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eHam Forums => Misc => Topic started by: KB1TJY on October 23, 2012, 04:40:03 PM



Title: MFJ-434B / Icom IC-718 / Heil ICM Microphone
Post by: KB1TJY on October 23, 2012, 04:40:03 PM
I am thinking of buying the MFJ-434B voice keyer which has received very good reviews on Eham.Net (4.2/5.0), the usual MFJ QA/QC issues notwithstanding. Are there any known incompatibilities with this unit, the Icom-718 and the Heil ICM microphone? More so specifically the Microphone as the MFJ-434B provides for the IC-718 via internal jumpers but I read about potential voltage issues with various microphones. I've sent Heil support and email but haven't heard back yet.

Any input greatly appreciated.

Many thanks,

Best,

Lyman
KB1TJY


Title: RE: MFJ-434B / Icom IC-718 / Heil ICM Microphone
Post by: KB5ZSM on November 16, 2012, 12:31:47 AM
Hey Skip, I see no reason for it not to work but to really verify I would need to look at the schematics (especially for the MFJ). I would be asking MFJ and not Heil but good luck getting an answer from them. Heil is usually good about answering questions. Icom usually has an 8 volt bias on their microphone audio pin. I would hope MFJ took this in to consideration. Your ICM expects to see that voltage and will not work without it.

Win (KB5ZSM)


Title: RE: MFJ-434B / Icom IC-718 / Heil ICM Microphone
Post by: KB5ZSM on November 20, 2012, 11:54:24 PM
I checked the MFJ manual and it will work. Just be sure to enable the 8 volt jumper behind the green LED.