mic wiring

[KC9AJR]

Does anyone know if it is possible to wire a mc-50 mic to a modular plug for an Icom 706? I've already got 1 vote in each direction.

[K9STH]

It is possible to wire any microphone to any transmitter / transceiver. The real question is will it work! Most "modern" equipment uses "medium" impedance (around 600 ohm) microphones. If the MC-50 microphone has this impedance then it should work. If it requires a voltage to make it work then you will have to find some means of applying the voltage (if the rig doesn't have this available on the microphone connector).

If the microphone is of a higher impedance then you will have to match it to the impedance of the rig. Also, if it is high impedance you might have to build a preamplifier. If the microphone is "low" impedance then you will have to use a transformer to get it up to the impedance of the rig. Most low impedance microphones are "carbon compatible" and require a voltage to make them work.

As you can see, "off hand", I am not that familar with the MC-50 and am just "talking" in general.

Glen, K9STH

[K7FE]

You bet it is. Just follow the pin connection guide in your manual. You may need to solder on some wire extensions that will fit into the module connector.
73,
Terry, K7FE

[KD7WHQ]

Inline opposite sex connector, and an RJ-45 plug with CAT-5 LAN wire between.
Can be done.

[KC9AJR]

Would anyone happen to know the wiring diagram? The stock mic has some connections the mc-50 doesn't.

[N8YV]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (KC9AJR @ Dec. 04 2003,13:55)</td></tr><tr><td id="QUOTE">Would anyone happen to know the wiring diagram? The stock mic has some connections the mc-50 doesn&#39;t.[/QUOTE]<span id='postcolor'>
Be cautious&#33; Many ICOM rigs use a &quot;hot&quot; audio line, carrying what is known as &quot;phantom&quot; voltage. This is a requirement to furnish electret-condenser mics with +VDC. The audio line in a non-electret microphone often needs to be isolated thru a capacitor, to prevent this DC from toasting the voice coil and/or other circuitry. ICOM mics source their operating voltage from this arrangement, which precludes the use of external preamps and batteries.

I cannot say for certain this is the case for the &#39;706, but I have owned a number of ICOM rigs that have all employed
rig-supplied DC on the audio line.

[W9GB]

First, the Kenwood MC-50 microphone was an accessory for the TS-820 transceiver. The most common Kenwood connectors and their pin-outs can be found on the Kenwood web page:
http://www.kenwood.net/indexKe....CatID=6

Second, I recommend NOT cutting off the factory-installed connector on this microphone. The preferred method is to build a small adapter cable between your desired radio and the Kenwood MC-50 connector.
Heil Sound has the HSTA-706 - which may work for your application (if you do not wish to build your own - Heil can also build to a specific spec)
http://www.heilsound.com/hsta-706.htm

Tower Electronics http://www.pl259.com
and Mouser http://www.mouser.com
have appropriate female connectors IN STOCK to mate with the MC-50 connector.

Third, your Icom 706 manual will have the proper pin-outs for the 8-pin modular connector. The Kenwood microphone is a dynamic element. Most Icom radios use an elecret element. I pass this information from Bob Heil&#39;s web site:
All of these products work well with the great little IC 706. You need the ADM-706 modular adapter and with one of the new high performance Heil &#39;iC&quot; elements in the &#39;iCM&#39;, Traveler 706, etc. will make a new transceiver out of the little jewel. The IC 706 will NOT work well with our HC or Goldline elements, as the 706 is short on mic preamp gain, so you need to solve the low audio problem with one of the new Heil &#39;iC&#39; products. Be sure and adjust the carrier balance control (Q4 or Q6) for the desired transmit tone. This is VERY important.

http://www.heilsound.com/harmonics.htm#DC

All ICOM transceivers &#39;phantom power&#39; their microphone inputs. Borrowed technology from the recording studios, d.c. power to power the f.e.t. element is fed down the mic line. At the same time d.c. flows DOWN the mic cable the mic audio is fed UP the same wire. Of course this signal is a.c. D.C. flows one direction while A.C. flows the other direction - all on the same cable. Pretty cool huh?.....until you start having all kinds of RFI but we&#39;ll cover that in another addition of &#39;Harmonics&#39;.

The BIG problem with this is when you try using a REAL microphone ....the good old copper wound, magnetic bobbin, dynamic. Connecting a dynamic into your mic input will provide a nice short of the +8 v.d.c, power straight to ground. SMOKE CITY&#33;&#33;&#33;

To use any dynamic element on these phantom powered inputs (which should NEVER be applied to a mic input of a radio transmitter &#33;&#33;&#33;) the input must be de-coupled so the mic audio a.c. signal can pass through to the mic preamp and yet, block the d.c. voltage from that mic element. Simply install a 1 mFd. non-polar tantalum capacitor in series with mic lead. You may get by with a .68 or a .47 mFd but anything less (.01, .005 etc) will not pass any speech audio worth listening to). The cap MUST be a non-polar. This will keep the D.C. from getting across the dynamic element while passing the speech audio through the cap into the mic preamp circuitry.

All Heil microphones have a 1 mFd. capacitor inside. All AD-1 boomset adapters have the decoupling cap installed the 8 pin Foster connector. The coupling cap is NOT installed in our new high impedance GOLDLINE &#39;VINTAGE&#39; microphone as they will never be used with ICOM low impedance inputs.

w9gb