Odd Behavior with 6700 and WSJT-X FT8

  • 1
  • Problem
  • Updated 3 weeks ago
I was running the F6700 with v2.3.7 SSDR.  Several issues came up while I was trying to work KH1/KH7Z on 30m.  The first issue occurred when I moved the mouse across the SSDR screen.  The flag disappeared as though I lost the slice.  Not sure how to bring back the slice so I powered the 6700 down and back up.  The second issue happened after KH7Z called me and FT8 in response starting xmting, however, the set freq was 10.131.000 mhz but when the xmt began it changed to 10.131.500mhz.  When this happened I could not acknowledge KH7Z so I lost the contact.  I decided to exit from WSJT and close SSDR.  I attempted a second contact and again the same thing happened.  Don't know if it is the SSDR or WSJT forcing the freq change.  All I can say is I lost making the contact with KH7Z on 30m, however, I was successful making the contact on 20m.

Don - kx9q
Photo of Don - kx9q

Don - kx9q

  • 402 Posts
  • 18 Reply Likes

Posted 3 weeks ago

  • 1
Photo of David Chen

David Chen

  • 8 Posts
  • 0 Reply Likes
1, I met this issue once.
2, WSJTX will control your frequency during TX, that is normal. But we notice KH1/KH7Z meet some (WSJTX software) problem on 30m ft8 mode. It spent me 1 hour to work them but fail to get last rr73. Actually they logged my call sign already. I think Don/N1DG will tell us what happened on the island when they back:-)

73 de ba4rf, David
Photo of Don - kx9q

Don - kx9q

  • 402 Posts
  • 18 Reply Likes
I am curious to know if others have experienced the first issues.  Interesting if this was a problem on their end.  I am not sure how often they update the online log so I will wait and see what they may show if there was a contact made or not.

Don - kx9q
Photo of Bill W2PKY

Bill W2PKY

  • 448 Posts
  • 78 Reply Likes
Don did you have "Fake It" checked? If so WSJT-X will control the frequency during transmit. This feature is not needed on SSDR radios. 
Photo of Don - kx9q

Don - kx9q

  • 402 Posts
  • 18 Reply Likes
Fake it was checked.  How would set up SSDR without using fake it?
Photo of Bill W2PKY

Bill W2PKY

  • 448 Posts
  • 78 Reply Likes
Fake It is for rigs with SSB filters so the transmit VFO is kept within the band pass. You were probably okay to make the Q as the offset is computed by the software. Since SSDR radios can have wide band pass, no offset is required. I know Fake It is recommend to be checked but not necessariy for our radios. Hope this makes sense. You can find more in the FT8 user manual.
Photo of Jim  KJ7S

Jim KJ7S

  • 126 Posts
  • 21 Reply Likes
Thanks for the advice as I also used (per general wsjtx setting suggestions) and the same thing happened to me with kh7z so I'll try not 'Faking it' and see if the results are more genuine hihi.  I seem to remember seeing that, also it shifted the frequency but I believe it actually kept the tones in the right place, but I could be wrong.
Photo of Paul W5PF

Paul W5PF

  • 47 Posts
  • 4 Reply Likes
Don,

In 2,3,7 the slice flag will disappear if you click on the blue slice letter at the top of the flag. If you click on the letter again the flag will come back. That could possibly be what happened.
Photo of Don - kx9q

Don - kx9q

  • 402 Posts
  • 18 Reply Likes
There was nothing no flag, no letter and if the flag got moved off screen there would be < or > letting you know where it went.
Photo of Dennis ODell

Dennis ODell

  • 13 Posts
  • 2 Reply Likes
This is the normal behavior of WSJT-X v1.9.1 in 'Hound' mode.  Once the 'Fox' station acknowledges your call, the software moves your transmit below 1000Hz for easier decode.  Depending on your split mode, it will either move your actual transmit frequency, the tone frequency feeding your input, or a combination of both.  I too was concerned the first time I saw it happen, then I realized what was going on.

I heard way too many stations calling KH1/KH7Z below 1000Hz where they would never be heard for a contact by the 'Fox' station, who was listening only above 1000Hz for calling stations.

73, de N4QM
Photo of KY6LA - Howard

KY6LA - Howard, Elmer

  • 3522 Posts
  • 1378 Reply Likes

FT8 DX Hunting Tricks of the Trade

201 FT8 Countries so they do work OK


1.I NEVER use FAKE IT or Rig Split for FT8. even for DXpedition Mode  -

WHY;  Because FLEX radios can transmit anywhere in the transmit bandpass without degradation.

2. I  normally set my TX Bandpass to 4K

3.  I make sure that the TX level Never hits red  -IF I run power - I even keep it out of yellow.

4.I never transmit on the DX Stations Frequency... too many Newbies QRMing themselves.,

5.  Rather I set my TX Frequency and uncheck follow the RX frequency

Very easy to bust a pileup that way because the Newbies are all on the RX Frequency.

6.  I run enough power commensurate with the other guys signal level... EG if you are hearing him at -24 then you better be running a KW or he will not hear you.

7.  DAX is MUCH better at decoding than external boxes such as a Signal Link... Since the other guy likely does not have a Flex... if he is weak, he is definitely not copying you unless you run power.

8.  FT8 is a WEAK SIGNAL MODE... NOT a Low Power Mode...

9.  If you do run power, make sure you are NOT Splattering since overdriving your radio will make your signal difficult if not impossible to copy

10.  JTAlert is a really good friend to DX Hunters as you do not need to waste time sitting in front of your radio until something you need shows up

(Edited)