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sBitx V2 went deaf after about an hour #rx #sbitx_v2

 

Hello all!

I have received my v2 yesterday and was very happy that it was very sensitive on receive. 50-55 RF gain was more than enough for FT8 and even weak cw signals. Any higher and only the noise floor would rise. I've updated the sBitx as instructed in the manual and sent one or two FT8 CQs at low power (drive <30). Didn't make a QSO but was happy with my callsign appearing on PSKReporter.
I continued to play with it on rx only for about an hour on 20m. The whole time everything was fine until I left the room for a quick bathroom break. The radio was on cw receive with drive at the lowest setting (just to be safe) and RF gain still at about 55. When I got back it suddenly was very deaf and only hears very strong signals. Even at RF gain 100 the waterfall shows no noise floor anymore. Only very few strong FT8 stations show a very faint line.
The only other thing I see on the waterfall is some weird noise that only appears between 42 and 45 RF gain and very few birdies. This noise is the same on all bands and doesn't change when tuning around.
TX still seems to be fine. I've tested tx with very short transmissions to not kill anything and slowly increased drive every time. The power meter in my ATU-100 did report about 20-22W at drive 100. In my experience the ATU-100 reads a little low by about 5W. After reading Farhans post about calibration I think the reduced power output is fine since I didn't calibrate yet.

I did make an image of the provided SD card as a backup before i turned it on the first time. Since it worked flawlessly in the beginning, I burned this image to a second SD card to rule out any software issues, but unfortunately it shows the same behavior.

The first picture shows FT8 decode with very few stations and one strong station appearing in the waterfall at RF gain 100. The second picture shows the weird noise between 42 and 45 RF gain.

Does anyone have any suggestions what I could do?

73,
Nanak, OE3NQA

1043555055.1684337648847.jpeg
1555612781.1684337713846.jpeg

 

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What time of the day was this? Around 1600 UTC a solar flair took out north America and maybe some of EU.

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Sent from for Windows

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From: Nanak
Sent: Wednesday, May 17, 2023 12:37 PM
To: [email protected]
Subject: [BITX20] sBitx V2 went deaf after about an hour #sbitx_v2 #rx

?

Hello all!

I have received my v2 yesterday and was very happy that it was very sensitive on receive. 50-55 RF gain was more than enough for FT8 and even weak cw signals. Any higher and only the noise floor would rise. I've updated the sBitx as instructed in the manual and sent one or two FT8 CQs at low power (drive <30). Didn't make a QSO but was happy with my callsign appearing on PSKReporter.
I continued to play with it on rx only for about an hour on 20m. The whole time everything was fine until I left the room for a quick bathroom break. The radio was on cw receive with drive at the lowest setting (just to be safe) and RF gain still at about 55. When I got back it suddenly was very deaf and only hears very strong signals. Even at RF gain 100 the waterfall shows no noise floor anymore. Only very few strong FT8 stations show a very faint line.
The only other thing I see on the waterfall is some weird noise that only appears between 42 and 45 RF gain and very few birdies. This noise is the same on all bands and doesn't change when tuning around.
TX still seems to be fine. I've tested tx with very short transmissions to not kill anything and slowly increased drive every time. The power meter in my ATU-100 did report about 20-22W at drive 100. In my experience the ATU-100 reads a little low by about 5W. After reading Farhans post about calibration I think the reduced power output is fine since I didn't calibrate yet.

I did make an image of the provided SD card as a backup before i turned it on the first time. Since it worked flawlessly in the beginning, I burned this image to a second SD card to rule out any software issues, but unfortunately it shows the same behavior.

The first picture shows FT8 decode with very few stations and one strong station appearing in the waterfall at RF gain 100. The second picture shows the weird noise between 42 and 45 RF gain.

Does anyone have any suggestions what I could do?

73,
Nanak, OE3NQA

?

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F29A98661C5445EC99A0EC5C97A9D1BB.png

 

Hi Barry,

unfortunately I can rule that out. I switched back and forth between the sBitx and my FT-450D to rule out antenna problems or propagation. A few hours ago I had another opportunity to directly compare my v2 to a friends Developer edition on the same antenna.
While the DE's waterfall was lighting up with signals at 60 RF gain, mine stayed almost completely black at 100 gain. Only the strongest signals showed a very faint line, just like in the first picture.
 

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Just a thought….I turned on my K2 around noon yesterday and thought I had an antenna issue. Very little noise and weak signals. ?

Good luck with figuring out your problem. No sbitx radio here yet.

73

Barry

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Sent from for Windows

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From: Nanak
Sent: Wednesday, May 17, 2023 5:32 PM
To: [email protected]
Subject: Re: [BITX20] sBitx V2 went deaf after about an hour #rx #sbitx_v2

?

Hi Barry,

unfortunately I can rule that out. I switched back and forth between the sBitx and my FT-450D to rule out antenna problems or propagation. A few hours ago I had another opportunity to directly compare my v2 to a friends Developer edition on the same antenna.
While the DE's waterfall was lighting up with signals at 60 RF gain, mine stayed almost completely black at 100 gain. Only the strongest signals showed a very faint line, just like in the first picture.

?

53130873C4A540F98800FB3431CF2866.png
D0BC6B01C474493EB2F8C50225081173.png

 

Hi Nanak - I am having a very similar problem with the sBitx_v2. I can see some noise in the waterfall display if I raise the rf gain but no stations at all. Even very strong ones.
The noise level doesn't even raise or fall if I plug or unplug the antenna. So far I haven't found a solution. Let us know if you find something. Maybe it's related to my problem.
73
 

Hi loopMasta
It does indeed sound similar to my problem but I can't see any noise floor at all. Only this odd chirping noise shown in my second picture.
Connecting/disconnecting the antenna also does nothing for me, no audible change in noise nor visual on the waterfall. Just very strong stations show up (and are barely audible with audio gain turned up high) as described in my initial message.
If I find something I'll be happy let you know. I hope to get some guidance here to what I can try.
73, Nanak
 

Hi Nanak,?
Were you able to fix the poor receive of your sbitx?
73, Dave
 

Same issue here. Out of the box, worked excellent. Just started getting used to the settings. All of a sudden RX seemed to disappear. I thought maybe it was something I did.? Disconnecting and re-connecting antenna did nothing.?? I have not transmitted at all yet on this either.
 

I powered down and opened the unit up and poked around. Wiggled all of the toroids and tapped on all of the ICs. Re-seated all external boards (except the PI). I noticed warmth coming out of the board but touched everything I could be a potential problem and and everything seemed good. Nothing stood out to be a problem. I left the cover separated and plugged power and antenna. Now everything works. It is now receiving like it did when I first powered it on.? Not quite sure what the issue was as I had rebooted several times with the original problem thinking it was a software issue and it was still deaf.? I did find my antenna adapter was a little loose. Possible it was this?? When I played with this at a specific spot, it went deaf. But I played with this the last time so not sure if this was it or not. Will keep posting if I see more issues.? I am happy so far, the receive is great and very strong.

Aaron

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