Craig, if you’re going with an external USB sound card, I can highly recommend a Behringer UCA202 or UCA222.  Both work great for 9600 packet and for DUV telemetry with FoxTLM.    These sound cards go both low and enough in frequency to be versatile and of great use for many radios. Price is quite reasonable, too. 

Mark N8MH 
On Sun, Mar 28, 2021 at 7:29 PM D. Craig Fox <> wrote:

If you are using an external sound card interface to tx 9600bps to Falconsat with a base transceiver, can you please provide details- ie, homebrew, commercial.  As I mentioned in an earlier post, the older Signalink isolation transformers attenuate most or all of the 9600bps data stream.  Some ops have reported being able to install a jumper or other connection in their radio’s data port to somehow avoid the Signalink datastream attenuation.  Unfortunately I have not determined if such a modification is possible on my TS2kx. And I want to retain all functionality for other dig modes and 1200 aprs.  So if I’m left with having to obtain another external sound card interface, fine, but I want to be sure it will definitely do the trick. Of course, if someone has more specifics on such a modification for the TS2K, then by all means please provide details.  Mark N8MH mentioned having “bypassed” the transformers in his Signalink before he went to a TNC, which makes me wonder if it could be as simple as installing a microswitch in the Signalink and some bypass circuitry.


Thank you for the bandwidth and help in advance.


73, Craig



NOTICE: This communication may contain privileged or other confidential information. If you are not the intended recipient of this communication, or an employee or agent responsible for delivering this communication to the intended recipient, please advise the sender by reply email and immediately delete the message and any attachments without copying or disclosing the contents. Thank you.


Sent via AMSAT-BB(a) AMSAT-NA makes this open forum available
to all interested persons worldwide without requiring membership. Opinions expressed
are solely those of the author, and do not reflect the official views of AMSAT-NA.
Acceptable Use and Privacy Policies available at

View archives of this mailing list at
To unsubscribe send an email to amsat-bb-leave(a)
Manage all of your AMSAT-NA mailing list preferences at

Mark L. Hammond [N8MH]