Evan, I have gotten things mostly straightened out, proper voltage to R77, 5.6v to D6, etc. I still get the 3v on Q10 for the Tx signal, but Q9 just doesn't switch. The voltages on the excel sheet match the steady receive state, but things aren't
switching when the Tx is applied. Suggestions?
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-------- Original message --------
From: "Evan Hand via groups.io" <elhandjr@...>
Date: 3/6/25 2:07 AM (GMT-05:00)
Subject: Re: [BITX20] reviving my sbitx v3
Michael,
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The TX signal works (recieve at 0.15 volts, transmit at 3 volts).
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The pins on Q9 are marked in this photo:
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The gate (pin 1) of Q9 should be higher, and the tab (Pin 2 or drain) should be 0 volts when receiving and close to 12 volts on transmission.? It could be a failed Q9, Q10, Q101, or combination.? I would start with Q10, as it should pull down the gate
of Q9 to turn it on and supply the 12 volts to the driver stages.??
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Q101 is a 2n7002 MOSFET.? This can not be replaced with a 2n2219.??
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The above is based on not getting 12 volts on the tab of Q9.
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73
Evan
AC9TU
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-- Mike - K8MCB?
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sBitx Toolbox for 64 Bit has been upgraded to v3.01.
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This upgrade includes new and enhanced applications.
- Re-added Screen Resizer
- Updated USB headset for lower latency
- Added volume slider to voice keyer recording function
- Added update manager utility
- Added DroidStar controller (installed on v4.2 or later PI OS image)
- Fixed Screen Scaler medium and large buttons
- Added CW Detector
- Updated Toolbox launcher with new theme and UI controls
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To get the latest update; Go to the Update menu and select Check for Updates
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https://github.com/drexjj/sBITX-toolbox64
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- JJ
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Re: sBitx Mic input - assist request
Now I wish I hadn’t removed so many parts, Hope I can get the back in without too much difficulty! #LoveThroughHolePcbs!
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Yes, that is why I sent the picture.? Unfortunately, there is no tracking process for minor revisions, only the major ones, such as DE, V2, V3, and V4.? The V4 has just been announced.
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With HFsignals, you always need to verify the schematic against the board.? My DE had some changes that have never been documented on a schematic.??
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73
Evan
AC9TU
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Re: sBitx Mic input - assist request
Yes, that is why I sent the picture.? Unfortunately, there is no tracking process for minor revisions, only the major ones, such as DE, V2, V3, and V4.? The V4 has just been announced.
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With HFsignals, you always need to verify the schematic against the board.? My DE had some changes that have never been documented on a schematic.??
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73
Evan
AC9TU
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Re: sBitx Mic input - assist request
I just realized your picture does not have RD2 in it. Perhaps different revisions of sBitx V3 ??
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Re: sBitx Mic input - assist request
On Mon, Mar 10, 2025 at 02:09 PM, Evan Hand wrote:
I measured my v3 mic input at 11.6 volts with a 12-volt supply, and no mic was connected.
Exactly what I would expect. Interesting that RD2 is not on the schematic. I'm befuddled as to what is happening with my PCB. I should have 11.xx v on either side of LD6. Even more so with the list of components I have removed. I might try to reinstall all and see what happens.?
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Re: sBitx Mic input - assist request
Hi Rob,
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I measured my v3 mic input at 11.6 volts with a 12-volt supply, and no mic was connected.
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Here is the picture of the preamp area:
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RD2 is not there.
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If you want a different bias value, adjust RD2 to get whatever value you need.
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73
Evan
AC9TU
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Re: sBitx Mic input - assist request
Well, there ya go!? ?change that resistor to get the bias voltage you prefer and you should?be in business!! I didn't have that (to my knowledge) in any radio I have worked on, and I added resistors to get the voltage under 10 V? (a lot of electrets want it below 10V)
In order to get adequate?volume, I had to use very high output mics -- around -25 dB or -30 dB in their way of measuring it.? ?? Wish you good luck!? ?there is always something to learn -- and in this case comparing what IS to what is SUPPOSED TO BE is the trick!
Congratulations!!
Gordon KX4Z
RD2 ? I do not see this resistor on the and appears to be in parallel with C29. That would make your answer correct.
It would be great if another sBitx V3 owner could measure the Mic +ve on the tip of the mic TRS connector with mic unplugged.
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Re: sBitx Mic input - assist request
RD2 ? I do not see this resistor on the and appears to be in parallel with C29. That would make your answer correct.
It would be great if another sBitx V3 owner could measure the Mic +ve on the tip of the mic TRS connector with mic unplugged.
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I think everyone needs to take a deep breath and recognize a few things.
1) This is new product, and to expect military precision for its release does not seem reasonable, especially with a smaller firm. Think of releases by Elecraft, QRPLabs, ant of course the "Big Three"; they may state a release date but really that should be taken as the beginning of a date range.
2) Asher and his group have made a couple of important additions to the zBitx based on changes to the operating plans for the rig. This benefits the end user but takes some extra time to implement. Waiting a bit longer to get a more complete product?!? This sounds like a no-brainer to me.
3) Some of the processes involved cannot be sped up by "adding another man to the job"; in fact, it may slow down the process.
4) Gordon makes an excellent point here. Asher only took on 2) above because he felt it would be advantageous to us end users at minimum disruption of the manufacturing process and minimum delay to getting them into our hands. In doing so, he made the same sort of decisions that all manufacturers make. If he had been much earlier in the design process, a more powerful CPU may have been a better answer, but it is not practical at this point.
73 de Lee KX4TT
> On 03/10/2025 1:39 PM EDT Gordon Gibby KX4Z via groups.io <docvacuumtubes@...> wrote:
>
>
> I’m somewhat incredulous that people would urge a complete redesign of a product that is potentially days away from shipping, likely already built. The only issue is how to manage upgrades, something that demonstrates some foresight!
>
> I don’t think you redesign a product, even changing the chip set , when it is ready to market.
> Validation of such a radical change would substantially delay delivery of the product to those who have already paid for it
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> My 2 cents,
> Gordon kx4z
>
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Please don't confuse a labor of love by a fellow HAM with a large company's professional product. I am appreciative of the development of this very innovative,state of the art, product by such a dedicated team of fellow hobbyists sharing their love of the hobby with us! Nothing like it anywhere and they have always said that it is an experimental project for tinkers!
This is one reason why I wait until a product it out and vetted before ordering one.
Mike N2MS
> On 03/10/2025 1:39 PM EDT Gordon Gibby KX4Z via <docvacuumtubes=[email protected]> wrote:
>
>
> I’m somewhat incredulous that people would urge a complete redesign of a product that is potentially days away from shipping, likely already built. The only issue is how to manage upgrades, something that demonstrates some foresight!
>
> I don’t think you redesign a product, even changing the chip set , when it is ready to market.
> Validation of such a radical change would substantially delay delivery of the product to those who have already paid for it
>
> My 2 cents,
> Gordon kx4z
>
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This is one reason why I wait until a product it out and vetted before ordering one.
Mike N2MS
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On 03/10/2025 1:39 PM EDT Gordon Gibby KX4Z via groups.io <docvacuumtubes@...> wrote:
I’m somewhat incredulous that people would urge a complete redesign of a product that is potentially days away from shipping, likely already built. The only issue is how to manage upgrades, something that demonstrates some foresight!
I don’t think you redesign a product, even changing the chip set , when it is ready to market.
Validation of such a radical change would substantially delay delivery of the product to those who have already paid for it
My 2 cents,
Gordon kx4z
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I’m somewhat incredulous that people would urge a complete redesign of a product that is potentially days away from shipping, likely already built. The only issue is how to manage upgrades, something that demonstrates some foresight!
I don’t think you redesign a product, even changing the chip set , when it is ready to market. Validation of such a radical change would substantially delay delivery of the product to those who have already paid for it
My 2 cents, Gordon kx4z?
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On Mar 10, 2025, at 13:20, Shirley Dulcey KE1L via groups.io <mark@...> wrote:
? I sit corrected. But I wonder what the wireless in the Pico will be used for? Have to wait and see! On Mon, Mar 10, 2025 at 12:40?PM Charudatt Uplap via <charudattu= [email protected]> wrote: Guys, let's not speculate, the designer is not a fool. You already know him from his earlier offerings.
I suggest, let's wait for the rollout and then discuss.
Right now we don't know much of what's in the offering. So have patience.?
de VU2UPX?
Farhan explicitly stated the zBitx will have an RPi Pico W:
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"Hence, the zbitx sports a new microcontroller, the Raspberry Pico W (with Wifi and Bluetooth on it!) that handles the front panel. This offloads the user interface to this microcontroller that handles the 3.5 inch TFT display. The two talk to each other over the I2C bus (Pi is the master, Pico is the slave)."
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Clipped from yesterday's update.
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Ken, N2VIP
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I sit corrected. But I wonder what the wireless in the Pico will be used for? Have to wait and see!
On Mon, Mar 10, 2025 at 12:40?PM Charudatt Uplap via <charudattu= [email protected]> wrote: Guys, let's not speculate, the designer is not a fool. You already know him from his earlier offerings.
I suggest, let's wait for the rollout and then discuss.
Right now we don't know much of what's in the offering. So have patience.?
de VU2UPX?
Farhan explicitly stated the zBitx will have an RPi Pico W:
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"Hence, the zbitx sports a new microcontroller, the Raspberry Pico W (with Wifi and Bluetooth on it!) that handles the front panel. This offloads the user interface to this microcontroller that handles the 3.5 inch TFT display. The two talk to each other over the I2C bus (Pi is the master, Pico is the slave)."
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Clipped from yesterday's update.
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Ken, N2VIP
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Guys, let's not speculate, the designer is not a fool. You already know him from his earlier offerings.
I suggest, let's wait for the rollout and then discuss.
Right now we don't know much of what's in the offering. So have patience.?
de VU2UPX?
Farhan explicitly stated the zBitx will have an RPi Pico W:
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"Hence, the zbitx sports a new microcontroller, the Raspberry Pico W (with Wifi and Bluetooth on it!) that handles the front panel. This offloads the user interface to this microcontroller that handles the 3.5 inch TFT display. The two talk to each other over the I2C bus (Pi is the master, Pico is the slave)."
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Clipped from yesterday's update.
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Ken, N2VIP
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Farhan explicitly stated the zBitx will have an RPi Pico W:
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"Hence, the zbitx sports a new microcontroller, the Raspberry Pico W (with Wifi and Bluetooth on it!) that handles the front panel. This offloads the user interface to this microcontroller that handles the 3.5 inch TFT display. The two talk to each other over the I2C bus (Pi is the master, Pico is the slave)."
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Clipped from yesterday's update.
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Ken, N2VIP
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The Raspberry Pi Pico is $4. The Pico 2 (a newer version with more CPU power and flash memory) is $5. The wireless variants are an extra $2 but I don't think the zBitx is using one; it already has wireless in the Zero 2 W so it doesn't need it in the Pico.
The WiFi and Bluetooth capabilities in the Zero 2 W bring some useful capabilities. WiFi can be used for NTP time synchronization (valuable for best results in FT8 and similar modes), for connection to spotting sites, and for networked contest logging. Bluetooth allows the use of a Bluetooth headset for audio input and output, and for linking with a keyboard and mouse (for software maintenance, or for controlling the software if you connect an external monitor).
Using a well established board with ongoing support means there may be a future upgrade path. There will likely be a Raspberry Pi Zero 3 W in the future, which would be a useful upgrade for some users, especially for additional?RAM if it's offered. Of course, a version with 1 GB or 2 GB RAM will probably cost more than $15 :(? If you don't care about the form factor you could take the zBitx out of the box and replace the Zero 2 W with a larger Raspberry Pi board, but at that point you're likely to be better off buying an sBitx.
On Mon, Mar 10, 2025 at 07:17 AM, Richard Neese wrote:
Farhan might I ask whi the pico and not just add a pc8575 or pc8574 i2c gpio expander into the mix if you need more gpio.
I think the z2w over pico w is alot better and mre power performance.
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The zBitx is called the zBitx because it is based on the RPi Zero 2 W (Zero Bitx), and the RPi Pico W is being added to compliment the RPi Zero 2 W, not replace it.
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As for the Pico vs ESP or other microcontroller, I'm not sure there is a significant cost advantage of one over the other (Pico W on a board is just a couple US dollars, how cheap are ESP boards?)
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I suspect even if there is a greater cost for the RPi Pico W vs say an ESP processor, the engineers/designers may be more familiar/comfortable/productive in one environment vs another, and the RPi Pico W has a lot of interesting capabilities that owner/hackers may be able to exploit down the line.
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I hope that helps, at least that is what I understand about the selection of the RPi Pico W.
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Ken, N2VIP
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On Mon, Mar 10, 2025 at 07:17 AM, Richard Neese wrote:
Farhan might I ask whi the pico and not just add a pc8575 or pc8574 i2c gpio expander into the mix if you need more gpio.
I think the z2w over pico w is alot better and mre power performance.
?
The zBitx is called the zBitx because it is based on the RPi Zero 2 W (Zero Bitx), and the RPi Pico W is being added to compliment the RPi Zero 2 W, not replace it.
?
As for the Pico vs ESP or other microcontroller, I'm not sure there is a significant cost advantage of one over the other (Pico W on a board is just a couple US dollars, how cheap are ESP boards?)
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I suspect even if there is a greater cost for the RPi Pico W vs say an ESP processor, the engineers/designers may be more familiar/comfortable/productive in one environment vs another, and the RPi Pico W has a lot of interesting capabilities that owner/hackers may be able to exploit down the line.
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I hope that helps, at least that is what I understand about the selection of the RPi Pico W.
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Ken, N2VIP
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Re: sBitx Mic input - assist request
Hi Rob,
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I wonder if there is a 2KOhm or so resistor that is not on the schematic?? That would explain the voltage on RD21.? With LD6 removed, the mic is out of the picture.
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Can you send a picture of the board area?
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73
Evan
AC9TU
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The Pico brings something to the table that those alternatives do not: PIO peripherals. Those let you take most hardware protocols, including non-standard ones, and turn them into something that is supported in hardware by the microcontroller. (The PIO libraries for support of addressable LEDs are a good example.) Not bad for a board that costs $4. At some point it might make sense to engineer its RP2040 microcontroller (or the next generation RP2350) directly into the zBitx design to shave a bit more off the build cost; the chip costs less than $1 (though it also needs some support parts like flash memory), but simply adding a Pico board made it possible for HF Signals to respond to the display issue more quickly and keep the design on track. On Mon, Mar 10, 2025 at 9:22?AM Shawn Rutledge K7IHZ / LB2JK via <social= [email protected]> wrote:
In general, GPIO is not the best way to interface a display IMO: it might lead you away from being able to use the GPU, and even worse, maybe you’ll waste cycles with bit-banging. ?(It’s been that way since the first pi: they gave us a machine with a middling CPU and ok-for-its-time GPU, but people mostly neglected the latter and pretended that it’s a high-power microcontroller or low-powered PC.? Most of the software could have been better all along.) ?Of course in this case we can just say the pico is acting as the GPU for this little display: the main CPU can use some sort of language to tell the display what to show, and sending that out might be more efficient than actual rendering.? That leaves the main pi’s GPU free for doing SDR acceleration (well it could, probably won’t though), running the external HDMI display and so on.? But the wifi and bluetooth also seem redundant at first glance (when the radio and display are in the same box).? Setting it up as a remote head was mentioned: two more ways to connect it then, besides the gpio.
I suspect it will ship with some sort of one-off display protocol just for the zbitx (and then how often will its firmware need updating as the feature set improves?), but it’s a long-term interest of mine to come up with a more reusable remote-UI protocol that scales really well.
Alternatively, I would ask , why a PICO and not an ESP32 ? Cheaper also !
Regards VU2UPX? On Mon, 10 Mar, 2025, 5:47 pm Richard Neese via , <n4cnr.ham= [email protected]> wrote: Farhan might I ask whi the pico and not just add a pc8575 or pc8574 i2c gpio expander into the mix if you need more gpio.
I think the z2w over pico w is alot better and mre power performance.
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Lee
Shirley Dulcey KE1L