[Elecraft] OT - WSJT-X & K3s

[Joe Subich, W4TV]

On 9/4/2017 11:12 PM, Jim Brown wrote:

 > http://k9yc.com/USB_Interfaces.pdf

Since you specifically cite me: the output of a sound card is typically
1 Volt RMS or more.

A transceiver designed for use with a dynamic mic (Kenwood, TenTec,
Kenwood, etc.) typically expects 5 mV (or less) on the mic input.  The 
attenuation needed to reduce 1 V to 50 mV is 46 dB (20log(.005/1)).

Transceivers using electret mics (e.g., Icom), have a typical mic input
around 0.05 V RMS  which implies the need for a 26 dB attenuator.

Note, the mic preamp stage of transceivers designed for an electret mic
typically has lower gain (~20 dB less) than those with dynamic mics are
are thus far less likely to be driven into clipping.

73,

    ... Joe, W4TV


On 9/4/2017 11:12 PM, Jim Brown wrote:
> On 9/4/2017 5:05 PM, Barry wrote:
>> with digital modes for 2 reasons, they are inexpensive and they can 
>> key your transmitter directly. 
> 
> The only good reason I can think of for using the SignaLink is if that's 
> all you have and you can't afford to replace it. It is NOT a good audio 
> interface. More times than I can count, I've posted a link to my 
> recommendations for much better audio interfaces that are MUCH cheaper, 
> AND they're stereo. That means, for example, that with two VFOs or two 
> receivers, you can have two instances of WSJT-X running either copying 
> different frequencies or doing diversity reception! In addition to WSJT 
> modes, I use my stereo sound card to do SO2R SSB and RTTY contesting.
> 
> http://k9yc.com/USB_Interfaces.pdf
> 
> And as Don has noted, the SignaLink derives PTT from the audio stream by 
> a process known as VOX.  :) Your rig can do that as well.
> 
> 73, Jim K9YC
> 
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