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can you wire an astatic microphone to an yaesu 857-D

Posted: Wed May 30, 2007 3:15 am
by KC2RKS
can anybody please tell me if an astatic mic can be wired to an yaesu 857-D. i picked up a real nice astatic desk mic with the bullet head i heard they sound good on sideband,it is amplified,can anybody please help?
thanks
KC2RKS

Astatic Mic

Posted: Sun Jun 03, 2007 7:11 pm
by N8PQB
First let me make a broad statement.
Any mic can be wired to any radio.
Now before I get flamed let me clarify this statement.

The purpose of the mic is two-fold, One to key the transmitter, and secondly to convert the moving coil into electrical signals that can be converted back into speech.
Will an Astatic mic work WELL on every radio, probably not. My suggestion is that you direct the question directly to the Astatic folks. Not all mics use the same kind of element, depending on the requirement of the radio, some mics sound better than others. Once again, your best source of information is the factory direct. Most have technical support groups.

Posted: Wed Jun 06, 2007 2:33 am
by KC2RKS
has anybody ever put an astatic microphone on a yaesu 857-D.if so can you tell me how .i tried to wire it from the astatic page and it did not work.
thanks
Bob
KC2RKS

Posted: Sat Jun 23, 2007 2:51 am
by KE3WD
Bullet head was a crystal mic element although i do seem to recall some that might not have been. dynamic then. The dynamic element would be the better choice for this radio, hands down. Sometimes the dynamic element had a transformer located inside it to allow use on the older rigs, which were all High Impedence input. If that is the case, you could bypass the transformer and it would likely match the Low Impedence input of the newer rig. But the preamp would have to be bypassed down in the base, too.

Astatic with bullet head is very likely to be a High Impedence xtal mic.

Modern transceivers like that 857 have Low Impedence input.

If mic is hooked up properly, meaning to the correct terminals, likely you won't get much if any output because the Low Impedence input will load down the High Impedence output of the mic.

Heil makes a mic transformer for impedence conversion, so does Shure and you can get a knockoff of the Shure at a Radio Shack. Looks like a tube with XLR on one end and 1/4" on the other, open it up at the XLR end where the little screw is on the side and remove the internal transformer, noting the high impedence from low impedence side, and hook it up inside the base of the Astatic mic such that low impedence (typically 2-wire side of xformer) is connected to audio coax to rig, high impedence (typically 3-wire, try the two outside wires first) to output of preamp, if too hot use one outside and middle) and tack the tiny transformer under the base with a dot of hot glue to the plate.

It will likely look real cool and sound like crap with too much treble at the other end, but there ya go. Also very easy to overdrive the new radio into SSB splatter. Start with the preamp control turned darn near all the way down, a (very!) slight tweak until audio just starts is in order here. Overdriven sideband is not a readable signal at all.

Have some fun experimenting with the thing, though.

Hey, its ham radio, this is a hobby.


73,

d-104 to yeasu

Posted: Mon Aug 27, 2007 9:30 pm
by w2rdt
Hi, I just wired my d-104 for my ft-726r unit.
On dx/mods,. there is a mod consisting of chocks-fet-resistors
this will give you true fm audio. mine worked without the
mod, but it is very tinny sounding due to the terrible
mis-match of impedience.
Good luck
Russ==KC2RKO

WORDS OF A MASTER HAM

Posted: Fri Oct 05, 2007 7:16 am
by Mark Johnson
WAS A BREATH OF FRESH AIR TO READ THAT POST ON WIRING THE ASTATIC BULLET TO THE NEW RIG SEEMS HE'S BEEN THERE AND DONE THAT A FEW TIMES AND LIKE A GOOD HAM HE'S WILLING TO SHARE EVEN MINUTE DETAILS OF HIS FINDINGS I WAS VERY HAPPY TO READ SUCH A QUALITY POST. TO HELP ONE WHO SEEMS A LITTLE LIKE A NEWBIE, NO INSULT INTENDED I WAS A NEWB BACK IN 54 AND CRYSTAL MICS WERE STANDARD
AND NO DIGITAL READOUTS,OR UP DOWN BUTTONS ON MICS EITHER...SEEMS MUCH SIMPLIER BACK THEN TILL YOU REMEMBER CALIBRATING TO WWV.........73'S :shock: :D

More information please...

Posted: Fri Oct 05, 2007 1:03 pm
by K4ICL
If the bullet mic is a hi-Z model, it will sound distorted on you lo-Z (low impedance) transceiver. You can connect it but unless the hi-Z is converted to lo-Z it will be distorted. For example, the D-104 is a high impedance (hi-Z) mic. This is why is sounds bad on a 600 ohm (lo-Z)) transmitter or transceiver.

There is a cure. Use a hi-Z to lo-Z impedance matching transformer or build a relative simple hi-Z/lo-Z matching network.

The bottom line: the effort expended to make the bullet mic work might not be worth the benefit. The effort is not trivial and will go beyond just wiring the mic to be functional on the rig.

Cheers,

AL

Posted: Fri Dec 10, 2010 10:34 pm
by jakjamm
KE3WD wrote:Bullet head was a crystal mic element although i do seem to recall some that might not have been. dynamic then. The dynamic element would be the better choice for this radio, hands down. Sometimes the dynamic element had a transformer located inside it to allow use on the older rigs, which were all High Impedence input. If that is the case, you could bypass the transformer and it would likely match the Low Impedence input of the newer rig. But the preamp would have to be bypassed down in the base, too.

Astatic with bullet head is very likely to be a High Impedence xtal mic.

Modern transceivers like that 857 have Low Impedence input.

If mic is hooked up properly, meaning to the correct terminals, likely you won't get much if any output because the Low Impedence input will load down the High Impedence output of the mic.

Heil makes a mic transformer for impedence conversion, so does Shure and you can get a knockoff of the Shure at a Radio Shack. Looks like a tube with XLR on one end and 1/4" on the other, open it up at the XLR end where the little screw is on the side and remove the internal transformer, noting the high impedence from low impedence side, and hook it up inside the base of the Astatic mic such that low impedence (typically 2-wire side of xformer) is connected to audio coax to rig, high impedence (typically 3-wire, try the two outside wires first) to output of preamp, if too hot use one outside and middle) and tack the tiny transformer under the base with a dot of hot glue to the plate.

It will likely look real cool and sound like crap with too much treble at the other end, but there ya go. Also very easy to overdrive the new radio into SSB splatter. Start with the preamp control turned darn near all the way down, a (very!) slight tweak until audio just starts is in order here. Overdriven sideband is not a readable signal at all.

Have some fun experimenting with the thing, though.

Hey, its ham radio, this is a hobby.


73,
Thanks for the information .....

Jak