Author Topic: Pop eliminator  (Read 1227 times)

G3EJS

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Pop eliminator
« on: April 22, 2018, 01:51:06 PM »
Decided to try a different approach.


Using a PIC to sequence the mute of the RX and change to TX


The PIC responds to the PTT going low by muting the audio amp, and 100ms later, passing the PTT low state to the raduino.
When the PTT is released, it stops the PTT to the raduino, then 100ms later un-mutes the AF amp.


On the breadboard version, it was a silent transition.


Made some boards this morning, this time I remembered to duplicate them and make more than one, saves setting up a second time.









The hole drilling is one of the best things about the CNC router making the boards :)









The almost finished boards, decided to make the different functions on separate boards, and the AGC board will probably function as the mute circuit later. (The top of the resistor nearest the chip is wrong! It should go to the +ve rail, not -ve, see the photos of the larger board on later posts)







Hex file for 12F629 attached
« Last Edit: May 28, 2018, 04:02:25 AM by G3EJS »

G3EJS

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Re: Pop eliminator
« Reply #1 on: April 29, 2018, 05:02:57 AM »
Pop / click totally gone.


Slight change, I tried different AGC circuits, and decided the one with the LED>LDR did the best job overall, so I combined the mute with the AGC.


Once I have finished, I will put all the small PCBs onto one larger one to eliminate some of the wire.



G3EJS

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Re: Pop eliminator
« Reply #2 on: April 29, 2018, 12:40:32 PM »
All worked very well, so built it all on one board, and added a meter driver and an audio amp on the end to take it to the level neede for the amp module I will use.


Will have to wait for next weekend to try it out :)







« Last Edit: May 28, 2018, 04:05:20 AM by G3EJS »

G3EJS

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PIC circuit for pop eliminator
« Reply #3 on: May 28, 2018, 05:03:38 AM »
Have drawn the circuit for any one interested.
Hex code is in a previous post