[ARC5] BC-454-B Dymamotor Question

[Mike Hanz]

Put a scope on it and determine the fundamental noise frequency in the 
audio.  The chopping frequency of unfiltered input and output 
commutators is pretty high.  I wouldn't call them a "buzz" spectrum - 
they are more of a "singing" spectrum.  Definitions are key.  Are you 
using the same 28 volt DC supply for both tests?

On 1/17/2013 7:39 PM, Mark K3MSB wrote:
> When using the dynamotor on the BC-454-B, there's a constant loud buzz in
> the audio that I would think is coming from the dynamotor as it sounds like
> a motor sound.   I tried both dynamotors in the radio and one seems a lot
> less pronounced, but still strong.
>
> I then wired in separate 250V and 28V supplies (non dynamotor) and the
> receive audio is great.
>
> Is what I'm hearing with the dynamotors normal?
>
> 73 Mark K3MSB
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