Date: Fri, 2 Mar 2001 19:28:08 -0600 From: "Dave & Judi Jaksa" Subject: RE: [Elecraft] KSB2 and Heil HMMIC Hand Microphone No Power Steve, I had a similar problem with my Heil mics which are wired for Kenwood radios. I am assuming you do not have a preamp in the mic. If that is the case, you probably don't have enough audio from the mic. To solve this problem, I increased the value of R14 on the KSB2 board from 1K to 10K. This change presents a higher load impedance to the mic which has a nominal impedance of 2K. The single resistor change has been enough to solve the problem for several of us who are using Heil mics. With the resistor change both my Heil HM-10 Dual desk mic and my Heil Pro Set drive the K2 to full output with a 1 to 2 bar ALC indication. The monitor scope Christmas tree pattern looks good too! Hope this helps. 73, Dave, W0VX - -----Original Message----- From: owner-elecraft at qth.net [mailto:owner-elecraft at qth.net]On Behalf Of steve Sent: Friday, March 02, 2001 5:51 PM To: elecraft at qth.net Subject: [Elecraft] KSB2 and Heil HMMIC Hand Microphone No Power I recently completed the construction and installation of a KSB2 in SN 1741. All works well on receive and I did the coarse carrier balance adjustment with no problems. Since none of my microphones had an 8 pin plug, I purchased a Heil HMMIC hand mike and wired the KSB2 for an Icom microphone as listed below. AF pin 1 PTT pin 5 DN pin 3 5V pin 1 thru a 10K resistor GND pins 6 and 7 There is no DN button on the mike, but the PTT works and audio is getting through because I can hear myself on another receiver, but there is no measurable RF output unless I yell into the mike. Even yelling only produces a small blip on the SWR meter. If I turn on the 10 dB pad there is a noticeable drop in the audio on my monitor receiver. I am looking for an answer so I can hopefully be in the ARRL SSB DX Contest this weekend. 72, Steve - -- LINUX Where /sbin/init is still job 1 Steve Kalafus W9NQP Phoenix, Arizona stevekalafus at inficad.com