Hi Anthony,

An audio signal will give you 50% power because it is active during the 'high' part of the signal and inactive during the 'low' part. If you use the RF carrier, the active 'high' pulse is further reduced by 50% because of the carrier switching on and off at a 50% rate. Therefore you only get 25% overall power, however the frequencies are still there and they are still doing the job of penetrating body tissue.

Whenever I want to check for RF signals, since I can't feel them so easily, I quickly touch the handhelds across my tongue (lower power setting). Like testing a 9V battery. I don't have a GB4000, but I am pretty sure that it works the same way. Rgds.