SmartSDR loses connection with 6400 during transmit

Phil N3ZP

In the last several days I have been experiencing SmartSDR 3.3.33 losing connection with the radio. Nothing has been changed with my PC or antenna. It does not seem to be on a specific band and has occurred running both FT8 and RTTY with the radio at approximately 8 to 10 Watts feeding an Elecraft KPA500 amp at about 150 to 200 Watts. My antennas are verticals and have low SWR. I also have a KAT500 tuner which I can use it to reduce the SWR on some bands as needed. I have good grounding and bonding and have not had any RFI issues. When this happens, I get a red flashing LED with 2 flashes. Rebooting the software seems to correct the problem.

I have not replaced the SD card or had any problems with the radio before. I have done all the updates since receiving the radio in approximately December, 2019. I'm not sure if this warrants a support ticket but it is new and very annoying.

Thanks,

Phil N3ZP

KD0RC

Hi Phil, Yes, I would submit a help desk ticket. This sounds suspiciously like an SD card issue, but the Flex Support Team can tell you for sure.

David Decoons, wo2x

I had some weird connection issues earlier today and also a radio reboot during transmit

I checked and found a significant voltage drop on a steady carrier transmit. The cause was the radio power cable had pulled partially out. It happens sometimes.

Might be worth checking all cable connections.

Dave wo2x

Mike-VA3MW

Assuming it isn't a voltage drop issue or RFI, then it might be a hardware issue. It is possible that you didn't observe something that has changed, but it could be something you have yet to observe.

I did open a support ticket for you.

Phil N3ZP

Mike,

Thanks for opening a ticket. I'll wait to hear from support before trying anything. The radio is connected to my JetStream JTPS28 power supply terminals with an 8 in. power pole jumper. There is a PARADAN Power **** 4 with a meter also attached to the supply that is used for a few accessories. All are low current draw items. I don't notice more than a .1 or .2 Volt drop in the 13.9 Volt display when transmitting. I am considering getting a beefier linear supply like an Astron RS-35 but haven't bought one yet.

Any help is appreciated.

Thanks,

Phil N3ZP

Phil N3ZP

Mike-VA3MW

Hi Phil

You want to load FRStack and then look at the meters internal to the radio when you go into TX.

They will ask you to make tests without the amplifier online starting at low powers of 1 - 5 watts to see if the same problem happens. The goal is to eliminate anything that could cause an RFI issue first.

If you have a dummy load, testing on that will help as well. If not, Dummy Loads for 500 watts are not very expensive and highly recommended. The MFJ-264 is a great choice and you can find them at a any Ham store.

Keep in mind the radio crashing is the symptom but it might not be the root cause of the problem.

GL

Phil N3ZP

Hi Mike,

I will download FRStack and try the tests. I do have an MFJ high power dummy load.

Thanks,

Phil N3ZP

Phil N3ZP

After going through the troubleshooting process as detailed in Ken's reply to my support ticket, the problem was traced to a Paradan antenna disconnect unit. After going through connections one by one I finally resolved the issue by removing the antenna disconnect. So far everything is working Ok. I have also replaced my Jetstream switching supply with an Astron RS35M.

Thanks for the replies.

Phil N3ZP