Stefan,
I would use a spectrum analyzer like the TinySA Ultra with the appropriate attenuators.? You need a minimum RBW of 200Hz to see the distinctions in the tones.
An alternative would be to use a PC audio spectrum analyzer sourced from the R56/Q6 junction.? Here, you should see two clear tones around 12kHz.? Most PC-based audio analyzers should be able to go up to 24kHz.? You will need to build a probe to isolate the DC components.? A 1uF or greater capacitor should work.
73
Evan
AC9TU
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Ok. So after a lot of reading it seems that the best way to check my modulation on a HF signal is to build a RF Tap / Sampler device first and use its output with a scope. Then I should see if my 2Tone signal is ok. It's a rabbit hole. :-)
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I use a 4gig.. If you use digital wsjtx etc and other pms like grid tracker.. More memory makes run smoother. If the price was right I would put an 8gig, even though it is overkill.
You can use any good quality microsd card I use sandisk 32gig but there many other good ones. Also choose the high speed versions. The make your loading much better.
Joe VE1BWV?
On Wed, Oct 18, 2023, 12:46 p.m. carl schlueter via <kf0aru= [email protected]> wrote: I’ve got 5 V going into the RPI. But nothing is being displayed ?so I’m pretty sure the main board is OK. Is the SD card unique to the RPI/Main board? HF signals is indicating that is the case. They said I got a new SD card which I did not get hopefully that’s all it is
?
If I had to replace the RPI I know it’s a version 4 Is there a sub model like a B?? How many gigs would you go
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I’ve got 5 V going into the RPI. But nothing is being displayed ?so I’m pretty sure the main board is OK. Is the SD card unique to the RPI/Main board? HF signals is indicating that is the case. They said I got a new SD card which I did not get hopefully that’s all it is
?
If I had to replace the RPI I know it’s a version 4 Is there a sub model like a B? ?How many gigs would you go
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Re: Set frequency alignment
Roland, That diagram has been wrong for a long time.? I used it at first to explain the sideband reversal when I was corrected by one of the original contributors to the BITX40 and later the uBitx.? Many people are using the original software without the modifications.? If there has been a sideband reversal, it is most likely the BFO is set above the SSB filter midpoint and reverses the sideband in the demodulator stage. I have found that some of the documents for the BiTx series of transceivers have errors.? I try to verify with theory or inspection (of the circuit or code) to verify the information.? I had asked it to be corrected in the past.? The comments in the original v6 code agree with my prior post:
/**
?* The uBITX is an upconnversion transceiver. The first IF is at 45 MHz.
?* The first IF frequency is not exactly at 45 Mhz but about 5 khz lower,
?* this shift is due to the loading on the 45 Mhz crystal filter by the matching
?* L-network used on it's either sides.
?* The first oscillator works between 48 Mhz and 75 MHz. The signal is subtracted
?* from the first oscillator to arriive at 45 Mhz IF. Thus, it is inverted : LSB becomes USB
?* and USB becomes LSB.
?* The second IF of 11.059 Mhz has a ladder crystal filter. If a second oscillator is used at
?* 56 Mhz (appox), the signal is subtracted FROM the oscillator, inverting a second time, and arrives
?* at the 11.059 Mhz ladder filter thus doouble inversion, keeps the sidebands as they originally were.
?* If the second oscillator is at 33 Mhz, the oscilaltor is subtracated from the signal,
?* thus keeping the signal's sidebands inverted. The USB will become LSB.
?* We use this technique to switch sidebands. This is to avoid placing the lsbCarrier close to
?* 11 MHz where its fifth harmonic beats with the arduino's 16 Mhz oscillator's fourth harmonic
?*/
The one difference is the reason for the BFO frequency selection. 73 Evan AC9TU
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Re: Set frequency alignment
Hi Evan,? I noticed the sidebands being reversed in the stock firmware myself when I made my own version of the firmware, and changed it in my version, then injected a carrier in the sidebands to verify.
I recently helped another person on this group who was experiencing the same problem with the N8ME software.? I made a mod to one N8ME file to swap the clk 1 frequencies and he tried it and said that it fixed the problem for him.??
The block diagram here () says that clk 1 should be at the lower frequency for USB.??
I'm not sure if there could be some other adjustment issue that might contribute to this or not.? ?I need to sit down and try to logic through the whole chain to see if I can figure anything out.
Or maybe you can see something and let us know.
73,
Rolan
N8LOV
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RF may be getting into your scope probe
I would try to listen at low RF power, with another receiver or with a nearby web SDR?
I don’t have the schematic right in front of me but when I do I’ll try to get back to you.? Gordon
toggle quoted message
Show quoted text
On Oct 18, 2023, at 05:00, Stefan Beck via groups.io <puncher_gallops0x@...> wrote:
?On Mon, Oct 16, 2023 at 03:01 PM, Gordon Gibby wrote:
try listening to the 2-tone and verify that it sounds correct.? ?That would allow you to diagnose it has having something to do with the microphone end alone.? ?Possible RF getting into the mic?? ?Above a certain value, there is distortion in the mic gain;? ?I run mine at 30 max, I think
Hi Gordon, what is a good spot to pick up the modulation signal on the board with a scope. Even the 2-tone modulation seems distorted at R56 / Q6
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On Mon, Oct 16, 2023 at 03:01 PM, Gordon Gibby wrote:
try listening to the 2-tone and verify that it sounds correct.? ?That would allow you to diagnose it has having something to do with the microphone end alone.? ?Possible RF getting into the mic?? ?Above a certain value, there is distortion in the mic gain;? ?I run mine at 30 max, I think
Hi Gordon, what is a good spot to pick up the modulation signal on the board with a scope. Even the 2-tone modulation seems distorted at R56 / Q6
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Addendum. Sbitx v2. Board # 0409
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Just got my new board yesterday install it today double checked all connections. I had taken pictures of the old before so I had good references back. Hooked everything up turn the power on and nothing. ?no display. When I turn off I hear slight noise so I know there’s power in the circuit
could it be a bad Sim in the RPi? ? corrupted possibly??
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Re: Si5351 PLL Loss of Lock detect via Reg 1 sticky register.
Gary,
It sounds like you have hit on something that might be very helpful to quite a few folks. (I am one of many who have a jittery si5351, which started during Nextion display modification on uBitxV6.) The coding that you describe is somewhat above me, at the moment. But perhaps someone will pursue it.
From what I have read, so far, the cure has been to replace the si5351 or the Raduino. If the si5351 is not responsive, because it has forgotten its address, perhaps there is some way to reset it? I'll be watching this thread.
Thanks for your insight.
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Re: Set frequency alignment
Andrea,
As I understand mixer operation, the signal that has the lower frequency is inverted.? If that holds true, the first IF inverts to LSB, and then the second IF would invert again if the LO is above 45 MHz.? If it is below, the signal is not inverted.? The BFO LO is set below the 11.059 MHz crystal filter to take advantage of the steeper slope on the upper edge.? That would mean that any signal remains the same sideband.? ?Assuming all before is correct, you should measure approximately 56MHz for USB and 33MHz for LSB, as you have.
73
Evan
AC9TU
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Si5351 PLL Loss of Lock detect via Reg 1 sticky register.
There have been reported issues of possible loss of PLL Lock on some Si5351s after attempts to convert to Nextion screen.
I wrote a simple diagnostic aid for troubleshooting Si5351 without the need of additional instrumentation.?
?
The Si5351 register list can be found in AN619.? Reg1 (Interrupt Status Sticky) description on page 15
https://www.skyworksinc.com/-/media/Skyworks/SL/documents/public/application-notes/AN619.pdf
?
Reg 1 gives us access to see if an interrupt had been taken due to PLL Loss of Lock, Crystal loss, Clk In loss etc from the viewpoint of the Si5351 since the last time it was zero'd.
?
I have what I believe to be a correctly working Si5351.? After power up, I read:
R1:0xF8
Then I Zero Reg 1 and I get repeated reads of
R1:0x10
Which indicates a CLKIN loss.?
That could fork into discussions of same die for all 3 variants?
I haven't put in any thought or reading into possible effects of this interrupt being set when the part should not be in a CLKIN mode.?
It's a curious rabbit hole, but no time to explore at the moment.
I do not have a misbehaving (high jitter) Si5351 to test, but some here do.
?
I'm using Reed's firmware as my base.? Not much program memory space available, even less with my previous modifications.
So a simple hack, that should be easily adapted to any version of firmware. Below are the code snippets for the diagnostic, I hope that it may be helpful or spark more ideas / discussion. Rgds, Gary
to si5351.cpp I added an i2cRead function
?
//AG5TX to read registers
uint8_t i2cRead(uint8_t reg) {? ?// read reg via i2c
? Wire.beginTransmission(SI5351BX_ADDR);
? Wire.write(reg);
? Wire.endTransmission(false);
? Wire.requestFrom(SI5351BX_ADDR, 1);
? uint8_t value = Wire.read();
? Wire.endTransmission();
? return(value);
}
?
then made this function as well as the existing read function available by adding the following lines in si5351.h
// AG5TX
void i2cWrite(uint8_t reg, uint8_t val);
uint8_t i2cRead(uint8_t reg);
?
I wholesale replaced ubitx_cat.cpp with?
?
#include <Arduino.h>
#include "si5351.h"
?
void checkCAT(){
? ? char buffer[11];
? ? int eos;
? ? uint8_t reg_val;
?
? ? while (Serial.available() > 0) {
? ? ? ? eos = Serial.readBytesUntil('\n', buffer, 10);
? ? ? ? buffer[eos] = '\0';
? ? ??
? ? ? ? if(!strncmp(buffer,"z1",11)) {
? ? ? ? ? Serial.println("Z1");
? ? ? ? ? i2cWrite(1,0);
? ? ? ? }
? ? ? ? else if(!strncmp(buffer,"r1",11)) {
? ? ? ? ? Serial.print("R1:0x");
? ? ? ? ? reg_val = i2cRead(1);
? ? ? ? ? Serial.println(reg_val,HEX);
? ? ? ? }
?
? ? }
}
?
?
?
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Re: Set frequency alignment
Hi Evan,?
you're right, you remember well about the bug.? When switching LSB/USB it is necessary to move up or down a little and clk#1 switches.? But I saw that the display command is reversed.? If I choose USB I should have 33,994.48 Khz while I have 56,000.50 KHz and vice versa.? Probably another bug.? Just let him know and move on.? Now I'll move on to the BFO.? I will brutally put in front of the Mike a bf generator with the frequencies of 300 + 2700 Hz, and I will see the RF signal via PC and sdr-rtl + hf converter.? Then I will generate a bf of 1 KHz and calibrate according to what I read on sdrsharp.? Obviously everything will be done after calibrating the receiver with the GPSCO signal.? The adventure continues.
73, de IK0XBC Andrea?
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Re: Set frequency alignment
Hi Biju, what you suggest is used with CEC software.?
Thank you.
73, de IK0XBC Andrea?
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Re: Set frequency alignment
In case of the adjustment not store on memory on ubitx through PTT press, then use bitx manager software to make the changes and upload.? Thanks de VU2TDD BIJU A P?
Hi,?
My ubitx v6.1 don't memorize the setup of frequency alignment. I have the rtx sintonized at 10000 KHz, USB CW, tone 1 KHz, on artifical dummy load and read the frequency out put of 10002.1 KHz. In LSB Cw read 10000.1. In setup frequency alignment I set - 2000 Hz and press the button. Then I switch off and then on. Nothing to do, the frequencies are the same. I have do also the pressing of Ptt, anything change. Where I am wroughting.
73, de IK0XBC Andrea?
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Re: Set frequency alignment
Andrea,
Did you follow the readme instructions?
I believe that you are not in the correct folder/directory per the instructions.
I know of a bug in the stock software that requires changing the frequency slightly to change sidebands.? I would try that.
73
Evan
AC9TU
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Re: Set frequency alignment
Hi Evan,?
I applied the correction factor 1Hz=875 on the display, therefore 165050. Now the Main Clock (Clk#2) is aligned at 55 MHz and verified with a frequency meter calibrated with GPSDO.
I continued with the work, and I realized that Clk#1 did not vary with the lsb/usb command. It remained at 56.050 MHz.
At this point I took Farhan's V6.3.1 sketch and tried to compile it with Arduino IDE V1.8.19.
A series of error messages.
Attached is the pdf file with the reported errors.
I would ask you and the other users of the Group who read us, where to correct the source to have a correct compilation.
Thanks to all.
73, de IK0XBC - Andrea - Roma - Italy
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I had some distortion when I got mine.??I put a couple of torrids on the mic cable and it went away.??RF must have been getting in through the cable
On Oct 16, 2023, 9:01 AM -0400, Gordon Gibby <docvacuumtubes@...>, wrote:
try listening to the 2-tone and verify that it sounds correct.? ?That would allow you to diagnose it has having something to do with the microphone end alone.? ?Possible RF getting into the mic?? ?Above a certain value, there is distortion in the mic gain;? ?I run mine at 30 max, I think.? ??
I lost the original mic and had to make my own.? ? The audio on my DE version has been excellent, and I think it is the same on the V2.? ??
However, I had to use a mic cartridge with -24 dB SPL type response!
Let us know what? you find!
Gordon KX4Z
On Mon, Oct 16, 2023 at 8:25?AM Stefan Beck via <puncher_gallops0x= [email protected]> wrote: Hi.
I testet TX today for the first time on my #sbitx_v2 and I can't get a decent modulation on USB/LSB on any band. I tried all kinds of combination of mic / comp settings and the modulated signal is always very weak, distorted and crushed. It sounds like a bit crusher effect and is not usable. With mic settings above 50 I get some kind of digital background noise feedback.
Has anyone else experienced this kind of behaviour and has a solution for it??
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try listening to the 2-tone and verify that it sounds correct.? ?That would allow you to diagnose it has having something to do with the microphone end alone.? ?Possible RF getting into the mic?? ?Above a certain value, there is distortion in the mic gain;? ?I run mine at 30 max, I think.? ?? I lost the original mic and had to make my own.? ? The audio on my DE version has been excellent, and I think it is the same on the V2.? ?? However, I had to use a mic cartridge with -24 dB SPL type response!
Let us know what? you find!
Gordon KX4Z
On Mon, Oct 16, 2023 at 8:25?AM Stefan Beck via <puncher_gallops0x= [email protected]> wrote: Hi.
I testet TX today for the first time on my #sbitx_v2 and I can't get a decent modulation on USB/LSB on any band. I tried all kinds of combination of mic / comp settings and the modulated signal is always very weak, distorted and crushed. It sounds like a bit crusher effect and is not usable. With mic settings above 50 I get some kind of digital background noise feedback.
Has anyone else experienced this kind of behaviour and has a solution for it??
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Stefan Beck
IK0XBC
Biju Apkrcl