Re: zBitx speaker noise?
#zbitx
I agree ... -
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I use self-adhesive copper tape to shield the lines.
This also allowed me in the past to get the sBitx free of digital
interferences.
The HF signal transceivers all have the same problem of insufficient or
complete no shielding of the digital units.
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73 ! Jens / HB9JOI
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From: Joel Caulkins/N6ALT via groups.io
Sent: Tuesday, April 15, 2025 4:39 PM
Subject: Re: [BITX20] zBitx speaker noise? #zbitx
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Ron,
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I have that same problem, in fact I would say every zBitx owner is having
this problem. There are some on this group that think this might be the SPI
serial interface updating the display and causing interference. It may be
reduced somewhat through firmware changes like how many writes to refresh the
display and such. Me not being a coder by any means am waiting to see what
others come up with to fix this annoying problem. All we cane do is wait and
see.
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Joel
N6ALT
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Re: Where is the line at for ZbitX's that are shipping.
My batch2 ZbitX shipped today and delivery is expected friday according to DHL.
-Dean
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Re: zBitx speaker noise?
#zbitx
Ron,
?
I have that same problem, in fact I would say every zBitx owner is having this problem. There are some on this group that think this might be the SPI serial interface updating the display and causing interference. It may be reduced somewhat through firmware changes like how many writes to refresh the display and such. Me not being a coder by any means am waiting to see what others come up with to fix this annoying problem. All we cane do is wait and see.
?
Joel
N6ALT
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Re: Should I start with uBITX, sBITX or zBITX?
If you have 807s and power transformers available then use what
you have.? Tubes are almost unavailable here and unused.? I
couldn't even give away a few 2E26 tubes - nobody wanted them.
Gerry
On 2025-04-14 23:42, Jon via groups.io
wrote:
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Thanks a lot Gerry for the clarification. I had
started a bit later in the hobby than most of you.
There are a few younger hams in this region still getting
hold of 807s and making linear amplifiers for their
Radioberry, with excellent on air signals.
Sorry that we have deviated from BITX because of cute
nostalgic memories.
Maybe someone may be interested in trying out those tubes
as linear amplifiers for BITX.
73
Jon, VU2JO.
Jon - the 12 volts is the heater voltage, not the
plate!!!? You still need that 750 volts on the plate.
Regarding high voltage - there were tubes made in the
early days of transistors that used a plate voltage of 12
volts.? They were used in car radios, where they were used
in the RF stages with transistors in the audio stages.?
Compared to "conventional" tubes, the difference is that
the control and screen grids are "reversed", with the
screen being 1st and the control 2nd.? They got rid of the
vibrator and power transformer that was used before that
to get the 250 volts or so for the tube plates.? Once
transistors with respectable frequency capabilities were
developed they disappeared.
Gerry
On 2025-04-14 10:15, Jon via wrote:
Gerry,
Thanks a lot for the detailed suggestions,
especially as you own all three versions.
I did not know that there is a 12V version of 807!
I thought that all vacuum tubes need high voltage. I
had wondered how the early car radios worked from
batteries.
Regarding the filters and all, getting them here
would be tough, though not impossible.
Maybe i will wait till sBITX v4 reviews are out and
then decide.
Hope to meet you on air some?time soon.
73
Jon, VU2JO
Jon
I would say the uBit is probably the easiest of
the lot for a new user to use, although it lacks
some of the features of the SDRs.? It's a much
less expensive radio than the sBit.? Since you say
you won't be operating portable, and you do have a
resonant antenna system, you can get away with
just an AC power supply and a key to start with.?
You might be able to build a suitable power
supply, or buy something ready made.? I'm in
Canada, so I don't know what it's like to get
things locally in India.? It's easy to add a few
features later to the radio, after you get
familiar with it.? The ones I would suggest are a
memory keyer, an audio filter, and an AGC system.?
The uBit isn't really designed to handle some of
the more modern things like FT8, etc., just plain
old CW and SSB.? It may be possible to use these
with a sound card and a computer.? I haven't tried
this.
With either of the SDRs, you are looking at
updates, especially with the zBit, as it is quite
new.? You won't have this issue with the uBit.
I have all 3 of these radios, so I do have some
experience.
Sotabeams has a good audio filter at a cost of
about ?25.00, plus shipping.? Hamcrafters
(K1EL) has the K16-EXT keyer, although at the
moment his situation is unsettled, as things are
uncertain in the USA with some of the
president's ideas on international trade.? A lot
of his raw materials are imported.? Both of
these can be built into the uBit, although the
keyer has some practice features that make it
very useful on its own.
Your comments about 807 tubes bring back
over half a century of memories with 1625s (the
12 volt version of the 807) and WWII surplus
equipment.? I used a 1625 in my first
transmitter, back in 1970.
Gerry Sherman
On 2025-04-13 23:45, Jon via wrote:
I do not have a BITX yet, but have been
closely following the discussions on the
group.
My experience in homebrewing was a few
decades back, of a VU2VWN QRP with BD 139
final and a 3 x 807 vacuum tube TX running
about 120W DC input.
That means I have not meddled with any
radio circuit for the past few decades.
Which one should I start with: uBITX, sBITX
or zBITX?
As of now, I have no option for portable
operations. Only a fan dipole for 40-10m and a
dipole for 80m.
Hoping to receive your valuable
suggestions.
73
Jon, VU2JO
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Evan,
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Thanks for the advice. Jeff returned from vacation and I placed an order on his site for the board kit. Very quick response and Jeff shipped an assembled board as an upgrade. Outstanding service is all I can say.
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Dean/ N2TNN
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The exact same thing happens to me. I'm a Morse code operator, and proper CW operation is crucial to me. Since I'm not very good at updating firmware and modifying the radio, I don't mind waiting a little longer than the estimated time if it means the radio is fully operational.
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Re: zBitx speaker noise?
#zbitx
I think this effect is due to its very small size. Probably shielding would eliminate the problem.
This could be aluminum or copper foil, which is insulated on both sides. Short circuits should be avoided.
If you feel like it, you can experiment with this.
This worked for sBitx, when the RPi flat display wire is shielded and a similar metal shield is placed between the pcb and the RPi.
The question is, which is the better shield: aluminum or copper or iron?
--
Gyula HA3HZ
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Re: zBitx Battery for real time clock missing
Shirley,
the problem and its suggestion arise from the fact that a piece of writing is missing from the shipping package, which draws attention to this.
We, who regularly read the forum posts, know this. Anyone who buys a product and does not regularly read forum posts - is unaware of these things.
In short: please send a message to the buyer that we ship it like this, the battery type is this and that, please buy it from a domestic dealer.
That's it
--
Gyula HA3HZ
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I hear a pulsing noise from my zBitx speaker, even with a dummy load connected instead of an antenna, and both the audio volume and IF gain turn down. Seems to pulse or hum 3 to 5 times per second. Is this normal? ?Or an issue that needs to be fixed?
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Anyone else hear this from their unit?
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If it¡¯s a problem with my unit, any ideas on where I should I look to diagnose and solve this noise issue?
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73, Ron
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Re: zBitx Battery for real time clock missing
The reason that the zBitx is not supplied with a battery is because of shipping restrictions on lithium batteries. The shipping time would be much longer if the battery were included because it would have to be sent by ship, not air. CR2032 batteries are inexpensive and readily available just about everywhere.
Hello Ragav,
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I bought a "CMOS BIOS CR2032 battery" for the real time DS3231 clock in the zBitx (BTW: a Raspi Pi5 rechargable battery will not work, as the DS3231/zBitx will not charge it!).
To be on the safe side, I checked the orientation of the J7 connector on the zBitx PCB against the +/- connectors of the battery:
The J7 connector was incorrrectly oriented! Perhaps this was the reasone, why no battery has been delivered with my zBitx.
If I would have just plugged in my battery, it might have killed the RTC in the zBitx.
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As a workaround, I cut the battery wires and swapped them. With this change, the RTC is now working.
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I was also considering to desolder/resolder the J7 battery connector on the zBitx PCB, but the zBitx is NOT made for disassembly:
You cannot unscrew the PA MOSFETs and the 5V voltage regulators, as you cannot reach the screw heads to hold them for unscrewing...
Trying to unscrew the nuts just rotates the screw as well. For unscrewing holes in the PCB to reach the screw heads would be required.
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73, Joerg - DB2OO
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Re: sBitx v3 - next final MOSFET killed
Michael, please note that the product is software published.
So much so that if you don't modify it, there's no joy in using it.
And which manufacturer publishes the CAD files? Then there would be a cheaper manufacturer who would skim the profits from the product, no matter how much energy was invested in it. So the manufacturer must protect the product from pirate manufacturers, but provide enough information so that you can find the part on the panel.
In recent years, the world's attitude to what to publish and what not to publish has changed a lot.
There are many clone manufacturers who haven't put any development into it, but they take the profits.
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Would you produce anything by publishing the data necessary for production?
By the way, for someone who can read between the lines and has made a similar product, copying would not be a problem, but there is also honor.
Which is a great treasure if everyone follows the written and unwritten rules.
That's why I say it's a rubber bone that can be chewed on, but it won't get us ahead.
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Gyula HA3HZ
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Re: zBitx complete software build instructions?
The dependencies are in install.txt on github. The run will not happen without hardware because it will be missing the components connected to the GPIO pins for proper operation.
The hardware is required for proper operation.
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Gyula HA3HZ
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Re: Where is the line at for ZbitX's that are shipping.
Jim,
Send us an email on sales at hfsignals dot com.? If you like we can hang on to your zBitx and ship it out? when you give us the green light or we can ship it to an alternate address if you prefer.
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73,
Ragav
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Re: Pi password for zBitx
Don,
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The default password is hf12345.
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73,
Ragav
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Re: Fixed: cw latency and wsjtx/flidigi sidetone
That's modem_next_sample in the above.
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You can read online about Flex cw keying issues in a $4500 radio.?
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I have a Peaberry V2.?? David the designer actually wrote a little windows driver program that operated the radio in CW mode only to address CW timing issues with HDSDR ( in that HDSDR is not used in CW mode any longer ).?? So a long term solution may be a stripped down SDR that is CW only that processes audio in blocks of 128 bytes if that is possible.
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Re: Fixed: cw latency and wsjtx/flidigi sidetone
Executive summary:?? The pin change interrupts could/should implement Dit latch and Dah latch that should be processed before reading the state of the keys with key_poll.
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In modem.c we have cw_tx_get_sample which implements the keying code.? That is called from
modems.c by function mode_next_sample and that is called by
sbitx.c function tx_process and that by sound_process in the same file.? Sound process is called from
sbitx_sound.c? in a function that ID's as the main processing loop.? This function processes blocks of audio of 1024 in size.
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Although the functions are called 96000 times a second they are called in blocks? separated by 10.667 ms in time.? So in reality the keyer code is "run" every 10ms.
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I could be wrong with some of the above but it should be close to how it works.??
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Doing some of the math of 1200/wpm to find timing in milliseconds,? I think 30 wpm would not work well but 20 wpm should be ok.???? I am not sure if one can press and release a paddle in 10ms in order to miss sending a dit.?
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But the pin change interrupts that actually read the paddles are asynchronous? to all of the above.? And if they latch key closures a dit will not be lost if one can close and open a paddle in 10ms.
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I don't have a zbitx or a sbitx so I can't really go any further will this.
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Re: Homebrew satellite control system that can run on sBitx
Gordon,?
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Just in case test the rx on the lower portion of the 70cm xverter band. Closer to 432mhz. The ones I have are not very broad banded. So maybe you have to adjust the transverter bandpass closer to the 435mhz.?
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The preamp is a great idea. I use around 15db on my 144mhz transverter setup.
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Great work on the k3ng rotator!!! Keep up the great work.
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Juan WP3DN
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Re: Help needed identifying board
On 4/14/2025 21:08, Tom Sevart via groups.io wrote: OK, thanks.? Yes, there is an S-meter installed in the front panel. I'll give a more careful listen to see if there's an audio difference between the switch positions.? So far I can't tell much of a difference. ?But now that I know what I'm looking for I might be able to determine it.
I don't notice much of a difference in the audio, but when the switch is up, which I'm assuming is the fast position, the meter needle drops faster than it does in the down position. I may remove the switch, jumper the pin in the fast position, and use the spot where the switch is for a CW keyer speed control. -- Tom Sevart N2UHC -- This email has been checked for viruses by Avast antivirus software. www.avast.com
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What? is the password for the zBitx Pi OS?
When I try to install a .deb file, I am asked for a 'user name'
which is filled in as 'Pi'.
What is the password I should use?
Thank you.? Don in Austin, N5CID
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Re: Help needed identifying board
On 4/14/2025 20:08, Evan Hand via groups.io wrote: Hello Tom.
That is an AmateurRadioKits.in AGC board. ?The switch is used to select fast or slow AGC.
Look on the web for the manual that explains how to hook it up. ?There is minimal documentation other than that manual. ?I assume there is a S- Meter connected to it as that is needed to complete setup.
73
Evan
AC9TU OK, thanks. Yes, there is an S-meter installed in the front panel. I'll give a more careful listen to see if there's an audio difference between the switch positions. So far I can't tell much of a difference. But now that I know what I'm looking for I might be able to determine it. -- Tom Sevart N2UHC -- This email has been checked for viruses by Avast antivirus software. www.avast.com
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Jens/HB9JOI
Joel Caulkins/N6ALT
HA3HZ
Shirley Dulcey KE1L