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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