President JFK -Microphone amplification
- rooth
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- Location: Roma
President JFK -Microphone amplification
Hello !
I have a President JFK radio with original dynamic microphone, which I am not satisfied with the modulation. Even with the maximum gain it does not sound too great. What can I do in this case?
I have a President JFK radio with original dynamic microphone, which I am not satisfied with the modulation. Even with the maximum gain it does not sound too great. What can I do in this case?
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- ch25
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Re: President JFK -Microphone amplification
Replace dynamic capsule with electret and add 1 resistor and one capacitor inside radio.
This thread: viewtopic.php?t=55896&p=510107
Chris
This thread: viewtopic.php?t=55896&p=510107
Chris
WE ARE MOTÖRHEAD, AND WE PLAY ROCK N' ROLL
You can't have too many antennas...
You can't have too many antennas...
- rooth
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Re: President JFK -Microphone amplification
@ ch25 :
Thanks for the info!
You have a beer from me!
I try ,and come back with an update .
Thanks for the info!
You have a beer from me!
I try ,and come back with an update .
-
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Re: President JFK -Microphone amplification
the best way to remake the microphone is to add an amplifier to the tangent on a single transistor 2sc945 and make power over the wire
- rooth
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Re: President JFK -Microphone amplification
+ Pozitive how do I send it via cable to the microphone? I don't have a separate cable for this ...
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- ch25
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Re: President JFK -Microphone amplification
Yes, via modulation cable. That's why resistor and capacitor are inside radio. I usually unsolder modulation cable from socket, put capacitor in series, that resistor and +8V available from many places inside radio.
Chris
Chris
WE ARE MOTÖRHEAD, AND WE PLAY ROCK N' ROLL
You can't have too many antennas...
You can't have too many antennas...
- rooth
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Re: President JFK -Microphone amplification
I can't understand that. You can attach or diagram ? Please ...
- ch25
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Re: President JFK -Microphone amplification
Put electret capsule to the microphone. Close it, you're done here.
Open radio, find a cable connected to pin 2 of mic socket. Make a change as marked pink on image I attached.
Open radio, find a cable connected to pin 2 of mic socket. Make a change as marked pink on image I attached.
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WE ARE MOTÖRHEAD, AND WE PLAY ROCK N' ROLL
You can't have too many antennas...
You can't have too many antennas...
- rooth
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- Posts: 55
- Joined: 27 Mar 2017, 19:29
- Location: Roma
Re: President JFK -Microphone amplification
I already burned something. I touched something with the tester on the microphone jack and I did not sound and it does not seem to sound when I press PTT.
A sound is heard in the dynamic microphone when you press PTT
I reached pin 6 (13.2 V) at pin 1 - modulation
A sound is heard in the dynamic microphone when you press PTT
I reached pin 6 (13.2 V) at pin 1 - modulation
- rooth
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Re: President JFK -Microphone amplification
I managed to start the radio again. I fixed the problem ... I found an interrupted minus route.
I try again to adapt the microphone with the electret
I try again to adapt the microphone with the electret
- 14CS06
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Re: President JFK -Microphone amplification
Hello
My post is gone
Is that normal
@+
Claude
My post is gone
Is that normal
@+
Claude
Photo Collector CB RADIO
- cb4ever104
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Re: President JFK -Microphone amplification
To get the best result make sure you pad around the electret using any suitable material . I cut some foam sheet to size and used that , making a small hole in the middle for the element .
S.
30TM060
Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.
Paul aka "Sammy". (108) PY60 Old Paisley DX Group (RIP Rab Markie)
Ex GM0 , now EA5 .
Handle "Fortune Hunter" back in "the day"
Radios ....? Anything that says "TAIWAN R.O.C" on the back.