The Hantronics is a good starter repeater to learn with, but you will
notice as you get better equipment, the quality of the system will
greatly improve. Look into a Yeaseu or Kenwood repeater or commercial
repeater. Cheap is good, but like they say, you get what you pay for.
Look inside the case and make sure that the transmitter and receiver
are completely shielded from each other as well. You are getting a RF
leak into the receiver is what is causing the choppy affect if it isnt
shielded.

To go cheap and really good quality get a comercial transceiver or two. The
GE Mastr ll is one of the best ways to go. Well shielded and sharp tuning
receiver. They can be had for less than $ 100 and about half that much more
for a set of crystals. Then add a controler such as a Cat 300 and you have
less than $ 500 in the basic unit. Then you add the expensive stuff such as
a duplexer, feedline, and antenna.