Up for this thread - BBC Radio 4 is doing a 2-part feature on Wolfman Jack and station XERA and the 'Border Blasters' at the moment. A very interesting broadcast - and they also mention the goat gonad injections !
The AM signal could apparently be picked up in continental Europe if the tropospheric conditions were right.
The birds flying near the transmitter tower literally dropped out of the sky.
and it would seem that, prior to arriving at XERA, Wolfman Jack started off as a DJ playing soul-jazz stuff by Jimmy Smith, Eddie 'Lockjaw' Davis etc.