Inconsistent power output;WSJT-X v2.1.0; Flex 6400 w/atu; SDR v3.0.27

dave

When operating in FT4/FT8 cannot transmit at full power.


When transmitting above 60 w, the output will not get beyond ~70w.  I have checked this to my dummy load and it is consistent.


My settings: ATU on; SWR 1.2
DIGU mode; 3.0k filter
All signal processing off.
DAX on.

DAX control window: TX Gain 50%
RX stream Slice "A", 50%

CAT control window
WSJT-X my port 5003
WSJT-X PTT
COM4

Please let me know if this is a common experience or if I am missing something.

Mike-VA3MW

KL4QG

What is max wattage on flex 6400M on SSB/CW /Diq/FM /AM

Mike-VA3MW

100 watts PEP SSB
100 watts CW FM
25 watts AM

Digital is part of SSB

KL4QG

Coolest

AH0U

Where is the power slider on the WSJT software set???? Set it at max

bahillen

Audio response can affect power output on ft8 and ft4. Check with audio tx at 1500, center of band. Audio Tx EQ can make a difference. And audio bar on SmartSDR TX applet should be just below the red as controlled by the DAX slider. Your computer audio level on the sound record maybe turned back looking at the properties. Just some ideas. When I have had these kinds of audio level problems it is very frustrating to work your way through it. Making a written checklist of things that caused issues helps cover up for my confusion factors and forgetting past things to check. 73 Bill

dave

Yes, 100%.  Normally, I transmit at ~55w; but, when trying to hit some far DX, I jump it up somewhat.  FT4/FT8 is "weak signal" but one still has to overcome the receiving stations local noise floor.

dave

I have been hesitant to adjust the TX audio gain while in DIGU; while I am certain the applet is right, I'm not sure that my tweaking won't splatter the signal and cause distortion.  This might improve the power, as seen from the indicated output wattage, but decrease the readability.  I'm just spitballing here - don't know if this correct or not; but I will mess it in a logical and repeatable way.

dave

This would make sense and my power supply is adjustable.  Next time I see it happening, I will (mal) adjust the PS output from 13.8 to 15vdc for testing. 

Michael N3LI

What do you have your streaming TX set at?

Michael N3LI

The Flex is much less likely to spew bad signals than legacy radios. I'd move the TX Streaming level up until you get the output you would like.  If your Audio meter is at around the right level (remember red is dead) you should be good to go.

Bob G W1GLV

Power output can be erratic if you try to transmit on the edge of the TX passband. The transmitter will try to reduce the power out. 

Larry _ NY8T

Michael N3LI

I keep mine at -10, but I think your levels are FB as well.

dave

50% on the slider

dave

I'm peaking just shy of the "red zone".

dave

Your pic looks identical to my output level throughout my transmitting power (~50 - 70 watts); but I get no higher than ~70 even when I have firewalled the TX power on both the Flex and WSJT screens.

Mike-VA3MW

Michael N3LI

What I would suggest is getting a good dummy load, and try switching bands to see if the power remains consistent or not. I'll bet it does.

Patrick

Some thoughts on setting the audio gain. DAX TX setting, I set this to -10 to -5 and leave it there. I use wsjt-x at this point to set the overall gain as represented on the audio gain meter in the control panel, setting it, as described by others , so that the peaks are just below red. I use the wsjt-x slider as my primary setting because it has the best accessibility. Please note that slider position is remembered by wsjt-x in both the TUNE and ENABLE button settings independently. Use tune first, Enable will be close to that setting. It also remembers it on a per band (frequency) and mode (FT8, FT4 and JS8Call), so once set it will be remembered.