There's also a step zero, Paul, that doesn't involve digging out, dusting off and connecting your dummy load: simply turn down your TX power output. Unless you are VERY unfortunate, a few watts or milliwatts of RF is unlikely to cause problems.
Gradually increase your TX power until the problems occur, and you have a strong indication that RF is the culprit. You then have the option to stay below the problematic level and carry on working stuff, meanwhile attempting to fix the issue with shielding, grounding, ferrites, layout changes, better feeders etc. until you're OK with higher power (if you need it). Problems that only occur on one or some bands are another clue that RF is probably the issue. 73 Gary ZL2iFB From: Paul Randall <paulfrand...@hotmail.com> Sent: 21 November 2019 10:31 To: WSJT software development <wsjt-devel@lists.sourceforge.net> Subject: Re: [wsjt-devel] Fwd: 40 Meter Power USB-D issue Anyone who experiences peculiar behaviour from their station on some band/frequency/antenna/rig upon activating the transmitter should firstly perform this most basic test. STEP 1A1A1 - Try to reproduce the problem with the transmitter directly connected to a dummy load. This test should virtually eliminate the possibility that simple EMI is the culprit (which it is in most cases). Having suffered the problem myself, I know first hand that the above is excellent advice. Kind regards and good DX to all, Paul G3NJV _____ From: Jim Jennings <w...@comcast.net <mailto:w...@comcast.net> > Sent: 20 November 2019 16:55 To: WSJT software development <wsjt-devel@lists.sourceforge.net <mailto:wsjt-devel@lists.sourceforge.net> > Subject: Re: [wsjt-devel] Fwd: 40 Meter Power USB-D issue The symptoms suggest to me RF getting into a USB cable between computer and the rig's CI-V USB port. My cousin had a similar situation with his FTDX-3000 on 40 and 30M FT8, where the rig would abruptly quit transmitting if he tried to exceed about 25 watts. The problem was solved by winding some of the "spare" length of the computer to CAT USB cable on a ferrite toroid (FT240-43 used in this case). He can now increase to full output power of the rig (100W) without anything "flinching." Just a thought. 73, Jim, W7XZ From: Christopher Diederich via wsjt-devel Sent: Wednesday, November 20, 2019 05:01 To: Paul Randall ; WSJT software development ; wsjt-devel-ow...@lists.sourceforge.net <mailto:wsjt-devel-ow...@lists.sourceforge.net> Cc: Christopher Diederich Subject: Re: [wsjt-devel] Fwd: 40 Meter Power USB-D issue I will run it into a dummy load to check though. Thanks for the suggestion. Chris Get Outlook for iOS <https://aka.ms/o0ukef> On Wed, Nov 20, 2019 at 7:53 AM -0500, "Christopher Diederich" <k1...@yahoo.com <mailto:k1...@yahoo.com> > wrote: I have not tested with a dummy load. Other digital modes and phone don't have the same issue, and SWR is 2.5:1 into OCF 80 meter dipole, which is tuned easily with my LDG. Get Outlook for iOS <https://aka.ms/o0ukef> On Wed, Nov 20, 2019 at 5:12 AM -0500, "Paul Randall" <paulfrand...@hotmail.com <mailto:paulfrand...@hotmail.com> > wrote: Does it do it when the rig is running into a dummy load? Sent from my Samsung Galaxy smartphone. -------- Original message -------- From: Christopher Diederich via wsjt-devel <wsjt-devel@lists.sourceforge.net <mailto:wsjt-devel@lists.sourceforge.net> > Date: 20/11/2019 01:59 (GMT+00:00) To: wsjt-devel@lists.sourceforge.net <mailto:wsjt-devel@lists.sourceforge.net> , wsjt-devel-ow...@lists.sourceforge.net <mailto:wsjt-devel-ow...@lists.sourceforge.net> Cc: Christopher Diederich <k1...@yahoo.com <mailto:k1...@yahoo.com> > Subject: [wsjt-devel] Fwd: 40 Meter Power USB-D issue Get Outlook for iOS <https://aka.ms/o0ukef> _____ From: Christopher Diederich <k1...@yahoo.com <mailto:k1...@yahoo.com> > Sent: Tuesday, November 19, 2019 8:26 PM To: wsjtgr...@yahoogroups.com <mailto:wsjtgr...@yahoogroups.com> Subject: 40 Meter Power USB-D issue Good evening, I am experiencing a recent issue that has arisen where my IC-7300 is transmitting on reduced power on 40 meters using FT8 with WSJT-X. Other digital modes and phone work fine, and no other bands have the low power issue. Also, the rig occasionally changes from USB-D to USB when keying. Any ideas? IC-7300 Win 10 Pro 64 bit HRD version 6.7.0.244 WSJT-X version 2.1.0 73 Chris Diederich K1LDO _____ _____ _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net <mailto:wsjt-devel@lists.sourceforge.net> https://lists.sourceforge.net/lists/listinfo/wsjt-devel
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