Some of the older cordless phones using the frequencies marked by the <*>
asterisk are paired with frequencies around 1.7 MHz. Listening to the 1.7 MHz
side will yield both sides of the conversation.
The best frequencies to monitor are the 46 MHz as they will repeat both sides
of the conversation. Power output of both base and hand units are less than
100 Mw or 1/10 watt so the range is limited. Careful monitoring will produce
some outstanding results. It is not uncommon to hear conversations up to a
mile away.