http://long-lines.net/index.html

So much great information.  Did you know the horn antennas of 1955 had a 6GHz gain of 43dBi and were tri-banders?  (4+6+11GHz)  To get an accurate radiation pattern measurement the engineers of yesteryear utilized a pulse measurement technique, which lets you avoid reflections in your readings!  http://long-lines.net/tech-equip/radio/BLR1155/403.html

How about browsing a nice microwave map of Washington:

http://long-lines.net/places-routes/maps/WA76.html

Looks like AT&T made many of the same site choices the current HamWAN map has, but decades earlier.  I am in awe of what old timey engineers managed to pull off before I was even born.  And it wasn't just phone calls, they moved television over that network!

--Bart