If you are a repeater owner or just like to tinker with commercial equipment you might want to check out the documents here.
Starting with....

Radio Basics For the Newbie

RF projects Antennas, line, cavity, path engineering, etc.

Tower page Also some notes about equipment installation

DC and AC power page for supplies and other goodies

Link Radios page FM'ing a transmitter,receiver notes, COR/AF board, etc.

C.T.C.S.S. (PL) information (such as the Commspec TS-32 decoder)

Digital Page Packet, Computers, Internet, Networking, Firewall and analog telephone

Author's manufacturing Practices and standards

Soldering ideas Small little page

Some details for SRG Spokane side

Repeater operation Originally was an in-person presentation for a group

Here's some sites that have technical discussions. Some might be redundant, but check them out, as each of us has some slightly different ideas, and it's nice to share.

Repeater builders By Kevin Custer who has more Tech tips ! Excellent Page
Also takes care of the reflector, below.