Date   

Spare 16x2 display

Kit Peters
 

I have a spare 16x2 display (the replacement Raduino I got from KF4FTR came with a 4 line display) sitting around. What could I do with it in the context of my uBITX?

--
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Simple UBITX Test Set

Scott McDonald
 

Jerry,

You're right, I think, a simple cheap standardized UBitx test set would really be a great tool, not just for a Ubitx but for anyone starting out without any RF test equipment.

I started down that road for a club talk last year and built a single 2N3904 oscillator with a color burst crystal that gave signals in or very close to all the HF bands except 60 meters.  

By juggling a few values I was getting reliable output on all those freqs at -20 dBm plus or minus probably 5 dBm, and this was reproduceable with 5 different color burst crystals (tho from the same batch).  Not enough to drive a diode ring mixer but otherwise pretty useful and consistent, I think close enough that you could count on the output being what you expected without measuring it.  

As an option adding a buffer with another 2N3904 would make it more useful, or maybe just use one of Diz's inexpensive new SMT HF amp kits instead of reinventing the wheel.

Added an IF crystal from Kits and Parts (it was for a V3) with a cap and coil to fudge it a bit and got a useful IF signal at the same level. 

Added a couple 50 dB Pi attenuators to give a choice of 50 over 9, S9 and a few tenths of a microvolt for signal level.  Standard resistors used that way yielded decent attenuators plus or minus 3 or 4 dB.

Did it on a piece of perf board using 0.1 inch headers and jumpers to switch crystals and attenuators so there were no switches or other hardware needed.

It was dirt cheap and pretty handy, adding the diode detector would be simple, and the attenuators possible useful with that, same for adding an audio generator.  That's got to be a 10 dollar or less project with bulk parts purchases.

It would make a great first build project too.  

If I had any board skills I would make a board and put in Osh Park... :)  But if anyone with some skills wants to collaborate on it, I'd be happy to get together, as I expect people troubleshooting with a known test kit would make the great advice you, Evan, Allison and others give on here even quicker and more powerful.  

73 Scott ka9p


-----Original Message-----
From: Jerry Gaffke via groups.io <jgaffke@...>
To: BITX20@groups.io
Sent: Sun, Oct 25, 2020 10:50 am
Subject: Re: [BITX20] My son's V6

The primary selling point of the uBitx is its simplicity,
would be good to keep it that way.
The circuit improvements moving from V4 to V5 are a major win,
badly needed and no significant added complexity.

Though I would have kept the +12V for the IRF510's separate, much safer to 
debug all but the final amp of the transmitter with those IRF510's disabled.
And allows flexibility in setting the output power by adjusting the IRF510 supply voltage.
A simple way to adjust RF gain would be good.

Moving from the V5 16x2 LCD to the V6 TFT display adds lots of overhead
to the Nano's firmware.  I'd prefer the uBitx had kept the 16x2, at least as an option. 

An SWR meter and antenna tuner with a suitable dummy load for the uBitx 
might be a good accessory.  Audio and RF signal generators, a diode RF probe
(or AD8307), complete instructions to debug the rig, those would be most welcome.   
Perhaps make them all part of a single accessory?  An audio CW filter too?

Jerry, KE7ER


On Sat, Oct 24, 2020 at 05:49 PM, Bob Lunsford wrote:
Using a tuner on an antenna that is designed/dedicated to a specific band or frequency would theoretically funnel the signal to that specific frequency but it would also, theoretically, suppress received signals up and down frequency from the tuner's settings. Since it is also a good approach to getting as much power as possible from a QRP radio to the antenna by allowing the transmitter's output stage to see a much better load and lessen the complications of a mismatch, it would/should be an automatic part of the system unless weight or system complexity are concerns. It is undoubtedly a prime candidate for experimentation to see if a tuner does indeed reduce the influence of a high powered transmitter either nearby in frequency or location.
 
Thanks, Curt, for your feedback on this. Sometimes a simple solution may be best even if not a complete solution. I agree that AGC may be nice but it is not always the best or necessary. For example, on my G90 if you turn off the AGC it reveals many weak stations and even if some others come booming in, it's a small price to pay to guarantee that all stations on the [net] frequency are heard. Unless it is truly excessive in volume, of course, and this is "in the ear of the hearer."
 
Bob — KK5R


Re: Low audio output #v5

Gerard
 

see the end of this topic
https://groups.io/g/BITX20/topic/77426301?p=,,,20,0,0,0::recentpostdate,,,20,2,20,0&allview=1
I had one amplifier
I have big sound now
cdt


Re: Electronic encoder (Not rotary)

Gerard
 

Evan,
Results of the tests:
The noise remains even after disconnecting the connection and its cables of nextion
Noise still exists, but less loud if I remove the module SI5153 (For me the continuous program to turn blind)
We can clearly see that the crude corresponds when sending data (Pulses) from the arduino (leg no 26 or 27 corresponding to the TX) don't remeber
I tried to put the jumpers resistors on the legs 26, 27 >> No improvement, same if I add a small capacitor.
but it is not the same type of mounting that I had done on the encoder (review the diagram)
Pulses come at the amplifier input. Weak and drowned in background noise.
You can see them better if the oscillo is connected without ground!! back to the ground of electrical connexion 220V?

And as already said, if I connect electrical ground on power ground, you ear 50HTZ.
So for me, the signal must interfere with lines on the copper, or there’s a mass loop, not obvious to find.
I spent my afternoon on this, so I’ll look again later
cdt


Re: Low audio output #v5

Evan Hand
 

I would verify that the speaker is 8ohms and not 4.  If that is an AmateurRadioKits speaker, then I would look into an audio amp.  That is what I had to do for my v5 that I put into a 3.5" case.  Luckily it came with an audio amp.  That made a big difference AFTER I nocked the gain of the LM386 internal to the yBITX down to 20 (Pop out pins 1 and 8).  Any 1 wat or better audio amp module on Amazon or eBay would work.

The other option is to use a more efficient speaker.  I need to run now so do not have time to look up what I bought.  It was on a recommendation on this site.

73
Evan
AC9TU


Low audio output #v5

Praba Karan
 

I have noted very low audio in my ubitxv5 even at high volume. Refer attached recording taken at high volume. Sensitivity is ok.
Any troubleshooting advices?


Re: My son's V6

Jerry Gaffke
 

The primary selling point of the uBitx is its simplicity,
would be good to keep it that way.
The circuit improvements moving from V4 to V5 are a major win,
badly needed and no significant added complexity.

Though I would have kept the +12V for the IRF510's separate, much safer to 
debug all but the final amp of the transmitter with those IRF510's disabled.
And allows flexibility in setting the output power by adjusting the IRF510 supply voltage.
A simple way to adjust RF gain would be good.

Moving from the V5 16x2 LCD to the V6 TFT display adds lots of overhead
to the Nano's firmware.  I'd prefer the uBitx had kept the 16x2, at least as an option. 

An SWR meter and antenna tuner with a suitable dummy load for the uBitx 
might be a good accessory.  Audio and RF signal generators, a diode RF probe
(or AD8307), complete instructions to debug the rig, those would be most welcome.   
Perhaps make them all part of a single accessory?  An audio CW filter too?

Jerry, KE7ER


On Sat, Oct 24, 2020 at 05:49 PM, Bob Lunsford wrote:
Using a tuner on an antenna that is designed/dedicated to a specific band or frequency would theoretically funnel the signal to that specific frequency but it would also, theoretically, suppress received signals up and down frequency from the tuner's settings. Since it is also a good approach to getting as much power as possible from a QRP radio to the antenna by allowing the transmitter's output stage to see a much better load and lessen the complications of a mismatch, it would/should be an automatic part of the system unless weight or system complexity are concerns. It is undoubtedly a prime candidate for experimentation to see if a tuner does indeed reduce the influence of a high powered transmitter either nearby in frequency or location.
 
Thanks, Curt, for your feedback on this. Sometimes a simple solution may be best even if not a complete solution. I agree that AGC may be nice but it is not always the best or necessary. For example, on my G90 if you turn off the AGC it reveals many weak stations and even if some others come booming in, it's a small price to pay to guarantee that all stations on the [net] frequency are heard. Unless it is truly excessive in volume, of course, and this is "in the ear of the hearer."
 
Bob — KK5R


Re: Electronic encoder (Not rotary)

Evan Hand
 

Gerard,
I am out of suggestions on how to eliminate the clicks when the frequency changes. 

I still believe that it is coming from the Si5351 when the LO is being changed.  That could be in the runs from either of the I2C control lines, the lines to the Si5351, or the lines to the Nextion.  There is a lot of updates going on with the Nextion screen, so I doubt that it is that set of lines.  The Si5351 is changed only when there is a change in frequency or USB/LSB.  That seems to be more in line with what you are describing.

Let us know what you find.
73
Evan
AC9TU


Re: uBITX V4 assembly instructions? #v4

Evan Hand
 

Chuck,
The link that Mark has provided has clearer instruction than the original.  For comparison here is the original:
https://www.hfsignals.com/index.php/ubitx/
https://www.hfsignals.com/index.php/ubitx-wire-up/

One change that I would make on the instructions that Mark provided is to change the 5 amp fuse to another 2 amp fuse.  The mainboard will only draw 300 milliamps on its own, depending on an audio amp or other accessories added.

The other is how the protection diodes are wired.  I would move the banded end to after the fuse so that the fuse is blown instead of the diode.  Easier to replace the fuse, not the cost of the component issue.  This is especially the case if you power with a high amp supply like those in a lot of Ham shacks.

73
Evan
AC9TU


Re: Electronic encoder (Not rotary)

Gerard
 

I forgot to tell you, but I kept the same kind of connection, but obviously I changed the copper tracks accordingly. So the picture can be misleading. It’s a 5V just for the Nextion.
cdt


Re: Electronic encoder (Not rotary)

Gerard
 

Evan
The electrical connection for Nextion is powered by a separate regulator and only for it. (An other addon)
see red circle on picture
We don’t see the PCB other side, but there’s also the resistor, capacitor, self.
Like you can see here
https://ubitx.net/2019/08/03/nextion-noise-in-rx/

Eventually, the only error would be that I put the resistance on the regulator input (+12). Should it be moved to the regulator outlet? (+5v).  It seemed more logical to me like that. However, I should add a small radiator, because it is quite hot.
cdt


Re: Electronic encoder (Not rotary)

Evan Hand
 

Gerard,
You told me about the Si5351 module before, I had forgotten that until you pointed it out.  In looking up the module information I found that it has the pull-up resistors (10k) on the module.  You would not want to put another set of resistor pull-ups.  

You should not need pull-up resistors for the Nextion data lines.  The resistor that I was trying to describe is in the 5volt power lead from your board to the Nextion display.  On the v4 and v5 HFSignals boards, the Nextion was noisy when the dimmer was adjusted below 95%,  This is due to the PWM power reduction used to dime the backlight on the Nextion.  The 10-22 ohm resistor with the bypass capacitors kept the noise from back-feeding into the radio.  That resistor will also dim the Nextion display.

I will go back and look at the schematics you provided again.  By chance do you have the board layout to see if there might be something with how the board traces are run and where things are placed.

73
Evan
AC9TU


Re: Electronic encoder (Not rotary)

Gerard
 

Evan,

My Si5351 generator is a plug-in module. See exemple
Maybe the resistor are on it? the module diagram should be. If someone have it.
To check, in any case it would cost not to add the 2 resistors on the connections in question.

When I did the editing, I had looked at all the problems a bit and so I did the modifications for the connection (self, etc.)
There, it’s still very comfortable. only a light click as soon as a digit changes.

My idea was to see if it changed anything by doing the same assembly on the TX and RX lines of the Nextion to Arduino + evently lines SDA and SCL
module example:
https://www.amazon.com/Comimark-CJMCU-5351-Si5351A-Generator-Breakout/dp/B07X39J647/ref=sr_1_2?dchild=1&keywords=si5351&qid=1603614841&sr=8-2

cdt


Re: uBITX V4 assembly instructions? #v4

 

Hi Chuck,

There are instructions right here in the wiki section:

https://groups.io/g/BITX20/wiki/5696

Write back if you have any questions.


uBITX V4 assembly instructions? #v4

Chuck WB6GPO
 

My uBITX V4 has been sitting in the shipping box until now.  I no longer see the assembly instructions on the hfsignals web site.  Is there some way I can find them?

Thank you,

Chuck WB6GPO


Re: My son's V6

Bob Lunsford
 

Using a tuner on an antenna that is designed/dedicated to a specific band or frequency would theoretically funnel the signal to that specific frequency but it would also, theoretically, suppress received signals up and down frequency from the tuner's settings. Since it is also a good approach to getting as much power as possible from a QRP radio to the antenna by allowing the transmitter's output stage to see a much better load and lessen the complications of a mismatch, it would/should be an automatic part of the system unless weight or system complexity are concerns. It is undoubtedly a prime candidate for experimentation to see if a tuner does indeed reduce the influence of a high powered transmitter either nearby in frequency or location.

Thanks, Curt, for your feedback on this. Sometimes a simple solution may be best even if not a complete solution. I agree that AGC may be nice but it is not always the best or necessary. For example, on my G90 if you turn off the AGC it reveals many weak stations and even if some others come booming in, it's a small price to pay to guarantee that all stations on the [net] frequency are heard. Unless it is truly excessive in volume, of course, and this is "in the ear of the hearer."

Bob — KK5R

On Saturday, October 24, 2020, 8:07:04 PM EDT, Curt via groups.io <wb8yyy@...> wrote:


Bob

using an antenna tuner is a decent step to evaluate the overload issue - and at least one user reported success with this technique.  I would exercise the tuner to see if it can reject the overload.  if this is successful, the the challenge is tuning it for the band of interest - and seeing if it still has rejection. 

if a high pass filter is needed -- this video discusses solutions - and I see W8TEE has illustrated one as well.  I did not do a thorough search to see what solutions are around.

the matter of AGC is much more of a creature comfort - less critical.  I don't have monster sized antennas here - my ubitx does not overload from ham signals, and the VK3YE AGC does very well at suppressing the large ones.  I would not work too hard to implement AGC as its a small impact to the overall rig behavior. 

73 curt


Re: My son's V6

Curt
 

Bob

using an antenna tuner is a decent step to evaluate the overload issue - and at least one user reported success with this technique.  I would exercise the tuner to see if it can reject the overload.  if this is successful, the the challenge is tuning it for the band of interest - and seeing if it still has rejection. 

if a high pass filter is needed -- this video discusses solutions - and I see W8TEE has illustrated one as well.  I did not do a thorough search to see what solutions are around.

the matter of AGC is much more of a creature comfort - less critical.  I don't have monster sized antennas here - my ubitx does not overload from ham signals, and the VK3YE AGC does very well at suppressing the large ones.  I would not work too hard to implement AGC as its a small impact to the overall rig behavior. 

73 curt


Re: Electronic encoder (Not rotary)

Evan Hand
 

Gerard,
Jack is talking about the SDA and SCL lines to the Si5351a clock chip.  Here is the original Raduion schematic for reference:

Note R13 and R14 are pull up resistors on the SDA and SCL lines to the Si5351a chip.  They are missing on your schematic of the Raduino section (page 3).

73
Evan
AC9TU


Re: Electronic encoder (Not rotary)

Evan Hand
 

Gerard,
There are two places that adding a resistor and capacitor filter like this would help
https://groups.io/g/BITX20/message/30226
The first is in the 12volts feeding the Raduino, the second is in the 5volts feeding the Nextion display.  The 10 ohms also helps with any backlight display noise when the brightness is turned down on the Nextion.

I am glad that the capacitors and pull up resistors on the encoder helped with the tuning clicks.  That to me supports the idea that rapid frequency changes could have caused the clicks.  With the Nextion power filtering (the capacitors and resistor) that should reduce the frequency.  

Anyway, glad you found a solution.
73
Evan
AC9TU


Re: noise reductor / squelch ?

Gerard
 

hello,
All electronic schemas are welcome

cdt

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