Hey, I remember those "transit" antennas! We maintained Capitol Trailways in Harrisburg, PA. They started out with "bird killers", but kept loosing the long whips, so they installed these and they were low band version made by Antenna Specialist. You had to keep them up as telemetry from the engine and transmission was sent out along with voice, they did not receive it, service call. I do not remember replacing any.