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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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.??
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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.??
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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: 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.?
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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?
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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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I talked about this, but I didn't post a picture, a picture always says more, so I'll post it now:
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--
Gyula HA3HZ
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Today I made a conversion of the original handheld microphone purchased with sbitx, similar to the 'Meeting MIC', which I documented in the attached file.
If I missed something, please feel free to ask, I will answer when I can.
--
Gyula HA3HZ
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?
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Hi Yvon!? Unfortunately not! It makes a lot of noise on the amateur band. You need to use a battery or a better quality power supply. Sorry. Yvon AE7YD via <Yvon= [email protected]> ezt ¨ªrta (id?pont: 2025. m¨¢j. 16., P 18:23):
Laci,
did you succeed to modify your power supply?
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73, Yvon
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Laci,
did you succeed to modify your power supply?
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73, Yvon
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Re: ZBitx Shutdown Function
#zbitx
I just use 'sudo shutdown' from the terminal.
Assume that properly shuts off the Pi-Zero.
Now, how do you shut off the Pico?
Don in Austin,? N5CID
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On
5/4/2025 6:49 AM, Karl Heinz Kremer, K5KHK wrote:
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After
working with Unix/Linux systems for a lifetime, i know
that bad stuff will happen if you just disconnect the
power on a regular basis. I still feel a twitch in my
fingers if I don¡¯t run sync; sync; sync; before a
shutdown or halt command ;)
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I¡¯ve
forked Farhan¡¯s code and added a button on the UI to
shut down the Pi Zero:
The
"Shutdown" function is behind the "Menu" button.
After selecting it and confirming, wait until the
LED on the Pi Zero (which you can see through the
covered USB connector) stop to blink. I moved the
confirmation button a bit up so that it¡¯s harder to
fat finger the shutdown with an unintentional double
tap on the shutdown button.
?
de
Karl Heinz - K5KHK
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Re: Update On Shipping Delays from HF Signals
Got my ship notice will be here next week.
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Jim
KE0VVU
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How to place an order for Zbitx from India?
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Re: Update On Shipping Delays from HF Signals
Wooohooo....got my ship notice (order #3941).? Be here next week
--
"POWER, WE DONT NEED NO STINKIN' POWER" - Every KX2 Owner
Always respect the air waves,
73 de KI7PBR, Gary
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Cory Lytle KO4SWI
HA3HZ
VU3OII - Sahir
Gary-KI7PBR