On Mon, Sep 21, 2009 at 11:09 AM, Gerald Stockinger < cliogunsm...@centurytel.net> wrote:
> > Good morning to all. Since I will soon be new to AM having been on SSB > since 1957 I need the benefit of others experience. Last week a good > amount of time was spent on audio quality so I thought I would ask here. > The rig is a Collins KW-1. I need a good quality (broadcast if you will) > microphone to use with it, I have a deep voice and I sound terrible on a > 300 to 3000 mic. I need more lows than that. I welcome any suggestions > on what microphone might fill my needs. > Welcome to the KW-1 club, Jerry. I've had mine since 1988, pretty sure it was my first AM transmitter on the air too, otherwise the 32V gets the honor. Rob brings up a good point: where your transmitter fell in the production (first or last half, basically) will determine how it will sound with any mic. Later production units had tighter audio and require a fattening of the coupling caps along with a few other tweaks to get better audio. Later models had better plate blocking and a few other perks though, so it all evens out. Required reading IMO if you don't already have it is Electric Radio #23, March 1991. It's a special edition entirely about the KW-1 with stories from then-current owners as well as an article by Jay Bromley W5JAY (then KA5DGH) on making audio improvements to the transmitter. I did most of these mods from a sheet sent to me by Uncle Ed, WA3PUN who is a former owner. Basically, bypass the clipper and splatter choke, fatten up the coupling caps from .01s to .1s, and change the grid resistor in the 12AXY mic input circuit from the stock 1 meg to 4+ megs (Jay suggests 5M or more, but I used 4.7 and it sounds good). I didn't replace the 872s with SS sticks, but instead used 4B32s which are a drop in sub that you can find with the same glass envelope as the 872s if aesthetics are important. I've always used a crystal D-104 with excellent results, both on the KW-1 and 32V. These mods are pretty much tailored to that impedence. Another good ER issue to read on this matter is October '93 #54 I think. Gary Halverson gives an excellent explanation of mics, audio, and what's involved. Personally, I've never heard a Heil mic I liked, but I haven't heard the newer ones and it's just my opinion. As soon as you start adding processing to change characteristics, it all goes out the window IMO. Gary's article is good for this info, such as having to equalize and boost the ribbon mics and such. Nothing against processing, but if you do the simple mods to the audio of your transmitter and plug in a decent D-104 (make sure the element is in good shape with a scope), you'll be very pleased. If you want to go the processed sound route, simple feed it into the phone patch jack (you'll still have to do the other mods) and you're good to go. You can probably make a soup can sound decent with enough processing, so mic choice becomes more a choice of preference and less one of performance. ~ Todd, KA1KAQ/4. ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Post: AMRadio@mailman.qth.net To unsubscribe, send an email to amradio-requ...@mailman.qth.net with the word unsubscribe in the message body. This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
