This page focuses mostly on propagation.

1. Nature's Invisible Radio Mirror
   That's the Ionosphere. James F. Van Delta WA2FQZ, Radio Electronics Nov 1961
2. VHF Ionospheric Propagation
   George Jacobs W3ASK and Stanley Leinwool, CQ Magazine Nov 1969. Good reading.
3. The Mystery Behind TV DX
   Article on tropospheric bending from Radio-Electronics May 1951
4. Interpreting Test Patterns
   Ken Kleidon, April 1952 Radio and Television News
5. The Effects of Co-channel Interference on KVOO during the Summer 1942
   Analyzing Es effects on KVOO. See page 14-16.