One of the old handheld Radio Shack frequency counters might work also
Radio Shack 22-306, LCD Frequency Counter, 1MHz - 1.3GHz
That won't work. You would need to be right on top of the transmitter and the bursts are so fast it's won't register. A longer transmission would be needed as I own one and plus their accuracy is not the greatest.
You get what you pay for.