Re: zbitx update, shipping, pico, et al
The zbitx main board has a Pi Zero 2W and the front panel has the pico W. The pico2W didnt work with the display, nor did we need it to work the front panel.
Which raspberry pi zero does it have?
the Pi zero W (Broadcom BCM2835 ARMv6 1GHz 1 core + WiFi)
or the pi zero 2W? (Broadcom BCM2711A1 Cortex-A72 1GHz Quad-Core 64bits +WiFi)
or the 1.3 (Broadcom BCM2835 ARMv6 1GHz 1 core no WiFi)?
?
Thanks for the clarification.
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Re: sBitx Mic input - assist request
the mystery continues.?
removed :
CD28
LD6
CD29
CD27
QD1
?
Still have 2.1v at junction of LD6 / CD29 [both removed].? With power off measuring about 2K to ground at that point. Going to tke a break and start over tomorrow... Welcome any thoughts.
?
?
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Re: zbitx update, shipping, pico, et al
<<
THEN:
The Raspberry Zero 2, that powers the zbitx (zero bitx because of? the RPI zero in it), can't handle this display as the GPIO pins on it are all used up. 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).
>>
I understand you had to modify the main board, which has now two microcontroller: the original Zero 2 to which is added a Pico W?
<<
NOW:
Future updates to the front panel (like moving the comms between the zbitx and the front-panel to bluetooth or even wifi to make it a remote head) will need a way to update the firmware to the Pico. It is usually done with an Arduino IDE running on a computer with micro USB cable from the PC to the Pico. That is the easy part. The hard part was that getting the Arduino going on a PC, installing the Pico package and then the TFT display libraries is like pulling teeth. There has to be a better way. We realized this last week when I shipped out the Pico firmware to our folks at HF Signals. If they(HF Signals) couldn't get the Arduino IDE setup on their PC within minutes, I?was very skeptical and most users of zbitx would.
>>
Did you manage to find an easy and better way for plain OMs to setup the Arduino IDE?
73 - Pierre - FK8IH
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Re: sBitx Mic input - assist request
the base-emittter voltage of QD1 schould be about 0,7 V but is
3,9 V -2.3 V = 1.6 V, my guess: defect transistor or wrong
measurement.
Am 09.03.2025 um 17:02 schrieb WF4RC
Carroll:
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I have a new sBitxV3 board only. Everything is working except
the Mic input. I started experimenting with some microphone I
had and the recorded transmission has lots of noise and very low
audio. I measure 2.1v on mic input tip. I think it should be 5v.
Can anyone guide me as to what the issue may be and where I
should look. Here are my measurements/ calculations.?
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Hi Michael,
?
AFAIK The schematic is correct. Double-check your tracing. Solder bridges on the board could also confuse the measurements. I use a magnified headset to verify traces. Since it is a two-sided board, no hidden traces exist between layers.
?
73
Evan
AC9TU
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Evan,?
?Is it possible that R5 and R6 are mislabeled on the schematic? After I removed Q9,Q10,Q101,R5 and R6, to check continuity of pads and traces, I found that bottom of R6 connects to the gate-pin1 of Q10, not the source-pin3, and connects to the source-pin3 of
Q101 and not the gate-pin1, as indicated in the schematic. The schematic is from Farhans github, titled sbitx v3 production. Let me know, thanks!
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Yes, I was somewhat relieved that I am getting the proper Tx signal. I feel that I may need to remove Q9, Q10, Q101 and check the continuity, rule out damaged pads/traces, and swap in new components. Also when I mentioned using
through hole for Q10,Q101, I was thinking about using regular 2n7000 in place of the sot23 2n7002. Would those work?
-------- 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,
?
The TX signal works (recieve at 0.15 volts, transmit at 3 volts).
?
?
The pins on Q9 are marked in this photo:
?
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.??
?
?
Q101 is a 2n7002 MOSFET.? This can not be replaced with a 2n2219.??
?
?
The above is based on not getting 12 volts on the tab of Q9.
?
73
Evan
AC9TU
?
-- Mike - K8MCB?
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Re: sBitx Mic input - assist request
CD29 could be leaking.? Without a mic connected, the voltage on the tip should be approximately 9.9/10th of the voltage supplied to the sBitx.? That assumes a 10meg input resistance on your meter.? There should be no current draw through RD21, though I suspect you derive the current reading from the voltage drop across it.? The voltage drops when the mic is connected.
?
Try disconnecting CD29 and measuring the voltage again.
?
Reducing RD21 can increase the bias voltage to the mic.
?
73
Evan
AC9TU
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Re: sBitx Mic input - assist request
Thanks for the input and replies,
There was no mic connected when I made the measurements. Can anyone verify/ confirm that the Tip of the TRS MIC plug should be at 5v? I suspect QD1 as well .? The mic I was using was electret and needed a 3.3-5v Vin. That was how I found out the Tip was only at 2.1.
Any ideas are wlecome. Thanks everyone.?
?
73.
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Re: zbitx update, shipping, pico, et al
Thank you for the update, very much appreciated.? ?Doug
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Re: sBitx Mic input - assist request
Even with a dynamic mic, QD1's operating point is incorrect. The emitter and base should have a difference of .6 to .7 volts. The listed voltages are 3.9 and 2.3 volts or 1.6 volts. The transistor is not in the linear mode. I would replace QD1 and remeasure.
?
73
Evan
AC9TU
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Re: Trying to update firmware in ubitx6.1
#v6
I just updated mine, and I had to use a new board. I have a programmer, and I was able to load the OG nano that came with the 6.1, but you have to be able to program via the 6 pin (which you have to solder on to the OG board) to do so. I think they programmed them without the stk500 bootloader.
Also, I tried the N8ME firmware, but the screen is unresponsive, and the pushbutton to menu didn't work either.
After loading the new 6.1 firmware, power on, holding the menu button down, so you can calibrate the screen.
--
-- J R Parrick (K0TBS)
Si vis pacem, para bellum!
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Re: sBitx Mic input - assist request
Exactly. ?
Dr.?William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton - J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com
email:??bill@... ?
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On Mar 9, 2025, at 9:31?AM, Gordon Gibby KX4Z via groups.io <docvacuumtubes@...> wrote:
? It is possible he’s trying a dynamic microphone
On Mar 9, 2025, at 12:23, K9HZ via groups.io <bill@...> wrote:
? Bad mic. ?Is drawing the bias provided by RD21 down from 11.9v to 2.1V.?
Dr.?William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton - J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com
email:??bill@... ? On Mar 9, 2025, at 9:03?AM, WF4RC Carroll <WF4RC@...> wrote:
? I have a new sBitxV3 board only. Everything is working except the Mic input. I started experimenting with some microphone I had and the recorded transmission has lots of noise and very low audio. I measure 2.1v on mic input tip. I think it should be 5v. Can anyone guide me as to what the issue may be and where I should look. Here are my measurements/ calculations.?
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Re: sBitx Mic input - assist request
It is possible he’s trying a dynamic microphone
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Show quoted text
On Mar 9, 2025, at 12:23, K9HZ via groups.io <bill@...> wrote:
? Bad mic. ?Is drawing the bias provided by RD21 down from 11.9v to 2.1V.?
Dr.?William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton - J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com
email:??bill@... ? On Mar 9, 2025, at 9:03?AM, WF4RC Carroll <WF4RC@...> wrote:
? I have a new sBitxV3 board only. Everything is working except the Mic input. I started experimenting with some microphone I had and the recorded transmission has lots of noise and very low audio. I measure 2.1v on mic input tip. I think it should be 5v. Can anyone guide me as to what the issue may be and where I should look. Here are my measurements/ calculations.?
|
Re: sBitx Mic input - assist request
Bad mic. ?Is drawing the bias provided by RD21 down from 11.9v to 2.1V.?
Dr.?William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton - J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com
email:??bill@... ?
toggle quoted message
Show quoted text
On Mar 9, 2025, at 9:03?AM, WF4RC Carroll <WF4RC@...> wrote:
? I have a new sBitxV3 board only. Everything is working except the Mic input. I started experimenting with some microphone I had and the recorded transmission has lots of noise and very low audio. I measure 2.1v on mic input tip. I think it should be 5v. Can anyone guide me as to what the issue may be and where I should look. Here are my measurements/ calculations.?
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Re: sBitx Mic input - assist request
Yeah, tell us everything about the microphone!!!
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Show quoted text
On Mar 9, 2025, at 12:02, WF4RC Carroll via groups.io <WF4RC@...> wrote:
? I have a new sBitxV3 board only. Everything is working except the Mic input. I started experimenting with some microphone I had and the recorded transmission has lots of noise and very low audio. I measure 2.1v on mic input tip. I think it should be 5v. Can anyone guide me as to what the issue may be and where I should look. Here are my measurements/ calculations.?
|
sBitx Mic input - assist request
I have a new sBitxV3 board only. Everything is working except the Mic input. I started experimenting with some microphone I had and the recorded transmission has lots of noise and very low audio. I measure 2.1v on mic input tip. I think it should be 5v. Can anyone guide me as to what the issue may be and where I should look. Here are my measurements/ calculations.?
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He could offset the carrier a bit one way or the other, (maybe by 1500 Hz ?) and then plot the response of the filter by looking at the noise pattern on any waterfall display
It would be a great learning exercise also!!
Gordon kx4z?
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On Mar 9, 2025, at 10:37, Evan Hand via groups.io <elhandjr@...> wrote:
? Hi Ted,
?
Since you have the Memory Manager software, I suggest you save the values to a file and do the BFO adjustment again.??
?
I thought about the symptoms again and do not believe the modulator failure is the most likely cause.? The carrier is significantly reduced in the video.? If the modulator failed, I would expect a much higher value for the carrier (BF0).? Also, the SSB crystal filter would limit the output to a 3KHz span.? It could be that the SSB filter is damaged somehow.
?
Hopefully, others can chime in here, as I cannot explain the data.
?
73
Evan
AC9TU
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Hi Ted,
?
Since you have the Memory Manager software, I suggest you save the values to a file and do the BFO adjustment again.??
?
I thought about the symptoms again and do not believe the modulator failure is the most likely cause.? The carrier is significantly reduced in the video.? If the modulator failed, I would expect a much higher value for the carrier (BF0).? Also, the SSB crystal filter would limit the output to a 3KHz span.? It could be that the SSB filter is damaged somehow.
?
Hopefully, others can chime in here, as I cannot explain the data.
?
73
Evan
AC9TU
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Re: zbitx update, shipping, pico, et al
Thank you Ashar! Thanks for all your hard work making our hobby fun, innovative, and affordable! Truly state of the art! Doing what no one else has done! I appreciate it greatly!
Jay NM2M?
Ashhar,
?
Thank you for all the time you have put into the ZBitx. Hopefully, after this weekend you’ll get a much needed break
?
Thank You again,
Robert AG6LK
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?
Hi, Evan, and all.
?
I appreciate the leads.? Here are some answers to your queries -
?
On Fri, Mar 7, 2025 at 08:29 AM, Evan Hand wrote:
Can you pull up the software settings page and note the BO value?? It should be close to 11.056 kilohertz.?
?
?
See attached;? SSB is set tp 11.056875. That would have been a really good call, though I'm not against trying all over again.??
?
If you think this may help, I happen to have a small "TinySA" that I've played with, but the best I can do while learning what it can do is to compare an IC-706MK2g signal on the same frequency, and see how they differ.?
?
?
If the calibration values seem correct, then the only test I know for the modulator is to pull the diode and replace it with a known-good one.? That does require SMD rework skills.? I suggest not using discrete diodes for this replacement, as they may not have the matched characteristics.
I happen to have a previously-abused mainboard handy. Swapping out the dual diode would not be that much trouble here.
?
Before you start tearing apart your radio, I have a question: The video clip shows USB as the communication mode.? Were you running a USB on 40 meters?
?
I'd been working a number of other folks before and after this follower came along, so either the video fails to show his entire screen and something's missing, or, maybe he swapped sidebands on his end before gathering evidence.? And now at home - using the redundant radio - I can indeed hear equally well on both side bands from 2 feet away at least.
?
So,? unless the collective believes the BFO or other calibration is off, I'm willing to swap the diode pair and will stand by.....
?
?
72,
?
Ted
K3RTA
?
?
?
?
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J R Parrick (K?TBS)
K9HZ
Ted