View Single Post
  #7   Report Post  
Posted to misc.phone.mobile.iphone,sci.electronics.repair,alt.internet.wireless,comp.mobile.android
Jeff Liebermann Jeff Liebermann is offline
external usenet poster
 
Posts: 4,045
Default WiFi sensitivity question for Jeff Liebermann & anyone well versed in antennas

On Sat, 30 Jul 2016 21:54:55 -0400, nospam
wrote:

the iphone 4 was not 10x worse.


Well, you're certainly entitled to an opinion. Personally, I prefer
opinions based on repeatable tests, measurements, numerical results,
and calculations. However, I'll accept your assertion for what it's
worth. However, I did make one mistake. The iphone wasn't 10 times
worse, but more like 6 to 18 times. Citing my web page:
http://802.11junk.com/jeffl/cellular/cell-test.htm
"The worst phone I tested dropped the rx signal 16 times
(-12dB). The iPhone 4 rx signal dropped 100 times (-20dB)
to 288 times (-24.6dB). That's a 6 to 18 times worse signal
drop for the iPhone 4... "

One problem was that I didn't have access to an iphone 4 at the time
of the controversy. None of my friends would trust me to jailbreak
their phone just so I could get a signal strength reading in dBm
instead of "bars". So, I had to use the test results from the
Anantech article. A friend has an iPhone 4 that he's not using, so I
could probably repeat my test given sufficient inspiration.

it was comparable to other phones and in many cases, those other phones
were substantially worse, even dropping to no service, something the
iphone 4 didn't do.


Yeah, that was cute. Initially, Verizon phones would stay connected
for quite a while after total loss of signal. I put a VZW iphone 4 in
a shielded box during a call, waited up to about 2 minutes, and was
able to resume the call uninterrupted. Nicely done by VZW. However,
AT&T was initially a different story. I did the same test with an
AT&T phone (not an iPhone) and found that it would disconnect after
only a few seconds. About a month later, after AT&T announced that
they had "upgraded" their network to match capabilities of the new
iPhone, it would also stay connected after 2 minutes of carrier loss.

palm pre drops to no service:
https://www.youtube.com/watch?v=zft3-Lwh2bo


I have an old VZW Palm Pre somewhere in the office. I'll try it on
Mon or Tues.

Interesting test. He's in a weak signal area. Grabbing the phone
drops the signal level enough to produce a loss of connection. That's
not surprising. It would be more interesting if he put the phone in
the Field Test Mode to see how much the signal drops. If the phone is
right at the bitter edge of disconnecting, and the signal drops a few
dB, I would expect it to umm.... disconnect. Note that all the phones
used in my test showed about a 9 dB drop in receive signal from a
death grip, which would produce exactly the same results in a weak
signal area as the Palm Pre.

droid incredible drops to no service:
https://www.youtube.com/watch?v=c4zbQ3f7H0U


This is almost as bad as the Pre test. Instead of being in a one bar
weak signal area, he's got 2 bars. I'm not so sure that the HTC Droid
Inedible (VZW only) has the antenna at the bottom. I tried to find it
on the iFixit teardown at:
https://www.ifixit.com/Teardown/HTC+Droid+Incredible+Teardown/42422
and couldn't find it. Other users are also having problems:
"FIX HTC INCREDIBLE S RECEPTION ANTENNA ISSUES"
https://www.youtube.com/watch?v=QHIdl1qrdkc (6:42)
Fast forward to 4:35 to see what he's done.
In other words, not the best phone or antenna system. Of course, the
author doesn't care about potential SAR problem.

droid 2 had serious issues:
https://techcrunch.com/2010/08/13/uh...ts-having-sign
al-issues/
The signal on one of the two units we received is all over the board,
dipping from full signal down to nearly none whilst sitting in the
same spot (and no, wešre not holding it wrong). Engadgetšs review
says that four out of four of their units show endlessly fluctuating
bar counts, and our buddy Rich Brome of Phonescoop says hešs having
bad luck with his, as well. Thats 6 review units, all showing signs
of signal woes. Not a good sign.


That's just a crappy phone. It could be anything from bad design, bad
implementation, bad parts, bad metering, or just having a bad day. I
assume that this has something to do with your defense of Apple, but I
lack the wisdom to make the connection.

Yes of course. Since I don't like Apple, every Apple is by definition
far worse than Android. Or course, for a nominal bribe, I can reverse
the situation.


that explains everything.


Even honesty has a price tag.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558