If the input impedance is really 47 ohms, you could use a T or an L or
simply a single series resistor. Think about 4700 ohm series resistor.
With that 47 ohm input Z that would drop the audio 100:1. Maybe simpler
than a complete cable, how about a pair of connectors back to back with
straight wires for all but that audio line. A little metal box would be
of benefit to maintaining the shielding.
Or if the interface to the USB dongle is a DE9 with a metal shell, it
might be possible to mount a tiny switch in that shell to insert the
4700 ohm resistor or short it out depending on the rig.
73, Jerry, K0CQ
On 12/19/2010 5:08 PM, Fred Moore wrote:
>
>
> On Sun, 2010-12-19 at 15:03 -0800, James C. Owen, III wrote:
>
>> Not wanting to re-engineer something that likely already has been done.
>> Here's
>> my problem! Recently got on the digital modes with a signalinkUSB that works
>> fine with the Argonaut V, all gain controls pretty much centered. Connected
>> to
>> the Jupiter and had nothing but overdrive even with all gain controls at
>> minimum. I then looked at the spec's of the two. Argonaut V 100mv into 47
>> ohms,
>> Jupiter 1mv into 47 ohms. So the Jupiter is 100 times more sensitive, so
>> that's
>> the problem. I'm thing of a simple T attenuator which will require me to
>> make
>> another cable. Has anyone come up with a good simple solution?
>> 73 Jim K4CGY
>>
>>
>>
>>
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>
>
> Havn't had the manual for the signalinkUSB for some time, but isn't
> there a jumper inside between two pins? perhaps a switch added to the
> signallink moving the jumper? in and out. You could also just change
> the master output for the USB device in the software depending on what
> rig you are driving.. . . Fred
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