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Flex 6600 + D-104 Microphone

Ray Member ✭✭
edited September 2018 in New Ideas
I love my Flex 6600 and I also have a soft spot in my heart, as many do, I suspect, for my up-until-now retired Astatic D-104 Microphone. It brings back so many happy memories of 40-50 years ago......

My D-104 is the original unamplified version (crystal element for working with the very Hi-Z audio-input tube rigs) with the plain vanilla "G-Stand." 

Heil Sound makes a "Heil HC-5.1 Retro Element Kit" that allows directly replacing the original D-104 crystal mic element with a dynamic mic element - everything is included in the kit.

So far so good, but the original D-104 mic element pin-out is Tip-Sleeve and the PTT is Ring-Sleeve on a single Tip-Ring-Sleeve 1/4' phone plug. I needed mic+, mic-, and shield/sleeve 1/8" mini-stereo plug for the mic jack on the 6600 rear panel, and a separate RCA jack for the PTT connection.

So I thought I'd use two cables taped together from the D-104 to the two mic and PTT 6600 jacks, but that would look a bit amateurish. I queried Mike VA3MW at Flex to see if there might be an old discarded cable that's used with the stock 6600 hand mic available, since it had a single cable/cord, professionally split off at the radio end with the exact plugs and plug connections I needed. Flex found one and sent it to me gratis (thank you Flex and Mike!) - I was in business.

I removed the RJ-45 connector at the mic end of the new mic cable, rang out the 8(?) wires in the cable, threaded the new cable into the D-104 G-Stand through the hole the original cable went through, and soldered the proper mic+, mic-, shield, and PTT wires from the cable to the internal connections in the mic stand. 

Thanks to the TX EQ sliders in the EQ tab of SSDR and the ability to do a "quick record/playback" of TX audio, it didn't take long to adjust the audio equalization to exactly what I wanted. Saved a Mic Profile for the arrangement (No Bias, +20db). 

Voila! 21st Century high-tech radio and my beautiful mid-20th Century D-104 sitting on the desktop in front of it. Life is good!

I think the above is clear enough for anyone to replicate what I did, but if not, feel free to contact me via my email address on QRZ.com.

Ray N6HE


  • VK7WH Winston
    VK7WH Winston Member ✭✭✭
    edited September 2018
    Thanks Ray, I very much appreciate you posting this information. The first microphone I purchased was in 1958, when I was a student in Melbourne. I paid 50 cents for an original D-104 with a crystal element. Sadly it was destroyed in the 1967 Tasmanian Bushfires, along with the rest of my gear. For purely sentimental reasons I managed to buy a mint condition D-104 at the Dayton Flea Market a couple of years ago. Going my the condition of the Mic and the Stand it is probably a replica, however it really looks the real thing. While I haven't yet opened it up to see what element it has, your article has spurred me on to connecting it up to my 6700. Thanks for posting the details of your experience. Winston VK7WH
  • John Watson W4JCW

    I have a D-104 and would love to run it on my Flex 6400...

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