I like these Zetron controllers for my repeaters.  Although they stopped being made many years ago, They are available in the used market and usually at a fair price.

Here are some tips and information I put together from my latest project.

This one is the Zetron 38a

I have had these same controllers with different names on the front including Johnson and Kenwood, but they all seem to be Zetron on the inside.

I program these on the workbench using a pair of Motorola mobile radios to get the controller close to where I need it and to test it out.

Programming is easily done from the front panel of the controller using a laptop computer running a program like Putty.

Here are some screenshots:

Also, Thanks to Repeaterbuilder for a lot of the information about controllers and Motorola radios.

http://repeater-builder.com/zetron/zetron-index.html

More to follow.

Zetron 39 on the Analog MSF5000 UHF Repeater.