Re: D4D mods

Adam Rong
 

Sounds good. I will modify the emitter resistor from 1.5k to 680 ohm and give it a try later this week.

Just FYI: After applying the diode modification to reduce NE602 power supply voltage from 5V to 4.3V suggested by BH4DCL, the carrier leakage is greatly reduced. Maybe your modification will help further.

Thanks,
Adam


On Wed, Jul 31, 2019 at 4:36 AM Steven Weber <steve.kd1jv@...> wrote:

Yes, Q1’s collector should stay above 5V when 12_V is applied.

Steve

 

 

From: Adam Rong
Sent: Tuesday, July 30, 2019 10:33 AM
To: crkits@groups.io
Subject: Re: [crkits] D4D mods

 

Hi Steve,

Thanks for your sharing. I will test them. One thing to confirm: If we add a diode between +5V and the collector of Q1, when 12V_R is present, the diode will be reverse biased? If not, I suppose it will mute the audio output.

Thanks,
Adam

 



--
Thanks,
Adam Rong

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