The KMC-2A and the KMC-22 should also work with the TK-840. ----- Original Message ----- From: Repeater-Builder@yahoogroups.com <Repeater-Builder@yahoogroups.com> To: Repeater-Builder@yahoogroups.com <Repeater-Builder@yahoogroups.com> Sent: Mon Apr 20 20:02:59 2009 Subject: RE: [Repeater-Builder] OT - Kenwood Microphone issue!
I forgot to include the info that the correct mike for a TK-840 or TK-840(N) is the KMC-18. 73, Eric Lemmon WB6FLY -----Original Message----- From: Repeater-Builder@yahoogroups.com <mailto:Repeater-Builder%40yahoogroups.com> [mailto:Repeater-Builder@yahoogroups.com <mailto:Repeater-Builder%40yahoogroups.com> ] On Behalf Of Eric Lemmon Sent: Monday, April 20, 2009 1:45 PM To: Repeater-Builder@yahoogroups.com <mailto:Repeater-Builder%40yahoogroups.com> Subject: RE: [Repeater-Builder] OT - Kenwood Microphone issue! Louis, I strongly suggest that you have the correct service manual in front of you before proceeding. Fortunately, the TK-840/TK-840(N) service manual B51-8287-10 is still available for about $20 from Pacific Coast Parts: <www.pacparts.com> The voltages you found do not jibe with those seen on similar radios. According to the TK-940 manual on the RBTIP, the mike jack pins are numbered right to left when looking into the jack. Perhaps you have reversed the numbering. When the numbers are reversed, they pretty much agree with what is in the TK-940 manual. Try this listing: Pin 1 (SB) Should be about 13.5 VDC Pin 2 (PTTG) Should be at ground potential Pin 3 (PTT) Should be about 4.7 VDC Pin 4 (MICG) Should be at ground potential Pin 5 (MIC) Should be 3k to 13k ohms to ground with power off Pin 6 (HK) Should be about 4.7 VDC 73, Eric Lemmon WB6FLY -----Original Message----- From: Repeater-Builder@yahoogroups.com <mailto:Repeater-Builder%40yahoogroups.com> <mailto:Repeater-Builder%40yahoogroups.com> [mailto:Repeater-Builder@yahoogroups.com <mailto:Repeater-Builder%40yahoogroups.com> <mailto:Repeater-Builder%40yahoogroups.com> ] On Behalf Of Louis Sent: Monday, April 20, 2009 11:38 AM To: Repeater-Builder@yahoogroups.com <mailto:Repeater-Builder%40yahoogroups.com> <mailto:Repeater-Builder%40yahoogroups.com> Subject: [Repeater-Builder] OT - Kenwood Microphone issue! Afternoon all! Sorry for being off topic, but I know there are a few on this list that have experience with these radios. One of these I have, will eventually be used for a repeater link radio, but for now, I am trying to resolve this issue with the MIC pinouts not matching up! Off board replies will be appreciated! Thank You! We have a pair of the 840(n)'s that are programmed for usage in the Ham bands. We did not get the microphones with them, so, have been working on a work around, even though there are some mics available! Anyhow, according to the known diagrams on the 840 microphone: Measurements taken with radio on, in a static mode connected to a dummy load (thus, no input) Pin 1 = 8.0 volts - mine is only 4.9 v Pin 2 = PTT gnd - this is indeed to ground Pin 3 = PTT - should be open, but this one is at ground Pin 4 = MIC gnd - this one is at 4.9 v Pin 5 = MIC input - this one 0 volts, open Pin 6 = Hook Signal - is at 13.87 volts (same as input) Some other notes: On the KCT-19 A-1 - MIC hook input is at 4.7 v A-2 - MIC grd - is at ground A-5 - MIC input - o volts, open A-8 - PTT input is at 4.7 v Now, with a Kenwood 8 pin microphone, with an adapter to the 6 pin, the radio keys, transmits, but audio is very low. Understandable, but low! There does not appear to have been any modifications done to the radios internally, other than the addition of the KCT-19 (done by myself recently) which is a plug in deal! The headset/boom mic I am attempting to wire for this radio, works on my Vertex and Yaesu's fine, with the proper wiring adapter. But with the pins not matching up with the schematics on the 840, cannot get it to work! Any suggestions, ideas, observations! Thanks in advance! Louis - K1STX
