Jim, If the end-to-end audio pre-emphasis and de-emphasis is not complementary, the audio will sound very bright, tinny, and noisy. Also, check to see if the audio is getting pre-emphasized twice- that will really make it bright. If you have access to an audio sweep generator and a digital storage o-scope, you can look at the audio responses and track down where it is not what is should be.
73, Eric Lemmon WB6FLY -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Jim Cicirello Sent: Saturday, November 03, 2007 8:11 AM To: [email protected] Subject: [Repeater-Builder] Micor Audio on VERY WEAK SIGNALS Hi Guys, A question for the MICOR fans that may have experienced a similar dilemma I am having with one of our three Micor Repeaters. All three are Micor VHF Bases, converted to repeater duty using the information I obtained from this group. All three have Cat 200 Controllers and unless I have missed something all are wired the same. When a weak signal, like from a portable radio or a station far away comes in I have quite a bit of background (white noise). I have noticed that if I listen to the audio from the Micor Speaker, it appears to me that much of the white noise is gone and the signal is much more understandable. Now this audio test is being performed with the TX on, so I have determined that there is no noticeable desense. The first thing I did was check the input audio into the Cat200 and make sure the voltages were set to the book, which they were. I have also taken into consideration that the Micor Speaker may reproduce the audio better than the HT or Mobile, but there is still enough difference that I wish the repeater audio, on weak signals only, sounded as good as the Micor RX direct to the speaker. I am using Discriminator Audio on all the repeaters and have the controller set properly for that. The only way to explain a weak signal is the background seems to be pumped up. Any ideas I will look into on my next trip to Pa. 73 Jim KA2AJH Wellsville, NY
