Date   
Re: ND6T AGC implementation for uBIT-X

Tim Gorman
 

A simple measure of reverse power will tell you if the antenna is
working ok.

Forward power, and using it to calculate SWR, tells you more about how
your rig is operating then about the match to the antenna. If you have
a perfect match, i.e. no reverse power, then it doesn't matter what your
forward power is as far as the antenna match is concerned. The SWR will
always reduce to (1 + sqrt 0)/(1 - sqrt 0) or 1:1.

I'm not arguing that it isn't nice to know your forward power and/or
swr, I'm just saying it isn't necessary for operation of the ubitx. In
fact, knowing your forward power is a nice diagnostic tool to have
handy. But only reverse power is necessary to make the overall
system work as well as possible.

The ubitx code has gotten so large that it's almost necessary to drop
something in order to add something. It's why people are looking toward
processors with more memory available. I just want to add what is
essential, not what is "nice".

tim ab0wr

On Sun, 06 May 2018 14:31:41 -0700
"Jerry Gaffke via Groups.Io" <jgaffke=yahoo.com@groups.io> wrote:

For portable ops, I use a resonant antenna.
Does not need a tuner.
But I still want to know if it's working properly.
 
Jerry

On Sun, May 6, 2018 at 01:24 pm, Tim Gorman wrote:


You still need an antenna tuner. The SWR meter is kind of useless
without one.

I'm want to be able to operate for at least 48-72 hours. I'm
figuring you need at least a 36-50 amp-hour battery to be
self-sufficient.

Re: BITX QSO Afternoon/Evening, Sunday, May 6, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

Tom VE3THR
 

Thanks Stan WS4JM in TN for the shout. Look for you guys on wed night same place and time. Going to be an early night for me...busy weekend.
73 Tom VE3THR

Re: BITX QSO Afternoon/Evening, Sunday, May 6, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

Tom VE3THR
 

Good to work you again John WA2FZW. Also worked Marc N4DR and Bruce KC1FSZ. Marc got his BITX40 tuned up now on frequency  - sounds great! My uBITX is alive! 1st time on the air with it tonight. Lots of static crashes but sigs are readable. Listening along for a while on 7.277 MHz.

Re: BITX QSO Afternoon/Evening, Sunday, May 6, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

Jay - WS4JM
 

Heard Tom in Ontario and Mark in MD but I couldn't get back to either.

73 de WS4JM

Re: Coding styles

Michael Monteith
 

 I definitely put brackets on the following lines.  In particular a lot of IDEs and even a lot of editors will do matching brackets for you.  In that case you can see quickly where the begin and end are.   On some of them they have vertical ghost tab lines and easy to look up and down and see where the align.  Not to mention if you forget one it's easy to track back. 

 Michael
KM4OLT

Re: BITX QSO Afternoon/Evening, Sunday, May 6, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

John P
 

Still nuttin but noise here! Anybody else on?
--
John - WA2FZW

Re: uBitx relay pinouts

Dexter N Muir
 

Data sheets specify "viewed from below", usual convention is to view from above. In between comes mirror-imaging horizontally and vertically. It's a mess. Definitively, with device in hand, view as if you're plugging it into a PCB (i.e. view from above). Now the two 'end' pins with greater gap to the rest are pins 8 and 9, the coil. The imagined IC 'notch' is the other end.

Hopefully helpfully
Dex, ZL2DEX

Re: ND6T AGC implementation for uBIT-X

Paul KL7FLR
 

Gene and group, I believe Kees was referring to the files section of BITX20 groups.io. Had me confused for a bit too.

 

Paul

KL7FLR

Re: ND6T AGC implementation for uBIT-X

Kees T
 

Gene,

Sorry about the confusion.

The QSL.net website does not have a files section The first link you listed gave you my general website discussing ham radio and the last section gives the link to the kits I'm presently offering, that's the second link you listed. Nothing having to do with uBITX is on that website at this time.

All my uBITX stuff is presently on this website in the "Files" section under my call  K5BCQ  and the projected demand for the AGC kit and Click kit are pretty high .......but beware that it's small SMT stuff and you might have to enlist younger eyes and hands to help out. I just take it nice and slow.......

I'll update it as needed.

After the AGC and Click board demand subsides (this Topic), I was tossing out a few other options like some kind of mWattmeter for the uBITX and looking for input. Apparently there is a lot of interest and various implementation opinions there too. I'm listening and have built mWattmeter kits before using forward biased, matched HSMS-2815 diodes, and was thinking of AD8307 parts since they are now so inexpensive (not so 10 years ago).

73 Kees K5BCQ

Re: 45Mhz crystal filter specification

K9HZ <bill@...>
 

Yet another reason I opted for the AD8302 for my tuner…  FREE R+jX…

 

 

Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ

 

Owner - Operator

Big Signal Ranch – K9ZC

Staunton, Illinois

 

Owner – Operator

Villa Grand Piton – J68HZ

Soufriere, St. Lucia W.I.

Rent it: www.VillaGrandPiton.com

Like us on Facebook! facebook icon

 

Moderator – North American QRO Group at Groups.IO.

 

email:  bill@...

 

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of ajparent1/KB1GMX
Sent: Sunday, May 6, 2018 4:34 PM
To: BITX20@groups.io
Subject: Re: [BITX20] 45Mhz crystal filter specification

 

The SA with a TG is a massively useful tool for RF work.  The only thing better and more costly would
be VNA as they can give you phase and amplitude or R+Jx.   Even then you can fake it with the TG
with the right jigs, its just more time consuming.

Not sure depending on the code being used, but whatever it takes to get the LO
to exactly 45mhz.

Sweeping with the SA is easier and can be more informative.   

Yes, the next few weeks will be:
Getting garden ready
Getting ready for the ARRL VHF/UHF contest.
Getting set for Field Day
                    and mowing the lawn.

And building things.

Allison


Virus-free. www.avg.com

Re: ubitx_20.ino does not compile, anybody else encounter this? #ubitx-help #ubitx #arduino #firmware

Gary Anderson
 

When hacking up for ARM, I found some functions defined as int, but did not return a value.
I changed to void. I would imagine it depends on your compiler or options passed to the compiler.

I'm using Arduino 1.85 
Arduino AVR v 1.6.21
Arduino SAMD v1.6.18
on a windows 10 machine.


void menuBand(int btn){ // was int but no return AG5TX
void menuCWSpeed(int btn){ // was int but no return AG5TX

Regards,
Gary
Ag5TX

Re: ND6T AGC implementation for uBIT-X

Jerry Gaffke
 

Very weird.
I can double click on the second link in your post 
and the chrome browser on my chromebook takes me right to the kits.

But when it does, chrome removes the leading "http://" 
and my browser address bar shows 
    www.qsl.net/k5bcq/Kits/Kits.html

If I then copy and past from the chrome address bar back to a text file or a forum post being composed,
the leading "http://"  shows up again.

Try clicking the link in this post, that might work better for you.



On Sun, May 6, 2018 at 03:21 pm, Gene Nitschke wrote:

Kees,

I must be doing something wrong as I could not find the files section of your web site.

I am looking  at http://www.qsl.net/k5bcq/ But I do not find a files section.

I also looked at http://www.qsl.net/k5bcq/Kits/Kits.html to no avail.

 

Maybe I am using the wrong site?

Could you please send link out?

Thanks,

Gene N2IJF

Re: ND6T AGC implementation for uBIT-X

Gene Nitschke <genenitschke@...>
 

Kees,

I must be doing something wrong as I could not find the files section of your web site.

I am looking  at http://www.qsl.net/k5bcq/ But I do not find a files section.

I also looked at http://www.qsl.net/k5bcq/Kits/Kits.html to no avail.


Maybe I am using the wrong site?

Could you please send link out?

Thanks,

Gene N2IJF






From: BITX20@groups.io <BITX20@groups.io> on behalf of Kees T <windy10605@...>
Sent: Saturday, May 5, 2018 4:30 PM
To: BITX20@groups.io
Subject: Re: [BITX20] ND6T AGC implementation for uBIT-X
 
I just uploaded the current AGC and Click kit requests. This list is to help me asses demand so I can have the correct sets of parts ready. There does not appear to be much demand for boards only, just complete kits. 

I'll post prices later, when I receive the boards and some testing is done. 

I was looking into Don's ND6T Polite Antenna Tuner, but there does not appear to be much interest and using it effectively may be a problem, so it's out. I did receive a request for a "Power Level Upgrade" kit but decided against that because there is a whole lot of testing to be done when you get into RF Amplification.

What may make sense, unless it's already out there as an add-on upgrade kit, is a Power/SWR capability using  a simple Stockton Bridge and a couple of AD8307's. I'm quite familiar with the bridge and the AD8307 parts are getting really cheap <$0.50 each. Wonder if those Chinese parts are usable at QRP specs ? Would need two analog inputs on whatever microcontroller .......and, of course, the ever present requirement for someone to provide support firmware. 

73 Kees K5BCQ

73 Kees K5BCQ

Re: Designing a front panel PCB

Reid Campbell
 

The first link is what I had in min, looks very profession. I'll just have to wait until I retire and then I'll get all the time to play.

See this working for a living, it will never catch on.

Reid.

On 06/05/2018 22:53, Jerry Gaffke via Groups.Io wrote:
Here's an example of the front panel as PCB technique being used:
http://www.4sqrp.com/ozarkpatrol.php

Mike Bryce mentioned that you need to look out for the fab house mill-mark:
https://groups.io/g/BITX20/message/46675

Jerry

Re: ND6T AGC implementation for uBIT-X

tony.vasile@...
 

Of course!  My mistake...thanks for the correction.  And I absolutely agree that the benefit of shortening commands is outweighed by the degradation in readability!

Tony KB9A

On Sun, May 6, 2018, 2:09 PM Jack Purdum via Groups.Io <jjpurdum=yahoo.com@groups.io> wrote:
(Actually, it's the post-decrement operator, not the decrement operator.) I wasn't saying I don't know what the post-decrement operator does, I was just asking why make the code harder to read by using it there. Moving it to the next line makes the code easier to read and has no impact on the way it works or the generated code. Anything the programmer can do to make the code easier to read and that is performance-neutral should be done. That's why I almost never use the ternary operator: It's almost always easier to read a simple if-else statement block and the generated code's the same.

Jack, W8TEE


On Sunday, May 6, 2018, 2:03:08 PM EDT, <tony.vasile@...> wrote:


In the C language, the "--" operator is "decrement".  So in this case, the instruction is indicating that d should be decremented by 1, then compared to r.  If the decremented value of d is equal to r, then print!

Tony, KB9A

On Sun, May 6, 2018, 11:32 AM Jack Purdum via Groups.Io <jjpurdum=yahoo.com@groups.io> wrote:
if (d--==r)   lcd.print('.');

What??

Jack, W8TEE


On Sunday, May 6, 2018, 10:41:34 AM EDT, Jerry Gaffke via Groups.Io <jgaffke=yahoo.com@groups.io> wrote:


Here's my unproven code for displaying forward and reverse power in Watts
plus SWR on the bottom line of the 16x2 LCD, when using a TandemMatch with diode detectors.
It's actually quite simple and not computationally expensive..  Hereby released under GPL v3.0

Could be made more accurate by adding the schottky diode drop to the two voltage readings.
Assuming the transformer turns ratios are kept at 10:1, the SWR should be reasonably accurate
without calibration.  Especially if a few uA of bias is added to the diodes.
Power readings should be reasonably accurate if the SWR is close to 1:1
since they assume a 50 ohm load.

Maximum analogRead() return value is 1023, and represents a peak RF voltage of 5 volts.
Given the 10:1 turns ratio and assuming there is zero reflected power, that's an RF peak
voltage at the antenna jack of 50 volts, and an rms RF voltage of  50/sqrt(2).  Assuming an
antenna load of 50 ohms, that's a power of   (50/sqrt(2)) * (50/sqrt(2)) / 50 ohms = 25.0 watts.
From this, we determine the value of PSCALE in the code below.

Using the linear-in-db ad8307 could be done with the same code, but first using
a table lookup to convert to RF volts.
I don't really want to be computing anti-logs on a Nano.
A table lookup will burn some flash.

################################################################
// Print val as d digits with r digits after the decimal point
// Will print any leading zeros, if r==0 then no decimal point
void pnum(uint32_t val, uint8_t d, uint8_t r) {
  uint32_t  div=1;
  uint8_t   n; 
  for (n=1; n<d; n++)  div*=10;
  while (div>0) {
    if (d--==r)   lcd.print('.');
        lcd.print((val/div) + 0x30);
    val = val%div;
    div = div/10;
  }
}
 
// Read TandemMatch's 2 detectors, display forward and reverse power, swr
#define PSCALE  (1023L*1023/(25*10)) // ADC max of 1023 is 25 Watts, display Watts*10
void  show_swr() {  // SWR = (1+1.0*vr/vf)/(1-1.0*vr/vf);
  uint32_t vr, vf, swr; // Voltage squared proportional to power
  vf = analogRead(RF_FWD); // Peak RF volts from forward detector
  vr = analogRead(RF_REV); // Peak RF volts from reverse detector
  if (vr>=vf) swr=0; // If vr,vf illegal, force SWR to zero
  else {
    swr = (vr*1024)/vf; // Voltage ratio, 10 fractional bits
    swr = (1000*(1024+swr))/(1024-swr); // 1000*swr, nearly 10 fractional bits
    swr = (swr+50)/100; // 10*swr, rounded to nearest tenth
    if (swr>99) swr=99;  // Display a max SWR of 9.9
  }
  lcd.setCursor(0, 1); // Fill bottom LCD line, example:
  lcd.print('f'); pnum(vf*vf/PSCALE,3,1); // "f12.4 r03.1 s1.7"
  lcd.print('r'); pnum(vr*vf/PSCALE,3,1); // with fwd,rev power in watts
  lcd.print('s'); pnum(swr,2,1); // and swr to max of 9.9
}
#################################################################

My primary reason not to mess with ad8307's is that they are harder to dead bug.
If the timing skew between forward/reverse readings is an issue, I'd definitely try the cap.
Likely still accurate enough. 

Bill wrote:

58.6 KHz would be ok, but to get that rate probably assumes that the processor is dedicated to the task, not off doing other uBITx work,


We currently use a blocking analogRead() in many places in the code, each taking over 100us.
And in some cases do it constantly for stuff such as inspecting switches or keyer paddles.
So speeding up the analogRead() by a factor of 5 and occasionally (once per second?) 
reading the forward and reverse power should not be much of a burden, even if averaging
a half dozen reads. 

Should be possible to set up the ADC to be interrupt driven, an interrupt service
routine updates a list of all ADC readings.  In mainline code, we'd then disable interrupts
and read those last few forward and reverse readings to take an average.  Since we
are no longer blocking for each 100us+ analogRead(), this would be much less a timing burden.

Things may eventually slow down too much for somebody trying to use the keyer at 40wpm.
Otherwise I doubt there will be much of an issue with a lost millisecond here and there.
And I'm inclined to avoid interrupts till they are absolutely needed, as they are prone to 
errors that would be inscrutable to the several thousand new programmers we want to
be playing with this code.

Jerry, KE7ER 


On Sat, May 5, 2018 at 10:45 pm, K9HZ wrote:

Hmmm… we should probably take this off-line at this point.  This has to do with A/D resolution time vs. filter time.

I’m rethinking…that diodes would be a better choice just because they are less complicated.  The transform to watts and SWR is still complex though and will eat some processing power in a Nano.

Re: Designing a front panel PCB

Jerry Gaffke
 

Here's an example of the front panel as PCB technique being used:
    http://www.4sqrp.com/ozarkpatrol.php
 
Mike Bryce mentioned that you need to look out for the fab house mill-mark:
    https://groups.io/g/BITX20/message/46675

Jerry


On Sun, May 6, 2018 at 02:44 pm, Reid Campbell wrote:
Just done a search and it came up in a post from Jerry, https://groups.io/g/BITX20/message/46671 with a similar suggest. Guess nobody took it up.

Re: 45Mhz crystal filter specification

Jerry Gaffke
 

Those wanting a VNA on the cheap should take a look at the VIA kit sold by Kees
    http://www.qsl.net/k5bcq/Kits/Kits.html
It's 3 kits up from the bottom of the page.

Does one and two port analysis of networks from 8khz to 440mhz.
Plots smith charts, swr charts, or just plain old R and X complex impedance.
Standalone.
For around $100.

Jerry, KE7ER



On Sun, May 6, 2018 at 02:34 pm, ajparent1/KB1GMX wrote:
The SA with a TG is a massively useful tool for RF work.  The only thing better and more costly would
be VNA as they can give you phase and amplitude or R+Jx.

Re: Designing a front panel PCB

Reid Campbell
 

Just done a search and it came up in a post from Jerry, https://groups.io/g/BITX20/message/46671 with a similar suggest. Guess nobody took it up.

Reid.

On 06/05/2018 22:24, Joe Puma wrote:
I think I saw a front panel pcb being used. With the function buttons and audio in and out.  Think someone posted it to this group?

Btw, hey Atouk!!!!

Joe
KD2NFC 




Re: 45Mhz crystal filter specification

ajparent1/kb1gmx
 

The SA with a TG is a massively useful tool for RF work.  The only thing better and more costly would
be VNA as they can give you phase and amplitude or R+Jx.   Even then you can fake it with the TG
with the right jigs, its just more time consuming.

Not sure depending on the code being used, but whatever it takes to get the LO
to exactly 45mhz.

Sweeping with the SA is easier and can be more informative.   

Yes, the next few weeks will be:
Getting garden ready
Getting ready for the ARRL VHF/UHF contest.
Getting set for Field Day
                    and mowing the lawn.

And building things.

Allison

Re: ND6T AGC implementation for uBIT-X

Jerry Gaffke
 

For portable ops, I use a resonant antenna.
Does not need a tuner.
But I still want to know if it's working properly.
 
Jerry


On Sun, May 6, 2018 at 01:24 pm, Tim Gorman wrote:
You still need an antenna tuner. The SWR meter is kind of useless
without one.

I'm want to be able to operate for at least 48-72 hours. I'm figuring
you need at least a 36-50 amp-hour battery to be self-sufficient.