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Lee
It will be interesting to see, and hear, how that T-32 carbon button microphone
works with the BITX.? It may need some attenuation because carbon microphones
usually output a fairly high level signal.? who knows...we could be seeing a new
trend of using carbon microphones for their inherent frequency limiting and high
output.?
Arv? K7HKL
_._
On Mon, Apr 23, 2018 at 10:32 AM, Lee <mr.olson@...> wrote: The microphone is a Model T-32 made by Kellogg Company for military communications.? It was sometimes used with the English T-1154 transmitter in WW2 Lancaster bombers.? Yes, they were used in many places after the war and one popular use was on a PA system in railroad yards.? Since I need 4 wires I am using a Cobra/Midland CB style 4 pin plug and jack with the locking ring.
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Simple . It works with a DC bias and resistance variation of carbon granules packed in a mic? convey the speech content.
?Only diffiernce is that the bandwidth would be much less as against electret or dynamic mics. regards sarma ?vu3zmv
On Mon, Apr 23, 2018 at 11:28 PM, Arv Evans <arvid.evans@...> wrote: Lee
It will be interesting to see, and hear, how that T-32 carbon button microphone
works with the BITX.? It may need some attenuation because carbon microphones
usually output a fairly high level signal.? who knows...we could be seeing a new
trend of using carbon microphones for their inherent frequency limiting and high
output.?
Arv? K7HKL
_._
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In continuation, i suppose that except salvaged ones , we may not be able to get carbon mics now a days.
On Mon, Apr 23, 2018 at 11:34 PM, Mvs Sarma <mvssarma@...> wrote: Simple . It works with a DC bias and resistance variation of carbon granules packed in a mic? convey the speech content.
?Only diffiernce is that the bandwidth would be much less as against electret or dynamic mics. regards sarma ?vu3zmv
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Arv, I'm not using the carbon button,? "The original carbon element was bad so I put in a electret mic and MAX9812 module board"? See the picture of the button holder.
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Carbon mics need a bit more bias current. Most can be revived by physical shock, breaking up clumps of granules packed by gravity in storage/disuse.
Challenge: the carbon mic that got me into electronics and eventually Ham Radio, some 60-odd years ago!
Take a (sorta fist-size to shoe-box) cardboard box lid.
Take 2 razor blades (single-sided are best)with wires attached.
Poke those blades up through the box-lid beside each other, (just) not touching. A twist of the insulated wires might help steady them.
Take a section of pencil-lead and balance that across the blade edges.
Connect up - you've got a mic!
73
Dex, ZL2DEX
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I made one from two carbon blocks, in a vertical configuration, with a dimpled area and a pencil sharpened at both ends.
On Mon, Apr 23, 2018 at 4:07 PM, Dexter N Muir <dexy@...> wrote: Carbon mics need a bit more bias current. Most can be revived by physical shock, breaking up clumps of granules packed by gravity in storage/disuse.
Challenge: the carbon mic that got me into electronics and eventually Ham Radio, some 60-odd years ago!
Take a (sorta fist-size to shoe-box) cardboard box lid.
Take 2 razor blades (single-sided are best)with wires attached.
Poke those blades up through the box-lid beside each other, (just) not touching. A twist of the insulated wires might help steady them.
Take a section of pencil-lead and balance that across the blade edges.
Connect up - you've got a mic!
73
Dex, ZL2DEX
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Back when I was in school, I once wrote an essay with a manual graphite display generator.
Jack, W8TEE
On Monday, April 23, 2018, 7:01:26 PM EDT, William Cullison <wa8vih@...> wrote:
I made one from two carbon blocks, in a vertical configuration, with a dimpled area and a pencil sharpened at both ends.
On Mon, Apr 23, 2018 at 4:07 PM, Dexter N Muir <dexy@...> wrote: Carbon mics need a bit more bias current. Most can be revived by physical shock, breaking up clumps of granules packed by gravity in storage/disuse.
Challenge: the carbon mic that got me into electronics and eventually Ham Radio, some 60-odd years ago!
Take a (sorta fist-size to shoe-box) cardboard box lid.
Take 2 razor blades (single-sided are best)with wires attached.
Poke those blades up through the box-lid beside each other, (just) not touching. A twist of the insulated wires might help steady them.
Take a section of pencil-lead and balance that across the blade edges.
Connect up - you've got a mic!
73
Dex, ZL2DEX
|
On Monday, April 23, 2018, 5:08:09 PM PDT, Jack Purdum via Groups.Io <jjpurdum@...> wrote:
Back when I was in school, I once wrote an essay with a manual graphite display generator.
Jack, W8TEE
On Monday, April 23, 2018, 7:01:26 PM EDT, William Cullison <wa8vih@...> wrote:
I made one from two carbon blocks, in a vertical configuration, with a dimpled area and a pencil sharpened at both ends.
On Mon, Apr 23, 2018 at 4:07 PM, Dexter N Muir <dexy@...> wrote: Carbon mics need a bit more bias current. Most can be revived by physical shock, breaking up clumps of granules packed by gravity in storage/disuse.
Challenge: the carbon mic that got me into electronics and eventually Ham Radio, some 60-odd years ago!
Take a (sorta fist-size to shoe-box) cardboard box lid.
Take 2 razor blades (single-sided are best)with wires attached.
Poke those blades up through the box-lid beside each other, (just) not touching. A twist of the insulated wires might help steady them.
Take a section of pencil-lead and balance that across the blade edges.
Connect up - you've got a mic!
73
Dex, ZL2DEX
|
Yep, with a #2 on it.
Jack, W8TEE
On Monday, April 23, 2018, 8:13:21 PM EDT, Paul Schumacher via Groups.Io <wnpauls@...> wrote:
On Monday, April 23, 2018, 5:08:09 PM PDT, Jack Purdum via Groups.Io <jjpurdum@...> wrote:
Back when I was in school, I once wrote an essay with a manual graphite display generator.
Jack, W8TEE
On Monday, April 23, 2018, 7:01:26 PM EDT, William Cullison <wa8vih@...> wrote:
I made one from two carbon blocks, in a vertical configuration, with a dimpled area and a pencil sharpened at both ends.
On Mon, Apr 23, 2018 at 4:07 PM, Dexter N Muir <dexy@...> wrote: Carbon mics need a bit more bias current. Most can be revived by physical shock, breaking up clumps of granules packed by gravity in storage/disuse.
Challenge: the carbon mic that got me into electronics and eventually Ham Radio, some 60-odd years ago!
Take a (sorta fist-size to shoe-box) cardboard box lid.
Take 2 razor blades (single-sided are best)with wires attached.
Poke those blades up through the box-lid beside each other, (just) not touching. A twist of the insulated wires might help steady them.
Take a section of pencil-lead and balance that across the blade edges.
Connect up - you've got a mic!
73
Dex, ZL2DEX
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kenselectronics.com carries carbon elements. They are used but they are available. If you have any 1960-1980 Western Electric standard telephones, especially dial type, check to see if they have carbon elements. tim ab0wr On Mon, 23 Apr 2018 23:36:24 +0530 "Mvs Sarma" <mvssarma@...> wrote: In continuation, i suppose that except salvaged ones , we may not be
able to get carbon mics now a days.
Regards
MVS Sarma
On Mon, Apr 23, 2018 at 11:34 PM, Mvs Sarma <mvssarma@...>
wrote:
Simple . It works with a DC bias and resistance variation of carbon
granules packed in a mic convey the speech content.
Only diffiernce is that the bandwidth would be much less as against
electret or dynamic mics.
regards
sarma
vu3zmv
Regards
MVS Sarma
On Mon, Apr 23, 2018 at 11:28 PM, Arv Evans <arvid.evans@...>
wrote:
Lee
It will be interesting to see, and hear, how that T-32 carbon
button microphone
works with the BITX. It may need some attenuation because carbon
microphones
usually output a fairly high level signal. who knows...we could be
seeing a new
trend of using carbon microphones for their inherent frequency
limiting and high
output.
Arv K7HKL
_._
On Mon, Apr 23, 2018 at 10:32 AM, Lee <mr.olson@...> wrote:
The microphone is a Model T-32 made by Kellogg Company for
military communications. It was sometimes used with the English
T-1154 transmitter in WW2 Lancaster bombers. Yes, they were used
in many places after the war and one popular use was on a PA
system in railroad yards. Since I need 4 wires I am using a
Cobra/Midland CB style 4 pin plug and jack with the locking ring.
|
I use the Retevis mic. Under $7 on
eBay. I cut off the connector and rewired it to the phono jack.
Despite what others have said about the wire colors, I found Red
it the mic, Black is ground, green is PTT.
Howard WB2VXW
On 4/23/2018 8:07 PM, Jack Purdum via Groups.Io wrote:
toggle quoted message
Show quoted text
Back when I was in school, I once wrote an essay with a
manual graphite display generator.
Jack, W8TEE
On Monday, April 23, 2018, 7:01:26 PM EDT, William
Cullison <wa8vih@...> wrote:
I made one from two carbon blocks, in a
vertical configuration, with a dimpled area and a
pencil sharpened at both ends.
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3d-printed body with stock mic element and switch
73
Mike N2HTT
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Lee
Michael Aiello
