At The Equipment; Another Example - Progress Direct Systems Volt Tattler 2 Owner's Manual

At the Equipment

Setting up VoltTattler 2 at the equipment can alert an operator to voltage drops between the power
source and your equipment. In addition hearing the "roger" beep (Morse 'R', .-.) can audibly alert you if
the power dropped out completely and then came back again (intermittent connection). This can be
very useful in troubleshooting a system.

Another Example

Attaching VoltTattler 2 near a ham radio transceiver can also tell you that your voltage has dropped
during high current draining conditions such as a radio transmitting. Insufficiently sized power leads,
bad connections and waning batteries can all contribute to voltage droop. Knowing that there is a
problem can help you avoid improperly operating equipment. In this way we can avoid transmitting
spurious signals that can be generated by improper transmitter voltage.