If you are a repeater owner or just like to tinker with commercial equipment you might want to check out the documents here.
Radio Basics For the Newbie
Tower page Antennas and tower hardware; Also some cabinet modifications
Power Supply Page Different 12 volt types
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, etc.
Receiver Desense Testing system performance
Path Engineering Calculate Fade Margine
Author's manufacturing Practices and standards
Logarithmic measurements Forget "watts" and "microvolts"
Some 147.20 Details Spokane side
Repeater (system) Voter by LDG Electronics
Here's a clever idea. Ever wonder if your Weller solder station is really working? Put a 1 ohm shunt resistor in series with the 24v loop feeding the tip, then put an LED across that shunt. There's just enough voltage drop to run it. While you have the unit apart why not install a green one to indicate there is 24v power to begin with. (use the appropriate series resistor for the green one, of course. 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.
Repeater Builder's site You can sign up to get in with the group.
Hall Electronics Home of a nice voter, Tech area by Duane Hall, KA8GVH
A word about printing: You are welcome to print these technical documents for Amateur Radio use. Sometimes WYSWYG is not true; it can depend on what brand of browser you are using, plus many other variables. Some of them are browser zoom and font settings, if they override web page fonts (if any), your operating system's desktop-graphics screen and/or card settings such as screen resolution, fonts and aspect ratio. The Author's tired very hard for uniform printing results. The only browser successfully is I.E. 8.0. Earlier versions have not be tested. Firefox printing is not perfected at this time.