Richard Knoppow wrote:

I am not surprized that no one makes crystal or ceramic
elements any more. For the most part microphones to fill
similar applications now are electrets.

Actually, there are a few companies making ceramic elements for military
applications. They can stand abuse that would kill even the Gentex military
electrets.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"Scott Dorsey" wrote in message
...
Richard Knoppow wrote:
"Scott Dorsey" wrote in message
...
coffelt2 wrote:

I am currently using an old Turner microphone and like
the
way it sounds.
Also I am a fan of some of the older EV desk
microphones,
which still turn
up cheaply at hamfests. If you find a low-Z mike that
you like, there is
no reason you can't just stick a step-up transformer in
the base to drive
the Viking.

Which model Turner?

Model 252. Low-Z version of the 250 with the lift switch
(which I strongly
discourage the use of). If you were using a Viking II you
would probably want
the 250 or to use a step-up transformer.
--scott

My one and only Turner mic is a 999, a low impedance
dynamic. I came into a windfall of good impedance matching
transformers (UTC 01 Ouncers) so matching is no problem. Its
a decent mic but may not be representative since I had to
remove a dent from the diaphragm. This can be done with
sticky tape and great care. The mic sounds good, less rise
in the high end than my Electro-Voice 635. I think this is
probably the original sound.
Turner seems to be the only one of the original big
four makers of PA mics that did not survive. Astatic,
Electro-Voice, and Shure Brothers all managed to navigate
the vicissitudes of life.
American Microphone was another company who did not
survive. Their last line of mics was a valiant attempt to
break into the high quality broadcast and recording market
but their technology left a lot to be desired. I have a
couple of their high-end cardioid mics.
A friend had a recording made on his Ampex part of
which was done with an experimental American pressure mic
intended for high quality recording and another section with
a "Telefunken" mic, actually a Scheops 201-M. No comparison,
the American mic made all the instruments sound like they
were made of paper boxes. The Schoeps mic is the one that
actually established Telefunken's reputation and is the mic
used for the Mercury Records "Living Presence" series.
The cardioid used a ribbon element with a dynamic just
under it. It has decent patterns in one plane going
horizontally around the mic but, of course, there is no
match whatsoever in the vertical plane and very poor
directivity. Actually, Brush made a similar microphone in
the mid or late 1930s, essentially an RCA Junior Velocity
mic with a Brush crystal element fixed to the top of the
ribbon and facing up. I suspect it had much the same
problems. Brush used a rather complicated network to match
the two sections. I don't think they made these for long.


--
Richard Knoppow
Los Angeles
WB6KBL

On 4/1/2010 9:56 AM, Scott Dorsey wrote:

You can no longer get either the original crystal element or the ceramic
element, but Astatic will sell you a dynamic replacement.

The dynamic is a whole lot smoother and less brittle sounding, but maybe
that's a bad thing in a pileup.


Hi,

You can install a Kobitone crystal element in the D-104 mic head,
Mouser.com P/N 25LM022
It has a raising freq characteristic similar to the old Astatic crystal
element.

Electric Radio Magazine, Jan 2010, had the how-to-do-it article.

73,
Ed Knobloch

"Edward Knobloch" wrote in message
...
On 4/1/2010 9:56 AM, Scott Dorsey wrote:

You can no longer get either the original crystal element
or the ceramic
element, but Astatic will sell you a dynamic replacement.

The dynamic is a whole lot smoother and less brittle
sounding, but maybe
that's a bad thing in a pileup.


Hi,

You can install a Kobitone crystal element in the D-104
mic head,
Mouser.com P/N 25LM022
It has a raising freq characteristic similar to the old
Astatic crystal element.

Electric Radio Magazine, Jan 2010, had the how-to-do-it
article.

73,
Ed Knobloch

I found this doing a Google search. They appear to be
available in several sizes and types and the company also
makes ceramic elements. I found prices varied by a 2:1 ratio
depending on who was offering them. Mouser had about the
lowest prices, only about $5 US each. I suspect these will
fit a lot of old crystal mics and make them useable again.

--
Richard Knoppow
Los Angeles
WB6KBL

Richard Knoppow wrote:
My one and only Turner mic is a 999, a low impedance
dynamic. I came into a windfall of good impedance matching
transformers (UTC 01 Ouncers) so matching is no problem. Its
a decent mic but may not be representative since I had to
remove a dent from the diaphragm. This can be done with
sticky tape and great care. The mic sounds good, less rise
in the high end than my Electro-Voice 635. I think this is
probably the original sound.

The 252 definitely has a serious rise on-axis and it's kind of
grating-sounding. That comes across nicely in a pileup.

Turner seems to be the only one of the original big
four makers of PA mics that did not survive. Astatic,
Electro-Voice, and Shure Brothers all managed to navigate
the vicissitudes of life.
American Microphone was another company who did not
survive. Their last line of mics was a valiant attempt to
break into the high quality broadcast and recording market
but their technology left a lot to be desired. I have a
couple of their high-end cardioid mics.

Are they any good? I remember American Microphone trying really hard
to sell into the broadcast market with really cool-looking handheld omni
mikes. The chief engineer of the radio station I worked for dismissed
them all as "crap that's designed to look nice on TV."

A friend had a recording made on his Ampex part of
which was done with an experimental American pressure mic
intended for high quality recording and another section with
a "Telefunken" mic, actually a Scheops 201-M. No comparison,
the American mic made all the instruments sound like they
were made of paper boxes. The Schoeps mic is the one that
actually established Telefunken's reputation and is the mic
used for the Mercury Records "Living Presence" series.
The cardioid used a ribbon element with a dynamic just
under it. It has decent patterns in one plane going
horizontally around the mic but, of course, there is no
match whatsoever in the vertical plane and very poor
directivity. Actually, Brush made a similar microphone in
the mid or late 1930s, essentially an RCA Junior Velocity
mic with a Brush crystal element fixed to the top of the
ribbon and facing up. I suspect it had much the same
problems. Brush used a rather complicated network to match
the two sections. I don't think they made these for long.

Actually, the WE 639 (later the Altec 639) used the same arrangement.
It could be a figure-8, an omni, or a cardioid, but it only sounded
even remotely decent as a figure-8 because the dynamic was just so awful.

I thought all the Living Presence recordings were done with Telefunken
condenser mikes?
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"Scott Dorsey" wrote in message
...
Richard Knoppow wrote:
My one and only Turner mic is a 999, a low impedance
dynamic. I came into a windfall of good impedance matching
transformers (UTC 01 Ouncers) so matching is no problem.
Its
a decent mic but may not be representative since I had to
remove a dent from the diaphragm. This can be done with
sticky tape and great care. The mic sounds good, less rise
in the high end than my Electro-Voice 635. I think this is
probably the original sound.

The 252 definitely has a serious rise on-axis and it's
kind of
grating-sounding. That comes across nicely in a pileup.

Turner seems to be the only one of the original big
four makers of PA mics that did not survive. Astatic,
Electro-Voice, and Shure Brothers all managed to navigate
the vicissitudes of life.
American Microphone was another company who did not
survive. Their last line of mics was a valiant attempt to
break into the high quality broadcast and recording market
but their technology left a lot to be desired. I have a
couple of their high-end cardioid mics.

Are they any good? I remember American Microphone trying
really hard
to sell into the broadcast market with really cool-looking
handheld omni
mikes. The chief engineer of the radio station I worked
for dismissed
them all as "crap that's designed to look nice on TV."

A friend had a recording made on his Ampex part of
which was done with an experimental American pressure mic
intended for high quality recording and another section
with
a "Telefunken" mic, actually a Scheops 201-M. No
comparison,
the American mic made all the instruments sound like they
were made of paper boxes. The Schoeps mic is the one that
actually established Telefunken's reputation and is the
mic
used for the Mercury Records "Living Presence" series.
The cardioid used a ribbon element with a dynamic
just
under it. It has decent patterns in one plane going
horizontally around the mic but, of course, there is no
match whatsoever in the vertical plane and very poor
directivity. Actually, Brush made a similar microphone in
the mid or late 1930s, essentially an RCA Junior Velocity
mic with a Brush crystal element fixed to the top of the
ribbon and facing up. I suspect it had much the same
problems. Brush used a rather complicated network to match
the two sections. I don't think they made these for long.

Actually, the WE 639 (later the Altec 639) used the same
arrangement.
It could be a figure-8, an omni, or a cardioid, but it
only sounded
even remotely decent as a figure-8 because the dynamic was
just so awful.

I thought all the Living Presence recordings were done
with Telefunken
condenser mikes?
--scott

It seems that many microphones designed for
communication purposes had/have a haystack in the
articulation range, i.e., rising above about 500 hz and
peaking around 3 to 5 K. As you probably know most of the
energy in the human voice is below about 500hz but the
frequencies that contribute to articulation are around 1k to
3k. Good articulation can be had even if no frequencies
below about 1500hz are included but naturalness requires
some of the lower frequencies.
The 639 dynamic element is the same as used in the 630A
"Eight-Ball" and 633A/B "Saltshaker". The diaphragms were
hard to make. They were annealed to get the hard spots out.
John Frayne told me that there was more than a 50% rejection
rate. Good ones sound decent many were not so good. Altec
was not as careful as WE even though they had to meet WE
specs. Doc Frayne told me that WE lost money on every 639
they made. It was a prestige item.
The 639 was arranged with the moving coil element facing
front where the American Mic had the element under the
ribbon facing up. This makes sense if one thinks about the
pattern in the horizontal plane only. The problem is that
the moving coil mic is not truely omnidirectional due to the
diffraction effects of the microphone case so there is no
match or a very poor match in the vertical plane. The 639
actually has reasonably good discrimination in both planes
because the directionality at high frequencies depends on
diffraction effects rather than the phasing of the two
elements, the ribbon is rolled off above about 3Khz. The 639
is a bit of a kluge but a very cleverly worked out one. BTW,
the Marshall and Harry patent shows the moving coil element
mounted _on top) of the ribbon, but facing forward. I think
the revesed arrangement on the production mics was done for
appearance. The case was a Raymond Lowey design and I think
the mounting was compromised for appearance.
The 630A was also expensive to make because it was
complex. The case has two parts with a baffle and acoustical
resistance between them. The 633 was an attempt to make a
cheaper version.
Altec made some plastic diaphragm versions of the same
capsule which were also used for small tweeters. I don't
know how they sounded in comparison to the metal diaphragm
version.
In general, I don't like moving coil microphones for
high fidelity applications. They alsways sound mushy to me.
They are eminently suitable for communications purposes
because they are extremely rugged and can be made to have
high output. Most moving coil mics rely on some sort of
resonator at the high end to keep the response up. The 630A,
which was thoroughly described in a paper in the Bell System
Technical Journal, has a cavity resonator plus a capacitive
resonator below the diaphragm. All these resonators combine
to produce a very sharp cut-off at the high end and
typically result in poor transient responce.
The American mics do not sound very good because the
moving coil elements are not very good. Again, metal
diaphragms and rather poor transient response. The
omnidirectional mic showed up on some of the local TV
station, I remember seeing them on KTTV, but were no
competition to Elecro-Voice who used molded plastic
diaphragms and had pretty smooth response. I think American
tried hard but simply did not have the technology to
compete. The cardioid mics are also adjustable pattern, they
have a board with jumpers under the label. I don't know a
lot about the history of the company. I think I did read
something or hear somethign about them long ago but its
faded away.
There were two other small microphone manufacturers in
the Los Angeles area in the 1930s and 1940s, they were
Universal Microphone Co, in Culver City and Carrier
Microphone Co. I beleive Carrier was the superintendent of
Universal. I am not sure of American Microphone personel had
any relation to these companies but think they might have.
American was in East LA at first but moved to Pasadena.
Telefunken never built any microphones but acted as the
marketing agency for both Neumann and Schoeps. I think they
even marketed some AKG mics at one time. While Neumann mics,
particularly the U-47 became famous under the Telefunken
name the Mercury Living Presence series was apparently made
using the Schoeps 201-M, a dual capsule cardioid/variable
pattern mic. They are shown in some publicity photos of the
sessions. Mercury used a single-mic pickup, somewhat unusual
for American recording at the time. They also used modified
Fairchild cutterheads. Mercury was one of the first
recording companies to adopt hot stylus (orinated at
Columbia) and variable pitch. The pitch variation was done
by hand by the recording engineer following a marked up
score. Not sure when the first automatic groove pitch
machines came out but it must not have been much later.
Meissner (SP ?) wrote a letter to Audio Engineering
magazine after an article describing the Columbia Hot Stylus
technique was published claiming he had developed a similar
system in the late 1920s or early 1930s which he attempted
to use at Brunswick. The management thought the resulting
records looked funny and did not ever use it in practice.
Hot stylus makes a lot of difference in both noise and in
high frequency response where the original is made on
laquer, perhaps less on wax but I am not certain of that.

--
Richard Knoppow
Los Angeles
WB6KBL

On 4/2/2010 9:38 AM, Scott Dorsey wrote:
[Turner] Model 252. Low-Z version of the 250 with the lift switch (which I strongly
discourage the use of). If you were using a Viking II you would probably want
the 250 or to use a step-up transformer.
--scott


Hi

By "lift switch" do you mean the switch contacts to complete the circuit
to the mic element? Or did that mic include a switch
on the bottom, so that when you pick it up, you transmit?

73,
Ed Knobloch

Edward Knobloch wrote:
On 4/2/2010 9:38 AM, Scott Dorsey wrote:
[Turner] Model 252. Low-Z version of the 250 with the lift switch (which I strongly
discourage the use of). If you were using a Viking II you would probably want
the 250 or to use a step-up transformer.

By "lift switch" do you mean the switch contacts to complete the circuit
to the mic element? Or did that mic include a switch
on the bottom, so that when you pick it up, you transmit?

It's a switch on the bottom so you transmit when you pick up the mike. There
is a locking switch that disables it, but the locking switch sometimes gets
dislodged when the mike is knocked over.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On Apr 2, 2:09*am, "Richard Knoppow" wrote:
"Scott Dorsey" wrote in message

...





coffelt2 wrote:

* * D-104C had a "ceramic" crystal element which was far
more tolerant of
moisture, shock, etc.
I can't remember just now what the frequency response was
(compared to the
original) but when
I used one, I was looked down upon as a traitor to
tradition.

You can no longer get either the original crystal element
or the ceramic
element, but Astatic will sell you a dynamic replacement.

The dynamic is a whole lot smoother and less brittle
sounding, but maybe
that's a bad thing in a pileup.

* * What was good about the D-104 types, was that you
didn't have to speak
directly into it. One
could just walk around the shack, and in some instances,
around the house
with little loss of
readability.

They were very, very omnidirectional compared other
communications mikes
back then. *The good part of this was the effect you note.
The bad part
is that noise sources like fans and people yelling in the
background were
also very readable on the air.

I am currently using an old Turner microphone and like the
way it sounds.
Also I am a fan of some of the older EV desk microphones,
which still turn
up cheaply at hamfests. * If you find a low-Z mike that
you like, there is
no reason you can't just stick a step-up transformer in
the base to drive
the Viking.
--scott

* * *There aren't many polar patterns published for cheaper
mics but the directional properties of mics like the D-104
are mostly due to the diffraction around the body. At low
frequencies they are almost perfectly omnidirectional but at
some frequency begin to have some directionality which
increases with frequency. The same diffraction effect causes
a rise in the frequency response unless its compensated in
some way. At a frequency where the path around the body
approximates a half wave length the microphone can approach
a super-carioide pattern, i.e., unidirectional with one or
more lobes toward the back. The shape is important, a flat
pancake shape like the D-104 will have a somewhat different
pattern than a bullet-shaped mic. The ultimate was the
Western Electric 630A "Eight-Ball". The spherical shape made
it quite omnidirectional to rather high frequencies but the
pattern was made even more uniform by the partial baffle
mounted in front of the diaphragm. Metro-Goldwyn-Mayer made
some microphones using probably standard Western Electric
condenser elements mounted in a spherical case to reduce the
diffraction rise typical of the older mics. I don't remember
whether these had baffles on them but the elements were
mounted in a way that also tended to reduce the cavity
resonance typical of both this and other large condenser
type elements. In some respects the rise was useful in
dialogue recording although it could also make some voices
sound harsh. All sorts of mechanical filters and baffles
were tried to aleviate this effect, mostly with limited
success. Electrical filters, which would have been a better
solution, while known in the telephone industry, were not
very well known outside of it. Much of the early theory of
electrical wave filters was developed by George A. Campbell,
of Bell Labs, in the mid 'teens. This was cosidered very
advanced stuff at the time.
* * *I am not surprized that no one makes crystal or ceramic
elements any more. For the most part microphones to fill
similar applications now are electrets.

--
Richard Knoppow
Los Angeles
WB6KBL
- Hide quoted text -

- Show quoted text -

Thanks Richard and everyone else here. (For some reason my email wasn
´t "beeped" when these responses came so I am a bit behind and have
some heavy reading to do here, but seems to be a wealth of important
info here that i have to digest, then start the search engines to find
an appropriate mic(s). Most Vikings I have seen have a D-104 with
them but the specifics as to their innards of course is a guess.
Thanks again and best 73s for now. Guess I better keep checking back
here from time to time. 73s,
Wayne

"SventheViking" wrote in message
...
On Apr 2, 2:09 am, "Richard Knoppow"
wrote:
"Scott Dorsey" wrote in message

...





coffelt2 wrote:

D-104C had a "ceramic" crystal element which was far
more tolerant of
moisture, shock, etc.
I can't remember just now what the frequency response
was
(compared to the
original) but when
I used one, I was looked down upon as a traitor to
tradition.

You can no longer get either the original crystal
element
or the ceramic
element, but Astatic will sell you a dynamic
replacement.

The dynamic is a whole lot smoother and less brittle
sounding, but maybe
that's a bad thing in a pileup.

What was good about the D-104 types, was that you
didn't have to speak
directly into it. One
could just walk around the shack, and in some instances,
around the house
with little loss of
readability.

They were very, very omnidirectional compared other
communications mikes
back then. The good part of this was the effect you
note.
The bad part
is that noise sources like fans and people yelling in
the
background were
also very readable on the air.

I am currently using an old Turner microphone and like
the
way it sounds.
Also I am a fan of some of the older EV desk
microphones,
which still turn
up cheaply at hamfests. If you find a low-Z mike that
you like, there is
no reason you can't just stick a step-up transformer in
the base to drive
the Viking.
--scott

There aren't many polar patterns published for cheaper
mics but the directional properties of mics like the D-104
are mostly due to the diffraction around the body. At low
frequencies they are almost perfectly omnidirectional but
at
some frequency begin to have some directionality which
increases with frequency. The same diffraction effect
causes
a rise in the frequency response unless its compensated in
some way. At a frequency where the path around the body
approximates a half wave length the microphone can
approach
a super-carioide pattern, i.e., unidirectional with one or
more lobes toward the back. The shape is important, a flat
pancake shape like the D-104 will have a somewhat
different
pattern than a bullet-shaped mic. The ultimate was the
Western Electric 630A "Eight-Ball". The spherical shape
made
it quite omnidirectional to rather high frequencies but
the
pattern was made even more uniform by the partial baffle
mounted in front of the diaphragm. Metro-Goldwyn-Mayer
made
some microphones using probably standard Western Electric
condenser elements mounted in a spherical case to reduce
the
diffraction rise typical of the older mics. I don't
remember
whether these had baffles on them but the elements were
mounted in a way that also tended to reduce the cavity
resonance typical of both this and other large condenser
type elements. In some respects the rise was useful in
dialogue recording although it could also make some voices
sound harsh. All sorts of mechanical filters and baffles
were tried to aleviate this effect, mostly with limited
success. Electrical filters, which would have been a
better
solution, while known in the telephone industry, were not
very well known outside of it. Much of the early theory of
electrical wave filters was developed by George A.
Campbell,
of Bell Labs, in the mid 'teens. This was cosidered very
advanced stuff at the time.
I am not surprized that no one makes crystal or ceramic
elements any more. For the most part microphones to fill
similar applications now are electrets.

--
Richard Knoppow
Los Angeles
WB6KBL
- Hide quoted text -

- Show quoted text -

Thanks Richard and everyone else here. (For some reason my
email wasn
´t "beeped" when these responses came so I am a bit behind
and have
some heavy reading to do here, but seems to be a wealth of
important
info here that i have to digest, then start the search
engines to find
an appropriate mic(s). Most Vikings I have seen have a
D-104 with
them but the specifics as to their innards of course is a
guess.
Thanks again and best 73s for now. Guess I better keep
checking back
here from time to time. 73s,
Wayne

As mentioned before while the D-104 was an excellent
mic for ham use it was not the only one. _Any_ high
impedance mic will work with the Viking, most have enough
output. For good speech intelegibility in the presense of
noise its desirable to favor the upper-mid frequencies,
i.e., from about 1000 to 3000 hz since that is where the
energy that carries the inteligence is. Most of the power is
below 1000 hz, so a system with a cut off of around 300 hz
and rising characteristic will put more of the modulation
power in the range necessary for understandability. However,
for naturalness you need some lows. Bell Labs, in their
research for minimum bandwidths for telephone service found
that inteligibility needs frequencies up to about 2800 hz
but that, on the low end, it was found that voices were
unnatural sounding unless the low end was extended to 250 or
300 hz. The phone company adopted a channel bandwidth of
2500 hz extending from 250hz to 2750hz. In fact, a wider
bandwidth will sound better. On a noise-free channel
wide-band, uncompressed speech has the best intelligibility
but in the presense of noise band limited speech with
spectrum shaping (fancy for rising frequency response) and
compression or clipping, is more inteligible. A paper by
Licklidder et.al, published in the _Journal of the
Acoustical Society of America_ about 1948 reported
experiments with _infinite_ speech clipping. Licklidder
found that if speech was put through a differentiator (6db
per octave high pass RC network) infinitely clipped (NO
amplitude variations at all left) and then integrated (6db
per octave RC low pass filter) the intelligibility was
perserved and improved where the speech was competing with
noise. In a quiet channel the unprocessed speech was better
but the clipped speech still has something like an 80%
articulation score. When in a very noisey channel the
clipped speech maintained its score where untreated speech
fell off severely.
Lots of mics, both old and new, will work this this
transmitter.


--

--
Richard Knoppow
Los Angeles
WB6KBL