Have any group members looked in a telezapper please? I can find no information about how it works and the company seems to have gone out of business?

I have been using one successfully for a number of years, with the only problem occurring when someone picks up a line while it is in use: Then the tele zapper sends out the three note signal (THIS NUMBER IS NOT WORKING- TAKE IT OFF YOUR LISTS) in the middle of a conversation.

Recently I have had to change telephone systems from a 1.9 GHz to a 5.8 GHz one.

Suddenly the tele zapper has started giving out the signal 10-30 seconds into a call, for no apparent reason. And it usually blasts my eardrum with the signal two to three times in a row.

(It does still operate to get rid of telemarketers, - I can still detect it sending out the signal when the phone picks up and lots of telemarketers disconnecting immediately their computer-dialers hear the signal)

The coincidence of the system apparently failing when I changed phones seems too great for this just to mean that the device itself is dying but does anyone hear have any idea what is going on please? There is only one way to connect this device and turning it around hasn't changed anything