grr, well most networks set the ring time to 15 seconds then divert to voicemail. You can change this to a value between 0-30 seconds.
you have to enter a feature code on the handset (as if dialling a number then hit send)
so if you want to increase the amount of time the phone rings to 30 seconds and your on orange you punch in
07973100123 is the standard orange voicemail number
press call and the phone will confirm the request
hope this helps
please note: different operators have different voicemail numbers and can be particular how they are entered for this command, for example Vodafone’s voicemail number is 121 and thats exactly how it’s entered, but orange needs to be 07973100123 even though 123 and +447973100123 are correct the command will be rejected unless you use 07973100123
I was wanting to do the same thing – ie extend the ring time before voicemail. If you are on Orange, try this… worked for me.
Step 1. Key into your phone *#61# then press the call button. This will return a telephone number and, on smartphones such as the Hero, the current delay time before voice mail kicks in .
Step 2. Write it down. (For Orange, the number should be 0793100123 and the delay 20 seconds)
Step 3. If you wanted, say, 30 seconds, before the Voice mail activated, then you would put 30 where the nn is in the following string and the telephone number from step 2 where the xxxxxxxx is.
Key in **61*xxxxxxxxx*11*nn# followed by the call/send button and it should update the delay.
For example, if I wanted a 30 second delay, I would key in **61*07973100123*11*30#
To check it worked do step 1 above again and it should report the new delay.
My HTC Hero on Orange came with a default 20 second delay, and 30 seconds seems to be the longest you can set it for.