At 3/14/2007 17:01, you wrote: >You completely missed the point. It's not up to the repeater to fix user >problems. Yes, it would be nice if all hams could properly maintain >their equipment. It would be nice if they could install a 3-wire CTCSS >encoder that has +, ground, and audio out. It would even be nice if all >hams knew how to actually operate their equipment. >---> But enough with fantasy-land <---
This is an issue where there are clearly 2 camps & neither is IMO clearly right or wrong. In regards to my own system, I agree: goesouta = goesinna except for necessary CTCSS stripping at the link hub TX. However, adding quality processing can certainly add value to the system in improving users' intelligibility. An excellent example is Jeff DePolo's linked system in eastern PA. It's been a few years since I've driven through that area, but I remember how good it sounded even when the output signal was near the 12 dB SINAD point in my TM-G707 mobile. As far as "flat audio" goes, I consider the links in my system to have "flat audio" even though the TXs use phase modulators. What I do is begin the RX deemphasis curve around the low end of the CTCSS range (50-60 Hz), & apply the TX audio directly to the CG input (phase modulator). This results in a "flat" response from 60 Hz all the way up to beyond 4-5 kHz. Not quite as good as direct FM due to the low-end PM distortion problems documented by Dave Karr a while back, but at UHF with the higher multiplication factor, it's acceptable to me. Certainly easier not having to worry about pre-emphasizing every non-radio audio source (tone generators, speech synthesizers, autopatches, etc.) as you need to do with the "unprocessed audio" repeater controller. Bob NO6B
