Consumer Reports magazine said on Wednesday that Apple iPhone 4 owners can eliminate reception problems by enclosing their phones in the "Bumper" case Apple sells.
The findings could presage a decision by Apple to offer iPhone 4 owners a free Bumper, as the publication confirmed yesterday that it has been in contact with Apple over its testing results.
Two days after the respected consumer testing organization said it could not recommend the iPhone 4 because of major reception issues when users touched the external antenna, the publication's engineers went back into their lab to retest with iPhones equipped with Bumpers.
Apple sells iPhone 4 Bumpers -- small plastic and rubber skirts that fit around the outside edges of the smartphone -- for $29. Until the iPhone 4's debut, Apple had stayed out of the phone case market.
"With the Bumper fitted, we repeated the test procedure, placing a finger on the Bumper at the point at which it covers the gap [on the lower left side of the case]," said Paul Reynolds, Consumer Reports's electronics editor, in an entry on the magazine's blog on Wednesday afternoon.
The publication tested only Apple's Bumper, although another Consumer Reports editor said yesterday that it was planning on evaluating several different cases.
"The result was a negligible drop in signal strength -- so slight that it would not have any effect, in our judgment."
On Monday, Consumer Reports explained its could-not-recommend decision by describing testing of three different iPhone 4s in its radio frequency (RF) isolation chamber, where a cell tower emulator simulates real-world signals.
The magazine's engineers also tested several other AT&T-sold phones, including the iPhone 3GS and the Palm Pre. None of those phones showed the signal-loss problems of the iPhone 4.
Complaints about the iPhone 4's call reception surfaced within hours of its June 24 launch, as buyers griped that touching the external antenna -- embedded in a steel band that encircles the case -- often dropped calls or caused the signal strength indicator to plummet.
Apple acknowledged that holding the iPhone 4 could weaken the cellular signal, then a week later claimed that the iPhone 4's signal formula was flawed and promised to update the software.
Consumer Reports was not the first to say that a case, even Apple's minimalist Bumper, prevented problems: Users and bloggers, including some with extensive antenna design experience, have said the same in the last weeks.
Apple also recommended a case in its June 25 statement, one of only two public comments the company has made regarding reception complaints. "Avoid gripping it in the lower left corner in a way that covers both sides of the black strip in the metal band, or simply use one of many available cases," Apple said then.