[BUG] UDP (local) spots can show an incorrect location of the spotter

[williamscody]

Describe the Bug

When delivering spots to OHC in UDP (local) mode, using a local app (like SDC's SKM Server or a logger program), the spotter QTH can be wrong. This can happen with vanity callsigns (like mine, K3CDY), where the spotter appears to be in Maryland, when in fact I'm in Denver. This can also happen when an operator moves to a different QTH, but keeps the same callsign.

The map below shows local CW spots captured by SDC at my QTH in Denver, but the spotter appears in Maryland, based upon "traditional" QTH determination.

To Reproduce

1. In SDC's SKM Server settings, set up the spotter field using a vanity callsign (K3CDY, for example):

2. Let SDC do its job, and send spots to OHC.
3. Witness that the spotter "lines" point to Maryland, even though I'm near Denver.

Expected Behavior

When using UDP (local) mode, the spotter's QTH should be based upon the operator's gridsquare as entered in OHC - and NOT rely on outdated FCC conventions that determine QTH.

Environment

• OS: Ubuntu 22.04
• Browser: Safari 26.4
• Node.js Version: 23.6.0
• OpenHamClock Version: 26.2.1
• Running As: Local Linux network PC build

Console Errors

N/A

Additional Context

I am the author/contributor of the UDP spots feature in OHC. I would be happy to provide the fix if you like.

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73 de K3CDY

[alanhargreaves]

It would also happen in VK now that they have relaxed those rules.

Does this look like the fix that you had in mind, in server/routes/dxcluster.js ?

        newSpots = (udpSession.spots || []).slice(0, 100).map((s) => ({
          spotter: s.spotter,
          spotterGrid: s.spotterGrid || CONFIG.gridSquare || null,  // adding this option
          dxCall: s.dxCall,
          dxGrid: s.dxGrid || null,
          freq: s.freq,
          comment: s.comment || '',
          time: s.time || toHHMMz(s.timestamp),
          timestamp: s.timestamp || now,
          id: s.id || `${s.dxCall}-${s.freq}-${s.spotter}-${s.timestamp || now}`,
        }));

[alanhargreaves]

/assign

[alanhargreaves]

For greater context of what I am suggesting, look at #907

I don't have a local UDP spotter set up. Could you let me know if this does the trick for you?

[williamscody]

I’ll give it a try and let you know. #907 looks like it encompasses my issue.

4/16/26 Update: Unfortunately applying the code you provided broke the UDP spot display altogether. It could have been me. In any case, I'll plan on contributing a fix since I have the environment to test it.