is keep nefarious types from using another > handset to outdial on your line. It in no way stops someone from > listening in on your conversations. > An AT&T phone is no "safer" than one of the el-cheepos. True ... but at least you'll SOUND better to the listeners! :) JR Copernicus V1.02 Elkhorn, NE [200:5010/666.14] (200:5010/2.14) [Moderator's Note: Maybe or maybe not. There was a sort of 'Pepsi challenge'-like contest a few years ago where people recieved calls placed from various models of cordless phones including AT&T. All were placed under the same conditions; same distance from base, etc. They were to identify one model of cordless phone from another. Most of the people could not identify the specific phone being used and about half the people could perceive no difference in quality. Radios are radios are radios. There are too many variables involved to firmly place the blame or good points with any one model. PAT]
Tad.Cook@cs.washington.edu (02/10/91)
In article <16506@accuvax.nwu.edu>, barefoot@hobbes.ncsu.edu (Heath Roberts) writes: > Cordless conversations are definitely legal to > receive (cellular too, but law enforcement can't use information from > cell telephones without a warrant). When did it become legal to monitor cellular phone calls? I know that cordless phones are legal, but I thought the Electronic Communications Privacy Act put this in the same class as wiretapping. Tad Cook Seattle, WA Packet: KT7H @ N7ENT.#WWA.WA.USA.NA Phone: 206/527-4089 MCI Mail: 3288544 Telex: 6503288544 MCI UW USENET:...uw-beaver!sumax!amc-gw!ssc!tad or, t ad@ssc.UUCP
mjkobb@media-lab.media.mit.edu (Michael J Kobb) (02/10/91)
In article <16490@accuvax.nwu.edu> nolan@helios.unl.edu writes: >ho@hoss.unl.edu (Tiny Bubbles...) writes: >>1. Are flexible antennas any good? They sell them for ten bucks or >> so at the local discount store (genuine AT&T), but they're pretty >> short compared to the "whip" that comes with it. Do they work as >> well as the whip? (Too bad they can't retract.) >I personally prefer the flexible antennas, as opposed to the three >foot extendible/breakable monsters. >BTW, I've had several cordless phones, and have had VERY good luck >with the higher priced Panasonic phones, especially the ten channel >model. (I missed the original posting, but get the impression it >slammed Panasonic.) I've not had much good luck with Sony cordless >phones, though. This is interesting, since it's 180 degrees away from my experience. I recently purchased a Sony SPP-120 cordless. Actually, I bought three cordless phones: the Sony, a Panasonic KX-T4000 (the one reminiscent of a StarTrek communicator), and a Panasonic KX-T3620. I bought these phones from a place with a thirty-day trial period, so I could pick the one I wanted to keep. All these phones have flexible antennas and ten channels. I recently moved into an apartment building, and the apartment was big enough to justify the cordless. The KX-T4000 was a catastrophe. Seven or eight times out of ten, I couldn't even get a dial tone. The phone would just beep at me in it's "I can't connect to the base unit" mode. This happened even with the phone directly next to the base. The KX-T3620 was more successful. It always linked up with the base, but I experienced pretty bad static problems with it (some of which I associate with the dinky antenna). Otherwise, I really like the phone (my standard phone is a Panasonic, and I've always liked it, too). The Sony was the clear winner. I get zero static most of the time, and its reception is good enough that I can walk down the exterior hall towards the elevator and still carry on a conversation (although there's a bit of static then). It works fine on my balcony. I attibute this success to the unit's nine-inch helical antenna, and the base unit's two foot antenna. A also like the Sony's battery systems. First, the handset has a one week standby / twelve hour talk endurance. Second, there's a second battery which is maintained charged in the base, so that the phone never need be without battery power to recharge. The base battery also acts as backup power for the base unit, in the event of an AC power failure. My only complaint is the sound quality. It has something of a "walkie-talkie" feel, like the microphone is too sensitive. Here's the question: I kept the Sony, and am quite happy with it. I do have one question, though: the display at the store claimed that it had 1,000,000 security codes, but there are no DIP switches (contrary what a previous poster claimed to have found on his SPP-120) or any mention in the manual of how to set them. Does the code come from the factory, unique to each phone? Or, does the phone pick a new one every time you hang up? (The latter seems unlikely, since the handset doesn't have a cradle, so I don't know how the phone could possibly recover if the code were somehow scrambled). Thanks, Mike
lemson@ux1.cso.uiuc.edu (David Lemson) (02/11/91)
Jim.Redelfs@iugate.unomaha.edu (Jim Redelfs) writes: >On 30-JAN-91, Robert Savery wrote: >> An AT&T phone is no "safer" than one of the el-cheepos. >True ... but at least you'll SOUND better to the listeners! :) >[Moderator's Note: Maybe or maybe not. There was a sort of >'Pepsi challenge'-like contest a few years ago where people recieved >calls placed from various models of cordless phones including AT&T. >All were placed under the same conditions; same distance from base, >etc. They were to identify one model of cordless phone from another. >Most of the people could not identify the specific phone being used >and about half the people could perceive no difference in quality. >Radios are radios are radios. There are too many variables involved to >firmly place the blame or good points with any one model. PAT] Another problem with a challenge like this is that it tests the transmission from the handset to the base only. If I'm not mistaken (and I'm sure people will be quite rapid to tell me if I'm not), the base unit does a much better job receiving the handset than vice versa due to its much better antenna. Also, I believe that some models (or was this just the earlier ones?) use the ground wire of the AC as an antenna to pick up the handheld unit. Whether or not this is technically true, I know from personal experience with about five different types of cordless phones that there is always much less static on the way from handset to base than base to handset. This once allowed me to receive a call next door, pick it up, hear nothing by static on my end, and tell the caller to hold on while I crossed over to my own house. He reported no static the whole time. David Lemson U of Illinois Computing Services Student Consultant Internet : lemson@ux1.cso.uiuc.edu University of Illinois, Urbana