How to write a card to unlock the US version of IPHONE4?

A new method designed by combining the above two methods (to be verified):

1. Unlock your sim card and get the imsi, ki, iccid and SMS center number of your own card.

2. Write imsi (brick corresponding service provider), ki (own card) and iccid (own card) SMS center number (own card) in the card number position 1.

3. Write your card's imsi, ki, iccid and SMS center number in the position of card number 2.

4. Insert the card and wait for 10 second, then dial 1 12 (no need to connect) and hang up within 2 seconds.

5. Turn on flight mode.

6. Select the card number 2 in the sim card application (some cards can be switched directly by entering a specific number).

7. Turn off the flight mode and you can receive the signal.

One advantage of using this method is that it saves the step of rewriting the card with the computer, and it does not need two cards to restart.

But if the card is unlocked, there will be serious signal drift when making a call.

I hope I can be satisfied.