niggle [...] dollops

I love the way everyone talks over there. Really.

Can't help, other than to consider that PERHAPS, just maybe your antenna is expecting to be connected to ground to make it raise, then cut off to make it lower... i.e. Ground common..

Although I doubt it, I *HAVE* seen it. Just required a relay between the antenna and the driving wire..

I guess a check would be to see if the antenna goes down when it's disconnected from the tuner. If it does, then soemthing may have gotten shorted in the tuner box..

Me.