[Boatanchors] Mic's / RED FLAG

[Todd, KA1KAQ]

On Mon, Jul 18, 2011 at 12:58 PM, Greg Mijal
<bluebirdtele at embarqmail.com> wrote:
> I'm wondering if something else is not correct with the transmitter's audio
> section.  The D-104 has tons of voltage output due to it's large size.  The
> Kobitone has less voltage out.  The only way a Kobetone would make an
> improvement is if Larry has a bunch of bad d-104 heads.  I suggest driving
> the audio with a signal generator to find the correct amount of audio
> voltage to get the job done, then compare it with the D-104's.

I agree with Greg - if for no other reason than the Kobitone is a
compromise at best over the original D-104 crystal element. True, if
you have a dead head, it's a definite improvement.

Possibly there's a problem elsewhere causing your symptoms, Larry.
D-104 crystal heads vary in output due to age, deterioration, and
other factors, so it's possible that one just has higher output than
the others and it's enough to show up in your test. Go the sig gen
route to confirm the mic heads as the problem before you write them
off. If it works fine and the heads are dead, nothing lost.

While these Astatic crystal elements will age and deteriorate with
time, they seldom just 'go bad'. More often it's a gradual degradation
of performance. I've got one here that came with a transmitter I
bought in an antique shop in 1988. It was an old(50s-60s), used mic
then. It's been used since as my primary mic until recently, has been
knocked over several times(once or twice from desk to floor), and
still works great. Greg has heard it on air. Sure, I'm lucky as hell,
but it also shows that the argument of absolutes is a foolish
approach. They can and do go bad, but that doesn't mean they
automatically are bad.

If your D-104 heads are crapped out, the Kobitone will be a good option.

~ Todd,  KA1KAQ/4