Scott Dorsey wrote:
K3HVG wrote:
Hmmmm. Crystal elements are, as pointed out, subject to failure
arguably far more frequently than dynamic and other types. I continue to
have good success with crystal D-104's, albeit I do take care of them.
Suitable replacement elements are still available at reasonable cost and
D-104's can sound very good on vintage AM gear.

Where are they available? The last I heard, CAD/Astatic was replacing
the crystal elements with dynamic ones if they came in for repair, claiming
they couldn't make the original crystal any more.

The crystal itself is sealed with a flexible goo... as long as that stays
sealed, it's fine, but as soon as it develops a small crack, atmospheric
moisture gets in.
--scott

OK... I probably should have been a bit more clear when I spoke of
replacements. What I meant was a crystal or dynamic element that would
fit the D-104. Your comments about the old Rochelle salt mic elements
are, of course, entirely correct. For further amplification of my post,
I just bought a couple of crystal elements from Mouser to replace an
element in a D-104 and a 10D head. They appear to work OK with adequate
output and good frequency response, especially given the usage on AM.
They are not original nor as big ones as in the original D-104 but with
a fabricated adaptor ring, they are good to go (and inexpensive!).
de K3HVG