How to zero beat CW signal SSDR and Flex 6600

  • 1
  • Question
  • Updated 1 month ago
  • Answered
Looking for some best practices or ways to zero beat a CW signal then tune away around 50 to 100 hz before transmitting to QSO ? Using Smart SDR 3.18

Previously I used  a CW SPOT feature on my KX3 !

Thanks
Photo of Steve Killeen

Steve Killeen

  • 49 Posts
  • 8 Reply Likes

Posted 2 months ago

  • 1
Photo of W5AP

W5AP

  • 161 Posts
  • 18 Reply Likes
This is a sad omission on the part of Flex.  As you said - the Elecraft radios have a spot button and I really miss that feature on the Flex 6600M.  Don't hold your breath.  I think many have wanted this feature as well as updates/bug fixes for a long time.
Photo of James Lee

James Lee

  • 10 Posts
  • 7 Reply Likes
I simply spread the panadapter display and then using the mouse drag my "vertical line" and put it right at the peak of the received CW signal.  Not sure why this isn't sufficient and easier than falling of a log. de NK7B
Photo of Rich McCabe

Rich McCabe

  • 1238 Posts
  • 259 Reply Likes
Steve, what is your reasoning for wanting to do this. Tune 50 to 100hz away.  Pardon my ignorance.

Rich
kd0zv

Photo of Steve Killeen

Steve Killeen

  • 49 Posts
  • 8 Reply Likes
I guess your right Rich, just lazy maybe .... Before I did not have a visual on the signal and now with SmartSDR I can tune away from the peak of the signal. Is that what you are doing ?
Photo of Rich McCabe

Rich McCabe

  • 1238 Posts
  • 259 Reply Likes
I always click on the peak to get it dead center and leave it. I adjust my "pitch" control on the Flex control panel to get the pitch I prefer.

I use the pitch a lot actually chasing weak stations. Sometimes even down to close to 400hz as it can really make the station pop out of the noise.

Rich
Photo of Steve Killeen

Steve Killeen

  • 49 Posts
  • 8 Reply Likes
Rich, do you tune away from the peak when you TX or do you use RIT so you don't zero beat ?
Photo of Rich McCabe

Rich McCabe

  • 1238 Posts
  • 259 Reply Likes
Steve, I do not tune away nor do I use RIT.

As I said I might be ignorant to what you guys are talking about. Why tune away?
Photo of Steve Killeen

Steve Killeen

  • 49 Posts
  • 8 Reply Likes
I thought it was common practice to tune away from the carrier so you can standout more and not zero beat.
Photo of Rich McCabe

Rich McCabe

  • 1238 Posts
  • 259 Reply Likes
Well if you are in a pile up working simplex it could help. But in my opinion could hurt too.

So I just go dead center. But you want to change your pitch to the other station bump your XIT a little.

I know its done on occasion as Bob Locher mentions that in his DX books.

But with the technology of a Flex zero beating is visual for me.
Photo of Steve Killeen

Steve Killeen

  • 49 Posts
  • 8 Reply Likes
OK dead center for zero beat is easy and visual. Can explain "But you want to change your pitch to the other station bump your XIT a little." 

A bit of a newbie question for me ! I usually always leave my pitch at 600 HZ. As far as the XIT bump, I gather this is where I offset the carrier to say 50 HZ or so ?
Photo of Rich McCabe

Rich McCabe

  • 1238 Posts
  • 259 Reply Likes
Well I assume and someone correct me if I am wrong the following:

If you click dead center on the peak the other station should hear you at 600hz if he is running a default 600hz setup.

If you bump your XIT up/down then he is not going to hear you at 600hz and will hear you at 100 +/- whatever the XIT offset is (assuming he does not re tune).

You can play with your pitch on the flex to adjust the tone you hear the other station at which also affects your side tone, Without actually changing your frequency.

As I said playing with the Flex pitch will change the tone in relationship to the noise floor pitch and often make a huge difference.
Photo of Steve Killeen

Steve Killeen

  • 49 Posts
  • 8 Reply Likes
OK Thanks Rich. 
Photo of KD0RC

KD0RC

  • 183 Posts
  • 26 Reply Likes
In today's world of very stable rigs and narrow, steep sided filters, I strive to be right on the other guy's frequency. 100 Hz away may be completely out of their passband. As a novice using xtal control in the old days, we all scanned the entire novice segment looking for a response. Other than split operation, I don't look around at all anymore - I just expect the other station to be zero beat.
Len, KD0RC
Photo of Steve Killeen

Steve Killeen

  • 49 Posts
  • 8 Reply Likes
Good point !
Photo of Jim, KJ3P

Jim, KJ3P

  • 103 Posts
  • 19 Reply Likes
Steve, I feel your pain...been waiting for years for an auto-zero feature.  It was a prominent feature in the older versions before SSDR, and I used it on my early Flex radios constantly.

I've used this grass-roots procedure:

--With the "Break-in" button OFF, I touch the key briefly and tune the received signal to match the sidetone frequency.  Then either tune to the offset you want, or use the TX RIT.  Then turn the Break-in back on.

Crude, I know.  Of course, if you're in a contest, you'll go nuts!  But for the casual CWer like me, it's an OK work-around.

  --jim KJ3P

(Edited)
Photo of Steve Killeen

Steve Killeen

  • 49 Posts
  • 8 Reply Likes
Thanks Jim, I will try that.
Photo of Tom

Tom

  • 37 Posts
  • 6 Reply Likes
I use the same method as James Lee. If there's a pile up, just move around a bit with either RIT/XIT or open a Split Slice and have it.
Photo of AC9S

AC9S

  • 151 Posts
  • 41 Reply Likes
On a big pile-up SSDR is a killer.  I spread the pile-up across the entire panadaptor and can tell visually where the DX is calling.  I listen to the DX, but usually mute the pile-up just to keep the chaos under control.  With a good guy on the other end you can see/hear the rhythm and it is usually so easy snag him.

Keith - AC9S
Photo of Geoff - AB6BT

Geoff - AB6BT

  • 240 Posts
  • 55 Reply Likes
I must be missing something here...

I was first licensed in the 60s, I operate CW frequently, and I honestly do not see the value of this zero-beat concept. I have made thousands of CW contacts and never fretted about zero-beating the other station.

Most of the time I have found it better to be off frequency.

Can someone explain the value of this to me?
Photo of James Lee

James Lee

  • 10 Posts
  • 7 Reply Likes
I have been licensed since the 1950s, I operate only CW in recent decades, and I see little in this discussion to force my underpants into a knot.

My habit of centering my transmit frequency on top of the received CW waveform  probably comes from being on two morning CW nets every day, where it is good practice to have everybody "on" the frequency of NCS.  And the reason for this is that not everybody runs their receive gear with huge passband settings.  I run my Flex 6500 most mornings with 100 Hz setting for CW bandwidth to keep out noise and/or QRM. Rarely I may need to generate a TNF overlay for QRM. Plenty of folks check in and are visibly outside that 100 Hz opening on my equipment.  Sure, I can hear any of them if I open my passband like a barn door, say 2000 Hz.  As for all DX work, I agree with you that there is hardly ever a reason to ever zero-beat on anybody. I cannot think of why that would be needed most of the time since we are operating split in which case "zero beat" has no meaning or relevance.  de NK7B
(Edited)
Photo of Geoff - AB6BT

Geoff - AB6BT

  • 240 Posts
  • 55 Reply Likes
Good point. If you are listening in a narrow passband in a net situation where everyone is listening on the same frequency, then transmitting close to that frequency can be a benefit. But I have no problem, as far as I know, setting my transmit frequency visually to within those tolerances.

Other that that, I see no particular advantage.
Photo of Rich McCabe

Rich McCabe

  • 1238 Posts
  • 259 Reply Likes
Well as the OP mentioned during a pile up adjusting your TX can differentiate you from 50 other guys running 600hz.

I certainly would not do it as a standard practice.

I like using MorseRunner as a practice tool. Different pitches do stand out and that usually the one I answer.

Photo of Al / NN4ZZ

Al / NN4ZZ

  • 1885 Posts
  • 700 Reply Likes
AutoZeroBeat would be useful when using CwSkimmer.  If you are off slightly,  CwSkimmer will not decode properly.  See more about the issue in this posting:

https://community.flexradio.com/flexradio/topics/sdr_bridge_cwskimmer_and_the_panadapter_shake

This feature should be an option as there will likely be some users or situations where AutoZeroBeat is not desired.

More here in the "idea" to add AutoZeroBeat as an option. 

https://community.flexradio.com/flexradio/topics/ssdr_autozerobeat_on_cw_click_tune

BTW, AutoZeroBeat for CW is the #2 most requested idea by votes ( 82 at last count)  in the list.  The only idea with more votes is the feature to Automate the AGC-T setting as an option. 

Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com
6700 Win10 SSDR V2.4.9
Photo of Geoff - AB6BT

Geoff - AB6BT

  • 240 Posts
  • 55 Reply Likes
Fair enough, but I have never used CwSkimmer. So for me I don't see how this would be of any use.

So now we have 2 use cases, CW nets and CwSkimmer.
Photo of Bill NE1B

Bill NE1B

  • 38 Posts
  • 10 Reply Likes
Reason #3 plus Offset:  Contesters, who Click and Pounce need NOT to be Zero Beat, but have a unique offset.  In a contest, I have been on the DX end with a huge Zero Beat pileup.  Logging Programs provide a Band Map to click on for mults and Qs.  Everybody ends up on the same frequency.  I usually pick out the signals with offset tones.  N1MM+ has added an offset feature, if selected.
Photo of Mike - K6QY

Mike - K6QY

  • 25 Posts
  • 8 Reply Likes
Hi guys. I use an audio spectrum analyzer to look at the AF output and just tune my audio signal to the tone (frequency) I've selected in SSDR (for me, typically 500Hz.) When I have tuned the audio to 500Hz, I have attained zero-beat.
Photo of Steve Killeen

Steve Killeen

  • 49 Posts
  • 8 Reply Likes
That's a smart way ! 
Photo of Ken

Ken

  • 1 Post
  • 0 Reply Likes
Mike, That's the way I do it as a new Flex user.

I was wondering why not place a marker in the receiver bandwidth spectrum window that displays the filter bandwidth. The small marker could follow the transmit frequency as it is adjusted to zero beat.

A zero beat menu item or button would also be good.

73,
Ken
KD2KW
(Edited)