On May 16, 2025, at 02:24, Jon / W2JON via groups.io <sigmazgfx@...> wrote:
Ahh, okay..
Thanks for clearing that up.
Why not do some development for the z?
It could use some love in certain areas. Yep. And of course the goal is to run the same software on both anyway. That¡¯s what I do. The pi in the zbitx is not as fast, but still ok to compile on, actually. I remember when a Pi 3 was the fast new kid on the block, and it¡¯s as fast as that.
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Re: ZBitx Shutdown Function
#zbitx
This is not about the sBitx - as you can see by the subject, this shutdown is for the ZBitx that is designed to be shut down by just pulling the power plug.?
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Karl Heinz - K5KHK
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Re: ZBitx Shutdown Function
#zbitx
If you can log in via a terminal, that¡¯s of course easy to do, but when portable without a computer (or, if you don¡¯t have an active terminal connection) then you need a way to properly shut down the Pi Zero. The Pico is not running an operating system or has any external storage that needs to be synced , there is no risk in just disconnecting the power.?
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Karl Heinz - K5KHK
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Re: Update On Shipping Delays from HF Signals
Hello Randy Rxxxxxxxx,
Your Order# 3948 has been shipped.
The tracking details are :
Transporter : DHL
Tracking ID: 790xxxxxxx
On its way!!!
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Thank you,
randy.ab9go@...
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Re: zbitx, compiler optimizations
#zbitx
Great work , Laci!! ?This system will get better !! This is real ham radio?
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gordon kx4z?
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Re: zbitx, compiler optimizations
#zbitx
It would be worth investigating the possibility of shading. Shield the entire front panel and the connecting ribbon cables.
In sbitx, I shielded the cable from the RPi to the display controller and the area between the RPi and the pcb.
As a result, I can control the reception sensitivity (IF) to a value of 80-90 instead of 60 (depending on propagation).
I insulated the shielding with 50 mm wide copper foil and the copper surface with Kapton tape of the same size. (Kapton can withstand higher temperatures).
?
?rdemes lenne megvizsg¨¢lni az ¨¢rny¨¦kol¨¢s lehet?s¨¦g¨¦t. A teljes el?lapot ¨¦s a hozz¨¢vezet? szalagk¨¢beleket is ¨¢rny¨¦kolni.
Az sbitx-ben az RPi-t?l a kijelz? vez¨¦rl?h?z men? k¨¢belt ¨¦s az RPi ¨¦s a pcb k?z?tti ter¨¹letet ¨¢rny¨¦koltam.
Ennek k?vetkezt¨¦ben a v¨¦teli ¨¦rz¨¦kenys¨¦get ?(IF) 60 helyett 80-90 ¨¦rt¨¦kig (terjed¨¦st?l f¨¹gg) tudom j¨®l szab¨¢lyozni.
Az ?¨¢rny¨¦kol¨¢st 50 mm sz¨¦les r¨¦zf¨®li¨¢val ¨¦s a r¨¦zfel¨¹letet ugyanolyan m¨¦ret? Kapton szalaggal szigeteltem le. (Kapton magasabb h?m¨¦rs¨¦kletet elvisel).
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Gyula HA3HZ
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Re: ZBitx Shutdown Function
#zbitx
RPi4 is built into the sbitx, the command line exit is not enough here either, after that the power supply must be switched off as well.
If you don't turn it off, it will remain under constant power. I have been using the command and power off for a year and a half now.
So far I have forgotten to turn off the power once and after about 5 hours I couldn't start it, I had to use the backup to restore.
--
Gyula HA3HZ
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Re: zbitx, compiler optimizations
#zbitx
HI! I found that all the noise is caused by the front panel and the front panel communication. I set it up with an external monitor and without the front panel. The radio became silent without the front panel. It would be a great improvement if the display and the market could be turned off in the menu. The display could turn on the next time it is turned on. If this is not possible, I will install a mechanical switch. HA8LKT Laci 
Sgawn, i think Dbus may be used for that
?
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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: zbitx, compiler optimizations
#zbitx
Sgawn, i think Dbus may be used for that
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https://www.baeldung.com/linux/dbus
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Re: Z bitx poor sensitivity
I've had display noise stuck in my head, but that doesn't seem to be the issue.? Decided to do a quick noise test before bed and the display is very noisy, but nearly none of the noise makes it through the upper PCB.? Had to be careful without a insulator on the probe.? Only noise I was really seeing under the top was around where the display pins that stick through the upper board as seen around 33 seconds in the video.? Almost clipped the pins of to shorten the 'little antennas', but need to get to bed.?
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?
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With how the case is made the 4 corner screws don't electrically tie the back plane and the 2 PCBs together.?
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Re: Z bitx poor sensitivity
It's just a pin header.? I'm just starting with the zbitx, so lots of things on my list of "hows this work" still lol?
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Re: Z bitx poor sensitivity
Look at the schematic and try to figure out what speed of communications is happening between them. Then try to match the type , cabling or shielding to match what would work there. ? I once tested a 6 foot I2C line and it worked perfectly.
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On May 16, 2025, at 21:06, Cory Lytle KO4SWI via groups.io <clytle374@...> wrote:
? Well, the difference between 500W and 5W is 20db, so I can by that much easily.? It seems that the receiver has plenty of gain as I can get the noise very loud.??
?
One thing is that switching between dummy load and antenna is less than S meter bar difference.? And the bands were very noisy that day.?
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I'm going to build a little cable for between the main and display board, think I can get away with a couple inches before I get errors??
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Re: Z bitx poor sensitivity
Well, the difference between 500W and 5W is 20db, so I can by that much easily.? It seems that the receiver has plenty of gain as I can get the noise very loud.??
?
One thing is that switching between dummy load and antenna is less than S meter bar difference.? And the bands were very noisy that day.?
?
I'm going to build a little cable for between the main and display board, think I can get away with a couple inches before I get errors??
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Re: zbitx, compiler optimizations
#zbitx
Any sensitivity issue should be solvable. And at the worst, you might have to add a one transistor preamp. Ashhar maximized dynamic range somewhat over sensitivity so it would work in highly congested environments.?
I suspect there are digital noise signals that will have to be tamed with a wee bit of shielding
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On May 16, 2025, at 18:50, Jody - K3JZD via groups.io <k3jzd.jody@...> wrote:
? Shawn,
?
You are thinking out into the future much more than am..? Quite honestly, I'm just trying to justify the purchase of my zBITX.? My focus has been on getting the mode that I like to use (Straight Key CW using QRP) to the point where it is usable.? However whenever I read the parallel posts talking about poor sensitivity, I have to wonder if I'm beating a dead horse.? If I cannot hear other QRP signals after I get it sending Straight Key CW to my satisfaction and put it on the air,, it will collect dust on the shelf.? ?I am not going to tear into the hardware and throw more money at it.?
?
72,
Jody - K3JZD? ??
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Nice contributions, Gyula. Many thanks.
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Bill VK7MX
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Re: zbitx, compiler optimizations
#zbitx
Shawn,
?
You are thinking out into the future much more than am..? Quite honestly, I'm just trying to justify the purchase of my zBITX.? My focus has been on getting the mode that I like to use (Straight Key CW using QRP) to the point where it is usable.? However whenever I read the parallel posts talking about poor sensitivity, I have to wonder if I'm beating a dead horse.? If I cannot hear other QRP signals after I get it sending Straight Key CW to my satisfaction and put it on the air,, it will collect dust on the shelf.? ?I am not going to tear into the hardware and throw more money at it.?
?
72,
Jody - K3JZD? ??
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Re: Z bitx poor sensitivity
¡° get a little more resolution between the two points¡±.?
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On May 16, 2025, at 15:37, Gordon Gibby KX4Z via groups.io <docvacuumtubes@...> wrote:
? If you¡¯re able to down between the two points that you¡¯ve got, success at -73 and failure at negative103 which are 30 DB apart, that would be a big step forward!
I wonder if the digital noise from various cables, etc., in the device are harming the basic sensitivity? ? As I remember, I think this device uses a diode mixer, and those generally can have a pretty well known sensitivity. ? ?But that could be covered up by internally generated noise. Those are things that can be fixed!
Thanks-?
Gordon kx4z?
On May 16, 2025, at 14:46, Tom via groups.io <tmoll150@...> wrote:
? Just got my zbitx yesterday and have begun playing with it. Made a bunch of FT-8 QSO's right away on 20m last night with 2w out to a vertical, so that was interesting and pleasantly surprising.
Did some receiver testing today.
The factory Test Report card that came with the xcvr indicates a sensitivity of -105dbm.
I attached my S9 signal generator set at -103dbm (about S4) and it could not be heard on any band, even with the IF gain at 100.
With the generator set at S9 (-73dbm) it could be plainly heard on all bands with the IF gain set at 50, however, the audio heard was not
perceived to be an S9 signal. Turning the IF up to about 65 helped a lot, but the radio seems to lack audio gain as well.
The S meter on the zbitx did read approximately S9 at this setting.
?
This lack of sensitivity surprises me greatly - even my super cheap and dated technology SoftRocks easily hear better than that, as does a simple analog rig like a QCX.
Something does not seem right to me. I expected better.
The concept of this radio is really great IMO, and obviously a lot of work has already gone into its implementation, so hats off to the developer, however,
this receiver performance seems to be a serious issue to me, even at this price point.
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Re: Z bitx poor sensitivity
If you¡¯re able to down between the two points that you¡¯ve got, success at -73 and failure at negative103 which are 30 DB apart, that would be a big step forward!
I wonder if the digital noise from various cables, etc., in the device are harming the basic sensitivity? ? As I remember, I think this device uses a diode mixer, and those generally can have a pretty well known sensitivity. ? ?But that could be covered up by internally generated noise. Those are things that can be fixed!
Thanks-?
Gordon kx4z?
toggle quoted message
Show quoted text
On May 16, 2025, at 14:46, Tom via groups.io <tmoll150@...> wrote:
? Just got my zbitx yesterday and have begun playing with it. Made a bunch of FT-8 QSO's right away on 20m last night with 2w out to a vertical, so that was interesting and pleasantly surprising.
Did some receiver testing today.
The factory Test Report card that came with the xcvr indicates a sensitivity of -105dbm.
I attached my S9 signal generator set at -103dbm (about S4) and it could not be heard on any band, even with the IF gain at 100.
With the generator set at S9 (-73dbm) it could be plainly heard on all bands with the IF gain set at 50, however, the audio heard was not
perceived to be an S9 signal. Turning the IF up to about 65 helped a lot, but the radio seems to lack audio gain as well.
The S meter on the zbitx did read approximately S9 at this setting.
?
This lack of sensitivity surprises me greatly - even my super cheap and dated technology SoftRocks easily hear better than that, as does a simple analog rig like a QCX.
Something does not seem right to me. I expected better.
The concept of this radio is really great IMO, and obviously a lot of work has already gone into its implementation, so hats off to the developer, however,
this receiver performance seems to be a serious issue to me, even at this price point.
|
Re: Z bitx poor sensitivity
Just got my zbitx yesterday and have begun playing with it. Made a bunch of FT-8 QSO's right away on 20m last night with 2w out to a vertical, so that was interesting and pleasantly surprising.
Did some receiver testing today.
The factory Test Report card that came with the xcvr indicates a sensitivity of -105dbm.
I attached my S9 signal generator set at -103dbm (about S4) and it could not be heard on any band, even with the IF gain at 100.
With the generator set at S9 (-73dbm) it could be plainly heard on all bands with the IF gain set at 50, however, the audio heard was not
perceived to be an S9 signal. Turning the IF up to about 65 helped a lot, but the radio seems to lack audio gain as well.
The S meter on the zbitx did read approximately S9 at this setting.
?
This lack of sensitivity surprises me greatly - even my super cheap and dated technology SoftRocks easily hear better than that, as does a simple analog rig like a QCX.
Something does not seem right to me. I expected better.
The concept of this radio is really great IMO, and obviously a lot of work has already gone into its implementation, so hats off to the developer, however,
this receiver performance seems to be a serious issue to me, even at this price point.
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Randy.AB9GO
HA3HZ
Cory Lytle KO4SWI