iPhone 4 loses 90 per cent signal strength

In tests conducted by German consumer group Stiftung Warentest, Apple's iPhone 4 was shown to lose up to 90 per cent of its signal strength when held in such a manner that a finger obscures the antenna dimly located on the outside of the gadget.

The outfit's laboratory tests show that the fact that the antenna is located around the outside of the phone makes is far more likely that the phone will suffer dropped calls when the user covers the blackspot at the bottom left-hand side of the phone with their fingers.

"In weak network areas this can break the connection," the outfit writes (our translation). "Internet connections become painfully slow."

Stiftung Warentest tested two other unidentified smartphones which have the antenna located in the the handset in a more conventional manner. The tests showed that these too can register a drop in signal strength but only by around 25 per cent.

In this case, conversations in areas on low coverage are still possible. Even the iPhone 3G, which has its antenna in the body of the phone, performs much better than the iPhone 4, the outfit writes.

The tests show that using a cover - or Bumper case, as Apple calls them - can improve matters somewhat.

Apple is shipping these out to poseurs who took the plunge and bought an iPhone 4 early, although you will have to install an App to get yours. Delivery can take up to five weeks, apparently.

In the meantime, use a land line.