Re: Dupes


Rob Robinett
 

Hi Alan,

Since 'dups'  are a frequent source of questions in my wsprdaemon group, I have included that group in this response.

Your 60M 'dups' are certainly not a problem for wsprdaemon, but due to limits in wsprnet.org's spot reporting, as detailed by Phil below, he can't easily detect your 'tx-generated-dups' among the many more 'receive-site-dups' recorded by receive sites which use multiple copies of WSJT-x or other SW packages.  Those 'receive site generated dups' waste transfer bandwidth, CPU time and storage space at wsprnet.org, and some sites are recording almost 20,000 dups per day.  And snce there is no way to differentiate between the antenna+receivers generating those duplicate spots, there is no useful information which can be learned from them.  Receive sites using my wsprdaemon SW separately report 60M and 60eu, but they are separate bands because one 3 kHz rx channel can't cover both of those 'bands'.  There is an analogous situation on the 80M and legacy 80eu bands.  

In contrast,wsprdaemon reports only one rx_band+tx_call+tx_grid signal for each WSPR cycle.  It also includes the capability to define a single logical receiver whose spots are taken from the antenna+receiver with the best SNR on each WSPR cycle.  Further, all spots from all antenna+receivers can be uploaded to the wsprdaemon.org database where the individual antenna+receiver spots can be analyzed and displayed.

 But if you want to compare the performance of your two transmitter+antenna systems, I would think you could learn a lot more if they used different transmit call signs.

73,

Rob

On Sun, Oct 31, 2021 at 2:58 PM Philip Barnard <vk7jj@...> wrote:
Hi Steve,

For the sake of Alan who is CC'd to this mail, as  per my reply to your first mail, the 20m and 40m "duplicates" shown in your email aren't duplicates, they have different SNRs meaning they are the same transmission reported by two different receivers.  The WD software normally selects the best SNR to upload and discards the rest but it appears that didn't happen in this case.

--

Re. the different 80m and 60m sub bands, here's a copy of a reply to a similar question about why they and other experimental bands are not available for searching  via the band menus of my apps and how to use advanced search to get them, it's very simple really.

Yes, I could put them in the band menu and add the frequency search behind the scenes but I'm not inclined to.  Some are not recognised as bands by various parties including WSPRnet and there a quite a few experimental bands out there. Thus there will always be a mechanism required to let people get at non-standard frequencies so it's better to keep the band menu as per the WSPRnet standard and empower people to use an advanced search that will cover all their options.

Hope that helps,

Regards,

Phil

---

All the 60m data we get from WSPRnet's API for the 60m band is a mixture of  5.2Mhz and 5.3MHz spots.

Thus Arne's db  can only be queried on the basis of  band = 5  and the WD database where wd_band = '60' and both dbs return a mixture of 5.2Mhz and 5.3MHz spots.


There is a solution using advanced search based on frequency.


For wsprd.vk7jj.com   (accessing the WD Postgres db) you should select 60m from the band menu and then use either

and "MHz" < '5.3'    or    and "MHz" > '5.3'   as per the screen shot below.


For wspr.rocks (accessing Arne's ClickHouse db)  the syntax is different

and frequency < '5300000'     or    and frequency > '5300000' 


The same works for the 4m band or for different segments of the 2m band or for 27MHz, though in those cases the band menu should be set to "all bands".

The queries can be combined, eg for 70MHz  the Spanish allocation is 70.150 to 70.200   ref.  https://www.wsprnet.org/drupal/node/4836

and frequency > '70100000' 
and frequency < '70200000

Regards Phil.




On 1 Nov 2021, at 6:35 am, Steve Sykes <steve@...> wrote:

Rob,

It looks to me that Alan is transmitting on both 60 meter frequencies which should be fine. ZKD splits out the two 80 meter and 60 meter frequencies, VK7JJ does not.  That would cover the 60 meter and 80 meter dupes. I am more concerned about the 40 and 20 meter ones.

Steve

On 10/31/21 6:59 PM, Rob Robinett wrote:
Hi Steve,

Phil's site shows me that in the last 24 hours almost all of your dups (and those of many other reporters) are on 60M where Alan G4ZFQ is transmitting on two 60 channels at the same time.  

Hi Alan,

Can you explain why you are transmitting on the same WSPR band at the same time with the same call sign?

73,

Rob


<Screen Shot 2021-10-31 at 11.51.36 AM.png>

On Sun, Oct 31, 2021 at 11:41 AM Steve Sykes <steve@...> wrote:

Phil.

I am seeing a high number of dupes and I don't understand why. The first one may be frequency but the others are showing a version of WSJT-X that I am not running. All my spots go through wsprdaemon. Any idea why I am getting these?

73

Steve KD2OM


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--
Rob Robinett
AI6VN
mobile: +1 650 218 8896



--
Rob Robinett
AI6VN
mobile: +1 650 218 8896

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