If you don't have one, you need one (Wattmeter). The unit pictured to the left was built by a craftsman. This old Bird (Bird Engineering) was nicely put together and fits with the nostalgia of the 310B-3 exciter/transmitter.

The unit to the right is the more modern unit fitted with the peak reading function. The Peak Reading function (note the push button switch on the side) will allow you to read the actual PEP delivered to the antenna. OK, OK it is an approximation but close enough for my work.

Various "slugs" (round device - diode) are selected for the application (power and frequency coverage). To read reflected power merely turn the slug around so that the arrow points in the reverse direction.