[Ham-Mac] Mac - SignaLink - CocoaModem

[Dick Kriss]

They may have added some amps in the SL USB. The older SL USB+1 was pretty plain.
I no longer have the schematic diagram.

On Jun 19, 2012, at 5:45 PM, Alan Bomberger wrote:

> Ok,  I guess I thought that sound cards contained A2D and D2A converters.
> I guess this USB sound "adapter" just gets the signals onto the
> USB bus and the Digital/Analog stuff is done in software.   I can
> live with that.  Still doens't quite explain why the input signal
> level is considerably higher with the power on..
> 
> Thanks for the info!!
> 
> 
>> On Jun 19, 2012, at 2:33 PM, Alan Bomberger wrote:
>> 
>>> How is it that CocoaModem (and fldigi) can read signals from the
>>> SignaLink when the Signalink power is off?   I noticed this the
>>> other day when I went to answer a CQ and the transmitter didn't go
>>> on.  No Power, No PTT.  Granted the receiver input is much lower than
>>> with power on but what is running the ADC chip?
>>> --
>>> It is seldom that liberty of any kind is lost all at once. - David Hume
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>> 
>> I am quoting from memory but as I recall the only active (or 
>> powered) circuit in the SignaLink is for the Auto-PTT.  It is almost 
>> passive for RX; however, when I had one I noticed some minor Rx 
>> attenuation and this was confirmed by Tigertronics.
>> 
>> Dick AA5VU
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> 
> -- 
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