Is there a cheap db-25 cable tester like the cat-5 cable testers available?
I can buy 3 × cat-5 testers and build one I guess.
Only ones I see are near $100.
Still better than building one, but this is a budget project.

 

By DB 25 do you mean the RS232 version that was in use before the 9db?
I recall them being quite cheap, although I built mine many moons ago.
Max.

 

A poor man's tester could be built for very little.
A connector for each end which connects the individual wires in series with resistors at each end and then do one resistance check test to confirm connection. Two connectors, 24 resistors, one resistance reading, should be 24 times whatever resistor you use.

 

Mine just used a Green and Red LED on each line to indicate the status (+ve/-ve).
Also I found that having each side connected by jumpers I could select or configure as needed.
A gender changer can be used for 25D to 9D, if needed.
Max.