I have supplemented the pdf file for easier understanding.
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Gyula HA3HZ
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Did you happen to increase the IF Value?
On Fri, May 16, 2025 at 11:52?PM Doug Backer via <dougbacker= [email protected]> wrote: Bought a Zbitx in Dayton es no receive, ?Hook a long wire to it es there is no change in signal or noise.? Guess it's back to the booth to have a visit with Ashhar in the morning?
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Re: No FT8 bandwidth, can't make FT8 contacts
Hi! Update the software again. You may have an update error. Make a new memory card. The procedure is described in the operating instructions. This helped me when I had no output power. HA8LKT Laci
Oh, and even after calling? CQ a bunch of times and calling others sending CQ PSK reporter did not have any reception of my calls, and an inline separate SWR meter showed 3 watts of power going to the antenna (other radios had no problems when? connected to the same antenna.
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Re: zBitx speaker noise?
#zbitx
Hi! The noise goes away when you disconnect the screen and use an external monitor. This is my observation. HA8LKT Laci Grant Brown via <grant.brown73= [email protected]> ezt ¨ªrta (id?pont: 2025. m¨¢j. 18., V 3:20):
Playing around with it a bit tonight - seems that a bit of shielding between the pi and the board may help, especially with some of the noises. I'm getting screen update noise and a periodic crunchy noise, and the latter was most obviously affected.
Moving the screen away from the body of the radio didn't help by itself.
Video here (volume up):
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Re: No FT8 bandwidth, can't make FT8 contacts
Oh, and even after calling? CQ a bunch of times and calling others sending CQ PSK reporter did not have any reception of my calls, and an inline separate SWR meter showed 3 watts of power going to the antenna (other radios had no problems when? connected to the same antenna.
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Re: zBitx speaker noise?
#zbitx
Playing around with it a bit tonight - seems that a bit of shielding between the pi and the board may help, especially with some of the noises. I'm getting screen update noise and a periodic crunchy noise, and the latter was most obviously affected.
Moving the screen away from the body of the radio didn't help by itself.
Video here (volume up):
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Re: No FT8 bandwidth, can't make FT8 contacts
Oh and yes it's populating with other FT8 calls and CQs
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Re: No FT8 bandwidth, can't make FT8 contacts
I'm somewhat familiar as I have done FT8 with my sBITX, I updated the radio, it synched up with the time server and set that, viewing the output on another receiver it looked like the carrier wasn't getting modulated
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Re: New zBitx - New User - CW operation
Been making a few Q¡¯s on 20CW at about 20wpm with TR delay at 500mS. Not too bad.?
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Re: ZBitx Shutdown Function
#zbitx
That's an interesting thought regarding the shutdown process for the ZBitx. Expanding on your idea, it seems quite logical to have a dedicated button displayed on the user interface that initiates the shutdown procedure for the primary Raspberry Pi Zero. Following the activation of this shutdown command, once the Pi Zero has completed its shutdown sequence, it would cease transmitting data via the I2C communication protocol. The secondary microcontroller, in this case, the Pico, could then be programmed to monitor the I2C bus for the absence of this data. Upon detecting that the Pi Zero is no longer sending any I2C signals, the Pico could then trigger a visual cue on the screen, perhaps a message indicating that it is now safe to disconnect the power supply. This approach offers a more user-friendly and potentially safer method for powering down the ZBitx, particularly in situations where accessing a terminal to issue a shutdown command is not feasible. It elegantly utilizes the existing communication pathway between the main processor and the display controller to provide a clear indication to the user when it is appropriate to remove the power. Thanks, David
On Sat, May 17, 2025 at 10:43 AM, AndyH wrote:
Even well behaved Pis corrupt and SD card from time to time, so it's "always" a good idea to have a ready backup or three regardless.
?
Correct, yet corruption is even less likely if you do an orderly shutdown.? The OP coded a way to do that when you don't have a keyboard, which is supposed to be a major use case for zbitx.
?
It feels to me that this point is being missed, quite possibly because the community has not found a good way to get fixes/improvements into the official code base.
?
If you really want to test your backups, I could write a program that you could install that occasionally zeros out random blocks on your SD card just to see how long it takes to corrupt something important.? If the next boot happens to be at a POTA/SOTA site and the boot code needs info from that zero'd block, it'll teach a lesson about how important it is to bring up-to-date backups with you everywhere you intend to operate.
?
I think the idea is to both have good backups, and to not need those good backups.
?
Yet, as above, the fix/improvement will probably end up living on only in unofficial forks.
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Regards,
Dave, N1AI
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Re: Sbitx high swr on a 1 to 1 antenna
Perhaps. I have seen issues similar to that with poor neutralization on a tube amplifier,? although the bad oscillation was never a higher amplitude than the intended signal in my experience.? I personally would still lean, for now, toward a bad connector or solder joint in the amplifier chain,? throwing the impedance way off. If all bands are bad into a dummy load, it would almost have to be in the final amp path. Be sure to check the BNC and adapters. Keep us posted.
Scotty WD4PYT?
I think your symptoms point to an instability in the final amplifier or drivers.? The off frequency oscillation shows as higher power and high SWR.? Since it is intermittent I would look for a part that has little or no solder.?? Or maybe pots that set the bias point are intermittent.
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Re: Sbitx high swr on a 1 to 1 antenna
That¡¯s a good theory also!
toggle quoted message
Show quoted text
On May 17, 2025, at 17:23, Ron Carr via groups.io <rcarr@...> wrote:
? I think your symptoms point to an instability in the final amplifier or drivers.? The off frequency oscillation shows as higher power and high SWR.? Since it is intermittent I would look for a part that has little or no solder.?? Or maybe pots that set the bias point are intermittent.
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Re: Sbitx high swr on a 1 to 1 antenna
I think your symptoms point to an instability in the final amplifier or drivers.? The off frequency oscillation shows as higher power and high SWR.? Since it is intermittent I would look for a part that has little or no solder.?? Or maybe pots that set the bias point are intermittent.
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Re: ZBitx Shutdown Function
#zbitx
On Sat, May 17, 2025 at 10:43 AM, AndyH wrote:
Even well behaved Pis corrupt and SD card from time to time, so it's "always" a good idea to have a ready backup or three regardless.
?
Correct, yet corruption is even less likely if you do an orderly shutdown.? The OP coded a way to do that when you don't have a keyboard, which is supposed to be a major use case for zbitx.
?
It feels to me that this point is being missed, quite possibly because the community has not found a good way to get fixes/improvements into the official code base.
?
If you really want to test your backups, I could write a program that you could install that occasionally zeros out random blocks on your SD card just to see how long it takes to corrupt something important.? If the next boot happens to be at a POTA/SOTA site and the boot code needs info from that zero'd block, it'll teach a lesson about how important it is to bring up-to-date backups with you everywhere you intend to operate.
?
I think the idea is to both have good backups, and to not need those good backups.
?
Yet, as above, the fix/improvement will probably end up living on only in unofficial forks.
?
--
Regards,
Dave, N1AI
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Re: No FT8 bandwidth, can't make FT8 contacts
Are you seeing callsigns, etc, and other activity?with?good signal levels?? Or is it that you just can't?actually make a contact?
Make sure your time is properly?synced, as for FT8, it is critical.
Ensure AGC? is off, Split off
Joe? VE1BWV
Been unable to make any FT8 contacts, I discovered that if I look at the received waterfall on a separate receiver the transmission begins with a normal looking bandwidth for a few seconds ?then drops out and ?looks like just a carrier, I hear the audio tones on the zBITX when transmitting, any ideas?
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No FT8 bandwidth, can't make FT8 contacts
Been unable to make any FT8 contacts, I discovered that if I look at the received waterfall on a separate receiver the transmission begins with a normal looking bandwidth for a few seconds ?then drops out and ?looks like just a carrier, I hear the audio tones on the zBITX when transmitting, any ideas?
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Re: Sbitx high swr on a 1 to 1 antenna
(meter reads a much higher POWER, not impedance)? ? So some of the readings you are seeing go together. Gordon
On Sat, May 17, 2025 at 11:25?AM Gordon Gibby KX4Z via <docvacuumtubes= [email protected]> wrote:
Usually?those power meters actually measure VOLTAGE, and presume 50 ohms, then use the equation P = V*V / R to find the "power"
If the impedance they are looking into jumps way UP, then the transmitter output voltage may go significantly higher?(because it isn't being loaded down by 50 ohms any more) so then V*V is much much larger, but the meter is still calibrated for R=50 and hence reads a much higher impedance.? ??
In this case your power tripled or quadrupled, suggesting that your voltage went up by 2 times.? ? And your measured SWR by the bitx also went up.? ?Those make sense together.?
We have experienced all manner of poor connections in PL-259 / SO-239 connectors; there is always the possibility that you are experiencing a poor connection that is variably changing.? ?We have switched to certain types of connectors as a result to reduce bad connections, which are really really difficult to troubleshoot during contests, etc.? ? Something is weird?and connectors are often the problem.
Gordon KX4Z
On Sat, May 17, 2025 at 10:58?AM W1WCI via <timothy.macdonald= [email protected]> wrote: Will open things up later this weekend.? Also notice another change, on 20 meters getting more power out for a give drive setting, a (FT8) setting of 65 was good for 2 watts, now 7 to 8( measured on the out board meter). Sent from me and my iPad ? Have you made any progress?
Scotty On Thu, May 15, 2025, 12:40 PM W1WCI via <timothy.macdonald= [email protected]> wrote: Sbitx - antenna switch - swr/power coupler - antenna
?
Previously radio showed power and 1.0 swr on 15, 20, and 40 meters with similar readings on the off board meter.
As of this morning swr on the radio and the off board meter show high SFR 2 to 3:1.
Removed the radio from the antenna line and replaced it with an antenna analyzer, it shows a perfect 1:1.?
Another radio shows 1:1 on the radio and the off board meter.
?
Previously, maybe a month ago I had the same problem, spent time chasing down the antenna to no avail. Then one day all was well with no intervention at or in the radio.
?
All bands that were workable for the antenna show the same behavior today.
?
Trouble shooting help welcomed.
?
Tim
?
?
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Re: Sbitx high swr on a 1 to 1 antenna
Usually?those power meters actually measure VOLTAGE, and presume 50 ohms, then use the equation P = V*V / R to find the "power"
If the impedance they are looking into jumps way UP, then the transmitter output voltage may go significantly higher?(because it isn't being loaded down by 50 ohms any more) so then V*V is much much larger, but the meter is still calibrated for R=50 and hence reads a much higher impedance.? ??
In this case your power tripled or quadrupled, suggesting that your voltage went up by 2 times.? ? And your measured SWR by the bitx also went up.? ?Those make sense together.?
We have experienced all manner of poor connections in PL-259 / SO-239 connectors; there is always the possibility that you are experiencing a poor connection that is variably changing.? ?We have switched to certain types of connectors as a result to reduce bad connections, which are really really difficult to troubleshoot during contests, etc.? ? Something is weird?and connectors are often the problem.
Gordon KX4Z
On Sat, May 17, 2025 at 10:58?AM W1WCI via <timothy.macdonald= [email protected]> wrote: Will open things up later this weekend.? Also notice another change, on 20 meters getting more power out for a give drive setting, a (FT8) setting of 65 was good for 2 watts, now 7 to 8( measured on the out board meter). Sent from me and my iPad ? Have you made any progress?
Scotty On Thu, May 15, 2025, 12:40 PM W1WCI via <timothy.macdonald= [email protected]> wrote: Sbitx - antenna switch - swr/power coupler - antenna
?
Previously radio showed power and 1.0 swr on 15, 20, and 40 meters with similar readings on the off board meter.
As of this morning swr on the radio and the off board meter show high SFR 2 to 3:1.
Removed the radio from the antenna line and replaced it with an antenna analyzer, it shows a perfect 1:1.?
Another radio shows 1:1 on the radio and the off board meter.
?
Previously, maybe a month ago I had the same problem, spent time chasing down the antenna to no avail. Then one day all was well with no intervention at or in the radio.
?
All bands that were workable for the antenna show the same behavior today.
?
Trouble shooting help welcomed.
?
Tim
?
?
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Re: Sbitx high swr on a 1 to 1 antenna
Will open things up later this weekend. ?Also notice another change, on 20 meters getting more power out for a give drive setting, a (FT8) setting of 65 was good for 2 watts, now 7 to 8( measured on the out board meter). Sent from me and my iPad
toggle quoted message
Show quoted text
On May 17, 2025, at 8:26?AM, Scotty R via groups.io <Theroadcalls1@...> wrote:
? Have you made any progress?
Scotty On Thu, May 15, 2025, 12:40 PM W1WCI via <timothy.macdonald= [email protected]> wrote: Sbitx - antenna switch - swr/power coupler - antenna
?
Previously radio showed power and 1.0 swr on 15, 20, and 40 meters with similar readings on the off board meter.
As of this morning swr on the radio and the off board meter show high SFR 2 to 3:1.
Removed the radio from the antenna line and replaced it with an antenna analyzer, it shows a perfect 1:1.?
Another radio shows 1:1 on the radio and the off board meter.
?
Previously, maybe a month ago I had the same problem, spent time chasing down the antenna to no avail. Then one day all was well with no intervention at or in the radio.
?
All bands that were workable for the antenna show the same behavior today.
?
Trouble shooting help welcomed.
?
Tim
?
?
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Re: ZBitx Shutdown Function
#zbitx
This has been covered in another thread fairly well.? The TL;DR is that even though the main computer is running an OS, very little data is being written, so it's safe to operate it like a controller and pull the plug.
?
Even well behaved Pis corrupt and SD card from time to time, so it's "always" a good idea to have a ready backup or three regardless.
?
73, Andy
(Sysadmin/netadmin of a mixed Windows/*nix/Solaris monstrosity in a past life.)
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HA3HZ
Scotty R
Dave, N1AI