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And of course the DE had relays….

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To answer your question: I have not looked at the earlier stages. However this radio passes on some bands but fails on others. ?

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I think I had no further problem with the DE when I was finished and I suspect that if I went back to it it would be even cleaner I haven’t gotten rid of the diode in the Heathkit Cantana?

pr maybe Gordon,

I have not seen others post this type of problem.? Even my DE has compliance with all bands.? I would suggest a component issue with one of the mixers that does not provide a symmetrical response that increases the 2nd harmonic.? Or maybe it is an issue with the driver.? Have you looked at the spectrum of the driver feeding the PA?? The driver is also a push-pull class AB amp.? An imbalance there would cause a signal to be amplified as if it is part of the base signal.??

73
Evan
AC9TU

Other DIODES to consider are the "pin" diodes 1N4007, and also the diodes in the SWR/power measuring circuit.
I don't know if the rf power supply 1n4148s are the problem, but the MFJ QSK unit uses DC 600 volts developed from the power supply of the amplifier to run it.... See:? ?

Just not sure where the harmonic energy is coming from....with the filters looking NICE.? ??
Of course, ANYTHING generated by the "antenna connector"-sided diode would have zero filtering....
Gordon KX4Z

What about the DIODES in the RF power supply that generates the HV to back bias the switching diodes?? ?They are connected through a 47pf to the main output of the amp.? ?could THEY be generating stronger harmonics???

I'm still very puzzled, even after fixing errors in my experimental setup (principally the DIODE in the Heathkit cantenna!)? that I still appear to have harmonics that are above the limits.? ?Even when using a commercial high power "pad" and no heathkit at all.? ??

I was concerned that the low pass filters might not be robust enough.? ? To study that theory, I realized that I could lift the power output wire from the big transformer of the final stage....and inject spectrum analyzer tracking generator (through a 6dB pad) right there at the beginning of the filter system.? ?I could read the output of the low pass filters by connecting (through a 6dB pad) the RF input of the Siglent spectrum analyzer to the output.? ?I set the DRIVE at 1, and mic gain at 0, and lower sideband on all bands.? ?There was no apparent signal that the spectrum analyzer saw before turning on the tracking generator.??

A schematic of my setup:


There could be a mistake that I'm not recognizing, so here is a PHOTO of my setup:


When I measured the frequency response of the filters, they looked very very effective.? ?Here is a table of the -1dB point, the 2nd harmonic point, the -24 db point, and the 3rd harmonic point.? ? Frequently at the tails my measurements were "in the noise" with my settings (approx 10kHz VBW and probably 20dB of internal attentuator -- it didn't dawn on me to adjust that)

BAND? ? ? -1db point? ? ? ?2nd H. Freq? ? -24 dB point? ? ?3rd H. freq
80 M? ? ? ? ? 5.4 MHz? ? ? ? ? -22dB? ? ? ? ? ? ~ 7.06MHz? ? ?~-60 dB
40M? ? ? ? ? 11.4 MHz? ? ? ? ? -21 dB? ? ? ? ? ~ 14.6 MHz? ? ?-51 dB
20M? ? ? ? ? ?16.4 MHz? ? ? ? -44dB? ? ? ? ? ? ?21.6 MHz? ? ? ? -57 dB
15M? ? ? ? ? ~3dB@...? ? ?-21 dB? ? ? ? ? ? ?43 MHz? ? ? ? ? -57 dB? ?(I had to change the Siglent to go to much higher frequencies to get this one measured)

Those look (to me) like rather impressive filtering!!!? ?When your 3rd harmonic frequency (as proxied by a tracking generator, tiny signal) is being attenuated by 50-60dB....how in the world can you end up with a signal stronger than -43dBc???

It appears to me that there are a few possibilities:
A)? The Siglent is measuring improperly when measuring the power from the sBitx.? ?(However, it sees a used ICOM 718 as completely clean)
B)? With full transmittter power,? something in my MEASUREMENT system is generating harmonics -- clearly I had some issues there, but now I'm able to make measurements using ONLY commercial pads.... and the Siglent....-- and besides, this didn't seem to happen with the Icom 718??
C)? With full transmitter power, something in the SBITX is generating harmonics.

Does anyone see why it wouldn't be (C)??? ?Am I missing something?? ? ?Maybe I'm doing something stupid again???

Here are photos captured as I mapped out the various filters - they look very impressive to me.
Gordon Gibby KX4Z

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Noel - I am in Winnipeg Manitoba, Canada.? I have placed a few orders.? All have been shipped by DHL.? I have seen times as short as 50 hours from India to my apartment door,? and as long as about double that.? I imagine your time would be about the same.? Maybe DHL has a fleet of cargo rockets, hi,hi.

Gerry Sherman

Sent by the Windows 11 Thunderbird

Visual Studio (VS) code has a Microsoft extension, Remote-SSH, that allows you to run VS Code on one computer and do the software development on another over SSH. This works with the Raspberry Pi (sBitx) as the remote computer. This allows you to run VS Code on a more powerful computer with a larger screen (without having to connect a HDMI display to the sBitx.

This creates an environment where I edit the code on my PC or Mac (where I have a 4K monitor), but still build and run it on the sBitx. Intellisense code highlighting and git version control work, including integration to my repo on GitHub.

--
73,
Mark, N8ME

You are correct Bullseye is now the legacy version. My question is how to get Buster (the previous legacy version). My understanding is that sBitx requires Buster.
--
73,
Mark, N8ME

Hi!?

im thinking of purchasing one of the sBitX transceivers. I have a question: are they shipped by DHL or someone else and how long do they usually take to arrive in the East Coast of the USA.

TY!
Noel, W1NCR

The download is up to you.
Anyone can download it if you know the link and have a downloader that can continue to download after interruption.
The link is a drive.google link available.
Next to the device, you received a note on measurement results in the box.
So since May you have received this, who ordered a complete device.
You only not received a CR2032 battery because it is not accepted by the supplier (hazardous substance).
If you have a complete device, it must also include the SD Card.
I bought it without RPi, and I got the SD Card in a separate bag.
Look at the box. You may have fallen out and you will find it below.
--
Gyula HA3HZ

Bullseye is available on the Raspberry Pi website and Imager app:

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I have notified hf dignal support ?of the inability to download ( nothing via mac and a windows pc).?

I figured it out. I had cloned the repo into /home/pi/Docuements. It needs to be cloned into /home/pi.? As a suggestion, could the code look for supporting files relative to where the sbitx file is located?
--
73,
Mark, N8ME

link with the latest version:?
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Gyula HA3HZ

I understand now. You need to send a message to the seller's support@... address, the solution is there.
If you want to download the nearly 3GB file, you can only do so with a browser or download manager that is capable of continuing the interrupted download.
For example, I use IDM integrated in the browser.
But there are several options.
Depending on the operating system, you then unzip this 3GB file and copy it to the SD card as an image.
Since 32GB turns out to be small in many cases, it is advisable to copy it to a 64GB and high-quality card.
I hope this helps.
--
Gyula HA3HZ

I was using an older install.txt file that didn't have the iptables instructions. I added the iptables commands found in the install.txt cloned from the repo. Now, I do connect to sbitx.local (port 80), but it's still just giving me the directory page. This is both on the RPi touch screen and if I try to connect with a web browser from another computer.

The command ./build sbitx completes without error and the old-style radio display on the RPi touch screen seems to launch and work just fine. It's just that when it lauches the web browser, it comes up with the directory. It's like it's not finding the directory with the HTML code.

I cloned the repo into the Pi's ~/Documents folder so the source code is in /home/pi/Documents/sbitx is that right or does it matter?
--
73,
Mark, N8ME

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KF0ARU. ?I bought a finished unit. Not a kit

Carl
do you have a call sign
Can you tell me what you bought?
complete device or boxed device without RPi or an assembled panel?
You are raging here on the net, while ignoring any helper.
If you want to download the contents of the SD card, the iPad is not enough for that, I'm just telling you.
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Gyula HA3HZ