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I finally managed to boot from an external USB on my zbitx.
I had to modify /boot/cmdline.txt? on the internal sdcard to point rootfs to the external device UUID.
Of course if I remove the external device the zbitx doesn't boot because it is waiting for the root file system which is not there .
Not sure how the zbitx boot process works but it appears that the internal sdcard is needed to actually boot from the external sdcard. Not sure why that is?
Once the zbitx is up and running on the external device I am able to unmount the internal sdcard and everything runs ok.
/dev/sda1 is mounted as /boot and
/dev/sda2 is mounted as /rootfs
It looks like what is needed is a? check to see if the internal card is present and the external card is not then boot from the internal card and its file systems otherwise boot from the external sdcard?
Ideas?
?
Leo, AI5II
?
?
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Re: zBitx +-2 MHz transmit spurs? --> SHOWSTOPPER for transmitting
"This is as far as I have gotten. The Q3 stage may need to have an LC band-pass filter added to it's input or its output to better filter out the RF being picked up from the transmitter stages. I'm hopeful that a simple solution is going to be found soon, that results in a clean transmitter with plenty of margin for spectral compliance. ? 73; Steve, N3SB"
Steve, what about a series LC tuned to 40 MHz instead of the C22 capacitor?? ?That might give much faster rolloff of gain at HF?? ? If that isnt?enough, then a series LC in the output or a parallel LC shorting the output at HF?? ? ?
Your assessment of RF coupling back to the power regulator seems perfect because then the RF appears on the?+V line having been injected into the ground connection (the same way a fixed regulator can be turned into a variable regulator by raising its "ground" pin.? ? You're already working to improve "ground" throughout the circuit.? ?Would adding additional bypass capacitors to reduce the injected RF into the power system help?? ?In my case, I found it often did, but once it caused a real problem because of some inductance I added with a wire to add the bypass.? ?
You are doing fantastic work! Gordon KX4Z
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Re: Failure on first use?
Russell,
Check your power supply (or batteries if using). ?Two of us from our club bought the zBitX at FDIM and bought batteries in the flea market. ?After about 15 minutes of just listening the screen flickered, went gray, and the radio shut down. ?We thought we had bought duds. ?But on getting home I used a stable power supply (and later with new 18650 batteries) it works well. ?Later we heard that the flea market seller was selling 8 year old batteries he had bought cheep as one of our group went back to exchange a defective charger.
Just hoping that is your problem.
toggle quoted message
Show quoted text
On May 23, 2025, at 9:57?PM, Russell Brown via groups.io <russterus@...> wrote:
? I received my new ZBitx last week and pulled it out for an initial operation today. Mostly checking out FT8, recriving signals and had answered a couple when suddenly the receiver started putting out noise and could not hear anything but the noise. ?Verified the antenna was good by hooking up another transceiver, checked and messed with the various options to no avail. ?Any thoughts on possible causes? ?I took some pics and videos and will reach out to HF Signals after the weekend unless anyone does have some suggestions. Definitely disappointed.
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Re: zBitx +-2 MHz transmit spurs? --> SHOWSTOPPER for transmitting
I remembered wrong because it was in the 3v3 circuit and the values ??were 47uH and 22uF.
--
Gyula HA3HZ
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Re: zBitx +-2 MHz transmit spurs? --> SHOWSTOPPER for transmitting
Steve,
I remember that it is possible to isolate individual circuits from the power supply with a series inductor and an electrolytic capacitor.
It would be worth trying if you are already so deep into measurements and I certainly wouldn't miss it as an option.
I remember when the Tiny spectrum analyzer was still in its early stages, some of us built and designed modifications and serial 22uH and 10uF isolation on the pcb for the 5 Volt supply.
I may not remember the numerical values ??well, because I have since changed PCs and store the data elsewhere. The series resistor placed in the signal path also has a noise reduction role.
--
Gyula HA3HZ
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Re: Failure on first use?
On its predecessor, the sBitx, the?codec would occasionally go out to lunch (usually on startup) and then you get zilch nada nothing.? ?There have been various improvements in the I2C connections, but the chip has been difficult.? ? I don't know if that is what is happening to you, but if it is, there is a decent chance it will work within a bit again.
And of course, there could always be a bad connection, too......the world of just-built radios is just like the world of "new cars" and "new houses" -- not everything is always perfect!
Gordon KX4Z
On Fri, May 23, 2025 at 9:57?PM Russell Brown via <russterus= [email protected]> wrote: I received my new ZBitx last week and pulled it out for an initial operation today. Mostly checking out FT8, recriving signals and had answered a couple when suddenly the receiver started putting out noise and could not hear anything but the noise.? Verified the antenna was good by hooking up another transceiver, checked and messed with the various options to no avail.? Any thoughts on possible causes?? I took some pics and videos and will reach out to HF Signals after the weekend unless anyone does have some suggestions. Definitely disappointed.
|
I received my new ZBitx last week and pulled it out for an initial operation today. Mostly checking out FT8, recriving signals and had answered a couple when suddenly the receiver started putting out noise and could not hear anything but the noise. ?Verified the antenna was good by hooking up another transceiver, checked and messed with the various options to no avail. ?Any thoughts on possible causes? ?I took some pics and videos and will reach out to HF Signals after the weekend unless anyone does have some suggestions. Definitely disappointed.
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Re: zBitx +-2 MHz transmit spurs? --> SHOWSTOPPER for transmitting
Thanks Gordon - I do remember all the work you did to reduce the spurs on your SBitx.
?
Your comments did remind me of something I tried - In it's stock configuration, Q3 gets its power from the same 9 Volt buss that feeds into the final transistors. I tombstoned R28 and ran a wire over to the output of the 5 Volt regulator - to see if it would block a potential path for RF from the finals reaching Q3. No significant change. Q3 does seem to work just as well at 5 Volts, so this mini-mod doesn't hurt...
?
73; Steve, N3SB
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Re: zBitx +-2 MHz transmit spurs? --> SHOWSTOPPER for transmitting
Here is a post where I summarize some of the work I did to clean up my (secondhand ) sbitx:
toggle quoted message
Show quoted text
On May 23, 2025, at 20:54, Gordon Gibby KX4Z via groups.io <docvacuumtubes@...> wrote:
? Steve, that is really admirable work!!
Without this kind of investigation, I¡¯m not quite understanding how this project proceeds.
I remember spending weeks and months trying to figure out Spurs in my sBitx. ? (Some of them I caused!!!) ? I learned quickly that absolutely anything that touched the analogue plus V voltage was a huge risk. ? ?I stayed away from it after figuring that out , and added a lot more bypass in various places. ?I believe I also dropped the drive to the SI 5351. ?Adjusted idle current to reduce no linearities?
Your idea of reducing gain at HF where it¡¯s not needed is a smart one. ?
It would be a fantastic thing to come up with solutions that made almost all of these units compliant. I don¡¯t know if we can get folks out there who have already bought the units to check there or two preemptively applied the fixes, but it¡¯s pretty important because this is eventually a great radio, and it does not need to have its reputation sullied by Spurs like this?
Gordon kx4z?
?? On May 23, 2025, at 20:42, Steve Beckman via groups.io <ssteven3sb@...> wrote:
? I got my ZBitx earlier this week, and put it on the test bench to check it out.
?
My setup is a Rigol DSA815 1.5 GHz spectrum analyzer, along with a newly build coupler with a -40 dB tap.
?
Here's what I'm seeing on 20 Meters - 14.000 into a 50 Ohm dummy load, about 5 Watts out:
There are spurs at 12 MHz and 16 MHz; the 12 MHz spur is borderline. there's also a spur at 2 MHz which is only about 30 dB down from the carrier.
?
I've briefly checked the other bands, and am seeing that 17 Meters is worse - results similar to those reported by others.
?
The observations by Joerger DB2OO appear to be right on. Harmonics of the transmitter output frequency are mixing with the 40 MHz IF. In the case of 20 Meters - the third harmonic of 14 MHz is 42 MHz, which when mixed with the 40 MHz IF is creating the 2.000 MHz and spurs at 14 - 2 as well as 14 + 2. When the transmitter is moved to 14.500, the third harmonic is moved to 43.500, which when mixed with the 40 MHz IF creates a spur at 3.5 MHz, as well as spurs at 14 - 3.5 and 14 + 3.5, which I've confirmed with spectrum analyzer measurements.
?
An aside - when I took apart my ZBitx to start experimenting, I tried to repeat my initial measurements, and I got the mess below:
A number of additional spurs were present - and a couple are above the limit. I checked the setup, and finding nothing wrong, I just put one of the M3 x 40mm cap cabinet screws back in place, and the new spurs went away.
?
The heat sink has a DC connection to ground through the tab of the TO-220 5 Volt regulator U2, a 7805. That regulator is on the far side of the board relative to the finals Q1 and Q2. My theory is that the mounting tabs of Q1 and Q2 are forming a capacitor with the heat sink through the insulators, coupling some RF energy into the heat sink. Lacking any other ground points, that energy finds ground at the 5 Volt regulator, which happens to be pretty close to the 40 MHz crystal filters, a mixer stage, and a couple of IF amplifier transistors Q3 and Q4.
?
By the way, the four cabinet screws have a black finish which is non-conductive. They pass through plated holes on the main board, but there isn't a positive mechanical connection at those points. In order to continue bench testing, I needed to have the main PC board positively grounded to the heat sink. I made a little grounding strap shown in the picture below:
It's a short piece of solder wick, soldered to the ground side of C107. It passes closely by the source pin of Q1, but that pin is at ground potential. While testing, I attach the strap to the heat sink with a 6-32 screw and nut as shown below:
<Ground Jumper Installed.jpg> Anyone wishing to try to duplicate my tests needs to be aware of this grounding issue.
?
When the case is installed, I will slip a star washer between the lug and the heat sink, then place the side panels and install the case screws. Tightening the case screws should create a positive contact between the lug and the heat sink. I did get some stainless M3 x 40MM cap screws that stand a better chance of providing a ground path at the other three corners. A no-cost alternative might be to sand the black finish off the screws provided.
?
I've focused my attention on the circuits surrounding the Diode Ring mixer comprised of dual diode packages D3 and D4. Changing C31, the DC blocking capacitor at the output of the SI5351, had no effect on the spurs. Providing a better termination for the mixer RF port at the low-pass filter had no effect. Moving to the transmit IF amplifier transistor Q3, changing the emitter bypass capacitor C22 from 0.1 uF to 1000 pF had a measurable effect, as shown below:
The spurs at +/- 2 MHz from the carrier have dropped about 10 dB, and are no longer a concern. Unfortunately the spur at 2 MHz is still too big, although it has dropped in level as well. The spurs seen on the 17 Meter band are also still too big.
?
The function of Q3 is to amplify the 40 MHz IF signal during transmit. It does not need the large value of emitter bypass capacitor that's currently installed. Reducing the value of C22 reduces the gain of Q3 at lower frequencies (which reduces Q3's gain in the HF bands where it's not desired) while maintaining good gain at 40 MHz. The result is less RF energy is getting into the IF mixer port along with the 40 MHz IF, reducing the amplitude of the spurs.
?
This is as far as I have gotten. The Q3 stage may need to have an LC band-pass filter added to it's input or its output to better filter out the RF being picked up from the transmitter stages. I'm hopeful that a simple solution is going to be found soon, that results in a clean transmitter with plenty of margin for spectral compliance.
?
73; Steve, N3SB
?
?
?
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Re: zBitx +-2 MHz transmit spurs? --> SHOWSTOPPER for transmitting
Steve, that is really admirable work!!
Without this kind of investigation, I¡¯m not quite understanding how this project proceeds.
I remember spending weeks and months trying to figure out Spurs in my sBitx. ? (Some of them I caused!!!) ? I learned quickly that absolutely anything that touched the analogue plus V voltage was a huge risk. ? ?I stayed away from it after figuring that out , and added a lot more bypass in various places. ?I believe I also dropped the drive to the SI 5351. ?Adjusted idle current to reduce no linearities?
Your idea of reducing gain at HF where it¡¯s not needed is a smart one. ?
It would be a fantastic thing to come up with solutions that made almost all of these units compliant. I don¡¯t know if we can get folks out there who have already bought the units to check there or two preemptively applied the fixes, but it¡¯s pretty important because this is eventually a great radio, and it does not need to have its reputation sullied by Spurs like this?
Gordon kx4z?
toggle quoted message
Show quoted text
On May 23, 2025, at 20:42, Steve Beckman via groups.io <ssteven3sb@...> wrote:
? I got my ZBitx earlier this week, and put it on the test bench to check it out.
?
My setup is a Rigol DSA815 1.5 GHz spectrum analyzer, along with a newly build coupler with a -40 dB tap.
?
Here's what I'm seeing on 20 Meters - 14.000 into a 50 Ohm dummy load, about 5 Watts out:
There are spurs at 12 MHz and 16 MHz; the 12 MHz spur is borderline. there's also a spur at 2 MHz which is only about 30 dB down from the carrier.
?
I've briefly checked the other bands, and am seeing that 17 Meters is worse - results similar to those reported by others.
?
The observations by Joerger DB2OO appear to be right on. Harmonics of the transmitter output frequency are mixing with the 40 MHz IF. In the case of 20 Meters - the third harmonic of 14 MHz is 42 MHz, which when mixed with the 40 MHz IF is creating the 2.000 MHz and spurs at 14 - 2 as well as 14 + 2. When the transmitter is moved to 14.500, the third harmonic is moved to 43.500, which when mixed with the 40 MHz IF creates a spur at 3.5 MHz, as well as spurs at 14 - 3.5 and 14 + 3.5, which I've confirmed with spectrum analyzer measurements.
?
An aside - when I took apart my ZBitx to start experimenting, I tried to repeat my initial measurements, and I got the mess below:
A number of additional spurs were present - and a couple are above the limit. I checked the setup, and finding nothing wrong, I just put one of the M3 x 40mm cap cabinet screws back in place, and the new spurs went away.
?
The heat sink has a DC connection to ground through the tab of the TO-220 5 Volt regulator U2, a 7805. That regulator is on the far side of the board relative to the finals Q1 and Q2. My theory is that the mounting tabs of Q1 and Q2 are forming a capacitor with the heat sink through the insulators, coupling some RF energy into the heat sink. Lacking any other ground points, that energy finds ground at the 5 Volt regulator, which happens to be pretty close to the 40 MHz crystal filters, a mixer stage, and a couple of IF amplifier transistors Q3 and Q4.
?
By the way, the four cabinet screws have a black finish which is non-conductive. They pass through plated holes on the main board, but there isn't a positive mechanical connection at those points. In order to continue bench testing, I needed to have the main PC board positively grounded to the heat sink. I made a little grounding strap shown in the picture below:
It's a short piece of solder wick, soldered to the ground side of C107. It passes closely by the source pin of Q1, but that pin is at ground potential. While testing, I attach the strap to the heat sink with a 6-32 screw and nut as shown below:
<Ground Jumper Installed.jpg> Anyone wishing to try to duplicate my tests needs to be aware of this grounding issue.
?
When the case is installed, I will slip a star washer between the lug and the heat sink, then place the side panels and install the case screws. Tightening the case screws should create a positive contact between the lug and the heat sink. I did get some stainless M3 x 40MM cap screws that stand a better chance of providing a ground path at the other three corners. A no-cost alternative might be to sand the black finish off the screws provided.
?
I've focused my attention on the circuits surrounding the Diode Ring mixer comprised of dual diode packages D3 and D4. Changing C31, the DC blocking capacitor at the output of the SI5351, had no effect on the spurs. Providing a better termination for the mixer RF port at the low-pass filter had no effect. Moving to the transmit IF amplifier transistor Q3, changing the emitter bypass capacitor C22 from 0.1 uF to 1000 pF had a measurable effect, as shown below:
The spurs at +/- 2 MHz from the carrier have dropped about 10 dB, and are no longer a concern. Unfortunately the spur at 2 MHz is still too big, although it has dropped in level as well. The spurs seen on the 17 Meter band are also still too big.
?
The function of Q3 is to amplify the 40 MHz IF signal during transmit. It does not need the large value of emitter bypass capacitor that's currently installed. Reducing the value of C22 reduces the gain of Q3 at lower frequencies (which reduces Q3's gain in the HF bands where it's not desired) while maintaining good gain at 40 MHz. The result is less RF energy is getting into the IF mixer port along with the 40 MHz IF, reducing the amplitude of the spurs.
?
This is as far as I have gotten. The Q3 stage may need to have an LC band-pass filter added to it's input or its output to better filter out the RF being picked up from the transmitter stages. I'm hopeful that a simple solution is going to be found soon, that results in a clean transmitter with plenty of margin for spectral compliance.
?
73; Steve, N3SB
?
?
?
|
Re: zBitx +-2 MHz transmit spurs? --> SHOWSTOPPER for transmitting
I got my ZBitx earlier this week, and put it on the test bench to check it out.
?
My setup is a Rigol DSA815 1.5 GHz spectrum analyzer, along with a newly build coupler with a -40 dB tap.
?
Here's what I'm seeing on 20 Meters - 14.000 into a 50 Ohm dummy load, about 5 Watts out:
There are spurs at 12 MHz and 16 MHz; the 12 MHz spur is borderline. there's also a spur at 2 MHz which is only about 30 dB down from the carrier.
?
I've briefly checked the other bands, and am seeing that 17 Meters is worse - results similar to those reported by others.
?
The observations by Joerger DB2OO appear to be right on. Harmonics of the transmitter output frequency are mixing with the 40 MHz IF. In the case of 20 Meters - the third harmonic of 14 MHz is 42 MHz, which when mixed with the 40 MHz IF is creating the 2.000 MHz and spurs at 14 - 2 as well as 14 + 2. When the transmitter is moved to 14.500, the third harmonic is moved to 43.500, which when mixed with the 40 MHz IF creates a spur at 3.5 MHz, as well as spurs at 14 - 3.5 and 14 + 3.5, which I've confirmed with spectrum analyzer measurements.
?
An aside - when I took apart my ZBitx to start experimenting, I tried to repeat my initial measurements, and I got the mess below:
A number of additional spurs were present - and a couple are above the limit. I checked the setup, and finding nothing wrong, I just put one of the M3 x 40mm cap cabinet screws back in place, and the new spurs went away.
?
The heat sink has a DC connection to ground through the tab of the TO-220 5 Volt regulator U2, a 7805. That regulator is on the far side of the board relative to the finals Q1 and Q2. My theory is that the mounting tabs of Q1 and Q2 are forming a capacitor with the heat sink through the insulators, coupling some RF energy into the heat sink. Lacking any other ground points, that energy finds ground at the 5 Volt regulator, which happens to be pretty close to the 40 MHz crystal filters, a mixer stage, and a couple of IF amplifier transistors Q3 and Q4.
?
By the way, the four cabinet screws have a black finish which is non-conductive. They pass through plated holes on the main board, but there isn't a positive mechanical connection at those points. In order to continue bench testing, I needed to have the main PC board positively grounded to the heat sink. I made a little grounding strap shown in the picture below:
It's a short piece of solder wick, soldered to the ground side of C107. It passes closely by the source pin of Q1, but that pin is at ground potential. While testing, I attach the strap to the heat sink with a 6-32 screw and nut as shown below:
Anyone wishing to try to duplicate my tests needs to be aware of this grounding issue.
?
When the case is installed, I will slip a star washer between the lug and the heat sink, then place the side panels and install the case screws. Tightening the case screws should create a positive contact between the lug and the heat sink. I did get some stainless M3 x 40MM cap screws that stand a better chance of providing a ground path at the other three corners. A no-cost alternative might be to sand the black finish off the screws provided.
?
I've focused my attention on the circuits surrounding the Diode Ring mixer comprised of dual diode packages D3 and D4. Changing C31, the DC blocking capacitor at the output of the SI5351, had no effect on the spurs. Providing a better termination for the mixer RF port at the low-pass filter had no effect. Moving to the transmit IF amplifier transistor Q3, changing the emitter bypass capacitor C22 from 0.1 uF to 1000 pF had a measurable effect, as shown below:
The spurs at +/- 2 MHz from the carrier have dropped about 10 dB, and are no longer a concern. Unfortunately the spur at 2 MHz is still too big, although it has dropped in level as well. The spurs seen on the 17 Meter band are also still too big.
?
The function of Q3 is to amplify the 40 MHz IF signal during transmit. It does not need the large value of emitter bypass capacitor that's currently installed. Reducing the value of C22 reduces the gain of Q3 at lower frequencies (which reduces Q3's gain in the HF bands where it's not desired) while maintaining good gain at 40 MHz. The result is less RF energy is getting into the IF mixer port along with the 40 MHz IF, reducing the amplitude of the spurs.
?
This is as far as I have gotten. The Q3 stage may need to have an LC band-pass filter added to it's input or its output to better filter out the RF being picked up from the transmitter stages. I'm hopeful that a simple solution is going to be found soon, that results in a clean transmitter with plenty of margin for spectral compliance.
?
73; Steve, N3SB
?
?
?
|
Thanks all!? I¡¯m not worried about simple issues. I don¡¯t CW. My use is voice and I want to try digital My big issue is I¡¯m sort of a nomad right now. I rent a small apt and work 2 jobs, (trying to retire at 60). So that limits my use. My goal of a small unit such as this is travel. When I go to help my mom around her place. My gal and I travel a lot. National parks and such. A perk of working in the medical field. I work a week and off a week.? I¡¯d like to get into POTA and SOTA type activations. I don¡¯t have the internet at my place, so that would be a damper on updates and certain uses of the radio. I do have access to the internet though. Just not daily.? I may just place an order and give it a shot. I¡¯ve surely wasted $200.00 on worse things!?
Gents,
Thanks for the info! I thought the review was great, BTW Dave! I look forward to fiddling around with this radio and honestly, weight isn¡¯t a huge issue for me as I am loading my e-bike down with the equipment and taking that to the parks. I also have a G90 setup for portable ops and a uSDX, so this is just another fun radio to experiment with.?
? As for the power issue, I was looking at maybe a Bioenno battery instead of using the 18650¡¯s. They have a 9V version in several different Ah capacities and also have a power pole to DC plug adapter that is the correct size for the zBitx.?
Our club also had a battery box build day recently and I have built several boxes with 15Ah, 20Ah, 3Ah and ?3 others that use Milwaukee, Ryobi or Ridgid batteries.?
On Fri, May 23, 2025 at 09:39 AM, W1WCI wrote:
POTA a perspective, many activations with zBitx.? Usually get five contacts in before taking a break for heat dissipation.? My fingers are my gauge. Running the radio at 75% drive usually change in a second set of batteries after the first drops to 6 volts.? Typically one and a half pairs of batteries per outing, the second set is usually still 7+ volts at the end. Did a five park outing on six batteries.? A lot less gear than using my Sbitx.
Tim - W1WCI
?
Thanks for that input.? I think it helps set expectations quite well.?
?
As a sbitx owner I think I'd find needing a break after five QSOs for the rig to cool down a bit frustrating, yet the sbitx is three times the cost of zbitx, takes up more space and weighs more, etc.
?
--
Regards,
Dave, N1AI
|
Gents,
Thanks for the info! I thought the review was great, BTW Dave! I look forward to fiddling around with this radio and honestly, weight isn¡¯t a huge issue for me as I am loading my e-bike down with the equipment and taking that to the parks. I also have a G90 setup for portable ops and a uSDX, so this is just another fun radio to experiment with.?
? As for the power issue, I was looking at maybe a Bioenno battery instead of using the 18650¡¯s. They have a 9V version in several different Ah capacities and also have a power pole to DC plug adapter that is the correct size for the zBitx.?
Our club also had a battery box build day recently and I have built several boxes with 15Ah, 20Ah, 3Ah and ?3 others that use Milwaukee, Ryobi or Ridgid batteries.?
On Fri, May 23, 2025 at 09:39 AM, W1WCI wrote:
POTA a perspective, many activations with zBitx.? Usually get five contacts in before taking a break for heat dissipation.? My fingers are my gauge. Running the radio at 75% drive usually change in a second set of batteries after the first drops to 6 volts.? Typically one and a half pairs of batteries per outing, the second set is usually still 7+ volts at the end. Did a five park outing on six batteries.? A lot less gear than using my Sbitx.
Tim - W1WCI
?
Thanks for that input.? I think it helps set expectations quite well.?
?
As a sbitx owner I think I'd find needing a break after five QSOs for the rig to cool down a bit frustrating, yet the sbitx is three times the cost of zbitx, takes up more space and weighs more, etc.
?
--
Regards,
Dave, N1AI
|
Yep. Putting the gps module inside is the best solution for portability. If there is no way to cram it in as-is, most of the case is 3D printed and with the stl files, it shouldn't be too difficult to remix a little extra space here or there.
|
It DOES go below 9V. I missed that at first!
|
I have been wondering the same.
?
one SEEMS to tick all the boxes and has some variability for other devices if needed.?
- 9V
- at least 3A (Is 5A too much?)
- Barrel plug is the right size and polarity
I'd like it if it would go below 9V to be on the safe side, but I wonder if someone at HF Signals could chime in here with perhaps a list of acceptable options??
Chris
?
?
|
Re: Unreliable WIFI on zBitx?
Joe and Jody, thanks for the additional details on your set ups and usage.? I was all excited to have gotten four hours out of it this morning before wlan0 crashed.? Rebooted and got five minutes before it happened again.? Ugh.
The 32/64 bit information is interesting though.?? I might have to look into that.?? I haven't actually taken the cover off yet, but this might be my incentive to do so!
73,
Steve KF8KI
toggle quoted message
Show quoted text
On 5/23/2025 2:07 PM, Jody - K3JZD via groups.io wrote: One of the things going on, which may or may not impact overall performance, it that (as I understand it) the zBITX is using a 64 bit RasPi Zero 2.? But as released, there is a 32 bit RasPi OS running on it.? I have to wonder if it might be more efficient if it were running a 64 bit RasPi OS.? ?If anyone tries that, please post your results.
72,
Jody - K3JZD
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I have wondered if putting one of these in the radio tied directly to the pi. I use this on a raspberry pi pico (no wifi) for a WSPR TX. They are tiny. I would think there is room in the zbitx(now I haven't open it myself. to look)? It's about the size of a nickel?cone.?
I haven't received my zbitx and haven't had my hands on it yet, so maybe my question is moot.?
?
With inexpensive and reliable GPS Modules such as the GT-U7, is there a way to implement it into the zbtix for time sync or maybe even location??
?
The GT-U7 can ouput NEMA data via serial USB or TTL. I have used this module (with Arduino) and it has been sensitive enough to use inside my house.
?
My first thought is to use an Arduino as an NTP server for the zbitz to sync to. However, I am curious if a more direct way could be possible so it can be used without networking.
?
Ed
?
?
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zBitX power and receive turnover
Still on a steep learning curve with this remarkable radio I got at FDIM in Dayton and had my first SSB QSO with a good audio report using the built in mic and awkward touch screen TX/RX buttons. I think I'll wire up a hand speaker mic. However, I note a LONG delay (around 2-3 seconds) when going from TX to RX either using the buttons or just returning to RX after sending CW. I haven't tried FT8 except to observe it receives OK. The delay is from a slow AGC recovery as it is absent with AGC off and it looks like like perhaps a "pop" that is filtered in the Audio. I've seen that in uBitX radios after version 3 where the audio delay in the last stage is just enough to hide the "pop", but if AGC is tapped ahead of that it gets affected. My solution in my uBitX was to limit the max the AGC could clamp down. Is there something similar that could be done in software?
?
I did measure CW power out running on 7.6v batteries, drive 100, into a dummy load with less than 1.2:1 SWR.
80m?? 8.0w
40m ? 6.5w
30m?? 3.8w
20m?? 7.0w
17m?? 6.0w
15m?? 3.0w
12m?? 3.5w
10m?? 3.0w
?
These seem similar to the Vpp shown on the test card, but a bit more pronounced. Not sure why 20 and 17 are so good.
?
=Vic=
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David Wilcox K8WPE
HA3HZ
Jay Bremner
Ed K.
Chris (KQ4AET)
Vic WA4THR