Monday, January 30, 2017


Soon after buying my Flex 6300 about 10 months ago, I made a blog posting comparing it to the K3 I'd owned for years. That comparison was mostly economical and can be read here. If a "Part 2" could be written to that comparison, it would probably center on the ease of digital operations with the Flex (or any true SDR radio).

Lately I've become more interested in digital modes of communications and the past few months have been spent mostly on JT9/65. Today I made my first-ever, in 39 years of ham radio, QSO's on RTTY. This is largely due to not having any new DX to work on CW until a major DXpedition comes along.

Two things make the Flex 6000 series of transceivers ideal for digital modes:

No need for this!
First, the cabling is greatly simplified over what would have been required with the K3 or most other rigs. I don't need a soundcard interface and I don't need separate cables to pass data to/from the rig nor is one needed for CAT keying and other commands. Regardless of whether I'm using my Flex as a CW-only rig or as a full-fledged, multimode transceiver, there is only one cable needed to connect rig with computer - a simple LAN cable.

Second, everything remains in the digital realm. Audio going to and from the rig is digital audio via the Flex's DAX interface (for Digital Audio Exchange). DAX is simply a digital equivalent of "virtual audio cables" that are built into the Flex operating software. There is no risk of ground loops, no need for audio isolation, no chance of hum being induced into the mix and no issues with audio-to-digital conversions. It's all digital, all the time.

Configuring the set-up to go from WSPR to JT65 to RTTY is a simple matter of a few clicks of the mouse with no spaghetti mess of wiring behind the rig. Once configured, a single click of the mouse (to select a saved profile in the Flex menu system) puts me on a specific band with the chosen mode.

See you on RTTY...


  1. Let me think of what contact you made with RTTY. I guess it was TG9AHM....This flexradio system you use is really easy. But you can't do anything with it without a computer. Every advantage has a disadvantage (not my own phrase). Still hope to meet you on JT mode one day. But I guess we have to make a sked for that. 73, Bas

    1. Hi Bas,

      TG9AHM was my 2nd RTTY contact - CO8LY was first. Nothing exotic from this part of the world and I still need to set up the macros but it was fun. Yes, I do need a computer to operate the Flex but I always have one on anyway to look at DX spots, operate JT or just to read blogs and other sites while operating. If the computer ever fails I will have the KX2 to play with :-)

      I saw a few days ago that you heard me on 60m JT65 but it was quite late for you, about 0300Z (10pm here).