Apparently my D74 transmits DSTAR when it is turned off.

Help with D-Star related issues
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g0hww
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Joined: Tue Jul 10, 2018 8:35 pm

Apparently my D74 transmits DSTAR when it is turned off.

Post by g0hww »

Some time ago I asked people in the Kenwood radios group about the apparent fact that my D74 seems to send DSTAR traffic to my Pi-Star Hotspot, even when neither VFO is running in DSTAR mode and it is tuned to a different frequency. There was some discussion about ensuring that position reports were turned off, which they were. I pretty much ignored the issue, but it did continue.

Recently, my D74 has been turned off. Yet, according to the Pi-Star dashboard, it is still transmitting DSTAR now and then.

Does anyone else experience anything like this?
M1DNS
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Re: Apparently my D74 transmits DSTAR when it is turned off.

Post by M1DNS »

Whats being reported on the dashboard when you see the transmissions. Where is it linked, if anywhere? what features do you have enabled remote control, timeserver etc? What time of day does the dashboard show the keyups occurring?

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Andrew M1DNS.
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G8SEZ
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Joined: Fri Apr 13, 2018 8:26 pm

Re: Apparently my D74 transmits DSTAR when it is turned off.

Post by G8SEZ »

Remove the battery and then you can be certain it isn't the radio.
--

Brian G8SEZ
g0hww
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Joined: Tue Jul 10, 2018 8:35 pm

Re: Apparently my D74 transmits DSTAR when it is turned off.

Post by g0hww »

Thanks for the responses. I have tried to attach a screenshot, but I am told that the forum quota has been exceeded, which isn't entirely helpful.

The Pi-Star dashboard shows an entry under Local RF Entries and under Gateway Activity, which is entirely consistent with a 0.4 second transmission by the D74, on this occasion having a BER of 0.4%. The displayed callsign is G0HWW/D74 (which is normal) and a target of CQCQCQ (which is normal), with Src of RF (also normal). In the case of the screenshot I took, it occurred at 0525hrs local time.

The only other displayed entry under Gateway Activity is from G0HWW/INFO to target CQCQCQ of duration 2.5 secs, which I expect is the "Not Linked" announcement occurring after an automatic update, coming from Src net.

In the case of the screenshot I took, the INFO announcement occurred at 0458hrs, so was 27 mins before the mystery transmission. I had considered the possibility that it might be a dashboard bug occurring after an update/restart, but that seems unlikely given the time interval.

The D74 did have its B side set for D-STAR mode on the hotspot frequency before it was turned off. When I first noticed this phenomenon, it was occurring when the D74 was powered on, but with its A side in FM mode tuned to the local repeater and its B side set for APRS. The mystery transmissions were mostly as described above, but with a higher BER of 14%.

Yes, totally removing power from the D74 would prove categorically that it isn't the D74 if the mystery signal occurs. For now, I am leaving it powered from DC (as is normal) but turned off and have an Icom IC-R30 receiver listening in D-STAR mode on the appropriate simplex frequency so that I can check its Rx History when the mystery transmission next occurs. My experience so far is that it happens with about a 2 day interval, so my best guess is that I expect something to happen in about 26 hours or so, from now.

This is very odd.

Edit: I tend to leave the hotspot unlinked when I'm not using it. Both D-STAR and DMR (BM) are enabled, but I am ensuring that there's no DMR activity (no static TGs, unlinked from last used TG) when investigating this issue. No remote control is enabled. Time announcements are turned off.
g0hww
Posts: 9
Joined: Tue Jul 10, 2018 8:35 pm

Re: Apparently my D74 transmits DSTAR when it is turned off.

Post by g0hww »

Hot news. I have apparently confirmed that the D74 does transmit D-STAR whilst turned off!
My IC-R30's Rx History clearly shows a transmission from the Pi-Star hotspot as G0HWW/INFO at 0320z followed by a transmission from G0HWW/D74 at 0353z.
That is consistent with what is shown in the dashboard and the log, the tail end of which is shown below. Note that on this occasion, neither VFO was in D-STAR mode or on the hotspot's simplex frequency, so as predicted, the BER was around 14%. The IC-R30's Rx History shows the same BER for the G0HWW/D74 transmission.
M: 2021-04-07 03:20:22.607 MMDVMHost-20200615_Pi-Star_v4 is running
M: 2021-04-07 03:20:22.648 D-Star, received network header from G0HWW /INFO to CQCQCQ
M: 2021-04-07 03:20:22.970 D-Star, received network end of transmission from G0HWW /INFO to CQCQCQ , 2.5 seconds, 0% packet loss, BER: 0.0%
M: 2021-04-07 03:20:32.606 DMR, Logged into the master successfully
M: 2021-04-07 03:52:38.462 D-Star, received RF header from G0HWW /D74 to CQCQCQ
M: 2021-04-07 03:52:38.788 D-Star, received RF end of transmission from G0HWW /D74 to CQCQCQ , 0.4 seconds, BER: 13.9%
I estimated that this might occur last sunday evening, but it didn't. I used the D74 on Monday afternoon, then this occurred on Wednesday morning.

Edit: cross-posted to D74 group https://groups.io/g/KenwoodTH-D74/topic ... 0,81915265
AF6VN
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Joined: Fri Jul 20, 2018 1:15 am

Re: Apparently my D74 transmits DSTAR when it is turned off.

Post by AF6VN »

g0hww wrote: Wed Apr 07, 2021 8:13 am Hot news. I have apparently confirmed that the D74 does transmit D-STAR whilst turned off!
My IC-R30's Rx History clearly shows a transmission from the Pi-Star hotspot as G0HWW/INFO at 0320z followed by a transmission from G0HWW/D74 at 0353z.
That is consistent with what is shown in the dashboard and the log, the tail end of which is shown below. Note that on this occasion, neither VFO was in D-STAR mode or on the hotspot's simplex frequency, so as predicted, the BER was around 14%. The IC-R30's Rx History shows the same BER for the G0HWW/D74 transmission.

<SNIP>

I estimated that this might occur last sunday evening, but it didn't. I used the D74 on Monday afternoon, then this occurred on Wednesday morning.

Edit: cross-posted to D74 group https://groups.io/g/KenwoodTH-D74/topic ... 0,81915265
Have you pulled the battery and let it sit unpowered for a few days? After all, if it is not transmitting D-STAR digital, Pi-Star should not even identify it. I'd be more likely to think someone in your neighborhood has stolen your credentials and is attempting to bootleg onto your system

--
AF6VN
Dennis L Bieber
g0hww
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Joined: Tue Jul 10, 2018 8:35 pm

Re: Apparently my D74 transmits DSTAR when it is turned off.

Post by g0hww »

I'm quite convinced that the D74 is doing the transmitting. The BER reported by the Pi-Star dashboard (and log) is:
a) 0%, if the D74 was left with a VFO in D-STAR mode, on the hotspot frequency, or
b) 14%, if the D74 was left with no VFO in D-STAR mode and not tuned to the hotspot frequency.

I'm fairly sure that there is nobody in my neighbourhood dicking around with me. Also, they would have to know what state i had left my D74 in before turning it off, and turn up every few days at stupid o'clock to do it.

Edit: Update, got my a) and b) examples confused, fixed now.
Edit 2: I have now changed the radio from the previous "G0HWW /D74" to "G0HWW /xxx" where xxx is a secret and has never been sent over the air by the radio when powered on. Nobody could know that secret token. It is easier to wait until something explicit happens than to wait for an unknown period of time for something not to happen.
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