Date   
Re: uBitX CAT problem on 40m #ubitx #ubitx-help #ft8

bill richardson
 

Sorry Dave was using a ubitx also.. 


On Jul 20, 2018, at 9:49 AM, bill richardson <ng1p.bill@...> wrote:

I have the same issue with both of my uBitx’s only on 40 meters. Last weekend I was at Lobstercon and Dave kd1na on his bitx40 also suffered from RF getting into his but again just on 40 meters. The two I have and Dave’s are v3 boards. Also I will add that both mine are shielded and Dave’s has his in a metal case. I have found using a different antenna helps.. ie using a end-fed it will always suffer from RF getting into the mic audio, using a dipole normally no issues as long as it’s at least 50 feet away. My 80 meter loop also works well. Using my 160m doublet will cause the issue. 40 meters again is the only band this happens on. 


On Jul 20, 2018, at 9:27 AM, R. E. Klaus via Groups.Io <reklaus@...> wrote:

I had the same issue with my Yeasu when I first started using Fldigi. I put snap on Ferrites on the audio leads and wound the control cable about 6 turns around a ferrite toroid and that solved the issue for me.

Re: I think this will work for the Ubitx...microphone

Kevin Rea
 

My screws were all Phillips on the one that I have.


On Fri, Jul 20, 2018, 7:45 AM <george.woods@...> wrote:
Hi Kevin,
What tool removes the screws holding the Baofeng microphone together? My small Phillips screwdriver doesn't work on it. 
Thanks, George, k1DX

Re: calibrate v4 ubitx

Jerry Gaffke
 

No, adjusting the BFO frequency is a bad idea.
That will change the audio characteristics on both transmit and receive.
And it will only "calibrate" the rig when operating at the frequency of the reference oscillator you happen to be using.

The si5351's reference oscillator is nominally 25mhz, but might be off by several ppm.
When using the si5351bx routines, the vco inside the si5351 is operating at a nominal frequency of 35*25mhz = 875 mhz.
The value of the variable si5351bx_vcoa has a nominal value of 875000000, what we want to do is adjust that value
until it is exactly equal to the true vco frequency.

So one way to do this is to measure the 25mhz oscillator of the si5351 reference,
perhaps using a separate well calibrated receiver instead of a frequency counter to avoid loading that crystal.
Let's call that value fxtal25mhz.
Then force si5351bx_vcoa to be equal to  35*fxtal25mhz.

Now the si5351bx routines use this new si5351bx_vcoa value when computing the output divider values
used to create clk0, clk1, and clk2.  All three should be dead on.

We need to calibrate all three clocks simultaneously, not just the BFO.
 
Was more complicated on the Bitx40, where we had a separate crystal oscillator for the BFO.
On the uBitx, we only have one reference oscillator.


An easy way to calibrate using a 50mhz reference might be to divide it by two using a flip-flop,
and calibrate using the resultant 25mhz signal using whatever calibration software is in
the firmware you are using.   I have not looked over the various firmware releases, but 
given some of the forum posts my impression is that is is not being done right.

Jerry, KE7ER


On Fri, Jul 20, 2018 at 07:11 AM, Joel Caulkins wrote:
I agree that calibration is a 'exercise', why does it need to be this hard. I'm no coder, but Don ND6T's calibration routine worked really good for me when I was calibrating my Bitx 60, http://www.nd6t.com/bitx/Calibration.htm  All we need to know is what our actual 25Mhz crystal frequency is and change that line in the sketch, then all we need to adjust is the BFO frequency which is easy when the rig is on frequency. I don't know how to code so I'm not sure what is involved in adding something like this to the existing sketch but it sure beats zero beating.

Re: (Some) Nextion Displays not working

Björn Pasteuning
 

Ok I have found the issue.

Due the fact I have used the nextion for previous projects, the fixed baudrate in them was changed.

I have fixed that by placing the command  "bauds=9600" on page 0 in the Preinitialize Event panel.

Tip!, Every Designer should place this in their code. to besure the nextion will always work with new and used nextions

--
73' Björn de PD5DJ
www.pd5dj.nl

Re: calibrate v4 ubitx

Jerry Gaffke
 

Don's method assumes you have an accurate frequency counter,
most uBitx users don't have one
There is no reason we can't calibrate this rig accurately using an off-the-air signal such as WWV
or an AM shortwave broadcast station.


On Fri, Jul 20, 2018 at 07:11 AM, Joel Caulkins wrote:
Don ND6T's calibration routine worked really good for me when I was calibrating my Bitx 60, http://www.nd6t.com/bitx/Calibration.htm

Re: calibrate v4 ubitx

 

Jerry,

You are right, I did use my calibrated HP 5384A frequency counter to determine the crystal frequency. I had forgot that. I found calibrating the hardest part of building my last uBitx transceiver, it just seems like it should be easier, but what do I know, I'm strictly a hardware man. I'm all for using WWV when the bands are good enough to actually hear it.

Joel
N6ALT

Re: calibrate v4 ubitx

Jim Sheldon
 

Jerry,
Regarding the BFO, after the master oscillator is calibrated to an accurate frequency, the BFO MUST be calibrated to the individual uBITX crystal filter as no two of them are exactly the same.  Such is the nature of filters built using bulk crystals, matched or not.  Matching them is never an exact science as I've been finding out here trying to match crystals to come up with an add-on, plug-in crystal filter using the headers supplied on a V4 board.  The BFO also cannot be adjusted to zero beat or you lose the ability of the filter to separate USB and LSB as well as CWU and CWL signals to give you what us ancient CW operators used to call "Single Signal" CW receive.  

So far I have not found an easy way to do this except trial and error "guesstimation".  I'm seriously hoping someone can come up with a really simple way to get this right.

Jim Sheldon, W0EB

------ Original Message ------
From: "Jerry Gaffke via Groups.Io" <jgaffke@...>
Sent: 7/20/2018 10:03:10 AM
Subject: Re: [BITX20] calibrate v4 ubitx

No, adjusting the BFO frequency is a bad idea.
That will change the audio characteristics on both transmit and receive.
And it will only "calibrate" the rig when operating at the frequency of the reference oscillator you happen to be using.

The si5351's reference oscillator is nominally 25mhz, but might be off by several ppm.
When using the si5351bx routines, the vco inside the si5351 is operating at a nominal frequency of 35*25mhz = 875 mhz.
The value of the variable si5351bx_vcoa has a nominal value of 875000000, what we want to do is adjust that value
until it is exactly equal to the true vco frequency.

So one way to do this is to measure the 25mhz oscillator of the si5351 reference,
perhaps using a separate well calibrated receiver instead of a frequency counter to avoid loading that crystal.
Let's call that value fxtal25mhz.
Then force si5351bx_vcoa to be equal to  35*fxtal25mhz.

Now the si5351bx routines use this new si5351bx_vcoa value when computing the output divider values
used to create clk0, clk1, and clk2.  All three should be dead on.

We need to calibrate all three clocks simultaneously, not just the BFO.
 
Was more complicated on the Bitx40, where we had a separate crystal oscillator for the BFO.
On the uBitx, we only have one reference oscillator.


An easy way to calibrate using a 50mhz reference might be to divide it by two using a flip-flop,
and calibrate using the resultant 25mhz signal using whatever calibration software is in
the firmware you are using.   I have not looked over the various firmware releases, but 
given some of the forum posts my impression is that is is not being done right.

Jerry, KE7ER


On Fri, Jul 20, 2018 at 07:11 AM, Joel Caulkins wrote:
I agree that calibration is a 'exercise', why does it need to be this hard. I'm no coder, but Don ND6T's calibration routine worked really good for me when I was calibrating my Bitx 60, http://www.nd6t.com/bitx/Calibration.htm  All we need to know is what our actual 25Mhz crystal frequency is and change that line in the sketch, then all we need to adjust is the BFO frequency which is easy when the rig is on frequency. I don't know how to code so I'm not sure what is involved in adding something like this to the existing sketch but it sure beats zero beating.

Re: uBITX adjustable power supply?

Tom, wb6b
 

Hi Jerry,

Thanks for your reply and links. It makes sense that they would specify the converter current on input current (based on what the switching transistor can handle), as the output voltage is adjustable and the ratio of available output current to input current is therefore variable, and the output current can't be reduced to one value on the spec sheet. 

Thanks for the data sheet, good to know the part has the possibility of being electronically switched on and off.

I have some other projects I'll need to spend time on, so likely I'll be able to order a new boost converter and it will be here before I'll need it for the uBITX project. But, my separate supply on each FET is a fun idea and if there is delay in getting a better boost converter, it is my backup plan.

Tom, wb6b

Re: uBITX adjustable power supply?

Ralph Mowery
 

The few converters like that I have tried are almost like DC transformers if there were such a thing.  not counting for the loss in the circuits, the power used vers the power input is a ratio.  Meaning that (not counting losses) if you put in 12 volts at 2 amps you can get 6 volts out at 4 amps if the device will handle that much current.  Same way with the boost circuits.  Input 12 volts at 2 amps and you can get out 24 volts at only 1 amp, again not counting circuit losses. 

de ku4pt


On Fri, Jul 20, 2018 at 12:02 PM, Tom, wb6b <wb6b@...> wrote:
Hi Jerry,

Thanks for your reply and links. It makes sense that they would specify the converter current on input current (based on what the switching transistor can handle), as the output voltage is adjustable and the ratio of available output current to input current is therefore variable, and the output current can't be reduced to one value on the spec sheet. 

Thanks for the data sheet, good to know the part has the possibility of being electronically switched on and off.

I have some other projects I'll need to spend time on, so likely I'll be able to order a new boost converter and it will be here before I'll need it for the uBITX project. But, my separate supply on each FET is a fun idea and if there is delay in getting a better boost converter, it is my backup plan.

Tom, wb6b


Re: calibrate v4 ubitx

Arv Evans
 

As Jerry mentioned, you only have to set the Si5351a calibration once and it will be right on for all
three clk-n outputs.  It might have been easier if the software designers had included PC-interface
for the calibration process.  Since PCs have larger screens it would have been possible to include
more user-friendly prompts and guidance during the calibration process.  But of course this would
take up more space in the Arduino for required text lines, so maybe not enough space for that
level of friendliness.

In my own Raduino code I have included "Serial.begin(9600);" so that whenever needed I can now
include various Serial.Write, Serial.Print, and Serial.readBytes action whenever a PC interface is
needed or desirable.  It is not necessary to do the "if(Serial.available)" test because nothing of a
serial nature happens unless you use a serial interface command.  It is necessary to avoid any
blocking action that would stall progress unless the PC was actually connected.  
Once I have performed the PC involved actions I can then disconnect the USB cable and proceed
without the PC connection.

Arv
_._


On Fri, Jul 20, 2018 at 9:15 AM Joel Caulkins <caulktel@...> wrote:
Jerry,

You are right, I did use my calibrated HP 5384A frequency counter to determine the crystal frequency. I had forgot that. I found calibrating the hardest part of building my last uBitx transceiver, it just seems like it should be easier, but what do I know, I'm strictly a hardware man. I'm all for using WWV when the bands are good enough to actually hear it.

Joel
N6ALT

Re: calibrate v4 ubitx

Don, ND6T
 

All, The 50 MHz oscillator can be divided by two, yielding a 25 MHz source that can be zero-beat calibrated in the uBITX if WWV is not receivable. A counter works best for me. Once calibrated I can listen to AM broadcast for long periods of time, right on advertised frequency. Changing sidebands sounds the same.
Jim, regarding the BFO: I use a white noise source modulating the transmitter while viewing the spectrum on a cheap SDR receiver or Spectrum Analyzer (I like the SDR best). You then adjust the BFO frequency for best band pass and sideband reduction. You can do it on the receive side with a stable signal generator but it takes longer. The visual spectrum is nicer, you can see the carrier, etc. Then you can check by switching sidebands to compare different frequencies and their comparative levels on receive. I built a 2-tone oscillator with noise generator into a candy tin with an audio amp and speaker. Holding the microphone over the speaker makes for a rapid test. Jacks are available for more accurate and cleaner testing but I find that I seldom use them since the speaker and such are quite adequate. -Don

Re: calibrate v4 ubitx

Bill Cromwell
 

Hi Jim,

The easiest way I have found to set the BFO is to use something like the graphical display in fldigi or Spectran - I prefer spectran. Set the display to show the audio frequency as opposed to showing you the radio frequency. The waterfall or spectral displays of the background noise will show a 'shadow' of your "system" pass band and that will be largely determined by the xtal filter passband. Be sure to disable or bypass any audio filters. My passband with my uBitx is about 1900 Hz wide. I see a broad, mostly flat curve with a slope at either end. Changing the BFO up and down will move the slope up and down the frequency scale. I adjust the BFO so that the low frequency slope starts to roll off at about 300 Hz. Thereafter, tuning SSB and AM signals (using synchronous AM detection) gives me clear voices. Music is not going to be good through that filter no matter what we do with the BFO. The master oscillator (25 MHz) must be calibrated first.

I hope this helps.

73,

Bill KU8H

On 07/20/2018 11:32 AM, Jim Sheldon wrote:
Jerry,
Regarding the BFO, after the master oscillator is calibrated to an
accurate frequency, the BFO MUST be calibrated to the individual uBITX
crystal filter as no two of them are exactly the same. Such is the
nature of filters built using bulk crystals, matched or not. Matching
them is never an exact science as I've been finding out here trying to
match crystals to come up with an add-on, plug-in crystal filter using
the headers supplied on a V4 board. The BFO also cannot be adjusted to
zero beat or you lose the ability of the filter to separate USB and LSB
as well as CWU and CWL signals to give you what us ancient CW operators
used to call "Single Signal" CW receive.

So far I have not found an easy way to do this except trial and error
"guesstimation". I'm seriously hoping someone can come up with a really
simple way to get this right.

Jim Sheldon, W0EB
--
bark less - wag more

Source for female connectors/pins/manual crimp tool?

Dave New
 

Greetings,

Sorry if this has been hashed over before on the list, but I couldn't find any reference to this, either here or on the various wiki/facebook, etc. sites I found.

I have a uBITX and one of the cases.  Between the two, there are a number of interesting PCBs, cables, etc.  There are two cables provided with the uBITX that are 8-way with female housings on one end of each cable (the other end is just loose wires).

The case comes with a front panel PCB, which has lands for 8-way BergStik-type male pins (which I was able to provide from my junque box).  Now I realize that I could've just soldered the loose wires from the cables provided with the uBITX into the front panel PCB, but now that I've gone and soldered all the male pins on the front panel PCB, I now need to find the appropriate female housings/pins and a manual crimp tool, to make it all look (and work) good/well.

I think I've found the appropriate stuff on Mouser, in their Amphenol/FCI brand, but I thought it might be helpful to find out what others on the list have used (or did they just solder the loose wires to the front panel PCB?).  A number of pictures I've seen of a uBITX installed in a case shows connectors on both ends of the digital and analog cables,  but no hint where to find such animals.

I did find a pre-made cable on Amazon (by searching on Relimate), but they wanted $90 USD for one cable, meaning that I would have to plunk down $180 USD for two!  That methinks goes against the spirit of the whole BITX thing, where the point is to come up with a reproducible inexpensive design.

So, links to messages, etc. would be greatly appreciated.

Thanks, and 73,

-- Dave, N8SBE

Re: Source for female connectors/pins/manual crimp tool?

Doug W
 

On Fri, Jul 20, 2018 at 11:57 AM, Dave New wrote:
I have a uBITX and one of the cases
This has come up many times but it is tough to search for something when you are trying to figure out what it is called.

You didn't say what case you have so I can't help there but the connectors on both the BITX40 and µBITX from HFsignals are Molex KK.  You can find them just about anywhere. 

Digi-Key
connector https://www.digikey.com/product-detail/en/molex-llc/08-50-0114/WM1114-ND/26475
housing (2 position to get you to the right section) https://www.digikey.com/product-detail/en/molex-llc/22-01-2027/WM2011-ND/171991

Tayda while lower cost only has the connectors with the "ears" on them from a reel that you have to trim off making them less than ideal.
https://www.taydaelectronics.com/connectors-sockets/wafer-housing-crimp-terminal/serie-2500-2-54mm.html

While not up to NASA standards, I crimp them with mini pliers like these https://www.amazon.com/gp/product/B01N7THAPR.  Buy a few extra connectors for practice.  I find folding over the stripped end of the wire gives you more to crimp on to.  I have zero doubt a proper crimp tool would work better but the pliers work for me.

--
www.bitxmap.com

Re: KD6CEC code and Nextion displays, tuning skips steps #radiuno #ubitx

Jack, W8TEE
 

I did this on the Forty-9er encoder (March, 2016, QST):

Inline image
The lines are often labeled CLK and DTA on the encoder.

Jack, W8TEE


On Friday, July 20, 2018, 7:53:53 AM EDT, Jim Reagan <jimreagans@...> wrote:


I had an issue with encoders several years ago, in a PIC application.  I looked at the A/B outputs and noticed spikes on the square waves.  Adding two .001uF caps across the outputs to ground, cured the issue.  Maybe that will help?  Most likely you encoder is easy to get to...
Your mileage may vary,
Jim W0CHL

Re: calibrate v4 ubitx

Jerry Gaffke
 

Yes, calibratoin should be easier.
Just needs appropriate firmware for the Raduino.
Should not require anything else.
No frequency counter.
No scope.
No host computer hooked up through the usb port.

Just tune the radio to an AM station such as WWV, enter the calibration routine,
turn the encoder knob till zero beat of the carrier is achieved, then hit PTT.
If you can't hear WWV, a shortwave broadcast station is almost always on an even 5khz frequency, within a few Hz.
The calibration accuracy will be proportional to the frequency of the station you calibrate to,
so WWV at 15mhz will give results 15 times more accurate than an AM broadcast station at 1mhz.

I haven't tried the various firmware releases, but from posts in the forum it seems none quite have it right.
Something patterned after the code in post  54501 (or post 35235 of last December) should just work.
My posts on how to do this correctly go back even further, into the Bitx40 days.

The only issue is detecting exactly where zero beat is, given the capacitive coupling
through the audio amps which limit the low freq response.
But as is, accurate enough to get within 10 hz.
Given that inherent uncertainty, may as well multiply the encoder reading by 100, not by 10, so you can find zero-beat more quickly.
That gives a granularity of 1e6 * 100/875e6 = 0.114 ppm.
Still plenty accurate, accurate enough that temp changes in the 25mhz crystal will be more of an issue.

Jerry, KE7ER

 

On Fri, Jul 20, 2018 at 08:15 AM, Joel Caulkins wrote:
You are right, I did use my calibrated HP 5384A frequency counter to determine the crystal frequency. I had forgot that. I found calibrating the hardest part of building my last uBitx transceiver, it just seems like it should be easier, but what do I know, I'm strictly a hardware man. I'm all for using WWV when the bands are good enough to actually hear it.

Re: #ubitx-help Strong Audio Tones in and outside audio receive passband #ubitx-help

John (vk2eta)
 

Hopefully the IOs on the new Arduino are all intact.

Good to know what to look for when changing the Arduino in the new Raduino version.

Did this fix the tone issue?

73, John

Re: New file uploaded to BITX20@groups.io

Dennis Yancey <bigbluedry@...>
 

Can’t find the file.... 

Re: Source for female connectors/pins/manual crimp tool?

Dennis Yancey <bigbluedry@...>
 

You can make a Cable out of DuPont wires. You get 6 or 8 pins, lined up and clamped and use large shrink wire if black tape to hold them together. You could touch the seams between the pins/sockets with Super Glue. I have never done it with 8 wires but have made several 3 or 4 wire cables this way. 

Budd Churchward has some good tips in his YouTube videos. 

Another satisfied uBITX owner.

RCC WB5YYM
 

Just gotta figure out how to get some labels on these switches and knobs. I did not stray much from the well known modifications. I did wire the KD8CEC extended switch mod slightly different, using a string of the same value resistor similar to the push buttons in the K1EL keyer. I also switched R250 to 100k which really helps the side tone. The main board is powered through a 12v regulator, with 13.8 volts to the PA.  It does have data capability with an internal duinovox. Microphone is a gutted lamp from Walmart $5.97, that happened to be the same color scheme.  The radio works really well and I have been getting good reports from it. So far, I have only used it on 40 meters due to the antenna situation.