How do you use the internet? Do you have a phone signal?
There's a reason all of the HFT folks are using microwaves.
[1]The voltmeter is for quick feedback on the signal level as you aim. Many high-capacity wireless radios have a connection point on the back that will adjust voltage to match the current receive signal level (measured in dBm). That's usually the fastest way to watch the signal level as you aim, especially if you're hanging off a tower while you do it.