RF Spikes

Dan Trainor

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

You mean this . . . My 6500 on AM

Talking

Whistling

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

Mike-VA3MW

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

Dan Trainor

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

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

rdwing

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

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.