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[{"insert":"Hi, I’m thinking of buying a 6600 and am curious about its CW capabilities? \nthanks\n"}]

Best Answers

  • KD0RC
    KD0RC Member, Super Elmer Moderator
    Answer ✓

    I regularly use my 6400 for CW. I am not a serious contester, but do participate in contests occasionally and almost always join the fun during Field Day. I enjoy chasing DX and casual ragchewing, so I am sort of a 'generic' CW operator. I find that the 12 easily programmable memories really work great for me during FD.

    Split operation, where you can see and hear the DX and the pileup (in different ears if you so choose...) is a real dream to operate. The days of pushing the A/B switch to alternately listen to the DX or the pileup are over! I find myself using split in CW much more than SSB just because it seems like DX CW ops are more likely to use split these days than SSB ops.

    One selling point for me is the high resolution panadapter/waterfall display. Some of the YaeComWood rigs let you put the small front panel screen up on a big monitor, but the resolution looks pretty crude compared to the Flex. The good screen resolution lets you see really weak CW signals so that you can zoom in on them to take a shot at working them.

    For me, the only downside to the CW operation of the Flex is the lack of CW macros. This is not a problem for serious contesters as they are likely using N1MM software, and therefore get a pretty robust CW function set. There are a lot of third party apps that seamlessly integrate with Flex, so that makes up for any perceived shortcomings.

    You don't mention what kinds of things you plan on doing with CW (EME, contesting, chasing DX, net ops, etc), so you might want to post that for more specific responses.

  • Stan VA7NF
    Stan VA7NF Member ✭✭✭
    Answer ✓

    There is one problem with CW in contesting - That is the general latency of the radio. The filter adjustments helped by slightly reducing latency at the expense of brick wall activity. It introduces a partial second delay in total message response as each turn-around involves latency.

    I like to set filtering to follow the bandwidth selected but in some cases set it reduce latency slightly. Reason is the filtering is SOOO good that at 50 or 100 Hz bandwidth I DO NOT hear a response say 150Hz off frequency and always watch the panadapter for any off frequency response.

    My F6700 is the BEST CW rig used. When visiting on multi-multi operations I bring my 6700 because the Icon radios there are nowhere near as good. p.s. the 50 and 100 Hz let me hear stations in the high noise and they do that without the historic ringing that happens with other rigs. AGC-T setting is important as background noise at that filtering can sound like ringing, but backing off the AGC-T makes the background quiet, even when the received station is less than 3 db over the greatly reduced noise.

    N1MM supplies a great tool with Flex with both pre-recorded cw messages and unexpectedly the focus option to bring you back to the N1MM menu if you click on something else.


  • KD0RC
    KD0RC Member, Super Elmer Moderator
    Answer ✓

    I find that the QSK capabilities of my 6400 are very fast and smooth. @Stan VA7NF - I agree completely with the narrow bandwidth and AGC-T adjustment. I can listen to 40 + WPM (can't copy that fast...) without ringing even at a 10 Hz bandwidth if I back off the AGC-T a bit.

  • Russ Ravella
    Russ Ravella Member ✭✭✭
    Answer ✓

    Hi sbachhuber,

    For what it's worth, I have a 6700 and don't see the transition performance implied by Dan's data in the last post. It was the same with my previous 6700 and all the 6600's I've had. With my PGXL in standby and the 20ms required TX delay in the radio's settings removed, nothing else in the signal path, AGC-T set just right, all filters set to their standard setting ("Auto"), ant tuner off with delay set to zero, and the volume all the way up listening in my headphones I can't even begin to hear RX between dah's or dits sent at even 20 wpm.

    My own take on this has always been I couldn't care less as long as I can hear at least a little between words and I can. So this has never been an issue to me. But despite the above numbers, at least to me Flex radios can't operate full QSK. My previous Yaesu could but I actually added delay to reduce the racket ! Also for what its worth, I totally agree with the comments in this thread regarding filtering. The filtering in Flex radios is really incredible.

    73 Russ KR6W


  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

    @sbachhuber You posted a pretty generalistic question.

    You don't win awards like this without a solid radio platform to go with the operator.


  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

    @Dan Quigley, N7HQ had this to say about latency

    It's simple math. 

    The word PARIS is the standard to determine CW code speed. Using Farnsworth, each dit is one element, each dah is three elements, intra-character spacing is one element, inter-character spacing is three elements and inter-word spacing is seven elements. The word PARIS is exactly 50 elements.

     5 WPM is sending 50 * 5 = 250 elements, 1 minute = 60,000ms   60,000/250 = 240ms per element. 

    20 WPM, 1000 elements, 60ms per element

     The TX/RX relay has two transitions per dit and dah, the actual character speed will vary but let's use all dits for a worst-case.

     500 dits in a minute = 1000 elements  @ 60ms per element, relays operate at 2x per element in this "all dits" case, so each TX/RX transition must occur within 30ms. 

     Doing the math...

     40WPM  requires TX/RX 15ms worst case. 

    60WPM  requires TX/RX 10ms worst case

    80WPM  requires TX/RX 7.5ms worst case

    100WPM  requires TX/RX 6ms worst case

    120WPM  requires TX/RX 5ms worst case


    A 6600 will transition from TX/RX in about 3ms 

  • sbachhuber
    sbachhuber Member
    [{"insert":"Thanks Russ, I really can’t do more than 15wpm these days. Arthritis in hands and hearing has gone somewhere. The filters are a big thing for me so I can eliminate as much clutter as possible.\n73’s K9SJB\n\n"}]

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