locked Re: CAT issue with FTDX1200 / 3000 #Cat_RigControl


Jim Brown
 

On 3/16/2020 7:47 AM, Kai-KE4PT wrote:
I've been running the Yaesu FT-817 on SSB to unsolicited rave reviews on the audio quality. Also no complaints on CW, RTTY (via sound card),
The problem with these cheap rigs aren't heard by the stations you're working, but by those on adjacent frequencies. I suggest that you look at it on a spectrum display with waterfall while TX SSB -- what I've repeatedly seen are pronounced widening of the signal on voice peaks on both sides of the 2.8 kHz bandwidth, and if the amplitude display is set for averaging or to accumulate peaks, I often see that the splatter is less than 20 dB below the 2.8 kHz envelope.

Same for the clicks. Here are reports I put together several years ago. The first is all ARRL Lab data which they sent me electronically, the second is all my own work.

http://k9yc.com/TXNoise.pdf

http://k9yc.com/P3_Spectrum_Measurements.pdf

I should put together another report with plots of clean and dirty rigs. A group of west coast contesters hangs out on LSB just above the FT8 watering hole on 160M. Most of the guys have a nice clean envelope, while a few splatter like mad, down into the top of the FT8 bandpass!

A great place to see this is on 40M.

W4TV, a retired broadcast engineer, looked into the this and chased down the reasons.

73, Jim K9YC

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