Welcome to the new FlexRadio Community! Please review the new Community Rules and other important new Community information on the Message Board.
If you are having a problem, please refer to the product documentation or check the Help Center for known solutions.
Need technical support from FlexRadio? It's as simple as Creating a HelpDesk ticket.

RF Spikes

I have received my Telepost LP-500 Power / SWR / Modulation monitor.and it's all set up. This is.an ultra fast and accurate professional test instrument. Proving to be an excellent diagnostic tool. On AM mode, I am observing RF spikes on the LP-500 RF waveform display and also the AM modulation monitor display is reading greater than 150% Positive AM modulation due specifically to these RF spikes. (This test instrument is fast enough to catch them and I can see them visually in the waveform screen). My goal is to achieve about 120% Positive modulation (which is ideal), but I can't get there with these spikes occurring. To note, this is not an audio issue as no spikes are occurring in audio chain. So, I have confirmed the presence of these RF spikes (objective evidence) and will open a ticket. I suspect this is a bug in the 6400 hardware/firmware. I just need to takes videos of same and send to flex in the context of a help ticket. if anyone else.is seeing this issue, please let me know - it would be good additional confirmation from another source. Thank You, dan de WA1QZX


  • AA1SS
    AA1SS Member ✭✭

    You mean this . . . My 6500 on AM



    Cant get positive below 140 no matter how I adjust carrier or mic gain

  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

    Don, when you open your ticket, please make sure you provide some screen shots. They will be helpful.

  • Dan Trainor
    Dan Trainor Member ✭✭✭

    AA1SS, Yes exactly what I am experiencing. My spikes are high. And like you, can’t get AM positive modulation down below 140%. Due to the spikes. Thank you for screen shots, I will do the same. 73, Dan WA1QZX.

  • Dan Trainor
    Dan Trainor Member ✭✭✭

    Yes Mike, screen shots from LP-500 to be included as part of help ticket submission. Thank you, dan WA1QZX

  • rdwing
    rdwing Member ✭✭

    Can you check on SSB too? I have see as high as 160 watts on my wavenode meter, in sideband. Funny because my radio went back to flex last year for a suspected issue re noise floor on higher bands, but nothing was repaired. I was told that every radio that crosses their bench gets aligned to factory spec. Unsure if this actually happened or not.

  • Dan Trainor
    Dan Trainor Member ✭✭✭

    I will check SSB also. I have a professional and calibrated measurement instrument for peak and hold power readings. It detects these RF spikes, as it samples at very high rates. It uncovers what usually can't be. I am Troubleshooting to find root cause. We don't know what "aligning to factory specs" means or if it covers the anomalies we encounter in the field.

Leave a Comment

Rich Text Editor. To edit a paragraph's style, hit tab to get to the paragraph menu. From there you will be able to pick one style. Nothing defaults to paragraph. An inline formatting menu will show up when you select text. Hit tab to get into that menu. Some elements, such as rich link embeds, images, loading indicators, and error messages may get inserted into the editor. You may navigate to these using the arrow keys inside of the editor and delete them with the delete or backspace key.