Stop TX audio

RobertPantazes

When I have a long QSO I notice that the TX stops operating. This happen after about 15 minutes in to a two way QSO, then when I am talking after about 30 seconds I have no TX audio, I un-key and then PTT again and the audio returns. I have change the microphone with no solution.
The 6400M's firmware is V3.2.39

J.C. W4QK

Hi Robert,

One possibility is that the DAX may be on. I have had that issue a few times with my 6400M. I hope you find the problem as it can be frustrating during a QSO.

73 - JC

W4QK

Mike-VA3MW

@RobertPantazes

To help diagnose this further we need to know more about your setup.

• Is this with a MIC connected to the back of the radio or PC audio
• If PC audio, is the PC you are using on a wired LAN or WiFi?
• How are keying the radio - where is your PTT connected to
• Does it happen all the time?

Sometimes, when we see this happen, it is related to a loss of network communications. If you are using the radio with the Mic and PTT switch plugged into the back of your 6400M then we may have a hardware issue with the radio and please open a support ticket.

73

RobertPantazes

The Microphone and PTT is connected directly to the 6400M. If I am on air in a QSO in SSB, about 15 minutes in the QSO I will loss modulation and power. To get back on the air, I un key and re-PTT and it works fine.

Mike-VA3MW

Sorry to hear you are having an issue.

You'll need to open a support ticket

https://helpdesk.flexradio.com/hc/en-us/articles/202118688-How-to-Submit-a-Request-for-Technical-Support

Jeff_W4DD

Interesting Robert.

I have had something similar happen randomly. While transmitting, I lose output power indications on the Flex and external meter, but I still see the audio level and compression meters indicating they see audio at normal levels so the audio is making it into the Flex. When I rekey PTT, everything works as it should. My audio goes directly into the back of the 6600. So far, I have not found any sequence where I can make it happen. It does occur during a long round table I have with others, but transmissions are relatively short and not too frequent. The smart SDR network connection is via a dedicated Ethernet switch that sits next to the radio (latency of 1ms, no packet loss). Smart SDR seems to be running perfectly. If you can get yours to happen regularly, it may be something different than mine.

Mike-VA3MW

Jeff, I hear what you say on no packet loss, but it is possible to have packet loss that you do not detect. I have friends who make a living on those failures. :)

I have a single LAN cable that when connected to the computer that I use for CW Skimmer cause CW Skimmer to crash, 100% of the time. Change the cable, no crashing.

Unless you have a managed switch, you have no way of knowing of any sort of packet loss failure. This is why these problems are hard to track down. Very challenging.

Jeff_W4DD

The mic audio and PTT is going in the back of the 6600. The 6600 is telling Smart SDR it sees the audio, aka the mic level and compression level indicators are achieving normal levels. But RF output is zero. The 1 gbps switch is only running at a few mbps but even if there was packet loss I would not expect it to cause loss of RF. Or perhaps you mean if the Flex misses a packet or two from Smart SDR the radio stops RF. That might explain the loss of RF.

John KB4DU

The network side can be really challenging. If possible, connect the computer directly to the radio just for testing.

I replaced a 1GB switch with a 100 mb router/WAP with the WiFi disabled, most of the connection related issues went away.

Jeff_W4DD

The mic audio and PTT is going in the back of the 6600. The 6600 is telling Smart SDR it sees the audio, aka the mic level and compression level indicators are achieving normal levels. But RF output is zero. The 1 gbps switch is only running at a few mbps but even if there was packet loss I would not expect it to cause loss of RF. Or perhaps you mean if the Flex misses a packet or two from Smart SDR the radio stops RF. That might explain the loss of RF.