CW QSK with 6400 & Maestro

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I've read countless (mostly contradictory opinion) postings about QSK in the various Flex 6000 products and it seems that at last posting, QSK was still not working quite right- at least not reliably. I'm looking at purchasing a new Flex 6400 & Maestro, but fully functional, silent QSK is a must for me. With that said, can anyone using a 6400 or 6600 with Maestro please answer the following:
1. My understanding is that Flex uses a PIN diode for the TX path in T/R switching, and a reed relay in the RX path. Can you hear the reed relay? Is it mechanically reliable? 
2. It seems that QSK with the antenna tuner in-line does not work. Is this still true? 
3. I've read that CW sidetone is generated locally by the Maestro, so there is no delay. If using Maestro connected via WiFi and running QSK, is there audio delay between elements due to the network latency? The same if connected via cable? 
4. Is there any appreciable difference when running a 6400M vs. a 6400 with a Maestro? I don't mean to over simplify, but It appears that they 6400M is essentially a Maestro hard-wired to the front of a 6400. However, I imagine the 6400M front panel may interface differently to the 6400 so may not suffer latency introduced via ethernet. Either way, audio delay due to processing or network latency is terrible and makes QSK impossible. 
I really appreciate any information that the group would be willing to share. 
Thanks and 73-  Jason  AC7JW

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Posted 5 days ago

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Photo of Joe N3HEE


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No Maestro here but I can answer items 1 & 2.  I have a 6600M.  QSK works reasonably well but still needs work.  It took me lots of tweaking to get it to sound good.  

1. I can hear the reed relay.  It is very quiet though.  Flex traded silent QSK operation for better RX performance.  Reed relay seems reliable so far.  I am mostly CW here.

2. Yes, still true.

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Phil N3ZP

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I work a fair amount of CW with my 6400 and Maestro. I have no complaints about QSK or noise from the relay. I use an external Winkeyer but have used the internal keyer in the Maestro with no problems. My Maestro is connected to the 6400 with a network switch but have used WiFi but with the Maestro in the shack and the keyer connected to the 6400. I use an external tuner and mostly operate CW with headphones connected to the 6400. I don't see any issues with the 6400 as a CW rig at least from my experience.

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Thanks for the replies Joe and Phil- I really appreciate your sharing this information. The QSK issue with internal antenna tuner is a bit perplexing- I hope they come up with a fix for that!
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Flex 6600 here. Not a M or Maestro.
QSK works very well and is silent using SmartSDR on computer and audio directly from 6600.