[Elecraft] CM-500 Question

[David Herring]

I am one of the ones who is experiencing difficulties with the CM500’s mic sensitivity.  Like some others with a recent model CM500, I have the preamp on and the mic gain pegged on my K4, the mic right up close to my lips, and I cannot get 5 bars without talking much louder than what should be necessary.

I can confirm that it works (albeit poorly) with bias on and does not work at all when the bias is turned off.

73,
Dave - N5DCH




> On Aug 7, 2023, at 3:08 PM, Alan Bloom <n1al at sonic.net> wrote:
> 
> Thanks Jim.  Unfortunately I'm several thousand miles away from home so I can't do that test right now.  I'm pretty sure it's an electret, but I'll check when I get home.
> 
> Alan N1AL
> 
> 
> On 8/7/2023 11:00 PM, Jim Brown wrote:
>> On 8/7/2023 12:44 PM, Alan Bloom wrote:
>>> I also use it for recording a radio show on a computer sound card. Again, I have to set the gain to near maximum to get proper levels.
>> 
>> Alan,
>> 
>> The CM500 has always had an electret mic, which requires bias, although the data sheet has always called it a dynamic mic. As a test, turn off bias and see if that changes anything. If it is a dynamic, turning off bias should make it work better.
>> 
>> My WAG is that what you bought might be a counterfeit. My experience buying all sorts of things in the last 5 years (kitchen tools, shoes, etc.) has been seeing lots of what appear to be either counterfeit or cheapened versions of stuff I'd previously owned and wanted a second one.
>> 
>> 73, Jim K9YC
>> 
>> 
>> 
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