Last update 04.06.2008 OH2NLT

JUMA-TRX2 and NUE-PSK Digital modem are perfect match. Below you can find instructions how to make the cable and how to configure TRX2 for to use with the PSK modem. There is also one suggested TRX2 hardware modification to achieve optimum PSK performance. Another TRX2 modification suggestion is to improve TRX2A PA thermal balance. Digital modes differ from CW and SSB by having sustained full carrier during TX overs.

Cable between JUMA-TRX2 and NUE-PSK modem

There are two different color schemes in the radio cables delivered with NUE-PSK kits. Please see NUE-PSK kit documentation for details. This illustration is for Type A cable. Radio connector pin numbers are same for both cables.

Picture of the cable. TRX2 front panel connector (Mic) can be 90-degree type.

Setup
1. Select AF in = Line from TRX2 Config
2. Adjust NUE-PSK TXAudio level so that TRX2 output power is max 5W
3. Other instructions please see NUE-PSK operator’s manual_

Recommended JUMA-TRX2 modifications for digi modes

• Line input modification for digi modes. This modification shuts audio processor (compressor) off when AF in = Line is selected. Digi mode modulation schemes do not like compression.
• All band PA modification for long key down operations. This modification reduces thermal stress of the PA board. Real heavy-duty users may also want to add heat sink on TRX2 back plate.