[Pea Hicks]

hello, i have an old tube condenser mic that has no markings on it
whatsoever, and have been trying to find out who made it via google
image search, with no luck. it has two rca 230 tubes in it, and i do not
have the power supply or any other accessories. here's a couple pics:

http://farm2.static.flickr.com/1059/...bdd858c9_o.jpg

http://farm2.static.flickr.com/1422/...d7d7cba8_o.jpg


thanks in advance for any help on this!

pea hicks

[nebulax]

On Sep 22, 8:38 pm, Pea Hicks wrote:
hello, i have an old tube condenser mic that has no markings on it
whatsoever, and have been trying to find out who made it via google
image search, with no luck. it has two rca 230 tubes in it, and i do not
have the power supply or any other accessories. here's a couple pics:

http://farm2.static.flickr.com/1059/...bdd858c9_o.jpg

http://farm2.static.flickr.com/1422/...d7d7cba8_o.jpg

thanks in advance for any help on this!

pea hicks


This isn't exactly it, but it's in the ballpark - http://www.coutant.org/we47/index.html

[Scott Dorsey]

Pea Hicks wrote:
hello, i have an old tube condenser mic that has no markings on it
whatsoever, and have been trying to find out who made it via google
image search, with no luck. it has two rca 230 tubes in it, and i do not
have the power supply or any other accessories. here's a couple pics:

http://farm2.static.flickr.com/1059/...bdd858c9_o.jpg

http://farm2.static.flickr.com/1422/...d7d7cba8_o.jpg

thanks in advance for any help on this!

Looks to me like a homebrew job... definitely looks to be hand-machined,
and it's definitely got some sort of omni capsule. Looking at the capsule
will probably tell you more.

A lot of this sort of homebrew stuff was built in Hollywood.

There are no "RCA 230" tubes. RCA used standard RETMA numbers for
consumer stuff and four-digit numbers for industrial stuff, and looking
in the big HB-3 book I don't see any industrial numbers that either begin
or end with 230.

Is it possible this is a Western Electric tube number? My 1933 Western
Electric book doesn't have a 230 in it, but it does have a 231D. If it's
a Western Electric type, it's a good clue to the origin of the mike since
WE tubes were not freely available at the local grocery store like RCA
stuff was.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Pea Hicks]

Scott Dorsey wrote:

Looks to me like a homebrew job... definitely looks to be hand-machined,
and it's definitely got some sort of omni capsule. Looking at the capsule
will probably tell you more.

A lot of this sort of homebrew stuff was built in Hollywood.

There are no "RCA 230" tubes. RCA used standard RETMA numbers for
consumer stuff and four-digit numbers for industrial stuff, and looking
in the big HB-3 book I don't see any industrial numbers that either begin
or end with 230.

Is it possible this is a Western Electric tube number? My 1933 Western
Electric book doesn't have a 230 in it, but it does have a 231D. If it's
a Western Electric type, it's a good clue to the origin of the mike since
WE tubes were not freely available at the local grocery store like RCA
stuff was.
--scott

hi scott, sorry for accidently responding to your email address. i'm
copying my response to the ng.

this mic came from the estate of a man who worked for bell & howell and
also was a sales rep for western electric sound systems. so maybe it's a
proto of some sort? not really homebrew, but a one-off nonetheless?

i took a pic of the base of one of the tubes:

http://farm2.static.flickr.com/1252/...df0a915e_o.jpg

thoughts?


pea

[Scott Dorsey]

Pea Hicks wrote:
this mic came from the estate of a man who worked for bell & howell and
also was a sales rep for western electric sound systems. so maybe it's a
proto of some sort? not really homebrew, but a one-off nonetheless?

Could well be. Or could be a G-job made for personal use.

i took a pic of the base of one of the tubes:

http://farm2.static.flickr.com/1252/...df0a915e_o.jpg

thoughts?

Bingo! That's a British number! Note the British logo on the base!

http://www.6v6.co.uk/archive/rca_radiotron/rc10-35.gif

That's a page from the 1929 Radiotron manual. Note that this is a super
high capacitance tube, compared with a modern 12AX7, so it very much dates
the microphone to the early to mid 1930s.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Ty Ford]

On Tue, 25 Sep 2007 09:48:43 -0400, Scott Dorsey wrote
(in article ):

Pea Hicks wrote:
this mic came from the estate of a man who worked for bell & howell and
also was a sales rep for western electric sound systems. so maybe it's a
proto of some sort? not really homebrew, but a one-off nonetheless?

Could well be. Or could be a G-job made for personal use.

i took a pic of the base of one of the tubes:

http://farm2.static.flickr.com/1252/...df0a915e_o.jpg

thoughts?

Bingo! That's a British number! Note the British logo on the base!

http://www.6v6.co.uk/archive/rca_radiotron/rc10-35.gif

That's a page from the 1929 Radiotron manual. Note that this is a super
high capacitance tube, compared with a modern 12AX7, so it very much dates
the microphone to the early to mid 1930s.
--scott


I love it when you talk like that!

Regards,

Ty Ford


--Audio Equipment Reviews Audio Production Services
Acting and Voiceover Demos http://www.tyford.com
Guitar player?:http://www.youtube.com/watch?v=4RZJ9MptZmU

[Pea Hicks]

Scott Dorsey wrote:


Bingo! That's a British number! Note the British logo on the base!

http://www.6v6.co.uk/archive/rca_radiotron/rc10-35.gif

That's a page from the 1929 Radiotron manual. Note that this is a super
high capacitance tube, compared with a modern 12AX7, so it very much dates
the microphone to the early to mid 1930s.
--scott

cool! although these tubes aren't globe style tubes like the one
pictured in the catalog scan you linked to... anyway, i was thinking
that was about the right date for this mic...

thanks for the info!

pea

[Scott Dorsey]

Pea Hicks wrote:
Scott Dorsey wrote:


Bingo! That's a British number! Note the British logo on the base!

http://www.6v6.co.uk/archive/rca_radiotron/rc10-35.gif

That's a page from the 1929 Radiotron manual. Note that this is a super
high capacitance tube, compared with a modern 12AX7, so it very much dates
the microphone to the early to mid 1930s.

cool! although these tubes aren't globe style tubes like the one
pictured in the catalog scan you linked to... anyway, i was thinking
that was about the right date for this mic...

Check the pinout and see. The grid should go to the capsule, the plate
goes to a high value resistor to the B+, the cathode goes to a low value
resistor to ground, and the filament leads go straight to the filament
supply. If the pinout matches, you've probably got the right tube.
If it doesn't, you certainly don't.
--scott

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