We were using the built in discriminator output (i forget which pin) but had unsatisfactory results because there is too much filtering between the discriminator and that output pin. So I went inside and found an unused wire running from near the front of the unit to the connector on the back of the unit and connected the wire to an easily accessible test point that was unfiltered discriminator audio direct from the discriminator. If you have a service manual then these points should be easy to find. The results with this new discriminator output were excellent.
If you need help finding the test point then I will have to visit the repeater site and pick up the manual that I left there before I can give any details.
Chuck