Wnb missing information in mNUAL HOW TO ACTIVATE

James Madden

In the mamual there are many instances of specificatins for functionality but no information about how the function is accessed. WNB is such an example. The paragraphs describe how wonderful WNB is but thereis no information how to access it. Can someone rell me how please. Especially flexemployees as you created this error in the manual. Thanks.

Walt - KZ1F

I should like to add a companion question to this question. That is, in the video presented in the flex meter question of the week or so ago, I believe it was Lee that did the video saying to drop the AGC-T 3db; please include Flex comment on that and is it important whether the ACC is in fast medium or slow. If it is true one should drop the threshold 3db, can't/shouldn't that drop be down programmatically in the radio or SSDRfX?

Rob Fissel

I would refrain from blaming Flex for an error in their manual when no such error exists. At all.

It's clear as day on what it is and how to implement it in SSDR. Specifically on Page, 41, 92 and 157 of the user guide, including a picture of it in the GUI. Control-F is your friend. 

http://www.flexradio.com/downloads/smartsdr-software-users-guide-pdf/

James Madden

Thanks page 92 talks about wnb but gives no example how to activate or does it call out the pages you mentioned which,imo, it should. Ill look at the pages you mentioned. Thanks. Jim

Rob Fissel

Check out 41 where it breaks down DSP, and specifically addresses WNB as the first topic on page 42. It shows you where WNB is within SSDR. It's as simple as activating any of the other DSP features, by clicking on WNB (just like you would with ANF, NB, or NR). 

Walt - KZ1F

I wouldn't say 'just like " as wbn is extremely sensitive to the proper AGC-T setting, which may be different than as described in the manual.

James Madden

Thanks this solved the issue. Now the question becomes what does one do about band noise. On every band i experience a noise kevel of -120db. If i adjust agc-t gain so the noise goes away then i cant here broadcasts or get digital text. Maybe i want too much? Jim

Walt - KZ1F

This is why I asked that related question as it is relevant to the 'proper' operation of of WBN. I say proper as I am not sure we (general public) know yet. Lee, at least I think it was Lee, said to drop the AGC-T down 3db. I suspect that is meant to mean below the noise 'knee'. What if it is dependent upon the AGC mode? Maybe those that 'have the wrong noise' just have the AGC set wrong. Rather than pontificate amongst ourselves it would be nice if someone from FRS would weight in on this. If, -3db is accurate it seems to me this can be done automatically. I didn't realize there was a separate meter for AGC-T so I added it to my list. It would, however be nice if the radio did it. Should that be the default position of AGC-T in all cases and, from there, people can salt to taste??

Walt - KZ1F

Ah...God's country! Gosh, did I love it out there! Yes, I believe there is, I think it is listed as HWALC, in the code base. In the YouTube video Lee, I think it was Lee, had an instance of Flex meters running that displayed in units of dbFS, as I recall. I thought it was dropped more than 3 but, even 3db would be cutting the noise by half telling me it is more than simply the knee.

George KF2T

-120 db as the baseline of the panadapter? Sounds pretty "typical" but not a "true" reading, since varying degrees of zoom, etc., will move the baseline (search the Community for details). You can get a more standard measurement using the dBm meter in the S-meter pane (hover over the meter for dBm), as long as you use a standard bandwidth. I think 500 Hz will work. 400 Hz won't be far off. Here's a good article on background noise. http://g4fkh.co.uk/wp-content/uploads/2012/07/August-2012-RadCom.pdf And one ham's measurements:

Walt - KZ1F

George, I am not following where you are going. I think I know why you are referring to 120db, Lee (or whoever) was claiming that was the noise floor. It didn't actually look that way to me but it wasn't far off what my guess would have been. What was being measured wasn't dbm on the slice, it was, I believe, HWALC. I would have guessed what he dropped was closer to 5dbfs. I haven't been able to ascertain if dbfs is a measure of alc. What I recall from properly setting the AGC-T is to find an unused freq and turn all dsp functions off, set AGC-T to 100 and work backwards until the point where the noise starts to diminish. If one wanted that level to be down 3db it would be, I believe, far lower than the very point where it starts to drop.

Are we even talking about the same subject? And as it relates to WBN does agc mode (rise time) play a role? I, and I am sure others, would love to understand why it doesn't appear to work for them. In the two cases where it actually did work for me the ambient noise around my qth was the same. It was just one of the many times I tried to get it to work and, Shazaam!, it did. I believe nothing else had changed in that instance, but clearly something did, just nothing I can point my finger to, like a thunder storm or low flying Geese.

George KF2T

Hi Walt, I was responding to Jim and Kevin's comments on their received background noise level. Just an observation on the ambient levels. You're quite right about adjusting the AGC. Especially on digital, I usually run exactly as you describe. I'm not sure on all the WNB calculations, but as I recall, it does best with "correlated" noise in the panadapter spectrum, and shouldn't be much affected by AGC. AGC adjustments i the slice can have a really big impact on SNR, of course, so adjusting NB, WNB, and AGC will have a cumulative effect on reception. Finding the sweet spot is not always easy, for sure.

Walt - KZ1F

Ah, OK, sry fer confusion. Yeah, correlated noise, a cross between Close Encounters of the Third Kind and NFC. Well, a fix for agc-t made it on the list for XPSSDR.