One of the interesting upgrades out, is for the HK-232 / PK-232 series of TNC's. Not only does the HK / PK232 series of TNC have excellent passive hf filters, now they are further improved with cascaded DSP filters.
The ability to take the load off of the CPU is a great reason to use a TNC. There are also several software programs out there that recognize the upgraded TNC's and switch them in and out of TNC / Sound Card Mode automatically. For example the Airmail program for Winlink uses the Pactor TX/RX and Dsp functions of the HK-232 in Pactor One mode. The interface to the Ham Rig here is a HK-232 (kit form of the PK-232) upgraded with Timewave ( http://www.timewave.com/ )MBX (mail box), DSP, Low Power Chips, and the PSK31 interface switch modules. In essence when the PSK31 interface module is switched to sound card mode for programs like Scamp, the Tnc is bypassed and transformer isolated adjustable audio amplifiers for input and output to the sound card and ham rig is switched in. This same circuit is used when in Tnc mode, but then the internal modes, filters and dsp are used rather than any computer sound card programs. Thus I use the HK-232 with PSK31 in Sound Card mode when using Scamp, but use it in Tnc mode when using Airmail for Pactor Mode One receive and transmit only using the Tnc and internal Dsp support. When ever possible, I always choose a TNC function when available for a mode over software. Heck, I can put the TNC into a mode that will leave me on the air with a radio for vhf packet email, and receive email with no computer running. When I fire up the computer there it is .... do that with software .... hi hi 73 from Bill - WD8ARZ The K3UK DIGITAL MODES SPOTTING CLUSTER AT telnet://208.15.25.196/ <a href="http://dxcluster.blogspot.com";><img src="http://feeds.feedburner.com/DigitalSpotter.gif"; height="67" width="200" style="border:0" alt="Digital Spotter"/></a> Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
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