Jim, this can easily happen with any brand of repeater, if audio is not adjusted correctly.
The transmitter has a deviation control, yes? Well, that control has <nothing> to do with what I am talking about. Some transmitters could have another control called -mic gain-, -mic sensitivity-, something else, or not have it at all. But there is an adjustment(s) somewhere in your audio chain that does exactly the same thing. This is <how much> audio you are feeding to your transmitter from your controller, BEFORE the clipper/filter. Normally, you first set the deviation control, usually for nominal 5 kc. deviation, making sure that the clipper is being "hit" hard enough to be the stage that is determining the max deviation. Now, you set the amount of audio into the transmitter, normally for maybe 2 kc. in/2 kc. out of the repeater. It is tempting to crank this a little, because the repeater audio gets a little louder, and louder is good, right? <g> But adjusting this to perhaps 2 in/3 or 4 out invariably causes noisy signals coming into the repeater to get (sound) noisier; the amount depending on how much you have cranked up the audio. I know, because I have, and am still tempted to do so myself. Check this ratio, and stick to 2 in/2 out. Laryn K8TVZ --- In [email protected], "Jim Cicirello" <[EMAIL PROTECTED]> wrote: > > 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 >
