Astatic D-104 Silver Eagle Mic Mods Connection to Yaesu

Astatic D-104 Silver Eagle Mic Mods Connection to Yaesu

Astatic D-104 Silver Eagle Mic Mods Connection to Yaesu


The Astatic D-104 desktop microphone has a very sharp sound due to it’s crystal microphone capsule and it has also has a great preamp to get enough voice level in the transceiver that gives you a great advantage for DX. Also the sharp modulation is heard better through noise on your QSOs.

But the mic doesn’t sound well on all transceivers cause of their internal high-, low- or band-pass AF filters. On most modern transceivers the modulation sound too much sharp or tiny cause of the lost of basses.



So in my research according to other Ham ops modification, I found out my best results by doing this:

• Put 3 holes with a needle in front of the capsule
• Change 3 capacitors of the internal preamp
• Add a resistor in the preamp input in the green line which is coming from the capsule and is going to the input of the preamp
• On some transceivers it is possible to shorten the “Mic Line” of the PTT switch to suppress contact losses on old or dirty PTT contacts. This eliminates the scratch sound on your transmission.
• On some transceivers you can use the +9V line of the mic socket to supply the D-104 and the to save the 9V battery for the future. That also gives the same audio output and sound all the time because the 9V does drop after a while of use. I have done this on my Yaesu FT-450D and FT-897.

This mod will give you a very powerful crisp clear modulation with additional basses and the D-104 should work with all transceivers very well. But it is surely depends on their built-in filters and EQ settings. You can’t get superb modulation when the transceiver doesn’t sound good as well.