Sbitx high swr on a 1 to 1 antenna
Sbitx - antenna switch - swr/power coupler - antenna
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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.
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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.
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All bands that were workable for the antenna show the same behavior today.
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Trouble shooting help welcomed.
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Tim
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Re: zBITX Crashes - Suspect Memory Leak
#zbitx
Ron : I will have to spend some time with the code snippet that you highlighted - I do not have any experience at all with the gtk library.
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Gordon : I thought that mine had crashed with version 3.021.? But I was doing so many things working with it then, any of those things that I was doing could have caused my version 3.021 to crash.? ?So, maybe what I am remembering was self-induced.? This is good info though.? Always suspect the last change that you made whenever problems surface is the golden rule.
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Today I got lucky.? I had my unit running beside me while I was doing some other things.? Mostly it was just sitting there in Receive Mode.? ?But I was sending some Straight Key CW once in a while to make sure that it was still responsive.? ?I had a SSH login.? After about 1.5 hours, my Receiver noise got sporadic.? Sending CW got very choppy - it was totally unusable.? ?My SSH login was sluggish. but still usable.? I ran HTOP.?
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What I found supported my Memory Leak theory.? See the attached.? ? sbitx runs from the start.sh script.? ?I highlighted that line.? 73.8% of the memory consumed.? ?Swap Space maxed out.? Total Memory very close to being maxed out.? As the system choked, my SSH connection became super sluggish.? ?I got HTOP to run again, but it took about 15 minutes to come up and rarely updated.? ?Memory consumption looked pretty much the same - I guess the RasPi OS keeps some memory in reserve.? ?So I guess the zBITX RasPi is not totally crashing - it is just becoming very unresponsive and from the outside it looks like it crashed.?
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So, I guess it is time to do Diffs on all of the changes made in the files that were changed last month to create version 3.052.? Mostly it was adding the input pin IRQs and changing the program control structure to give manual CW priority.? But some changes were also made to support some problems that had been reported whenever using FT8 and other digital modes.?
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While I have other stuff on my plate, this problem seems to keep grabbing my attention.? So. I will try to fit in some more time to look at it.? In the mean time, it you have version 3.052 installed, just power down / power up your zBITX every 30 minutes or so.
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72,
Jody - K3JZD? ??
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My zBitx has been listed as packed and ready to go.? ?My number is 3926.? ?Just waiting for tracking info.
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Thank you
Jim
KE0VVU
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Re: HELP! - FT8 - 25Khz drift between RX & TX frequency
RIT and SPLIT do not work with ZBitx. I think you should reinstall the memory card. I had no output, but this helped.
HA8LKT, Laci
Raj vu2zap via <rajendrakumargg= [email protected]> ezt ¨ªrta (id?pont: 2025. m¨¢j. 15., Cs 14:07):
First thing I spotted. You have a good eye Gyula.
Raj
On 15/05/2025 5:09 PM, HA3HZ via
wrote:
On Thu, May 15, 2025 at 12:20 PM, BigJonn - G8DVB wrote:
you should turn the RIT button off!
That's why there is some difference between the transmit and
receive frequencies.
RIT shifts the receive frequency in the + or - direction.
--
Gyula HA3HZ
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Re: Sbitx DE running V4.4 Loss of spectrum display
On Tue, May 13, 2025 at 02:15 PM, Rick Beatty wrote:
Hello to the group -- The yellow spectral display just above the waterfall has disappeared. I think the waterfall is acting a bit strange too, but that might just be noise. I have tried to adjust the IF but it does nothing to bring the spectral display back.
Suggestions on how to fix this would be appreciated.
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Thanks -- Rick W7RNB
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You can try adjusting the scope size to see if it resolves the issue. It is in menu 2. 
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-JJ
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Re: HELP! - FT8 - 25Khz drift between RX & TX frequency
First thing I spotted. You have a good eye Gyula.
Raj
On 15/05/2025 5:09 PM, HA3HZ via
groups.io wrote:
toggle quoted message
Show quoted text
On Thu, May 15, 2025 at 12:20 PM, BigJonn - G8DVB wrote:
you should turn the RIT button off!
That's why there is some difference between the transmit and
receive frequencies.
RIT shifts the receive frequency in the + or - direction.
--
Gyula HA3HZ
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Re: HELP! - FT8 - 25Khz drift between RX & TX frequency
On Thu, May 15, 2025 at 12:20 PM, BigJonn - G8DVB wrote:
you should turn the RIT button off!
That's why there is some difference between the transmit and receive frequencies.
RIT shifts the receive frequency in the + or - direction.
--
Gyula HA3HZ
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Re: HELP! - FT8 - 25Khz drift between RX & TX frequency
Subsequently with research I think I need to look at at Split configuration on FT8.
I am away from the shack and will need to investigate when connecting a External KVM.
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I occured to me that the display showed RX and not denoting the VFO in use. I cannot see the Split indicator or toggle so will need to investigate on the full screen.
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73,
Jonn, G8DVB
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Re: zBITX Crashes - Suspect Memory Leak
#zbitx
My sBitx can be left for hour after hour & never crashes. ?So NEW CODE for the ZBitx might be the hunting ground & display code probably changed¡
Gordon kx4z?
toggle quoted message
Show quoted text
On May 14, 2025, at 21:59, Ron Carr via groups.io <rcarr@...> wrote:
? What causes a crash??? Typically pointers to zero, buffer overruns, memory leaks, pointers to auto class variables.? Others?
My C skills are very rusty but this function looks suspicious to me as it seems to return a pointer to an auto class.? It is in sbitx_gtk.c
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static struct font_style * set_style(cairo_t *gfx, int font_entry){
? ? struct font_style *s ?= font_table + font_entry;
? ? ? cairo_set_source_rgb( gfx, s->r, s->g, s->b);
? ? cairo_select_font_face(gfx, s->name, s->type, s->weight);
? ? cairo_set_font_size(gfx, s->height);
? ? return s;
}
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Re: zBITX Crashes - Suspect Memory Leak
#zbitx
What causes a crash??? Typically pointers to zero, buffer overruns, memory leaks, pointers to auto class variables.? Others?
My C skills are very rusty but this function looks suspicious to me as it seems to return a pointer to an auto class.? It is in sbitx_gtk.c
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static struct font_style * set_style(cairo_t *gfx, int font_entry){
? ? struct font_style *s ?= font_table + font_entry;
? ? ? cairo_set_source_rgb( gfx, s->r, s->g, s->b);
? ? cairo_select_font_face(gfx, s->name, s->type, s->weight);
? ? cairo_set_font_size(gfx, s->height);
? ? return s;
}
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Going to wait for the SBITX V4.
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Barely used for SWL plus 4 batteries and a 2-cell charger.
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$230 shipped within USA.
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Re: zBITX Crashes - Suspect Memory Leak
#zbitx
I have been compiling right on the xBITX device.? I use SSH and Putty to login as? ?pi / hf12345? ?and get a terminal window.? ? Then I do a? ?cd? sbitx.? ?There is a build script there - just execute? ?./build.? ?That will create a new sbitx application in the same subdirectory which auto-starts whenever the zBITX device is powered up.? You can manually shut down the running sbitx application that was auto=started? and run it manually from there with? ./sbitx? ? The second RasPi processor that runs the LCD GUI remains running and it all reconnects whenever manually starting sbitx.?
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I have never used the zBITX remote web interface feature.? When you use that, It looks like that is a separate web interface task that then connects to the zBITX's sBitx application.? ?If your remote web interface. connection; is being terminated, is is probably the? sbitx? program crashing, which probably causes the the web interface program to revert back to its login page.? ?Just my guess.
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Finding memory leaks? is difficult.? I do not have any silver bullets for that.? If it is my program, I am better at it because I have ideas about where I might have gotten careless or took shortcuts.? And I always suspect my latest revision(s) .? With someone else's program, I generally trace all of the activity associated with every variable.? One thing I look at very closely is global variables .? And I look for same named local variables in functions..? Some compilers will catch that - some will not.? And simple variable names being reused for different purposes in many different places are suspicious.? (for example, in sbitx_gtk.c,? the variable name? f? is heavily used for many different purposes). ?There are tools to do this time consuming job, but I don't have any of them.
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Watching available memory diminish in a program like this one that is busy doing many things while in Receive Mode will not help you figure out why.? Probably will need to turn off one of the 'things' that are active and let it run for a few hours to see if? the memory is no longer being diminished and if it no longer crashes.? If that didn't cure it, then move on to stopping the next active 'thing'. and do it again.? One generally needs a good understanding of the program to figure out how to stop just one 'thing' from running.? And a of of time.
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Forgive me if I ramble on - I tend to think and expand as i type.? Short stories become long stories.
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72,
Jody - K3JZD
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Re: Update On Shipping Delays from HF Signals
I am 3926 so when I hear I will post.
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Thank you
Jim
KE0VVU
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HELP! - FT8 - 25Khz drift between RX & TX frequency
Hello Team,
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Can anyone explain and assist as to why there is a defecit on FT8, a 25Khz drift between RX & TX frequency
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If I set my RX to 14.059 on 20M and then track on PSKreporter I can track everything going out, but there is nothing on the RX because I assume it is totally wrong.
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If I set my RX to 14.074 I can hear all the traffic, but nobody can hear me :-(
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I have found 1 site in Romania that reports me on 14.101~ so out of band.
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Is it something obvious that I have done wrong ?
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I have tried with and without my ATU-10-0A and it makes no difference.
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I have had similar offset issues with 10M & 15M respectively.
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Just looking for a little guidance.
I'm very happy getting ~2500KM at 2W on a VSWR of ~1.0 - 1.1
But the config needs a little tweak me thinks!
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Many thanks for any help.
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73,
Jonn, G8DVB
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I have a problem with the timestamps of the zBitx logbook. They are 8 hours ahead of UTC. And yes, I changed the country and timezone. The web interface shows the correct UTC and local time but still log times are 8 hours ahead. Suggestions anyone?
73 Frank PA3CNO?
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Re: zBITX Crashes - Suspect Memory Leak
#zbitx
Jody, I see something similar, though the sbitx program seems to keep running. After a while (anywhere between 15 minutes and an hour) the tcp connection dies. I had the web interface running and an open ssh session, and the web interface reverted to the login page and the ssh session terminated. Rebooting brought everything back to normal. This has happend a couple of times. Receiving was still OK though.
73 Frank PA3CNO?
After letting my zBITX sit unattended in Receive Mode for a while, the main RasPi CPU crashes.? I have never timed it because I'm not just sitting there watching it.? But it seems like it only takes about an hour or so to crash.? I am not able to get a SSH connection to the main CPU at that time.? The display CPU is still running at that time.
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While the device is warm whenever this occurs, I do not think that it is a thermal issue because if I disconnect and reconnect the power it reboots and runs fine.
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I have never stopped the sbitx application to see if something else on the RasPi could be causing it.? I have SSH and VNC enabled, but I am not using either of those connections.? I do not have anything else running on the RasPi.? So, I really do not think that it is some other RasPi appllication.?
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I think that it is probably a sbitx application memory leak.? ?Don't see how something like a character array overflow would occur after just sitting there unattended for that period - nothing is being done on the GUI during that time.
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This crashing occurred whenever I had version 3.021 installed,? And it is still occurring with version 3.052 installed.
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If you are running on batteries, the batteries may be depleted before this crash occurs.? You will never see it.? I am using a 7.5vdc power supply.??
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72,
Jody - K3JZD
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Re: New zBitx - New User - CW operation
Hi Gordon, yes I have been following Jody¡¯s efforts pretty closely. As someone who worked in real time embedded systems for most of my career, I have no doubt the CW timing issue is fixable. Jody has a good latest approach, I think. I am not sure when the right time to try that code personally is.?
Perhaps a more serious issue is how insensitive the receiver is. It¡¯s pretty bad even for being a simple receiver. Not sure that software can fix that.?
Also I really want to be able to touch a signal on the waterfall and have the frequency jump there¡ just a matter of software.?
Steve AK0M
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Re: zBITX Crashes - Suspect Memory Leak
#zbitx
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I have used htop and top to track memory usage. ?The original 32bit software would have memory usage grow and then reset back to the minimum. ?I did that monitoring, not writing to a file. ?I believe it is possible to pipe the output to a file.?
73
Evan
AC9TU
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Re: zBITX Crashes - Suspect Memory Leak
#zbitx
I wondered why the zBitx crashed after some time... Makes sense, because the PI Zero 2W would NOT work as a 'normal' internet browsing setup, after a few minutes and some websites past, the memory would be filled 100%.
Good luck!
Martin, PD0ZZ
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is there a list we can get on? do we have a round about cost? want to get in and hopefully get these before the 90 day pause is lifted
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Raj vu2zap
HA3HZ