Flex 6000 as a Signal Generator

KD0RC

I figured out a way to use my Flex 6400 as a really good, clean signal generator capable of less than -10 to +10 dBm output. I add a transverter using the XVTR tab of Radio Setup and give it a 1:1 RF:IF relationship. I arbitrarily chose 1.000 MHz. This will now work across the full tuning range of the radio.

I set the transmit antenna to an available transverter port (XVTA on the 6400), and set Tune Pwr to 100% to get the output specified in the Max Power box. I can adjust Tune Pwr down to anything less than 100% to fine tune the output from there.

Because it uses the transverter output, it will output the signal anywhere the radio will tune. Since my Rigol DSA 815 spectrum analyzer is capable of handling up to a +20 dBm signal, the +10 dBm max of the Flex is perfectly safe to pipe directly in.

If you have a transverter, make sure that it is not connected to the transverter port if you experiment with this.

CAUTION: If you use this as a sig gen, be very careful what you hook it up to. Injecting a signal into the IF of an old tube rig could potentially put a Flex-destroying high voltage into your transverter jack. Flex does not advertise or mention this use of the rig at all, so you are totally on your own here.

On the other hand, hooking up a short wire to the center pin of the transverter jack to provide a steady signal to another piece of gear without any physical connection should be fine.

Note that any modulation the radio is capable of, the "signal generator" is capable of as well.

Mike-VA3MW

Excellent idea.

KD0RC

Thanks Mike. With a little creative programming (third party), I could see a sweep function coupled with Full Duplex to show filter response - how cool would that be?

Mike-VA3MW

You know, that could work.

KD0RC

I think it might... I am playing around with learning C# and the FlexLib. I had a really steep learning curve trying to learn C++ for my TeensyMaestro, but with that under my belt, the C# is much quicker to learn.

I already have several functions in my little test program working reliably. I will fool around a bit more to see if I can get a reasonable sweep speed out of it. I may add a new tab on this screen to be a function generator. In the meantime, I figured out how to get the following info from the radio and to change mute and frequency, including copying frequency from one slice to the other.

If I get anything workable, I will post back here.

KD0RC

Well, I fiddled around, and got the rig to scan, but without a peak-hold function on the spectrum analyzer part of the panadapter, it really isn't very useful for looking at filter responses. There is definitely potential for a test equipment function of the Flex radios, but I don't know what the interest in something like that would be.

To make it really useful would probably require the functionality to be built into the radio in conjunction with a GUI like SmartSDR but for the test instrument functionality. Food for thought...