Clean transmitter

  • 3
  • Praise
  • Updated 2 years ago
There are a lot of things I'd like for Flex to improve.  But one thing they have nailed is very low IMD on transmit.  When I see a Flex 6000 on the air, I have noted how clean the transmissions look on the display compared to other rigs.  I just finished talking to an Anan "Pure Signal" user & he said my Flex 6400 is as clean as any Anan Pure Signal user.  High praise. 

So this is something I'd like Flex to improve:  I think you should be making a much bigger deal about how clean the 6000 units are.  Some folks are going to Anan products for Pure Signal.  Well they do not need to.  The 6000 series is good enough without having to jump thru hoops to enable Pure Signal.
Well done, Flex!
73 Bob W8RMV
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Posted 2 years ago

  • 3
Photo of David Decoons wo2x

David Decoons wo2x, Elmer

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Yes, my Flex 6600/Power Genius XL is nice and clean. Not as clean as Pure Signal but VERY acceptable on the air. MUCH cleaner than most Y* brand radios I see and definitely cleaner than the single device LDMOS amps.

The panadapter on modern radios is a double edged sword. You can see so much in the spectrum including stations you might otherwise not work. But you also see people's signals and if you do not understand what you are looking at people can think a transmitter is "dirty" where the unwanted transmitter noise is well within FCC limits, especially on signals that start exceeding 20 dB over S9 and higher.

My two cents...

Dave wo2x
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Art - N4QNT

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I totally agree that these radios are very clean, but I feel the operator also plays a roll and the quality of the Amplifier as well.. I see massive IMD’d from Flex, Yaesu, Icom rigs just to name a few when the operator is over driving a poorly made solid state or tube amp to get every last watt out then the Mic and Processor gains are turned to the right.. Example photo.. I know the gent on the left side signal with his Flex 6300 and Ameritron 1306 solid state amp... Now the operator on the right we can only guess what their operating..
Photo of Homer1952


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Bad practices can always ruin a good radio.  That goes without saying.I should have mentioned I was running 100W from my 6400.  That is another thing to praise.  It seems when I run the 6400, I have less need to run an amplificator.  The nicely done processing on SSB gives me enough punch without the distortion to be heard barefoot on 80M when many others are running amps.73 Bob W8RMV
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Rob N4GA

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I've never measured the IMDs but can tell you the harmonics are WAY down.
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Bill -VA3WTB

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I have measured the signals here when Dave is strong here, at S 10 here is usually 40db down.