Interesting RF problem

Larry Williamson

I have interesting RF issue on the 5000a. The other day someone said they thought I had some RF in the mic. After recording my signal several times on different bands and changing things about the shack--- I finely got smart and tried it into a dummy load, sure enough-- same thing. I can easily hear it when listening to the rig monitor function. this still occurs with the power setting at 0 watts out.

My focus now was on the radio and headset. Changing to different headsets and microphones didn't change. Even changing to the front mic input---- Still RF---

Just by I accident I turned off the VAC 1--- RF disappeared  So I then turned the vac back on---no RF. I am pulling my teeth out trying to figure out what is going here. This morning the same thing-- I hear the rf and notice the VAC1 is on--clicking it off and the RF immediately disappeared.

Again switching the vac1 back on-- the RF does not come back.

Any thoughts about what the heck is going on??

Regards,
Larry

Patrick Greenlee

Gremlins.  For a finder's fee I can put you in touch with an electronic exorcist.

Actually I got some once in awhile reports of an echo/reverb sound on my audio, possibly RF.  It was not consistent.  Some sessions had it and some didn't.  Hasn't happened lately so couldn't T-shoot it.  Now I will have to have a look at VAC.  Sorry I don't have your answer but your keen powers of observation may have helped me.

Best of luck with your situation.

Patrick        NJ5G

WX7Y

What version of VAC are you running? it seems to me I remember 1 or 2 releases of VAC had that problem.

It really isn't RF I don't think from the test you made but rather something coming in from a VAC audio source.

I think the bad versions of VAC was 4.10 and maybe 4.12 that had this problem with some computer combinations, I am not sure of other versions as I stayed with 4.09 with my FLEX1500, 3000, and 5000 radios

4.09 I know works well.

hope this helps 

73's 
Bret
WX7Y

Byron Armstrong

RF feedback is the same as any other feedback but they don't all sound alike. An over the air report of RF feedback is a guess as to cause. But many problems cause similar symptoms. VAC is a clue, not a cause.
Power setting zero means NO RF feedback. So suggests all bands.
You CAN using a test generator and an oscilloscope, carefully compare in vs out
Your description implies a problem with a threshold. That smells of settings.
SDRs are sensitive to improper settings.
OR
There is an excellent setup tutorial description starting with MIC setting and step by step through the processors. If you follow it exactly, you'll probably have to look no further
73,
Byron, W8SYD

Larry Williamson

I am running the current version of VAC 1.15.  I have went back through G7CNF setup tutorial and all appears to be right.

I guess the next step will to determine if it still has issues with the VAC off to start with--- Will turning the vac "on" have the same change as before ( clicking it to the off setting)

Will update this post----TBD

Regards,
Larry

Larry Williamson

Ok---- I just restarted the rig and PC this time with VAC off.
key up and still have what sounds like rf in the audio. This time, turning the VAC 1 on--- audio immediately cleared up.----I am lost now!

Could it be the PC?

Larry Williamson

I am still waiting patiently-- listening to the Jeopardy theme song????

Byron Armstrong

Have you tried the tutorial alignment yet? Most problems sing to me operator related comma from personal experience hi

Tim - W4TME

With the FLEX-5000 and FLEX-3000, RFI ingress, which is indicated by an echo on your transmitted signal is usually happening on the Firewire cable or improper grounding of the mic cable (shield is not connected to the FLEX-5000 Foster connector shield and MIC- is connected to GROUND).

 If you are connected to a dummy load and you have the issue, then I don't suspect RFI and the issue is something different.

Larry Williamson

Tim

This happens using a dummy load and the power set at 0. I have even disconnected all the radio cables--- ground, ptt etc. and still know change. It appears to re-appear once the radio is shut off and turned back on.

Larry

Larry Williamson

I have to admit I am only a year old into this  SDR radio stuff. I am not aware of this alignment procedure you mention. I did a search for the word alignment in the manual nothing came up. You may be referring the general setup of audio/VAC etc. 

Larry

WX7Y

I relies you may have already done so but I would try to reset the database to factory defaults and before you make any changes to the radio try it to see if you still have the issues.

73's
Bret
WX7Y

Tim - W4TME

Larry, what version of PowerSDR are you using?

Larry Williamson

Using KE9NS latest version v2.8.0.16

Tim - W4TME

Since you are not using a FlexRadio version of the software, I recommend that you contact KE9NS for troubleshooting.

Larry Williamson

Thanks Tim,

I never thought about that! I will use the original software off the Flex down load page and see what happens.

So to sum things up here I have too options left to try.

1. Try it will the original software
2. Try it will a different computer

Will update my findings in a couple days.

Thanks for the help

Larry

Larry Williamson

Thought I would update my issue with this----- Per Darrin's  suggestion's I swapped out computers and the problem seems to be solved. Will keep it like this for a while and see what happens.

Thank You all who responded!

PS----I am now eyeballing the Flex 6500????

"It sort of sounds like some kind of windows audio driver issue is either causing intermittent excessive CPU%,  or the driver is just bad, and messing with your DPC latency, so when VAC1 is on it may mess with your audio by way of messing up the DPC. You can run the Flexradio icon and view your DPC latency.

All sorts of programs and/or drivers on your PC can do this.

VB-Cable and "virtual audio cable" programs can sometimes do this.

Also, One easy way to check would be to install PowerSDR on a different computer and run your Flex on it for a while."