What you need is a GAIT phone, which has GSM and then switches to TDMA when GSM is not available.
Go to eBay and do a search, you will find many used GAIT phones for very cheap. Try one of those if you wish.
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Acc. to Consumer Reports the Siemens S46 and Nokia 3595 use GSM technology with TDMA as a backup, to help maximize coverage in AT&T?s networks. But they both are only average for voice quality. Any recommendations for similar multinetwork phones which have good sound quality/signal? I'm in Sacramento and also call to/from SF.

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