My Flex 6400 Tx is showing "hiccups" in its output waveform! Help, please!

N7DK Dave

I've been running my Flex 6400 for more than 5 years with great results -- over 16,000 FT8 contacts with few problems and the best DX I've ever enjoyed! However --

Please see the attached image of spectrum output into a 50-ohm dummy load. The output appears to be "hiccupping" periodically.

I have seen something similar in the past when I would run the rig 24x7 for days at a time. Based on an old recommendation from Tim, I learned that killing and restarting "DAX" would put me back in business. However this new "hiccupping" isn't cured with this method, making my think my beloved Flex 6400 may be dying of old age(?)!

Has anyone else seen this problem? Are there any things I might try to fix this?

Many thanks in advance for any suggestions!

73, Dave, N7DK, [email protected]

KT5N Jeff

Same here with my 6500. I thought it was possibly coming from a malfunctioning remote antenna coupler but it persists while using the ZS6BKW as well. I am running 3.4.23.

Eric-KE5DTO

First, I would recommend updating to the latest version (currently v3.5.9). There is a possibility this alone will address what you're seeing.

If that doesn't get you going, to get to the bottom of this I might temporarily change the network setup to directly connect the radio to your PC. This will eliminate any other network devices/config between the PC and the radio. If this eliminates the issue, then it may be time to look at any cables and devices (switches, routers, etc) in the original configuration.

Let us know what you figure out.

David Decoons, wo2x

Besides WSJT-X, what other software is running? Anything changed recently? What version of SmartSDR? If you haven’t upgraded to the latest version SSDr, try that.

Usually the “pops” which show as wide horizontal lines in FT8 happen when TCP commands are being sent to the radio while it is transmitting.

Dave wo2x

N7DK Dave

Replying to Jeff, KT5N, and Eric KE5DTO --

Thanks, Jeff -- it's a comfort to know I'm not alone! I was theorizing I have a marginal/intermittent connection in somewhere in my shack connections & remote tuner (swr monitors, scope, tuners, linear, coax switches, ... ) so I just tried a dummy load on the radio itself -- and the problem persists.

Thanks Eric -- I do have an older version of the software on the radio, and I'll try updating it. Because the "hiccups" occur even with a 50-ohm dummy load connected directly to the Tx output, there is something in the radio itself that has gone awry. I've been running the radio nearly 24x7 since April of 2018, so I've been guessing my final may be "aging out", but from comments of others, it seems more likely it's a software issue of some sort.

I'll post again if I learn more ...

73, Dave, N7DK

N7DK Dave

Replying to David, WO2X

I'm running Version 3.3.32 which is way out of date. It had been working so well that I didn't want to tamper with it. But the first thing I'll try is a software upgrade to the latest version.

Thanks & 73 -- Dave, N7DK

KT5N Jeff

So today I installed 3.5.9 and the pops went away!

Strange thing is why they started in the first place.

Jeff