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Design Flaw in iPhone 4, Testers Say
http://www.nytimes.com/2010/07/13/te...apple.html?hpw "Consumer Reports, America’s trusted source of product reviews, said it would not recommend the iPhone 4 because of a hardware flaw with its antenna that sometimes resulted in dropped calls. "... its antenna, which is built into a steel band that encases the phone. "After users reported problems with signal strength and dropped calls when they touched the lower-left portion of the phone, however, Apple suggested that consumers hold the phone differently or use one of many bumpers to insulate the antenna. It also said that all phones suffered from similar problems when they were cradled a certain way. "These comments were widely laughed at in gadget blogs. " Just thought I would submit this to the Laughing Academy. 73's Richard Clark, KB7QHC |
Design Flaw in iPhone 4, Testers Say
On 7/12/2010 8:30 PM, Richard Clark wrote:
http://www.nytimes.com/2010/07/13/te...apple.html?hpw "Consumer Reports, America’s trusted source of product reviews, said it would not recommend the iPhone 4 because of a hardware flaw with its antenna that sometimes resulted in dropped calls. "... its antenna, which is built into a steel band that encases the phone. "After users reported problems with signal strength and dropped calls when they touched the lower-left portion of the phone, however, Apple suggested that consumers hold the phone differently or use one of many bumpers to insulate the antenna. It also said that all phones suffered from similar problems when they were cradled a certain way. "These comments were widely laughed at in gadget blogs." Just thought I would submit this to the Laughing Academy. 73's Richard Clark, KB7QHC I can't tell from your comments if you think there is a problem with the phone or Consumer Reports. From what I've heard there are repeatable problems, but I've heard no coherent explanation of what might be occurring. The thing that seems to be consistent is that left handed users have more reported problems than right handed users. tom K0TAR |
Design Flaw in iPhone 4, Testers Say
On Mon, 12 Jul 2010 21:19:06 -0500, tom wrote:
On 7/12/2010 8:30 PM, Richard Clark wrote: http://www.nytimes.com/2010/07/13/te...apple.html?hpw "Consumer Reports, America’s trusted source of product reviews, said it would not recommend the iPhone 4 because of a hardware flaw with its antenna that sometimes resulted in dropped calls. "... its antenna, which is built into a steel band that encases the phone. "After users reported problems with signal strength and dropped calls when they touched the lower-left portion of the phone, however, Apple suggested that consumers hold the phone differently or use one of many bumpers to insulate the antenna. It also said that all phones suffered from similar problems when they were cradled a certain way. "These comments were widely laughed at in gadget blogs." Just thought I would submit this to the Laughing Academy. 73's Richard Clark, KB7QHC I can't tell from your comments if you think there is a problem with the phone or Consumer Reports. Hi Tom, By any account, there's a problem. Now, as the iPhone has had demonstrable connection issues in the past, it was blamed on AT&T who bore the brunt of that criticism. Reports long following this past connection problem has borne out that AT&T had adequate 3G capacity, and AT&T chose to take the bullet for their customer (Apple, if anyone has lost track) who had a marginal design in their protocol stack (poor through-put and high retry traffic). From what I've heard there are repeatable problems, but I've heard no coherent explanation of what might be occurring. The NYT article's symptomology bears out across many reports from a variety of sources. The thing that seems to be consistent is that left handed users have more reported problems than right handed users. That would be apocryphal, at best. The short answer is that fashion trumps technology. The rising trend of using the iPhone as an eReader flies in the face of what was formerly a nebbish activity. Fashion forced the turnaround, not the technology (I've been reading books on my Palm Pilot for 6 years - I have not suddenly become an über-hip literary savant overnight by virtue of that trend as anyone here will quickly testify.) The only thing that remains a mystery, for me if for no one else here, is the literal specification of the antenna. Google (gasp) fails me. 73's Richard Clark, KB7QHC |
Design Flaw in iPhone 4, Testers Say
On 7/12/2010 9:46 PM, Richard Clark wrote:
The only thing that remains a mystery, for me if for no one else here, is the literal specification of the antenna. Google (gasp) fails me. 73's Richard Clark, KB7QHC And that does seem to be the crux of the matter. What is the antenna? And what does it interact with that's not, be it part of the phone or part of the user? tom K0TAR |
Design Flaw in iPhone 4, Testers Say
On Mon, 12 Jul 2010 21:54:17 -0500, tom wrote:
On 7/12/2010 9:46 PM, Richard Clark wrote: The only thing that remains a mystery, for me if for no one else here, is the literal specification of the antenna. Google (gasp) fails me. 73's Richard Clark, KB7QHC And that does seem to be the crux of the matter. What is the antenna? And what does it interact with that's not, be it part of the phone or part of the user? Hi Tom, The antenna is reported as being the metal trim that surrounds the perimeter of the phone. As that is much too large for the frequencies involved to be taken literally, there is more to the story that remains clouded. Maybe I'm wrong.... If the loop (or dipole) is suitably matched, it doesn't give much polarization diversity. Perhaps no phone does anyway. Insofar as being "part of the user," we well know the EM of HTs and the hand/body contribution. If such were the case, then this would be an agnostic problem that users of all mobile phones would complain of (which mildly refutes what the gadget blogs dismissed). On the other hand, the über-hip, whose complaints are more vocal for their "pain," would be outraged at the notion of their simply enjoying the identical experience of techno-trash. Amazing what a 10 fold cost differential brings to your perception of quality of service. 73's Richard Clark, KB7QHC |
Design Flaw in iPhone 4, Testers Say
In article ,
tom wrote: From what I've heard there are repeatable problems, but I've heard no coherent explanation of what might be occurring. The thing that seems to be consistent is that left handed users have more reported problems than right handed users. A drawing of the iPhone 4 I saw recently (I think it was in a recent SJ Mercury News) indicates that there is a deliberate gap in the metal rim of the iPhone 4 - the rim that serves as the antenna. This gap is located near the lower left corner of the phone. If I understand correctly, the iPhone 4 has a tendency to drop calls if it's held in a way which allows the user's hand to bridge across this gap... presumably "short-circuiting" the antenna in some way. A left-handed grip on the phone would put the user's palm right across the gap - this may be the worst-case situation. Applying an insulation of some sort to the area of this gap (an iPhone case, or duct tape), or holding it in a way which doesn't cause the hand to bridge the gap, reduces or eliminates the problem. It sounds as if this iPhone has some sort of dipole or loop antenna design, which requires that a high RF impedance be maintained at this point. The low RF impedance of human skin is apparently enough to de-tune or load the antenna in some way which disrupts its function. Has anyone run across a web site showing a "tear-down" of the iPhone 4, which might clarify its antenna design? -- Dave Platt AE6EO Friends of 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! |
Design Flaw in iPhone 4, Testers Say
In article ,
tom wrote: On 7/12/2010 9:46 PM, Richard Clark wrote: The only thing that remains a mystery, for me if for no one else here, is the literal specification of the antenna. Google (gasp) fails me. 73's Richard Clark, KB7QHC And that does seem to be the crux of the matter. What is the antenna? And what does it interact with that's not, be it part of the phone or part of the user? tom K0TAR There are a number of issues here, that are Mutually Exclusive, but added together cause the iPhone4 to seem to have some problems. Issue One. Apple has already admitted that the Signal Level algorithm, used in the IPhone4 was seriously flawed in how it displayed Signal Level. (Bars) When the Phone displayed 4 or 5 Bars, it may actually only be receiving at a 1-2 Bar Level. This they have corrected with a Software Patch. Issue Two. The Multi-Band Antenna design in the iPhone4 is a Kludge Compromise at best, and burying it in the Metal Frame where Left Hand users put the flesh against it, seriously detunes it. Apple is in the process of hiring a small group of Engineers, with expertise in this area. The combination of these two issues seems to cause, what appears to be a High Signal Level, to drop to "No Bars" when some users grasp the iPhone4 in a particular way. The "Simple Fix" is don't hold it that way. The more complex "Fix" is to redesign the Cellular Antenna, and move it to the Top of the iPhone4. This would require that the BlueTooth/Wifi antenna be redesigned as well. Apple is looking to do that in the 2nd Generation iPhone4. Just remember that Apple isn't particularly adept in the RF Arena, and the iPhone/iTouch/iPad are their only small products that have RF Antennas, this small. Also remember that some of their Laptops, of past years, had some serious Wifi Antenna placement problems, and remember that Wifi at that time was only a Single Band, not a Three Band System, like the iPhone4. Just saying. -- Bruce in alaska add path after fast to reply |
Design Flaw in iPhone 4, Testers Say
Richard Clark Inscribed thus:
On Mon, 12 Jul 2010 21:54:17 -0500, tom wrote: On 7/12/2010 9:46 PM, Richard Clark wrote: The only thing that remains a mystery, for me if for no one else here, is the literal specification of the antenna. Google (gasp) fails me. 73's Richard Clark, KB7QHC And that does seem to be the crux of the matter. What is the antenna? And what does it interact with that's not, be it part of the phone or part of the user? Hi Tom, The antenna is reported as being the metal trim that surrounds the perimeter of the phone. As that is much too large for the frequencies involved to be taken literally, there is more to the story that remains clouded. Maybe I'm wrong.... I think you're right. "Design Flaw" Someone messed up testing big time. If the loop (or dipole) is suitably matched, it doesn't give much polarization diversity. Perhaps no phone does anyway. Aren't cell stations vertically polarised. The one near me is, and one of the IF's is smack on 144.005 Mhz. Insofar as being "part of the user," we well know the EM of HTs and the hand/body contribution. If such were the case, then this would be an agnostic problem that users of all mobile phones would complain of (which mildly refutes what the gadget blogs dismissed). On the other hand, the über-hip, whose complaints are more vocal for their "pain," would be outraged at the notion of their simply enjoying the identical experience of techno-trash. Amazing what a 10 fold cost differential brings to your perception of quality of service. 73's Richard Clark, KB7QHC From a casual look at the phone the metal band seems to be a continuous loop. Its unlikely that there is a physical coupling between it and the RX/TX, so any tuner or coupling is going to be affected by the hand grasping it. Since suggestions have been made to hold the phone in a different place, I would guess that the coupling method is suseptible to adsorbtion effects and that the hot parts are near the base of the phone. FWIW Every mobile phone I've played with has the antenna and coupling circuitry near the top behind the display. 73's -- Best Regards: Baron. |
Design Flaw in iPhone 4, Testers Say
Baron wrote:
Richard Clark Inscribed thus: On Mon, 12 Jul 2010 21:54:17 -0500, tom wrote: On 7/12/2010 9:46 PM, Richard Clark wrote: The only thing that remains a mystery, for me if for no one else here, is the literal specification of the antenna. Google (gasp) fails me. 73's Richard Clark, KB7QHC And that does seem to be the crux of the matter. What is the antenna? And what does it interact with that's not, be it part of the phone or part of the user? Hi Tom, The antenna is reported as being the metal trim that surrounds the perimeter of the phone. As that is much too large for the frequencies involved to be taken literally, there is more to the story that remains clouded. Maybe I'm wrong.... I think you're right. "Design Flaw" Someone messed up testing big time. If the loop (or dipole) is suitably matched, it doesn't give much polarization diversity. Perhaps no phone does anyway. Aren't cell stations vertically polarised. The one near me is, and one of the IF's is smack on 144.005 Mhz. Insofar as being "part of the user," we well know the EM of HTs and the hand/body contribution. If such were the case, then this would be an agnostic problem that users of all mobile phones would complain of (which mildly refutes what the gadget blogs dismissed). On the other hand, the über-hip, whose complaints are more vocal for their "pain," would be outraged at the notion of their simply enjoying the identical experience of techno-trash. Amazing what a 10 fold cost differential brings to your perception of quality of service. 73's Richard Clark, KB7QHC From a casual look at the phone the metal band seems to be a continuous loop. Its unlikely that there is a physical coupling between it and the RX/TX, so any tuner or coupling is going to be affected by the hand grasping it. Since suggestions have been made to hold the phone in a different place, I would guess that the coupling method is suseptible to adsorbtion effects and that the hot parts are near the base of the phone. FWIW Every mobile phone I've played with has the antenna and coupling circuitry near the top behind the display. Not any more.. recent phones (last several years) put the antenna at the bottom to reduce the SAR number, since the top of the phone is next to your head, and the bottom isn't. There's a really good explanation from a guy who does, oddly, wireless device antenna design consulting.. http://www.antennasys.com/ specifically http://www.antennasys.com/antennasys...-antennas.html http://www.anandtech.com/show/3794/t...one-4-review/2 has some information |
Design Flaw in iPhone 4, Testers Say
On Tue, 13 Jul 2010 13:51:46 -0700, Jim Lux
wrote: http://www.anandtech.com/show/3794/t...one-4-review/2 has some information Thanx Jim, Everything Apple didn't want you to know (Antennas, and oddly enough, a report giving it an A+++ for signal quality). 73's Richard Clark, KB7QHC |
Design Flaw in iPhone 4, Testers Say
On Tue, 13 Jul 2010 10:05:54 -0800, Bruce in alaska
wrote: Issue One. Apple has already admitted that the Signal Level algorithm, used in the IPhone4 was seriously flawed in how it displayed Signal Level. (Bars) When the Phone displayed 4 or 5 Bars, it may actually only be receiving at a 1-2 Bar Level. This they have corrected with a Software Patch. Hi Bruce, Jim's second link (which I quoted in my response to him) gives very specific signal levels. Aside from that, and as is obvious by the numbers, the "bars" are merely window (with apologies to M$) dressing in any phone (except as a RF exposure risk indicator). Issue Two. The Multi-Band Antenna design in the iPhone4 is a Kludge Compromise at best, and burying it in the Metal Frame where Left Hand users put the flesh against it, seriously detunes it. Apple is in the process of hiring a small group of Engineers, with expertise in this area. A bumper would seem to mitigate the risk. Conformal coating would to some lesser extent. All-in-all, the amount of metal seems to be consistent with best engineering practices (but, perhaps, not best consumer packaging practices). 73's Richard Clark, KB7QHC |
Design Flaw in iPhone 4, Testers Say
If the phone is disturbed by touching with dry skin, a thin insulating
layer won't help. At cell phone frequencies, the capacitive coupling will have less impedance than skin. Roy Lewallen, W7EL |
Design Flaw in iPhone 4, Testers Say
On 7/13/2010 3:12 PM, Baron wrote:
Aren't cell stations vertically polarised. The one near me is, and one of the IF's is smack on 144.005 Mhz. EME'r? tom K0TAR |
Design Flaw in iPhone 4, Testers Say
On Jul 13, 3:51*pm, Jim Lux wrote:
Baron wrote: Richard Clark Inscribed thus: On Mon, 12 Jul 2010 21:54:17 -0500, tom wrote: On 7/12/2010 9:46 PM, Richard Clark wrote: The only thing that remains a mystery, for me if for no one else here, is the literal specification of the antenna. *Google (gasp) fails me. 73's Richard Clark, KB7QHC And that does seem to be the crux of the matter. *What is the antenna? And what does it interact with that's not, be it part of the phone or part of the user? Hi Tom, The antenna is reported as being the metal trim that surrounds the perimeter of the phone. *As that is much too large for the frequencies involved to be taken literally, there is more to the story that remains clouded. *Maybe I'm wrong.... I think you're right. *"Design Flaw" Someone messed up testing big time. If the loop (or dipole) is suitably matched, it doesn't give much polarization diversity. *Perhaps no phone does anyway. Aren't cell stations vertically polarised. *The one near me is, and one of the IF's is smack on 144.005 Mhz. Insofar as being "part of the user," we well know the EM of HTs and the hand/body contribution. *If such were the case, then this would be an agnostic problem that users of all mobile phones would complain of (which mildly refutes what the gadget blogs dismissed). *On the other hand, the über-hip, whose complaints are more vocal for their "pain," would be outraged at the notion of their simply enjoying the identical experience of techno-trash. *Amazing what a 10 fold cost differential brings to your perception of quality of service. 73's Richard Clark, KB7QHC From a casual look at the phone the metal band seems to be a continuous loop. Its unlikely that there is a physical coupling between it and the RX/TX, so any tuner or coupling is going to be affected by the hand grasping it. *Since suggestions have been made to hold the phone in a different place, I would guess that the coupling method is suseptible to adsorbtion effects and that the hot parts are near the base of the phone. FWIW Every mobile phone I've played with has the antenna and coupling circuitry near the top behind the display. Not any more.. recent phones (last several years) put the antenna at the bottom to reduce the SAR number, since the top of the phone is next to your head, and the bottom isn't. *There's a really good explanation from a guy who does, oddly, wireless device antenna design consulting..http://www.antennasys.com/ specificallyhttp://www.antennasys.com/antennasys-blog/2010/6/24/apple-iphone-4-an... http://www.anandtech.com/show/3794/t...-4-review/2has some information My new antenna can easily handle this job. You make it for the lowest frequency and it will handle all the frequencies above at a constant impedance..... and with more gain and the radiater smaller in size! |
Design Flaw in iPhone 4, Testers Say
On Jul 13, 8:27*pm, Art Unwin wrote:
My new antenna can easily handle this job. You make it for the lowest frequency and it will handle all the frequencies above at a constant impedance..... and with more gain and the radiater smaller in size! Is it fractal? |
Design Flaw in iPhone 4, Testers Say
On Jul 13, 9:10*pm, Bill wrote:
On Jul 13, 8:27*pm, Art Unwin wrote: My new antenna can easily handle this job. You make it for the lowest frequency and it will handle all the frequencies above at a constant impedance..... and with more gain and the radiater smaller in size! Is it fractal? No! Total resistance = R1+ R2 The trick is to reduce R2 in value so more current is being applied to radiation. Very simple my dear Watson. |
Design Flaw in iPhone 4, Testers Say
On 7/13/2010 9:42 PM, Art Unwin wrote:
On Jul 13, 9:10 pm, wrote: On Jul 13, 8:27 pm, Art wrote: My new antenna can easily handle this job. You make it for the lowest frequency and it will handle all the frequencies above at a constant impedance..... and with more gain and the radiater smaller in size! Is it fractal? No! Total resistance = R1+ R2 The trick is to reduce R2 in value so more current is being applied to radiation. Very simple my dear Watson. And he tells you nothing. And he provides no proof. The master of vaportennas. tom K0TAR |
Design Flaw in iPhone 4, Testers Say
On Jul 12, 9:30*pm, Richard Clark wrote:
http://www.nytimes.com/2010/07/13/te...apple.html?hpw "Consumer Reports, America’s trusted source of product reviews, *said it would not recommend the iPhone 4 because of a hardware flaw with its antenna that sometimes resulted in dropped calls. "... its antenna, which is built into a steel band that encases the phone. "After users reported problems with signal strength and dropped calls when they touched the lower-left portion of the phone, however, Apple suggested that consumers hold the phone differently or use one of many bumpers to insulate the antenna. It also said that all phones suffered from similar problems when they were cradled a certain way. "These comments were widely laughed at in gadget blogs. " Just thought I would submit this to the Laughing Academy. 73's Richard Clark, KB7QHC The rumor I heard was that they tried to put in a "better" antenna to cure problems with dropouts. While it does have more gain it is sensitive to the way it's held. Basically they traded one problem for another. Any confirmation or rebutal would be appreciated Jimmie |
Design Flaw in iPhone 4, Testers Say
JIMMIE wrote:
The rumor I heard was that they tried to put in a "better" antenna to cure problems with dropouts. While it does have more gain it is sensitive to the way it's held. Basically they traded one problem for another. Any confirmation or rebutal would be appreciated Jimmie There's a whole raft of issues.. One is that cellphones aren't analog FM anymore, so they suffer from the "digital cliff" problem.. If the Eb/No is good enough that the FEC works, then it works great, but a dB or so worse, and it doesn't work at all. This is so different from most people's practical experience with communications that it is disconcerting. E.g. if you walk away from me while talking, your voice gets fainter and the SNR gradually drops, but it's not like you've walked out of the "cone of silence" where it goes from fully intelligible to not at all intelligible in milliseconds. And, the fact that this happens on a packet by packet basis means that at the threshold, it "stutters", which is also non-intuitive and non-physical. And then, the cellphone companies have managed to convince us that really crummy sound is ok, even at the full bit rate of 8kpbs. The voice codecs are impressive, but face it, it still doesn't sound like 56kbps u-law or 25 kHz NBFM, what used to be called "toll-quality" |
Design Flaw in iPhone 4, Testers Say
Jim Lux Inscribed thus:
Baron wrote: Richard Clark Inscribed thus: On Mon, 12 Jul 2010 21:54:17 -0500, tom wrote: On 7/12/2010 9:46 PM, Richard Clark wrote: The only thing that remains a mystery, for me if for no one else here, is the literal specification of the antenna. Google (gasp) fails me. 73's Richard Clark, KB7QHC And that does seem to be the crux of the matter. What is the antenna? And what does it interact with that's not, be it part of the phone or part of the user? Hi Tom, The antenna is reported as being the metal trim that surrounds the perimeter of the phone. As that is much too large for the frequencies involved to be taken literally, there is more to the story that remains clouded. Maybe I'm wrong.... I think you're right. "Design Flaw" Someone messed up testing big time. If the loop (or dipole) is suitably matched, it doesn't give much polarization diversity. Perhaps no phone does anyway. Aren't cell stations vertically polarised. The one near me is, and one of the IF's is smack on 144.005 Mhz. Insofar as being "part of the user," we well know the EM of HTs and the hand/body contribution. If such were the case, then this would be an agnostic problem that users of all mobile phones would complain of (which mildly refutes what the gadget blogs dismissed). On the other hand, the über-hip, whose complaints are more vocal for their "pain," would be outraged at the notion of their simply enjoying the identical experience of techno-trash. Amazing what a 10 fold cost differential brings to your perception of quality of service. 73's Richard Clark, KB7QHC From a casual look at the phone the metal band seems to be a continuous loop. Its unlikely that there is a physical coupling between it and the RX/TX, so any tuner or coupling is going to be affected by the hand grasping it. Since suggestions have been made to hold the phone in a different place, I would guess that the coupling method is suseptible to adsorbtion effects and that the hot parts are near the base of the phone. FWIW Every mobile phone I've played with has the antenna and coupling circuitry near the top behind the display. Not any more.. recent phones (last several years) put the antenna at the bottom to reduce the SAR number, since the top of the phone is next to your head, and the bottom isn't. There's a really good explanation from a guy who does, oddly, wireless device antenna design consulting.. http://www.antennasys.com/ specifically http://www.antennasys.com/antennasys...-antennas.html http://www.anandtech.com/show/3794/t...one-4-review/2 has some information Jim. Thanks for the above links. The Youtube vid was most interesting. I certainly wasn't aware of the gaps in the metal banding nor of the SAR requirements. 73s -- Best Regards: Baron. |
Design Flaw in iPhone 4, Testers Say
tom Inscribed thus:
On 7/13/2010 3:12 PM, Baron wrote: Aren't cell stations vertically polarised. The one near me is, and one of the IF's is smack on 144.005 Mhz. EME'r? tom K0TAR Yep ! Totally drowns out any signals. A waste of time complaining. Leakage signals are within spec, according to them. Anyway I've now given up trying and taken the antenna array down. To be honest its been some time since I was last active. 73's -- Best Regards: Baron. |
Design Flaw in iPhone 4, Testers Say
On 7/14/2010 1:29 PM, Jim Lux wrote:
There's a whole raft of issues.. One is that cellphones aren't analog FM anymore, so they suffer from the "digital cliff" problem.. If the Eb/No is good enough that the FEC works, then it works great, but a dB or so worse, and it doesn't work at all. This is so different from most people's practical experience with communications that it is disconcerting. E.g. if you walk away from me while talking, your voice gets fainter and the SNR gradually drops, but it's not like you've walked out of the "cone of silence" where it goes from fully intelligible to not at all intelligible in milliseconds. And, the fact that this happens on a packet by packet basis means that at the threshold, it "stutters", which is also non-intuitive and non-physical. And then, the cellphone companies have managed to convince us that really crummy sound is ok, even at the full bit rate of 8kpbs. The voice codecs are impressive, but face it, it still doesn't sound like 56kbps u-law or 25 kHz NBFM, what used to be called "toll-quality" And then there's the PSTN ala 2010. We have been discovering a lot of new things about that that we suspect even the carriers haven't noticed, or at least appreciated. And it's all started showing up in the last year. Like average LD call completion failure has been 4% for 10 years. Yup it's actually that high. Except this year it's 6%. And possibly still climbing. Can't tell you the test conditions (NDA needed), but it's millions of calls per year. One of the first odd things we noticed was the occasional location code 3 from the supposed destination. That one is now obvious, but the first time you see it it's very perplexing. And more things are showing up, mostly disturbing if you expect the PSTN to remain the relatively predictable thing that it's been during the SS7/TDM/ISDN era. So much is changing we are making a new training program for our analysts on how to recognize what's now going on versus what used to go on. tom K0TAR |
Design Flaw in iPhone 4, Testers Say
On Tue, 13 Jul 2010 13:51:46 -0700, Jim Lux
wrote: Not any more.. recent phones (last several years) put the antenna at the bottom to reduce the SAR number, since the top of the phone is next to your head, and the bottom isn't. There's a really good explanation from a guy who does, oddly, wireless device antenna design consulting.. http://www.antennasys.com/ specifically http://www.antennasys.com/antennasys...-antennas.html http://www.anandtech.com/show/3794/t...one-4-review/2 has some information Here's my wild guess as to what's happening, borrowed from my posting in ba.internet and alt.cellular.attws. Apple announced that there's going to be a press conference on Friday, where they'll announce something. Note that I goofed on the location of the wi-fi/BT antenna, but I'll leave the mistake here for now. On Wed, 14 Jul 2010 13:05:27 -0700, AES wrote: Is your assessment here that placing RF-lossy human flesh (with a high water content) close enough to the phone antenna loads down (or maybe just detunes?) the RF circuitry of the transmitter final stage to a point that the active transmitter circuitry in the phone no longer oscillates effectively? -- but just putting a dry and non-lossy dielectric there doesn't, and also moving the flesh even a short distance away reduces its loading on the circuitry enough that the active circuitry still works OK? Nope. My wild guess(tm), based upon what little I can extract from the FCC ID page and from the iFixit autopsy, is that something drastic is happening in receive. The -30dB (that's 1000 times drop) in signal appears in receive, when you're NOT making a call and the xmitter is inactive. Well, the xmitter is sending keep alive bursts every few minutes, but nothing more. Methinks it's a receive problem, not xmit. I'll go out on a limb and suggest that the receiver front end (probably a GASFET or HEMT) might be a bit regenerative (border line oscillatory). This gives it lots of gain, but only if nothing else changes. In effect, the antenna becomes part of an oscillator circuit, where the oscillatory conditions are partly provided by the antenna Q (i.e. antenna efficiency). http://en.wikipedia.org/wiki/Regenerative_circuit Touch the antenna, and you reduce the antenna Q. The front end stops acting regenerative (barely oscillating), and the sensitivity drops like a rock. It's the only explanation I can conjure the will cause a -30dB drop in received signal. It's been demonstrated (by me and others) that strangling the antenna of other cell phones drops the rx signal up to -10dBm (10 times drop). That's what I would normally expect to see from touching a cell phone antenna. However, the -30dB drop of the iPhone 4 requires some extra circuit design screwups. Unfortunately, detecting the regeneration is going to require internal probes, test fixturing, and plenty of expensive test equipment. There's another related possibility. Most of the finger tests have been with the finger bridging the gap. That means they're touching BOTH the cellular and wi-fi/BT antennas. It's obviously the hot end of the cellular antenna, but I can't tell if it's the hot end or ground end of the wi-fi/BT antenna. If the hot end, another possibility it that coupling to the 2nd antenna causes this antenna to radiate into the case, thus causing the cellular front end to oscillate. If the oscillations are bad enough, the signal level will be high enough to induce blocking (overload) in the cellular front end. This can be easily detected with a spectrum analyzer probe in the vicinity. If touching/bridging the antennas causes a new signal to appear on the SA, that's the problem. It would be very interesting to know if touching ONLY the cellular part of the antenna (the part that goes up the side of the phone), and not the wi-fi/BT antenna (bottom of phone), causes the same drop in signal. It would also be interesting to test the wi-fi signal strength to see if it's effected by touching its antenna. I have a few other guesses, but these are the best I can currently conjure at this time. [I'm an EE, but with no RF circuitry experience, much less any cellphone experience. So, I can understand this happening with an active transmitting circuit -- though I have somewhat more trouble seeing how it would interfere in such a sensitive way with a passive receiving antenna.] Think regeneration and borderline oscillation. The bad news is that if Apple stabilizes the rx front end, and eliminates the oscillation or regeneration, my guess(tm) is that the resultant phone is going to have a serious rx sensitivity problem. If you look at the cellular antenna in the iPhone 3G and other internal antenna cell phones, they're not very simple looking devices. Lots of strange lumps, traces, pads, and oddities, all designed to optimize performance in the 800/900 and 1800/1900 MHz bands. Getting them to look like 50 ohms for minimum VSWR is also important. Lots of articles in the IEEE Antenna and Prop proceedings on the topic of cramming a dual band antenna in the smallest possible package. On the other foot, the iPhone 4 antenna is crude. As far as I can tell from here, it's a crude monopole (single wire) antenna. There's no matching circuit for VSWR reduction, and no attempt to optimize performance in the desired bands. I might have missed something in the dissection, but all I can see is an end fed monopole, without a counterpoise or underlying ground. Such an antenna is going to have resonances at odd frequencies, and miserable antenna efficiency. Disclaimer: I haven't found anyone willing to let me tear into their iPhone 4 yet, so all the above is guesswork. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Design Flaw in iPhone 4, Testers Say
On Tue, 13 Jul 2010 13:51:46 -0700, Jim Lux
wrote: Baron wrote: Richard Clark Inscribed thus: On Mon, 12 Jul 2010 21:54:17 -0500, tom wrote: On 7/12/2010 9:46 PM, Richard Clark wrote: The only thing that remains a mystery, for me if for no one else here, is the literal specification of the antenna. Google (gasp) fails me. 73's Richard Clark, KB7QHC And that does seem to be the crux of the matter. What is the antenna? And what does it interact with that's not, be it part of the phone or part of the user? Hi Tom, The antenna is reported as being the metal trim that surrounds the perimeter of the phone. As that is much too large for the frequencies involved to be taken literally, there is more to the story that remains clouded. Maybe I'm wrong.... I think you're right. "Design Flaw" Someone messed up testing big time. If the loop (or dipole) is suitably matched, it doesn't give much polarization diversity. Perhaps no phone does anyway. In my older phone, razor(sp?)I think the antenna is a spiral. Aren't cell stations vertically polarised. The one near me is, and one of the IF's is smack on 144.005 Mhz. Time to go legal limit on CW with a big EME array:-)) such as 4, or 6,8, or 12, 28-30 element long johns. Insofar as being "part of the user," we well know the EM of HTs and the hand/body contribution. If such were the case, then this would be an agnostic problem that users of all mobile phones would complain of (which mildly refutes what the gadget blogs dismissed). On the other hand, the über-hip, whose complaints are more vocal for their "pain," would be outraged at the notion of their simply enjoying the identical experience of techno-trash. Amazing what a 10 fold cost differential brings to your perception of quality of service. Except for the eyes, those phones couldn't heat water with the power they run. 73's Richard Clark, KB7QHC From a casual look at the phone the metal band seems to be a continuous loop. it's two segmented loops that appeared to be around the bottom left corner, right where it fits in the palm of your left hand. Its unlikely that there is a physical coupling between it and the RX/TX, so any tuner or coupling is going to be affected by the hand grasping it. Since suggestions have been made to hold the phone in a different place, I would guess that the coupling method is suseptible Yup, design flaw, and I hear there is now a recall coming up. to adsorbtion effects and that the hot parts are near the base of the phone. FWIW Every mobile phone I've played with has the antenna and coupling circuitry near the top behind the display. Not any more.. recent phones (last several years) put the antenna at the bottom to reduce the SAR number, since the top of the phone is next to your head, and the bottom isn't. There's a really good explanation from On mine the top is against your ear and the bottom against your cheek or upper jaw bone and I'm keeping it until it dies, but those kind of gadgets have a rather limited life around me. I just want a phone with voice mail. I have a camera thank you, and it doesn't have a tiny crappy lens that makes anything much over 1 megapixel nothing more than bragging rights. I don't want texting, The only thing I need is the ability to call and be called. I don't need a PDA either. Even in the old days when we had to use the day planners and even go to school on them, after the class I dumped everything out of it including the calendar and picked up a new interior from the stock room. Threw out every thing I didn't need and used it for a note book at meetings. To me a day planner would be about as useless and my profession was a computer systems project manager up until I retired. It's also my degreed field. 73 Roger (K8RI) a guy who does, oddly, wireless device antenna design consulting.. http://www.antennasys.com/ specifically http://www.antennasys.com/antennasys...-antennas.html http://www.anandtech.com/show/3794/t...one-4-review/2 has some information |
Design Flaw in iPhone 4, Testers Say
On Wed, 14 Jul 2010 23:02:21 -0700, Jeff Liebermann
wrote: However, the -30dB drop of the iPhone 4 requires some extra circuit design screwups. Unfortunately, detecting the regeneration is going to require internal probes, test fixturing, and plenty of expensive test equipment. Hi Jeff, Regenerative designs inhabit the naked edge of amplification/oscillation. You've already said as much. It has to be, thus, a design feature and not a hack. Otherwise every third one is going to break into oscillation and the FCC (or test lab) would have certainly picked up on that. Further, if it is designed in, you can observe that in the design. Special testing methods are too elaborate to explain this. Regen is not a design feature left to the vagaries of production variation in parasitic coupling. If I'm wrong and Apple does use parasitics to encourage regenerative feedback, then they may introduce a lanyard for hanging the phone around the neck and call it the lavaliere option. No doubt they will sell plenty of mirrors to see it, and someone will come out with an image reversal app. Can a stylus be far behind? Whoops! It will have to be chopstick for squeezing and expanding images. 73's Richard Clark, KB7QHC |
Design Flaw in iPhone 4, Testers Say
Jeff Liebermann wrote:
The bad news is that if Apple stabilizes the rx front end, and eliminates the oscillation or regeneration, my guess(tm) is that the resultant phone is going to have a serious rx sensitivity problem. If you look at the cellular antenna in the iPhone 3G and other internal antenna cell phones, they're not very simple looking devices. Lots of strange lumps, traces, pads, and oddities, all designed to optimize performance in the 800/900 and 1800/1900 MHz bands. Getting them to look like 50 ohms for minimum VSWR is also important. Lots of articles in the IEEE Antenna and Prop proceedings on the topic of cramming a dual band antenna in the smallest possible package. On the other foot, the iPhone 4 antenna is crude. As far as I can tell from here, it's a crude monopole (single wire) antenna. There's no matching circuit for VSWR reduction, and no attempt to optimize performance in the desired bands. I might have missed something in the dissection, but all I can see is an end fed monopole, without a counterpoise or underlying ground. Such an antenna is going to have resonances at odd frequencies, and miserable antenna efficiency. I doubt they're using regeneration or some such similar scheme (too hard to control for manufacturing variability).. However, the idea of self interference is interesting... (e.g. your finger couples the WiFi to the cellular front end, which blocks) It could even be as dumb as a dc bias shift thing (save a penny by leaving out the capacitor, oops, that removed the DC block) As far as match goes, in very compact systems, the idea of matching 50 ohms goes out the door unless one of your components happens to be 50 ohm impedance.. It's not like they're stringing together building blocks with SMA connectors inside there. Lots of these RF circuits are implemented with differential in and out these days, and the Z is whatever it happens to be. |
Design Flaw in iPhone 4, Testers Say
On Thu, 15 Jul 2010 00:37:22 -0700, Richard Clark
wrote: On Wed, 14 Jul 2010 23:02:21 -0700, Jeff Liebermann wrote: However, the -30dB drop of the iPhone 4 requires some extra circuit design screwups. Unfortunately, detecting the regeneration is going to require internal probes, test fixturing, and plenty of expensive test equipment. I goofed slightly. The Anandtech article shows -24dB maximum signal loss. Regenerative designs inhabit the naked edge of amplification/oscillation. Not designs. I don't think it was intentional. Someone else mentioned that Apple was so much into security on the iPhone 4, that prototypes were tested in a similar case made to look like an iPhone 3G. That implies that there was little field testing in the new case. You've already said as much. It has to be, thus, a design feature and not a hack. I beg to differ. Nobody wants oscillatory effects in the front end of their receiver. They're unstable, vary with temperature, are difficult to control in manufacturing, and will probably make the device fail Part 15 incidental radiation test. Designing a front end that's unconditionally stable with any antenna load does not yield the optimum sensitivity. If you want the best performance, amps that are unstable at specific loads will give better NF and gain. Otherwise every third one is going to break into oscillation and the FCC (or test lab) would have certainly picked up on that. Maybe. However, one would think that someone would have done a field test with the final iPhone 4 and noticed that touching the antenna gap produced a major signal drop. Also, FCC test are not preformed with human hands wrapped around the phone due to the limited supply of dismembered hands suitable for testing. Further, if it is designed in, you can observe that in the design. Special testing methods are too elaborate to explain this. Regen is not a design feature left to the vagaries of production variation in parasitic coupling. That might partly explain why some users claim that there's no call drop effect when they touch the antenna gap. Of course, users in strong signal areas are not going to see a dropout, while weak signal areas are going to be much worse. Incidentally, when Consumer Reports ran a test with the rubber ring thing, they slipped and didn't have the technician stand in front of the test equipment this time. http://blogs.consumerreports.org/electronics/2010/07/apple-iphone4-iphone-4-bumper-case-fixes-antenna-issue-problem-signal-loss-tested-verified-consumer-reports-labs-quick-fix.html http://802.11junk.com/jeffl/crud/iPhone4-cmu200.jpg (normal) http://802.11junk.com/jeffl/crud/iPhone4-cmu200-hand.jpg (with hand) It's a Rhodes and Schwarz CMU200. http://www2.rohde-schwarz.com/product/CMU200.html I'm not familiar with the operation. The "Reported Power" appears to be the signal generator output power (because it doesn't change when the antenna is touched). However, I can't devine what the "Avg" or "Peak Burst Power" means. Also, note that the difference in (something) between the first photo (+16.4dBm) and the hand on antenna measurement (-11.7dB) indicates a -28dB drop in signal level. Ouch. If I'm wrong and Apple does use parasitics to encourage regenerative feedback, then they may introduce a lanyard for hanging the phone around the neck and call it the lavaliere option. No doubt they will sell plenty of mirrors to see it, and someone will come out with an image reversal app. Can a stylus be far behind? Whoops! It will have to be chopstick for squeezing and expanding images. We'll find out after the press conference on Friday. My suggestion was to ship a rubber glove with the phone. I also suggested gluing a plastic thumb tack to warn against holding it improperly. Also, a low signal warning tone. Others have suggested tape, rubber prophylactic bump guards, duct tape, warning labels, rebates, bribes, and external antennas: http://gizmodo.com/5581253/there-fixed Unfortunately, that will require running the FCC type certification tests again. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Design Flaw in iPhone 4, Testers Say
On Thu, 15 Jul 2010 08:43:04 -0700, Jim Lux
wrote: I doubt they're using regeneration or some such similar scheme (too hard to control for manufacturing variability).. I'm not suggesting they did it intentionally. I'm suggesting that the front end is unstable and that nobody noticed. However, the idea of self interference is interesting... (e.g. your finger couples the WiFi to the cellular front end, which blocks) I was looking at the FCC ID web site photos again. I can't even tell which end of the antenna is hot or ground, much less where it's fed. If the hot end of both antennas are facing each other, it's certainly possible. However, if Apple did that, they wouldn't need two separate pieces of metal for the two antennas. They could simply declare some point along the frame as being the official ground point, and have the cellular antenna go one direction, and the wi-fi/BT antenna go the other. Because they didn't do that, my guess is that the hot end of the cellular antenna is next to the ground end of the wi-fi/BT antenna. It could even be as dumb as a dc bias shift thing (save a penny by leaving out the capacitor, oops, that removed the DC block) Methinks not. The duct tape solution just reduces the effect, not eliminates it. Assuming duct tape to be a good insulator, that would also suggest that it's not a DC effect. As far as match goes, in very compact systems, the idea of matching 50 ohms goes out the door unless one of your components happens to be 50 ohm impedance.. It's not like they're stringing together building blocks with SMA connectors inside there. Lots of these RF circuits are implemented with differential in and out these days, and the Z is whatever it happens to be. If you look at the inside photos of the BCG-E2380A on the FCC ID web pile, http://www.fcc.gov/oet/ea/fccid/ (don't forget to include the "-" as part of the product code), there's a module labeled "Acoustic and Cellular Antenna Feed" on Pg 9 and 10. https://fjallfoss.fcc.gov/eas/GetApplicationAttachment.html?id=1300576 There's a coax cable going across the module, which I assume is 50 ohms. http://802.11junk.com/jeffl/iPhone4/iPhone4-accoustic-and-cellular-ant-feed.jpg It doesn't appear to do any more than connect a tiny coax connector to the RF module on one end, and a gold screw lug to the frame antenna on the other. No matching in between. Due to the coax, someone must think the antenna is 50 ohms at 800/900 and 1800/1900. I've never seen a differential RF amp in a cell phone. If so, I would expect either a balanced antenna feed, or possibly two antenna connectors. Disclaimer: I'm doing quite a bit more guessing than usual. Please do not treat the above as authoritive. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Design Flaw in iPhone 4, Testers Say
On Thu, 15 Jul 2010 09:37:38 -0700, Jeff Liebermann
wrote: http://blogs.consumerreports.org/electronics/2010/07/apple-iphone4-iphone-4-bumper-case-fixes-antenna-issue-problem-signal-loss-tested-verified-consumer-reports-labs-quick-fix.html Consumer Reports to Apple: "You've been served!" The long and short of it is that Apple treats its product design like bulimic runway models. It's up to you to see they get as fat as necessary to live a productive life. In other words, there's no room left inside the iPhone for an antenna and it ruins the esthetics for it too bulge. So, if you don't want to be viewed as part of the pocket-protector crowd, suck up and hold your phone like Lady Gaga. Support our troops at: http://www.youtube.com/watch?v=-fMP0zZRIF4 73's Richard Clark, KB7QHC |
Design Flaw in iPhone 4, Testers Say
Roger Inscribed thus:
On Tue, 13 Jul 2010 13:51:46 -0700, Jim Lux wrote: Baron wrote: Richard Clark Inscribed thus: On Mon, 12 Jul 2010 21:54:17 -0500, tom wrote: On 7/12/2010 9:46 PM, Richard Clark wrote: The only thing that remains a mystery, for me if for no one else here, is the literal specification of the antenna. Google (gasp) fails me. 73's Richard Clark, KB7QHC And that does seem to be the crux of the matter. What is the antenna? And what does it interact with that's not, be it part of the phone or part of the user? Hi Tom, The antenna is reported as being the metal trim that surrounds the perimeter of the phone. As that is much too large for the frequencies involved to be taken literally, there is more to the story that remains clouded. Maybe I'm wrong.... I think you're right. "Design Flaw" Someone messed up testing big time. If the loop (or dipole) is suitably matched, it doesn't give much polarization diversity. Perhaps no phone does anyway. In my older phone, razor(sp?)I think the antenna is a spiral. Aren't cell stations vertically polarised. The one near me is, and one of the IF's is smack on 144.005 Mhz. Time to go legal limit on CW with a big EME array:-)) such as 4, or 6,8, or 12, 28-30 element long johns. I had 16 x 19 element Tigers up there on a big H frame. I could run a full gallon from a Tempo 2000. So yes I suppose I could have flattened the cell station IF... Insofar as being "part of the user," we well know the EM of HTs and the hand/body contribution. If such were the case, then this would be an agnostic problem that users of all mobile phones would complain of (which mildly refutes what the gadget blogs dismissed). On the other hand, the über-hip, whose complaints are more vocal for their "pain," would be outraged at the notion of their simply enjoying the identical experience of techno-trash. Amazing what a 10 fold cost differential brings to your perception of quality of service. Except for the eyes, those phones couldn't heat water with the power they run. 73's Richard Clark, KB7QHC From a casual look at the phone the metal band seems to be a continuous loop. it's two segmented loops that appeared to be around the bottom left corner, right where it fits in the palm of your left hand. Its unlikely that there is a physical coupling between it and the RX/TX, so any tuner or coupling is going to be affected by the hand grasping it. Since suggestions have been made to hold the phone in a different place, I would guess that the coupling method is suseptible Yup, design flaw, and I hear there is now a recall coming up. After forking out the sort of money they want for the things, I'd be asking for my brass back ! to adsorbtion effects and that the hot parts are near the base of the phone. FWIW Every mobile phone I've played with has the antenna and coupling circuitry near the top behind the display. Not any more.. recent phones (last several years) put the antenna at the bottom to reduce the SAR number, since the top of the phone is next to your head, and the bottom isn't. There's a really good explanation from On mine the top is against your ear and the bottom against your cheek or upper jaw bone and I'm keeping it until it dies, but those kind of gadgets have a rather limited life around me. I just want a phone with voice mail. I have a camera thank you, and it doesn't have a tiny crappy lens that makes anything much over 1 megapixel nothing more than bragging rights. I don't want texting, The only thing I need is the ability to call and be called. I don't need a PDA either. Agreed ! Even in the old days when we had to use the day planners and even go to school on them, after the class I dumped everything out of it including the calendar and picked up a new interior from the stock room. Threw out every thing I didn't need and used it for a note book at meetings. To me a day planner would be about as useless and my profession was a computer systems project manager up until I retired. It's also my degreed field. 73 Roger (K8RI) a guy who does, oddly, wireless device antenna design consulting.. http://www.antennasys.com/ specifically http://www.antennasys.com/antennasys...-antennas.html http://www.anandtech.com/show/3794/t...one-4-review/2 has some information -- Best Regards: Baron. |
Design Flaw in iPhone 4, Testers Say
Bruce in alaska wrote:
Just remember that Apple isn't particularly adept in the RF Arena, and the iPhone/iTouch/iPad are their only small products that have RF Antennas, this small. Also remember that some of their Laptops, of past years, had some serious Wifi Antenna placement problems, and remember that Wifi at that time was only a Single Band, not a Three Band System, like the iPhone4. Lesson: don't buy a cellphone from a company that doesn't know how to build one (and wants to be in the business of cellphone design without hiring the knowledge required). |
Design Flaw in iPhone 4, Testers Say
Jeff Liebermann wrote:
I've never seen a differential RF amp in a cell phone. If so, I would expect either a balanced antenna feed, or possibly two antenna connectors. Things like vector mods (RF2422) have differential in/out, for instance. Parts like the MAX2510 are similar. It's true by the time you get to PA stage, that single ended seems to be more common. |
Design Flaw in iPhone 4, Testers Say
On 7/13/2010 3:30 PM, Richard Clark wrote:
On Tue, 13 Jul 2010 10:05:54 -0800, Bruce in wrote: Issue One. Apple has already admitted that the Signal Level algorithm, used in the IPhone4 was seriously flawed in how it displayed Signal Level. (Bars) When the Phone displayed 4 or 5 Bars, it may actually only be receiving at a 1-2 Bar Level. This they have corrected with a Software Patch. Hi Bruce, Jim's second link (which I quoted in my response to him) gives very specific signal levels. Aside from that, and as is obvious by the numbers, the "bars" are merely window (with apologies to M$) dressing in any phone (except as a RF exposure risk indicator). Issue Two. The Multi-Band Antenna design in the iPhone4 is a Kludge Compromise at best, and burying it in the Metal Frame where Left Hand users put the flesh against it, seriously detunes it. Apple is in the process of hiring a small group of Engineers, with expertise in this area. A bumper would seem to mitigate the risk. Conformal coating would to some lesser extent. All-in-all, the amount of metal seems to be consistent with best engineering practices (but, perhaps, not best consumer packaging practices). 73's Richard Clark, KB7QHC When is everyone going to wake up. What we need is a USB dongle which is simply a recvr/xmitter and is software driven. This is the last "cell phone" you will ever need to purchase. It can incorporate an onboard antenna, however should also have an external ant connection so in fringe areas communication is improved. Isn't it about time we stopped buy a seperate TV, radio, phone, stereo, etc. A computer with the proper software and attachment(s) are all of these and more. It is time to end the stone age of electronics! Regards, JS |
Design Flaw in iPhone 4, Testers Say
On 7/13/2010 3:30 PM, Richard Clark wrote:
On Tue, 13 Jul 2010 10:05:54 -0800, Bruce in wrote: Issue One. Apple has already admitted that the Signal Level algorithm, used in the IPhone4 was seriously flawed in how it displayed Signal Level. (Bars) When the Phone displayed 4 or 5 Bars, it may actually only be receiving at a 1-2 Bar Level. This they have corrected with a Software Patch. Hi Bruce, Jim's second link (which I quoted in my response to him) gives very specific signal levels. Aside from that, and as is obvious by the numbers, the "bars" are merely window (with apologies to M$) dressing in any phone (except as a RF exposure risk indicator). Issue Two. The Multi-Band Antenna design in the iPhone4 is a Kludge Compromise at best, and burying it in the Metal Frame where Left Hand users put the flesh against it, seriously detunes it. Apple is in the process of hiring a small group of Engineers, with expertise in this area. A bumper would seem to mitigate the risk. Conformal coating would to some lesser extent. All-in-all, the amount of metal seems to be consistent with best engineering practices (but, perhaps, not best consumer packaging practices). 73's Richard Clark, KB7QHC When is everyone going to wake up. What we need is a USB dongle which is simply a recvr/xmitter and is software driven. This is the last "cell phone" you will ever need to purchase. It can incorporate an onboard antenna, however should also have an external ant connection so in fringe areas communication is improved. Isn't it about time we stopped buy a seperate TV, radio, phone, stereo, etc. A computer with the proper software and attachment(s) are all of these and more (all these, except for phone, are available on ebay.) It is time to end the stone age of electronics! Regards, JS |
Design Flaw in iPhone 4, Testers Say
John Smith wrote:
When is everyone going to wake up. What we need is a USB dongle which is simply a recvr/xmitter and is software driven. This is the last "cell phone" you will ever need to purchase. It can incorporate an onboard antenna, however should also have an external ant connection so in fringe areas communication is improved. Isn't it about time we stopped buy a seperate TV, radio, phone, stereo, etc. A computer with the proper software and attachment(s) are all of these and more. No it isn't. I don't want to take calls on my television. The XYL will talk for hours with friends. Seems like a bad thing to tie the TV up for that time. I don't want my telephone to be my computer either, or listen to my music on my telephone. It's for the same reason that I don't want to keep my frozen meat in my car. A whole lot of us prefer our devices to be purpose built instead of the myriad of compromises in having all in one instruments. History has shown that all in one devices tend to perform poorly or mediocre at best in all their functions. They kind of remind me of the Escalade SUV/Pickup trucks. Horrible pickup truck, poor SUV, and ugly as sin. It is time to end the stone age of electronics! I want faster, better looking, and higher performance. I don't want all-in wonders, which are always compromises. - Mike - |
Design Flaw in iPhone 4, Testers Say
On 8/3/2010 1:25 PM, Michael Coslo wrote:
John Smith wrote: No it isn't. I don't want to take calls on my television. The XYL will talk for hours with friends. Seems like a bad thing to tie the TV up for that time. I don't want my telephone to be my computer either, or listen to my music on my telephone. Only a damn fool would make a phone call on their TV, or even think about it. But, if the case is you and the wife can't afford seperate hand-helds/netbooks, well, get a better job! It's for the same reason that I don't want to keep my frozen meat in my car. A whole lot of us prefer our devices to be purpose built instead of the myriad of compromises in having all in one instruments. History has shown that all in one devices tend to perform poorly or mediocre at best in all their functions. Again, only a damn fool would think about keeping food in their palm-top/ereader/netbook, or even think about it. Hmmm, my computer is not a printer, but an external printer hooked up workes just fine. My computer is not a netcard, but a USB dongle netcard works just fine--plugged in, my computer is not a TV, but an USB dongle HD TV works fine--plugged in, etc. In fact, I have never noticed any problems with them running all at once. Perhaps you need new hardware. They kind of remind me of the Escalade SUV/Pickup trucks. Horrible pickup truck, poor SUV, and ugly as sin. Never seen wheels, steering wheel, gearshift, headlights, etc. on a palm-top/ereader/netbook/laptop/computer. This sounds more of mental condition and/or drugs. It is time to end the stone age of electronics! I want faster, better looking, and higher performance. I don't want all-in wonders, which are always compromises. Must be boring never using any USB or ported peripherals, as your post indicates! Try it, you will find that "all-in-one-wonders" are great! - Mike - Regards, JS |
Design Flaw in iPhone 4, Testers Say
On Tue, 03 Aug 2010 16:25:44 -0400, Michael Coslo
wrote: John Smith wrote: It is time to end the stone age of electronics! I want faster, better looking, and higher performance. I don't want all-in wonders, which are always compromises. Amen brother! The reality of 'one size fits all' is 'one size fits no one especially well'. |
Design Flaw in iPhone 4, Testers Say
On 8/3/2010 4:03 PM, Registered User wrote:
On Tue, 03 Aug 2010 16:25:44 -0400, Michael wrote: John Smith wrote: It is time to end the stone age of electronics! I want faster, better looking, and higher performance. I don't want all-in wonders, which are always compromises. Amen brother! The reality of 'one size fits all' is 'one size fits no one especially well'. You are a godsend to the hardware manufacturers, they love you! My TV, radio, stereo, MP3 player, DVD recorder/player, etc. all travel in my briefcase as USB Dongles or software. That size fits me well! ROFLOL To each his/her own, regards, JS |
Design Flaw in iPhone 4, Testers Say
On Tue, 03 Aug 2010 14:21:08 -0700, John Smith
wrote: On 8/3/2010 1:25 PM, Michael Coslo wrote: John Smith wrote: No it isn't. I don't want to take calls on my television. The XYL will talk for hours with friends. Seems like a bad thing to tie the TV up for that time. I don't want my telephone to be my computer either, or listen to my music on my telephone. Only a damn fool would make a phone call on their TV, or even think about it. But if as was suggested the computer is the TV and is the telephone and is the ... abstractly they are all one device. - quote - Isn't it about time we stopped buy a seperate TV, radio, phone, stereo, etc. A computer with the proper software and attachment(s) are all of these and more (all these, except for phone, are available on ebay.) - end quote - Literally by both connection and dependency they all become one device. No USB device is especially useful without a computer's USB port. But, if the case is you and the wife can't afford seperate hand-helds/netbooks, well, get a better job! It's a functionality question not a financial question. Should a second computer with all the USB peripherals be required just so Mike's Mrs. can use the telephone while he watches television? Being able to do something doesn't validate its worth. Using USB devices for the sake of using USB devices gains no efficiencies. It's for the same reason that I don't want to keep my frozen meat in my car. A whole lot of us prefer our devices to be purpose built instead of the myriad of compromises in having all in one instruments. History has shown that all in one devices tend to perform poorly or mediocre at best in all their functions. Again, only a damn fool would think about keeping food in their palm-top/ereader/netbook, or even think about it. Hmmm, my computer is Is this discussion about appliances with limited functionality such as "palm-top/ereader/netbook" or a fully functional computer? How well do the USB devices mentioned below work within the "palm-top/ereader/netbook" trifeca? not a printer, but an external printer hooked up workes just fine. My computer is not a netcard, but a USB dongle netcard works just fine--plugged in, my computer is not a TV, but an USB dongle HD TV works fine--plugged in, etc. In fact, I have never noticed any problems with them running all at once. Perhaps you need new hardware. Yourself as well, your USB spell-checker doesn't appear working properly ;) Your initial post alluded to convergence but all you're doing is daisy chaining peripheral devices. The only visible difference between now and ten years ago is the number and types of available USB devices. All those peripherals may work well together until disk, bus and/or processor activity becomes intensive. Regardless of optimism there are always limitations. They kind of remind me of the Escalade SUV/Pickup trucks. Horrible pickup truck, poor SUV, and ugly as sin. Never seen wheels, steering wheel, gearshift, headlights, etc. on a palm-top/ereader/netbook/laptop/computer. This sounds more of mental condition and/or drugs. You missed the point and taking a second cheap shot won't help you find it. The Escalade is an analogy about multi-purpose devices in general, not about using a computer as a multi-purpose device. If you've never seen wheels, steering wheel, gearshift, headlights, etc. on a computer you haven't looked at today's passenger vehicles. There's more processor power there than on/under your desk. palm-top/ereader/netbook/laptop/computer It is time to end the stone age of electronics! I want faster, better looking, and higher performance. I don't want all-in wonders, which are always compromises. Must be boring never using any USB or ported peripherals, as your post indicates! Try it, you will find that "all-in-one-wonders" are great! Pure conjecture. Mike's post provides no insights concerning his use or non-use of USB devices. For all you know his computer might be surrounded by cluster of USB devices. |
Design Flaw in iPhone 4, Testers Say
On Tue, 03 Aug 2010 18:10:33 -0700, John Smith
wrote: On 8/3/2010 4:03 PM, Registered User wrote: On Tue, 03 Aug 2010 16:25:44 -0400, Michael wrote: John Smith wrote: It is time to end the stone age of electronics! I want faster, better looking, and higher performance. I don't want all-in wonders, which are always compromises. Amen brother! The reality of 'one size fits all' is 'one size fits no one especially well'. You are a godsend to the hardware manufacturers, they love you! Why would that be when you are the one purchasing multiple USB accessories to fulfill your supposed all-in-one vision. My TV, radio, stereo, MP3 player, DVD recorder/player, etc. all travel in my briefcase as USB Dongles or software. That size fits me well! ROFLOL It sounds like you're describing my 3 y.o. laptop that has all that hardware built-in. To use the box and all the devices it is simply a matter of booting up. There is no need to unpack and connect a bunch of peripherals. When done I can close the lid and go w/o the need to disconnect and re-pack a bunch of peripherals. It's much closer to being an all-in-one device than your box with all its external accessories. You might want to refrain from using the term 'USB dongle' to describe anything that plugs into a USB port. To each his/her own, regards, JS |
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