Slots 646 to 659 are left closed. Channels 646 - 659 use the paired slots on the No. 1 board. Open all 59 slots on the board. In this case it is recommended by Silvertone that single conversion receivers should not operate on this field, especially AM single conversion receivers which do not have the advantage of capture effect to mask the intermodulation problem. . The same rules concerning single or dual conversion receivers apply.
Some clubs choose to only allow odd or even channels on their field.
In this case open the appropriate odd or even slots as required. Again the same rules apply regarding single or dual conversion receivers. It is important to understand that if there is even one single conversion receiver in the club or visiting the club then the high numbered slots 646 - 659 on the No. 2 board should be left closed and the paired slots on the No. 1 board used instead. The simultaneous operation of two transmitters 450 or 460kHz apart is therefore not possible. Silvertone recommends that the only time all slots should be opened is when a club decides upon an exclusive dual conversion receiver policy with both odd and even frequencies cleared for use.