Re: K2 - Strange Problem ?
Posted by
Stewart Baker on
Nov 30, 2004; 3:44pm
URL: http://elecraft.85.s1.nabble.com/K2-Strange-Problem-tp372185p372191.html
On Tue, 30 Nov 2004 08:01:25 -0800, Vic Rosenthal wrote:
> Stewart Baker wrote:
>> The amplifier only draws about 1mA, however because of noise on the 5A line,
>> mainly from the LED bar graph I have had to heavily decouple the pre-amp
>> supply
>> to stop the noise from being superimposed on my speech.
>> What I think is happening is that this decoupling is affecting the rise
>> time of
>> the 5A line which is used for the MCU reset amongst other things.
> Why don't you do this (must be viewed in fixed width font):
> 5V -------\\\\\\\----|----> to preamp
> large R |
> ---
> --- cap for decoupling
> |
> ---
> ///
> You will get better decoupling and isolate the capacitor from the 5V rail.
Thanks Vic,
That's what I was doing, however, because anything capacitive slows the rise of
the 5A rail, and hence the correct MCU initialisation, I was chasing my tail.
A better solution has presented itself.
73
Stewart G3RXQ
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