Icom and D104

[n1tko]

Got it... Thanks for all the help!!
N1TKO

[N1LAF]

You can find a manual to the D104 here:

Click on 'D104' under Microphones (http://www.kb2ljj.com/)

This is what I would do:
D104(White) to ICOM(Mic)
D104(Blue) to ICOM(PTT)
D104(Shield) to ICOM(Mic Shield or GND)

If the radio mic jack doesn't have a voltage source:
D104(Red) to ICOM(GND)

If the radio mic jack has a voltage pin (8 Vdc)
- Lift The D104(Red) off the contact, remember this position
- Clip off the 9V battery connector close to the connector as possible
- Connect the battery red to the D104(Red) wire you just lifted off the contact.
- Connect the battery black wire to the contact thet the D104(Red) was connected to
- Connect D104(Red) to ICOM(VDC Output)
This will eliminate the need for the external battery.

I use a Turner +3 on my ICOM, and power to the mic amp comes from the radio's 8VDC pin on the mic jack, and works fine.

[N1LAF]

For IC-735

+8 VDC supply is pin 2.

I am looking at the 4-wire D104

>> IC-735 Pin 6 to D104 Shield (GND)
>> IC-735 Pin 1 to D104 White (Mic)
>> IC-735 Pin 5 to D104 Red (PTT)
The switch inside the bottom plate should be placed in the "E" position

If you want to use the radio to supply voltage for the D104 amp, then do this:
>> Disconnect the black wire from terminal 6 in the base, and solder it to the same connection point as the battery red wire on the volume control. Tape up the battery connector (so not to short on anything inside)
>> Connect the black wire to IC-735 Pin 2 (8Vdc)

The D104 has a current draw of 1.2 mA

[n1tko]

Paul - Thank you very much. I do appreciate it. I have to do a bit of restoration on the D104 and then I'll wire it.
Thanks again for the info (and Quick!!)

Take care and 73
Jerry - N1TKO

[ki4tzx]

Would this work for the IC 745? I have a TUG8 base with a 10-DA head that sounds pretty good on other rigs, and would like to try on the ICom.

[n1tko]

I don't know for sure Richard, but it worked on the &#% very nice!

[N1LAF]

I am using the 10-DA head on the TUG8 base on my IC-7000, with the mic powered by the radio (no batteries), and it works great

[K7KBN]

Quote[/b] (n1tko @ Mar. 30 2007,20:38)]I don't know for sure Richard, but it worked on the &#% very nice!
Jerry - you really didn't like that &#% rig very well, did you? http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

[n1tko]

Hello Pat - HA!!! It would appear that way.... If I remember correctly I only wrote Icom where the &#.... etc is. Strange.....
73 Pal
Jerry - N1TKO

[ki4tzx]

Thanks for the reply. I will try it on the &#% or icom and see which sounds better.

[N1LAF]

http://paulfelgate.com/hamradio/station.jpg
10-DA head on TUG8 base connected to ICOM 7000
The Turner +3 connected to the Kenwood TM742A
The batteries are for my camera

[w9gb]

D.C. DE-COUPLING ON ICOM RIGS
ALL ICOM transceivers have 'Phantom Power' their microphone inputs.
Icom borrowed this technology approach (and using elecret elments) from the recording studios (music industry), 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'll cover that in another addition of 'Harmonics'.

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!!!

To use any dynamic element on these phantom powered inputs (which should NEVER be applied to a mic input of a radio transmitter !!!) 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 GM 'VINTAGE' microphone as they will never be used with ICOM low impedance inputs.
http://www.heilsound.com/amateur/harmonics.htm#DC

[N1LAF]

Both the amplified D104 and the Turner +3 have decoupling capacitors.

The D104 and Turner +3 uses a 5uf (in series). The D104 has a 33K resistor to ground, where the Turner +3 has a 22K resistor to ground, and an RF decoupling capacitor. The resistors to ground are of sufficient resistance so not to have affect with the ICOM bias voltage on the mic line.