[Yaesu] For Sale MD-100a8x 5 Volt Audio Filter Mod Kit

Thomas Giella KN4LF kn4lf at tampabay.rr.com
Fri Jun 27 12:14:08 EDT 2003

For Sale Yaesu MD-100a8x 5 Volt Audio Filter Modification Kit 

Many of us who own the excellent MD-100a8x desk microphone are painfully aware that we can not use
the built in audio filtering on many of Yaesu's rigs. The MD-100a8x was designed to be used with the popular FT-1000MP series and also the FT-900 and I think the FT-920. Rigs such as the FT-1000/D, FT-990, FT-890, FT-840, FT-757GXII, FT-747GX and others will not work with the internal active filtering of the mic, as these rigs do not supply the 5 volts output on the 8 pin male microphone plug necessary to power the mic. 

In the past Yaesu made available a technical bulletin that described a modification to allow the internal audio filtering of the mic to be used with most of it's modern transceivers. Unfortunately though the mod was complex and required physical changes to the rig and microphone that could be irreversible. 

I have designed a modification kit that overcomes the invasive and complex changes to the rig and microphone, to allow
use of the internal audio filtering. The mod kit comes with explicit directions, photographs and schematics, much like a Heath kit. The kit building level experience needed is just above beginner, requiring some simple soldering and the cutting of one easily restorable circuit board trace inside the mic.

The modification kit costs $29.95 plus actual USPS shipping costs. For an additional $10.00 I will build the kit and all you have to do is cut the one circuit board trace inside the mic.

For more information and questions email me at kn4lf at tampabay.rr.com . Later today I will place the mic mod on eBay and will post it back on the Yaesu email reflectors.

Thomas F. Giella, KN4LF
Plant City, FL, USA

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