Good question, I can’t remember checking at the time.
One end was on a tripod around 2 m up with most of the test area down a ramp, once I got more than about 10 m away the ground level was probably closer to around 4 m below the fixed antenna. The other end was on the top of a survey pole that I carried around. That put the other antenna at around 2.2 m above the ground.
I had space to walk out to a range of around 120 m before I ended up in some bushes. We were on channel 4. Some quick back of the envelope calculations I make it that with those heights I should be ok to around 200 m before the ground bounce becomes an issue with that setup.