Astatic D-104 Silver Eagle Mic Mods

Astatic D104 Silver Eagle Mic

lollipop 

The D-104 range of mics were first and foremost communications grade microphones. Remember that fact and say it twice.

The were not design to be recording units,but for amateur\non-critical\radio use. In that role, and coupled correctly, the D-104 is a great communications microphone. Clean, CRISP, highly intelligible audio that makes each syllable perfectly understandable.

Larry King audio... nope.....ESSB audio...nope, but if you want that, spend a ton of money or use AM or FM. SSB was designed ( and works well ) to be an efficient, narrow bandwidth mode. The audio part of it was deemed acceptable ...and still is.


They always had crisp, CLEAN, and understandable audio.


Used D-104's usually need to be re lubricated, and it does not hurt to re-solder all contacts.  Adding a electret element to replace a working UNDAMAGED original element is pure folly, and there are those that have done it. Kind of like putting a Ferrari engine in a Corolla and then hoping somehow that it will be a Ferrari.

There is NOTHING wrong with the audio of a D-104 if one remembers what it was designed to do ,AND if it is not over driven AND is electrically and mechanically working.

Most new hams, however, have no idea of the tonal design plan that was incorporated into this mic and think it should sound like a studio mike. Then again, even experienced hams still believe that somehow, someway, SSB can become and deliver AM or FM quality audio easily. Sorry folks but there is one word preventing that.......BANDWIDTH!!

Astatic D-104 Silver Eagle Mic Mods

Astatic D-104 Silver Eagle Mic Mods

Modifications for even more basses and warmer sound

The D-104 has been around since the 30’s and is still popular today for communications. The current ones are still pretty much the same except that in the early 70’s a two- transistor pre amp was added to the base. The D-104 is considered by many to be the coolest looking mike around.

The early elements used a Rochelle salts crystal but later a ceramic crystal was used to make the element more rugged. These elements are unique in that the diaphragm is convex instead of concave. Although these diaphragms were made of aluminum foil, Astatic used an ingenious method of placing batting in contact with the element. This eliminated the “tin” sound of these elements and they are capable of a surprisingly good sound. The peaky sound that we sometimes hear from these mikes is due to improper loading, not the diaphragm material.

Without the pre amp, these microphones sound very good with tube equipment that provided a very high impedance load to the element.

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.