Date   
Re: Bandwidth

Gordon Gibby <ggibby@...>
 

​wide enough to do all the modes I want!!!!



From: BITX20@groups.io <BITX20@groups.io> on behalf of John 2e0eii <2e0eii@...>
Sent: Sunday, December 31, 2017 6:02 PM
To: BITX20@groups.io
Subject: [BITX20] Bandwidth
 

Hi all
do we know the band width of the bitx40 v3 ,and is it possible to alter,

rgds John 2e0eii

Re: OOPS!! Re-factory alignment....

AndyH
 

My pleasure!  I remembered reading it but couldn't immediately find it when I 'needed' it.  (Story of my life.  LOL) 

Thanks for blazing this trail - I look forward to getting my rig on the air when it arrives.
(Why do I get the feeling that I'm going to end up with a couple of these radios?)

Happy New Year, Doc
Andy


On Sun, Dec 31, 2017 at 03:38 am, Gordon Gibby wrote:
aha!!!  yes, thank you, extremely helpful.
 
The factory alignment does essentially the same steps just slightly different ways.
 
 
Thank you for pointing that out, I hadn't seen it.
 
The way I selected the BFO frequency apparently is just a tad "bassy" for the preferences of the ALE algorithm.  shifting it (from my pick) to give another couple hundred hertz on the treble side would make the uBitx almost perfect for a ALE scanning.
 
One of the ALE expert's (looking at the schematic) pointed out my error:  upon closer examination, the transmit relays are NOT clicking at all when one merely scans receiving frequencies;  I was hearing small pops in the speaker and thinking those were relays clicking.
 
The uBitX  is able to scan at full speed, (selection: five frequencies per second), continuously, without the need for any relay  actuation.   Makes it almost a perfect receiver for ALE or similar scanning.

Sent from my iPhone

On Dec 31, 2017, at 04:26, AndyH <ahecker@...> wrote:
On Sat, Dec 30, 2017 at 12:01 pm, Gordon Gibby wrote:

 

 (A "manual" for factory alignment would be wonderful....)   

Useful?  http://www.hfsignals.com/index.php/ubitx-tuneup/

Re: Tuner? Well Sure!

Diver Martin <diver.martin@...>
 

K3NG provides a good starting point. But I found a few flaws in the algorithm that he uses, at least so I think.  Here is the comment I put in my code for my ATU, and my thoughts.  Warning:  Long read ahead.  You might wish to just mark this one as read unless you're into the nitty gritty of ATU code revD.

/* Tuning Algorithm Description
 * 
 * This tuning algorithm is a refinement of the algorithm used by k3ng and others.  
 * 
 * Editors note:  **This is based on my assumptions and understanding of the algorithms.  They could be totally wrong!
 * 
 * This algorithm allows for all possible L/C/CX combinations to be potential candidates.  For reference, the k3ng algorithm does a 
 * matrix scan, wherein (assuming 8 inductors, and 8 capacitors) it does a scan of all individual C values with all individual L 
 * values.  That is, if C and L are values from 0 to 255, a value of * 1 (0001) is say 0.0625uH, a value of 2 (0010) is 0.125uH, a 
 * value of 4 (0100) is 0.25uH, and so on.  Capacitor values start at 10pF would be 1=10pF, 2=20pF, 4=40pF, etc such that if you 
 * set C=180, that should be a value of 128 + 32 + 16 + 4 or 1800pF.
 * 
 * The K3NG algorithm** tries (almost) all values of L and C where only one L/C is selected, that is first C is set to 1 (10pF),
 * and then L is set to 0.0625, 0.125, 0.25, 0.5, 1, 2, 4, and 8uH.  (L = 1, 2, 4, 8, 16, 32, 64, and 128).  C is then set 2 (20pF), 
 * and this is repeated.  C is then set to 4 (40pF) and all 8 inductors are tried.  At this point, you now have an 8x8 grid / matrix
 * of SWR measurements.  Whichever combination yielded the best (lowest) SWR reading, you focus on that point and then scan from +/- 8
 * or 16 values depending on the algorithm for a 'best' match.  (You repeat this 8x8 array measurement, as you do it once for the
 * capacitor on the High-z side, and once on the low-z side, for 8x8x2=128 total measurements).  For example, say the first stage
 * yielded a result of CX=0, L=16 and C=32 as the lowest SWR of 2.5:1.  You would then scan from L=8 to L=24 and C=16 to C=48 in a
 * similar grid fashion to arrive at finding L=22, C=36 as the best combination yielding a 1.5:1 SWR.  Great, all tuned up!
 * Except there's a flaw in this algorithm, a significant one at that.  Lets say the first round yields best match at L=128 (for
 * the purposes of this exercise, lets assume capacitance is irrelevant).  You then scan from from L(round1) +/- 16 so you try all
 * values of L between L=112 to 144.  But you don't find a match...  why not?  Because the best match was at L=100.  So why did the
 * algorithm not try L=64?  Lets see.  L=64 +/- 16 yields L from 48 to 80.  L=100 is literally an unobtainable value.
 * 
 * So to refine on the algorithms used above, my algorithm is a 3-stage algorith, but instead of a non-linear power of 2 matrix, 
 * I use linear values.  Because this tuner has 7 inductors, 8 capacitors, and 1 relay for switching CX (high-z/low-z), I use a 
 * 7-6-6 and 6-5-5 matrix.  That is, I scan 7 values of C from 0 to 255, and 6 values of L from 0 to 128 in stage 1.  So the first
 * scan matrix is 7x6 values.  You'll note that when the algorithm is first triggered (look above about 115 lines up) that 
 * L=11 and C=18 are the initial values, and that each round, L is incremented by 22, and C incremented by 36.  This means we try
 * inductance values L=11, 33, 55, 77, 99, and 121.  C values tried are 18, 54, 90, 126, 192, 198 and 234.  The downside to doing 
 * a linear scan is that it will flip a lot more relays.  Boo hoo!  From there, the best L/C value is picked + highz/lowz, and 
 * then proceeds to stage 2, incrementing L/C by 4 and 6.  So if L=11 and C=18 are picked, then L=0+(4/2)=2, L=6, L=10, L=14, and 
 * L=18 (5 values)are tested to cover the L=0 to L=22 range (remember, round one tested L=11 and L=33, so we want to ensure we can 
 * cover to the midpoint between 11 and 33, which is 22).  The capacitor does the same, except it'll go from C=3, C=9, C=15, C=21, 
 * C=27, and C=33 to cover C=0 to 36 (round 1 was C=18 and C=54).
 * 
 * The final stage is naturally a simple by-1 increment.  So if L=2, C=3 were the best values, it'll do L=0, L=1, L=2, L=3, and L=4
 * as well as C=0, C=1, C=2, etc (I think you get the idea by now).
 * 
 * You'll notice an odd -1 in there... that's because the Actual L/C values are 0-127 and 0-255, whereas this algorithm really ends 
 * up covering 1-256 and 1-128, so I subtract one... at least, that's my story and I'm sticking too it.  Either way, we can show
 * coverage as well by simple multiplication:  6*5*5 = 150 (and we just need 0-128), so we're almost over-covered.  7*6*6 = 252, 
 * which is just a few shy, so there might be a few values (a grand total of 3) where we might not reach the best SWR, but we'll 
 * get pretty close.  
 * 
 * This algorithm could easily be extended to more rounds for faster search times.  This is an exercise for later, because I fear
 * one little issue:  THe SWR is not always linear with a clearly distinct 'null'.  For example of a 1-dimensional tuner (ignoring
 * capacitance), if during round L=33 gave SWR=3.0 and L=121 gave SWR=3.1, you'd pick L=33.  But what if L=33 was near a 'local' 
 * null in SWR where it never got better than 2.5:1, whereas the 'best' match was at L=140 with SWR 1:1.  You'd never find it. Now,
 * Granted, this can happen now... but the finer your first stage, the less likely, and this is an important consideration for 
 * going to multiple rounds.  For example, lets go extreme with 8 rounds, and only 2 values each.  Test L=32 and L=96 (L=0 to 128).  
 * You can see how a non-linearity in the SWR curve vs inductance might pick the wrong L value.  The one advantage to an 8-round
 * tuning system is (Lets say we have L=0-255 and C=0-255 for simplicity).
 * 1 round, extreme, you'd need 256*256 measurements = 65535 to cover all possible measurements
 * 2 rounds, you need 16*16 + 16*16 = 512 total measurements.
 * 3 rounds (as above), 7*6 + 6*5 + 6*5 = 102 total measurements
 * 4 rounds (4*4*4*4=256, works out nicely), you need 4x (4x4) matricies, or 4*16 = 64 total measurements
 * 6 rounds (256^ (1/6) = 2.51, so we'll have to go (3*3*3*3*2*2) or 39 total measurements
 * 8 rounds (2 each) = 4*8 = 32 total measurements
 * 
 * So as you can see, there is an advantage to doing more rounds, but your tradeoff is you're more vulnerable to local nulls in
 * the SWR of your antenna.
 * 
 */

On Sun, Dec 31, 2017 at 2:32 PM, Glenn <glennp@...> wrote:
My 1st post. Have a look at the K3NG ATU (Google K3NG TUNER). While he designed it as a balanced tuner, I have built an unbalanced version for around 20W or so. Using standard footprint 'cheap' relays. Actually the relays are the bugbear of an ATU, finding the right type and rating and low cost, since in this example there are 18 relays. From what I can see, latched relays are very expensive especially when you need 18. The trade-off is current draw, as per some posts here.

I used AD8307 Log detector chips in the SWR section. Caps used were 3kV rated 1812 sized smd although available in VK, might be harder to find in USA.

K3NG uses an Arduino NANO and a simple 2 line LCD module.  To keep size down, one of the 0.96" OLED displays might be a candidate.

glenn
vk3pe




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

Re: Tuner? Well Sure!

K9HZ <bill@...>
 

Glenn.  Welcome aboard and hope to work with you more…

 

Yes I see you have been working at this project for a while now.  You have developed some very nice boards.  I’ve used the AD8307 on a lot of projects too and they are wonderful for power resolution since they are native logarithmic/ decade devices, but they are not necessary for an inexpensive a tuner.  It also tells me that you are using a straight linear hunting algorithm to find the lowest SWR calculated from forward and reverse power.  I did that with the first tuner I built, but moved to using Phase and Magnitude measurements instead… as they give you more information (add L, add C, etc.)… and then just calculate power using math routines now available in the processor libraries.  If you make a revision to those boards, I strongly suggest you add two additional relays to put the capacitor network on either side of the inductor.  That completes the transform space needed to be covered for both hi-Z and low-Z antennas.  Again all subjects covered in Sabin’s book…

 

You are very right.  The relays make and break the project.  Been there, done that and suffered in between. 

 

I do like the caps you use…  I’ll see if I can source those here… don’t see why not, but they seem to be high current density devices… needed for RF designs like this.

 

 

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

 

 

email:  bill@...

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Glenn
Sent: Sunday, December 31, 2017 4:33 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Tuner? Well Sure!

 

My 1st post. Have a look at the K3NG ATU (Google K3NG TUNER). While he designed it as a balanced tuner, I have built an unbalanced version for around 20W or so. Using standard footprint 'cheap' relays. Actually the relays are the bugbear of an ATU, finding the right type and rating and low cost, since in this example there are 18 relays. From what I can see, latched relays are very expensive especially when you need 18. The trade-off is current draw, as per some posts here.

I used AD8307 Log detector chips in the SWR section. Caps used were 3kV rated 1812 sized smd although available in VK, might be harder to find in USA.

K3NG uses an Arduino NANO and a simple 2 line LCD module.  To keep size down, one of the 0.96" OLED displays might be a candidate.

glenn
vk3pe

Re: elves are at it

Tom Christian
 

Same here 12/23 date. Pretty excited!  Thank you, Farhan!
Tom
AB7WT

Re: Tuner? Well Sure!

Glenn
 

Hi Bill, thanks for the warm welcome.

I used the AD8307's because they work much better at lower power levels. And off ebay they are extremely cheap.

The project already has two relays for switching the caps to either end of the inductors. You can see them on the PCB, which by the way is 100 x 100mm which is the sweet spot for getting Chinese PCB's made these days.

I like the concept of using Phase and Magnitude from something like an AD8302, but I am a total noob re programming Arduino so elected to go down the path that K3NG has gone.
Glenn
vk3pe

Re: Tuner? Well Sure!

Glenn
 

My Control board takes a plug IN NANO baord and caters for a few different display type from parallel LCD's to I2C devices. It has provision for LED's to indicate which relay combination of L&C is slectedas it tunes.  Overkill really....... PCB could be made much smaller of course.

Re: Tuner? Well Sure!

KM4TRT
 

Bill-interested in a kit and could do some building also.
Andy KM4TRT

Re: elves are at it

chris gress <Chrisg0wfh@...>
 

I just ordered mine tonight so time to wait for it to come chris 

On 31 Dec 2017 23:36, "Tom Christian" <tmchristian@...> wrote:
Same here 12/23 date. Pretty excited!  Thank you, Farhan!
Tom
AB7WT

Re: elves are at it

Dave Bottom <ars.kd6az@...>
 

Happy New Year to all.

Received mine on the 24th (lucky I ordered on the 10th).

Got my case yesterday late afternoon and finished the case prep before turning in.

Wired up this morning. It’s alive!!!
First contact 600 Miles - 59 report.

See top of my QRZ page for pictures.

Off to build a Mic pre-amp with Mic Gain control. Then work on paddle interface.

Dave WI6R

Sent from my iPhone

On Dec 31, 2017, at 3:36 PM, Tom Christian <tmchristian@...> wrote:

Same here 12/23 date. Pretty excited!  Thank you, Farhan!
Tom
AB7WT

Re: elves are at it

Dave Bottom <ars.kd6az@...>
 

QRZ has changed their link policy so you’ll have to type in my call sign for now.

Dave WI6R

On Dec 31, 2017, at 3:55 PM, Dave Bottom <ars.kd6az@...> wrote:

Happy New Year to all.

Received mine on the 24th (lucky I ordered on the 10th).

Got my case yesterday late afternoon and finished the case prep before turning in.

Wired up this morning. It’s alive!!!
First contact 600 Miles - 59 report.

See top of my QRZ page for pictures.

Off to build a Mic pre-amp with Mic Gain control. Then work on paddle interface.

Dave WI6R

Sent from my iPhone

On Dec 31, 2017, at 3:36 PM, Tom Christian <tmchristian@...> wrote:

Same here 12/23 date. Pretty excited!  Thank you, Farhan!
Tom
AB7WT

Re: Tuner? Well Sure!

Diver Martin <diver.martin@...>
 

Glenn,

Nice PCB layouts!  Digging your projects as pictured on QRZ...  Do you have schematics/etc posted anywhere?  Love seeing other's homebrew stuff.

For now linear SWR-only tuning works, but eventually I should get to phase/magnitude detection.  What's interesting to me when I went and looked at the KX3 is that it doesn't actually have a phase detector that I can tell.  

Bill, now you've gotten me interested in Sabin's book, as if I didn't have enough reading material to begin with :)  I doubt I'll make an update to the amplifier design at this stage since I've gotten it working, but never know.

On Sun, Dec 31, 2017 at 3:50 PM, Glenn <glennp@...> wrote:
My Control board takes a plug IN NANO baord and caters for a few different display type from parallel LCD's to I2C devices. It has provision for LED's to indicate which relay combination of L&C is slectedas it tunes.  Overkill really....... PCB could be made much smaller of course.




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

Re: ubitx circuit, wiring, source code on github

Jerry Gaffke
 

From post 35235:  "The displayed frequency should be exactly   sig = clk2-(clk1-clk0)"
Looks like the github code causes the calibration to jump in steps of 10ppm,
which means clk0,1,2 all jump by 10ppm as well, and from the equation above the 
operating frequency "sig" will jump by 10ppm with each calibration step.
When operating at 30mhz the calibration steps are 300hz, which is quite coarse.
I think.


On Sun, Dec 31, 2017 at 12:56 pm, Jerry Gaffke wrote:
One possible issue with the current calibration scheme is that it apparently moves vcoa by leaps of 8750hz, or 10ppm.

Re: ubitx circuit, wiring, source code on github

Gordon Gibby <ggibby@...>
 

Not sure what rig that applies to, when I did the factory calibration at 10 MHz, it moved pretty smoothly.

Sent from my iPhone

On Dec 31, 2017, at 20:52, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:

From post 35235:  "The displayed frequency should be exactly   sig = clk2-(clk1-clk0)"
Looks like the github code causes the calibration to jump in steps of 10ppm,
which means clk0,1,2 all jump by 10ppm as well, and from the equation above the 
operating frequency "sig" will jump by 10ppm with each calibration step.
When operating at 30mhz the calibration steps are 300hz, which is quite coarse.
I think.

On Sun, Dec 31, 2017 at 12:56 pm, Jerry Gaffke wrote:
One possible issue with the current calibration scheme is that it apparently moves vcoa by leaps of 8750hz, or 10ppm.

Re: ubitx circuit, wiring, source code on github

Gordon Gibby <ggibby@...>
 

Then I just commanded it to 25 MHz for the sketch, measured the output frequency to the accuracy of my ICOM 718, then corrected the 25000000 base crystal  number in the sketch.

I forget exactly now, but I think it was 3.82 kilohertz high.   all the units I've measured have come between about 3 1/2 and 4 1/2 kHz high

I've checked that 718 against 10 MHz WWV, and I don't really have anything in my house any more accurate than it.  



Sent from my iPhone

On Dec 31, 2017, at 20:55, Gordon Gibby <ggibby@...> wrote:

Not sure what rig that applies to, when I did the factory calibration at 10 MHz, it moved pretty smoothly.

Sent from my iPhone

On Dec 31, 2017, at 20:52, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:

From post 35235:  "The displayed frequency should be exactly   sig = clk2-(clk1-clk0)"
Looks like the github code causes the calibration to jump in steps of 10ppm,
which means clk0,1,2 all jump by 10ppm as well, and from the equation above the 
operating frequency "sig" will jump by 10ppm with each calibration step.
When operating at 30mhz the calibration steps are 300hz, which is quite coarse.
I think.

On Sun, Dec 31, 2017 at 12:56 pm, Jerry Gaffke wrote:
One possible issue with the current calibration scheme is that it apparently moves vcoa by leaps of 8750hz, or 10ppm.

Re: Tuner? Well Sure!

Glenn
 

Tell me your favorite uBitx mods

Diver Martin <diver.martin@...>
 

Hello all,

As I'm doing a motherboard mod, I'm looking to incorporate a bunch of mods into one PCB.  Right now, what I've got going are the following:

* A tuner + SWR Bridge (phase detector maybe?)
* A spot for an RTL-SDR (blogV3) dongle
* AGC Modifications
* Integrating LCD and headphone/mic/BNC/Power/etc jacks into the PCB

Other things I've thought about, space depending:

*Adding in footprints for a chinese AD9850 DDS module for one of the clock signals

I would like to hear the top mods you've done, and what you'd love to see integrated into a motherboard PCB that fits on top of the uBitx.  Battery charger?  Battery adapter? I dunno, bring it on!  If you have a favorite AGC mod, please tell me about it, and make some suggestions as well.  This is not promising to be a cheap kit, and full of SMT, but something I might make available.

Happy new year,

--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?

Re: ubitx circuit, wiring, source code on github

Jerry Gaffke
 

Gordon,

The factory calibration on the uBitx is probably fine.
It adjusts the 875mhz vco by 875hz each step, so 1ppm.
A wee bit coarse when operating at 30mhz,  but most of us won't really notice.
Your 10mhz factory calibration was scooting over by 10hz for each tick of the encoder.

    if (knob > 0)
      calibration += 875;
    else if (knob < 0)
      calibration -= 875;
    else 
      continue; //don't update the frequency or the display


The code under   menuSetupCalibration()   for us mere mortals has this:

  while (digitalRead(PTT) == HIGH && !btnDown())
  {
    knob = enc_read();

    if (knob > 0){
      calibration += 8750;
      usbCarrier += 120;
    }
    else if (knob < 0){
      calibration -= 8750;
      usbCarrier -= 120;
    }

So the 12mhz BFO is getting adjusted by 120 hz each step, and the 875mhz vco by 8750 hz each step.  
That's 10ppm, and for a 30mhz operating frequency that means you can only set the rig to the nearest 300 hz.

Not a big deal, just leave it calibrated as shipped.
Or use the factory calibration procedure.
Or calibrate it as you (Gordon) have on the Bitx40 by jamming a correct value for the 25mhz reference oscillator into the sketch.
But I think the "on the air" calibration scheme in the code as shipped is going to be too coarse for most of us.
Easy enough to fix with a new sketch.

Jerry, KE7ER


On Sun, Dec 31, 2017 at 05:55 pm, Gordon Gibby wrote:
Not sure what rig that applies to, when I did the factory calibration at 10 MHz, it moved pretty smoothly.

Re: Tell me your favorite uBitx mods

Jerry Gaffke
 

What do you mean by motherboard?
Are you replacing the uBitx main board, for which the Raduino could be called a daughterboard?
Or perhaps you mean the Raduino board, for which the Nano could be called a daughterboard?


On Sun, Dec 31, 2017 at 06:29 pm, Diver Martin wrote:
As I'm doing a motherboard mod, I'm looking to incorporate a bunch of mods into one PCB.

Re: Tell me your favorite uBitx mods

Diver Martin <diver.martin@...>
 

My concept is to create a 6" x 5.5" PCB.  It would go on top of .5" standoffs on top of the uBitx main PCB.  One would remove the raduino, save the display, discard the nano/raduino (or better, use for a different project), and use the board as I'm creating it instead.  The idea is to create a clean, 2-PCB design, with a tuner, USB connectivity, built in connectors, etc.  It would replace some of the parts that come with the uBitx normally, make the case more compact, and remove the requirements to wire everything into an enclosure, allowing a clean 3D printed setup or however one would like.

On Sun, Dec 31, 2017 at 7:00 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:
What do you mean by motherboard?
Are you replacing the uBitx main board, for which the Raduino could be called a daughterboard?
Or perhaps you mean the Raduino board, for which the Nano could be called a daughterboard?

On Sun, Dec 31, 2017 at 06:29 pm, Diver Martin wrote:
As I'm doing a motherboard mod, I'm looking to incorporate a bunch of mods into one PCB.




--
Martin Held - AE7EU
http://ae7eu.com/
-------------------------------------------------------------------------------
If there aren't any questions, then what is there to learn?