Do I have a transmit problem with 1.5.1?

Phil M0VSE

Hi. 

I was one of the 6300 users that had distorted audio with 1.5 and was happy when 1.5.1 was released.

I have noticed with 1.5.1 that I seem to have a number of 'spurs' when I hit tune or otherwise transmit in SSB, There are no such artifacts when transmitting/tuning in CW mode however.

I wasn't sure if there were actually being transmitted or not so I thought I would try FDX mode and sure enough, they appear on the second slice. Am I right to be concerned about this?

Here are screenshots from SSB and CW mode.





73 Phil 

George KF2T

Almost certainly not a problem. The weak (-90) "Spurs" are likely an artifact. I've seen them forever.

Bob K8RC

While transmitting, drag the dbm scale down until you can see what your peak signal level is. You will probably find that the "spurs" are many, many db down.

Phil M0VSE

On the screenshot below, the peak level is around -20db and the first spur at just under 50dB. SSB transmit on most bands seems to show that the spurs are just under 30dB below the peak signal. I was just interested to hear peoples opinions on whether this was to be expected? I am pretty sure that I didn't see this phenomenon with 1.4.6.

Rob Fissel

In this picture, your mic drive level appears to be off the charts, with some pretty heavy compression on top of it. You might want to back off the mic gain and see if that improves anything at all. You should avoid tripping your ALC at all costs. 

For a quick view of an appropriate audio drive level when using a mic, check out Ken's video tutorial that he posted up yesterday. You'll notice his audio levels never even come close to tripping the ALC while he transmits in SSB. 

FWIW, I have a 6300 and haven't had any issues with 1.5 or 1.5.1 (other than the malfunctioning frequency offset calibration problem that's well documented here). 

Phil M0VSE

Yes I was trying to see how bad I could make it and was basically shouting into the mic but even turning processing off and speaking not letting the mic input peak, it is much the same.

As a professional audio engineer, I think I am ok with gain structures though

It does make me wonder why the 1.5.0 transmit problem only affected some users though and maybe these transmit "spurs" don't happen on all 6300s either?

73 Phil

Jay Nation

Can you do another one at an even lower mic gain level that isn't driving the peak indicator past 0dB into the red?

73, Jay - NO5J

Phil M0VSE

I would but interestingly now the Flex has been running for a couple of hours, I am not seeing any 'spurs' at all..... I will reboot it and see if I can make it happen again!

Mike NN9DD

Turn down your power to 1 watt. I'm a couple,of,the pictures you are transmitting on ant 1 and putting out slider power which appears to be around 30. You might be overloading the receiver

Phil M0VSE

Yes I noticed that after I posted the picture but it seemed to be the same regardless of what power I was using. I was moving round different bands and didn't always remember to reduce power......

Tim - W4TME

I have converted this topic to a support HelpDesk ticket (http://helpdesk.flexradio.com) for expedited issue resolution.  If anyone else is experiencing an issue similar to this one, please submit a HelpDesk support ticket for issue resolution.