[jagolden]

Day 3 on an 8330 for Verizon and I've some got concerns on the performance of the phone's radio. Most calls made were from home (where I have always gotten a strong signal) have been really good, but a couple of times the other party complained of slight echoing. The sound was always been very good on my end.

Signal quality varies any way on how you look at it.

• FWIW, usually three, rarely 4 bars on the indicator.
• "Check Signal" on the voice system usually reports low to good, sometimes high. It seems to have no relationship to the amount of bars or what is reported on the status screen.
• The status screen shows strength ranging from -86 to as low as -101 dBm, usually in the -90's. Sitting here next to the window on the 4th floor of my office, the strength is varying from -81 to -96 dBm, but usually in the -90s. (Coverage is usually strong in this area)

I was at a Verizon store yesterday (for another reason) and while there compared the signal strength of my 8330 to other BlackBerrys including Curves, 8830s and Pearls. All of the display phones were showing about 6 dbm more than my Curve when held side by side (-80 dbm vs. -86 to -92 dbm)

The difference of in signal strength between my 8330 and the display units seems to be odd. My 8330 is updated with the latest software provided by Verizon. I am finding that signal strength varies with how you hold the 8330.

Couple of questions -

• Does there seem to be a low signal strength problem with my particular 8330?
• What are normal acceptable values in dBm for signal strength?
• Why does the signal strength seem to fluctuate so much?

[jeffh]

-6 dBm is a lot. You're seeing 1/4 the signal level of the other phones in the store. I don't know about 8330's in general, but I think you might ought to consider replacing that particular phone while you can. It may have a poor electrical connection to its antenna, esp since you also report a large signal fluctuation based on how you hold it. My 8830 normally reads -80 dBm with 5 bars. -100 dBm is on the low end of a reliable connection.

[JRSCCivic98]

Reprogram your phone one more time and recheck. *22899 Send and wait for it to do it's thing. I noticed similar issues as well.... too early to conclude anything.

[jagolden]

JRSCCivic98 - Just tried reprogramming and saw a bit of a difference. There is still a tremendous amount of fluctuation in signal strength, but the higher end is now better. That said, sitting here on my desk its going from -81 to -96 dBw for no apparent reason. It seems to be a great deal of variation given the fact that I am line of sight from a VZW array about 0.25 mile away. The signal strength always drops when picking it up.

I think I may just return it all to Verizon and revert to the old phone and plan. The idea of getting into the tech support/switching out phones loop really just leaves me cold. The Curve does a lot of things well, but the phone function is foremost.

What kind of issues are you noticing?

[jeffh]

...sitting here on my desk it's going from -81 to -96 dBw for no apparent reason. It seems to be a great deal of variation given the fact that I am line of sight from a VZW array about 0.25 mile away. The signal strength always drops when picking it up...

Signal strength can vary for many reasons. The electromagnetic environment around you is probably the biggest single factor. But 15 dBm is a HUGE variation. Do you see the same thing when you're on another cell site; at home, for instance? If it varies that much everywhere you go, especially after you updated the PRL per JRSCCivic98, then I think you have a bad phone.

If you want the features of the phone, I wouldn't give up on it, just exchange it during the 30-day window.

[Pete6]

You should certainly change your phone. Why? If the second one deos the same thing then it is not the phone.

The signal strength variations you are seeing are large but are not out of order. A quarter mile from the tower an inside a buoldig when using CDMA is likely to give 10 - 15 dB variation. Especially if you are wearing a metal wristwatch or if your hands are damp.

The frequencies involved are liable to absorbsion by any number of things around them.

As JeffH says, 6dBM is 1/4 power because decibels are a logarithmic sacle and a 10db difference it 100 times more (or less).

This may sound a lot but the power levels involved are tiny when compared to the 0dB reference of 0.775v into 600 Ohms.

Hence you tend to get large swings because the Effecive Radiated Power (ERP) is measured in microvolts (millionths of a volt) thus a tiny change in the signal path can have a large effect on measured signal.

[Optimus_Prime]

about the dBm, what is better?
the lower the number or the higher the number?
fr example
-72dBm vs -80 dBm
Thanks

[jeffh]

The less negative, that is, the closer to 0 dBm, the better. -72 dBm represents over four times greater signal strength than -80 dBm. I typically show -80 dBm with 5 bars.

[JRSCCivic98]

I think I may just return it all to Verizon and revert to the old phone and plan. The idea of getting into the tech support/switching out phones loop really just leaves me cold. The Curve does a lot of things well, but the phone function is foremost.

Don't be discouraged. As long as you're within your 30 day window, go back to the store and ask for a replacement. Tell them it drops calls and has signal fluctuations. Make sure you take the box and everything you go with the phone with you. They will swap the phone for a NEW one in the store. If they refuse, ask to speak with a manager because that's the company policy for VZW. Anything after the first 30 days will be replaced with a refurb phone, so catch it early on and you're good.

[jagolden]

At the risk of this turning into a science project, I thought I'd check back in with a field report (because I am a scientist).

I didn't get a chance to change out the 8330 but I did notice that for the past two days the signal strength has been solid - ranging from -80 dB to -86 dB or so and unusually showing four bars. Today, it seems that the fluctuations are back, but not as bad as a few days ago. Its pretty steady sitting there, but drops by up to 10 dB when I pick it up - but still shows 3 bars.

The difference seems to be weather related. Rainy days seem to be associated with overall lower but highly variable signal strength as compared to fair weather performance. RF levels and fluctuation were "worse" on Monday when it was raining heavier than it is today. "Best" performance was on fair weather days. Could rain make that much of a difference?

As far as the bars on the 8330 go - four bars seems to mean -80 dB or better. Three bars seems to be from ~-81 to -100 dB. Never saw 1 or 2 bars, so I don't know how low this can go and still make and hold a call but if the phone works on 1 or 2 bars, its pretty impressive.

Its also become clear why most manufacturers provide only non-specific signal bars and keep actual readings safely tucked away on PIN protected field test screens...

[jeffh]

Rain can certainly affect RF. In my experience, wet foliage attenuates 2-meter FM; of course, that's much lower frequency than cell phones. Heavy rain can also block satellite tv reception temporarily, usually just when you need a report about a severe storm! But one of your earlier posts reported significant variations between your phone and other handsets while standing in the phone store, where whatever the weather was, it should have been affecting all devices equally. I still think you need to replace that handset while you're in your 30-day window.