Date   
Re: Coding styles

Ashhar Farhan
 

64x16? K&R?? Surely, you are not talking floppy shuffle on the Xerox 820 or (jerry pournelle, peace be upon him) a Kaypro?
BDS C was the only game in town. I brought up a CP/M system for my undergraduate project work. 
- f
- f

On Mon, 7 May 2018, 09:44 Jack Purdum via Groups.Io, <jjpurdum=yahoo.com@groups.io> wrote:
The brace thing is really a matter of choice. I learned C back in the late 1970's when K&R was the only C book and I had a 64x16 modified TV for a CRT, so I put things on the same line, simply so I could see more lines without scrolling:

   if (w == 5) {
      y = true;
   } else {
      y = false;
   }

Even though the braces are not required with a single statement, I almost always use them. When I don't, invariably I need to add another statement or a debug print statement, so I have to add the brace anyway. However, with function signatures, I always place the opening brace for the function body on a new line. I think people pick what works for them. No one style is "correct", so, to me at least, there's no reason to even debate what's correct when it comes to braces. However, we should all try to make our code as readable as possible.

When I was in high school, the football coach knew I was a ham radio operator and wanted me to build two Heathkit walkie talkies. I built them, and they didn't work. I was mortified. I barely slept that night. The next morning, my Mom told me I got up in the middle of the night and wrote something on the pad next to the phone. I read what I wrote, went downstairs and checked it and, sure enough, that was the problem. Ever since then, I keep a pad and pencil next to the bed. I can't tell you how many teaching examples I've used that came from that pad or programming problems that were solved by reading the pad the next morning. My experiences have convinced me that your brain continues to problem solve even when you're asleep.

Jack, W8TEE


On Sunday, May 6, 2018, 11:51:40 PM EDT, Jerry Gaffke via Groups.Io <jgaffke=yahoo.com@groups.io> wrote:


You guys take this so seriously.
Maybe you should find a hobby.   ;-)

Though I understand, I'm afflicted by the same malady.
Just a slightly different strain.
Here's a fix, no need to ever again deal with my coding style (one of many possible tools):
    http://uncrustify.sourceforge.net/ 

If you object to K&R style, there's a lot of it out there for you to sic crustify on.
Here's a few million lines to get you started:
    https://github.com/torvalds/linux

> You can also use Ctrl-T to format your code to a common C coding style.

I assume that's for the Arduino IDE, whose editor I mostly avoid.
Here's various tricks for vi/vim users:
    https://stackoverflow.com/questions/2355834/how-can-i-autoformat-indent-c-code-in-vim

Here's a discussion of the various indentation styles:
    https://softwareengineering.stackexchange.com/questions/99543/what-is-the-difference-between-kr-and-one-true-brace-style-1tbs-styles
They can't agree either.
But somebody in there did a study of error rates in code using the various styles.
Note that K&R style won, at least by a little bit.
Though perhaps that's because folks using the K&R style
are more likely to have read K&R (highly recommended).

I was quite serious about that back pocket thing.
If I have a difficult algorithm to work on, I code it tight so I can see
as much of the work at one time as possible.  Preferably so it all fits
on one side of a sheet of typing paper.  Better yet, half of one side.
Then pull it out at odd times during the day, jot notes when new insights come.
Works for me.

Didn't anybody have any comments about on how better to compute SWR? 

Jerry, KE7ER


On Sun, May 6, 2018 at 05:31 pm, Jack Purdum wrote:
Braces or brackets? Braces mark statement/function blocks while brackets are most often used with array sizes. The old K&R style was to leave the opening brace on the same line as the expression block, and then align the closing brace with the expression block start. I think that was done to get more lines on the screen when a 25 line display was common. Today, most seem to place the opening brace on its own line. If the block spans more than a page, the latest IDE shows the opening expression.

You can also use Ctrl-T to format your code to a common C coding style.
 

Re: 45Mhz crystal filter specification

Jerry Gaffke
 

The AD8302 is an interesting part, been around a couple decades now, about as long as the AD8307.
Curious that it doesn't get used more often by hams, virtually no google hits on projects using it.
Perhaps because most of us do our best to avoid thinking much about complex impedances. 

Ebay has the AD8302 for a buck, they're $20 on mouser.
But even if slightly out of spec, a vector network analyzer for $1 is not a bad deal.
Appears it won't be able to tell you if it was R+jX or R-jX.

The ebay AD8307's that I have show all the markings of legit parts.
If they are fallouts, I'd think Analog Devices would step on whoever's sourcing them.
But they've been getting sold cheaply for years now.

Jerry



On Sun, May 6, 2018 at 03:54 pm, K9HZ wrote:
Yet another reason I opted for the AD8302 for my tuner…  FREE R+jX…

#ubitx Powel Levels after SImple Mods #ubitx

astronuticus@...
 

I wanted a bit more power out of my uBITX, especially on the 20m and 30m bands, so I could operate with relatively inefficient portable antennas and still be heard (without the hassle of a separate linear amp).  So, after sifting through the suggestions here and over at ubitx.net, I implemented the following three relatively easy mods:
  • As suggested by Howard (WB2VXW): Added a 27 uH inductor in series with R86, and 220 pF caps in parallel with R87 and R88.  That improved power output at 14 MHz and higher frequencies.
  • As suggested by Bill (K9HZ): Replaced RV1 with a little daughtercard that uses three miniature relays (triggered by Q17, Q18, and Q18) to switch in a separate drive pot for each band group.  That way you can back off drive levels on the lower frequencies without sacrificing so much power on the higher frequencies.
  • As suggested by many folks, I separated the PA and mainboard power supplies, and upped the PA supply to 24 VDC (while keeping the mainboard at 13.5 VDC).
For anyone contemplating those mods, here is a list of the resulting output power level and power supply current level for each dial frequency (into a dummy load):
  • 3.573 MHz / 22 W / 2.6 A  (Initially 28 W, so I backed off RV1d a bit)
  • 5.347 MHz / 16 W / 1.96 A
  • 7.074 MHz / 22 W / 2.33 A  (Initially 28 W, so I backed off RV1c a bit)
  • 10.136 MHz / 12 W / 1.58 A
  • 14.074 MHz / 20 W / 2.13 A
  • 18.100 MHz / 12 W / 1.61 A
  • 21.074 MHz / 11 W / 1.40 A
  • 24.915 MHz / 9 W / 1.25 A
  • 28.074 MHz / 8 W / 1.24 A
Again, all of these tests were into a dummy load while using a 24 VDC supply for the PA , and 13.5 VDC for the mainboard (from a little LM2596 buck converter inside the chassis, so I don't need a second power supply).  I used the tune button on the WSJT-X software to drive the audio input (audio frequency set to 1500 Hz).  The finals got a little warm, but not too warm to touch, while I was adjusting the RV1a, RV1b, RV1c, and RV1d pots.  Nevertheless, I added a little DC fan (which will be switched on and off by a thermal switch, once the switch arrives).

Note that I was getting about 11 W at the lower frequencies, and 3 or 4 W at the higher frequencies, when I first assembled the radio (using a 13.8 VDC supply).

I was initially reluctant to mess with a 24 VDC supply, in that all of my portable power packs are 12 VDC.  But I found that a pair of 7AH Apex AGM batteries would only set me back $35, shipped.  That should be enough power to last a day or two at a far higher TX duty than is typical for me. (Current draw while receiving, with the fan on, is 148 mA.)

I also ordered a DROK boost converter ($11.99 on Amazon) that is supposed to be able to supply 24 VDC (up to 4A) from a 12 VDC supply.  That may make it practical to power my portable setup from a single car battery, assuming that boost converter is as quiet as my buck converters have been.  

To summarize, I now have as much power as I want for digital modes on all bands, even under lousy band conditions.  It has been a blast tinkering with this thing, but I'm going to try leaving it assembled for a while and focus on making some contacts.

73,
  Mark (AE7TO)
BTW, I haven't messed with bias levels on the finals, and don't plan to.  I'm confident those were adjusted correctly at the factory.

Re: Coding styles

Jack, W8TEE
 

The brace thing is really a matter of choice. I learned C back in the late 1970's when K&R was the only C book and I had a 64x16 modified TV for a CRT, so I put things on the same line, simply so I could see more lines without scrolling:

   if (w == 5) {
      y = true;
   } else {
      y = false;
   }

Even though the braces are not required with a single statement, I almost always use them. When I don't, invariably I need to add another statement or a debug print statement, so I have to add the brace anyway. However, with function signatures, I always place the opening brace for the function body on a new line. I think people pick what works for them. No one style is "correct", so, to me at least, there's no reason to even debate what's correct when it comes to braces. However, we should all try to make our code as readable as possible.

When I was in high school, the football coach knew I was a ham radio operator and wanted me to build two Heathkit walkie talkies. I built them, and they didn't work. I was mortified. I barely slept that night. The next morning, my Mom told me I got up in the middle of the night and wrote something on the pad next to the phone. I read what I wrote, went downstairs and checked it and, sure enough, that was the problem. Ever since then, I keep a pad and pencil next to the bed. I can't tell you how many teaching examples I've used that came from that pad or programming problems that were solved by reading the pad the next morning. My experiences have convinced me that your brain continues to problem solve even when you're asleep.

Jack, W8TEE


On Sunday, May 6, 2018, 11:51:40 PM EDT, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:


You guys take this so seriously.
Maybe you should find a hobby.   ;-)

Though I understand, I'm afflicted by the same malady.
Just a slightly different strain.
Here's a fix, no need to ever again deal with my coding style (one of many possible tools):
    http://uncrustify.sourceforge.net/ 

If you object to K&R style, there's a lot of it out there for you to sic crustify on.
Here's a few million lines to get you started:
    https://github.com/torvalds/linux

> You can also use Ctrl-T to format your code to a common C coding style.

I assume that's for the Arduino IDE, whose editor I mostly avoid.
Here's various tricks for vi/vim users:
    https://stackoverflow.com/questions/2355834/how-can-i-autoformat-indent-c-code-in-vim

Here's a discussion of the various indentation styles:
    https://softwareengineering.stackexchange.com/questions/99543/what-is-the-difference-between-kr-and-one-true-brace-style-1tbs-styles
They can't agree either.
But somebody in there did a study of error rates in code using the various styles.
Note that K&R style won, at least by a little bit.
Though perhaps that's because folks using the K&R style
are more likely to have read K&R (highly recommended).

I was quite serious about that back pocket thing.
If I have a difficult algorithm to work on, I code it tight so I can see
as much of the work at one time as possible.  Preferably so it all fits
on one side of a sheet of typing paper.  Better yet, half of one side.
Then pull it out at odd times during the day, jot notes when new insights come.
Works for me.

Didn't anybody have any comments about on how better to compute SWR? 

Jerry, KE7ER


On Sun, May 6, 2018 at 05:31 pm, Jack Purdum wrote:
Braces or brackets? Braces mark statement/function blocks while brackets are most often used with array sizes. The old K&R style was to leave the opening brace on the same line as the expression block, and then align the closing brace with the expression block start. I think that was done to get more lines on the screen when a 25 line display was common. Today, most seem to place the opening brace on its own line. If the block spans more than a page, the latest IDE shows the opening expression.

You can also use Ctrl-T to format your code to a common C coding style.
 

Re: Coding styles

Jerry Gaffke
 

You guys take this so seriously.
Maybe you should find a hobby.   ;-)

Though I understand, I'm afflicted by the same malady.
Just a slightly different strain.
Here's a fix, no need to ever again deal with my coding style (one of many possible tools):
    http://uncrustify.sourceforge.net/ 

If you object to K&R style, there's a lot of it out there for you to sic crustify on.
Here's a few million lines to get you started:
    https://github.com/torvalds/linux

> You can also use Ctrl-T to format your code to a common C coding style.

I assume that's for the Arduino IDE, whose editor I mostly avoid.
Here's various tricks for vi/vim users:
    https://stackoverflow.com/questions/2355834/how-can-i-autoformat-indent-c-code-in-vim

Here's a discussion of the various indentation styles:
    https://softwareengineering.stackexchange.com/questions/99543/what-is-the-difference-between-kr-and-one-true-brace-style-1tbs-styles
They can't agree either.
But somebody in there did a study of error rates in code using the various styles.
Note that K&R style won, at least by a little bit.
Though perhaps that's because folks using the K&R style
are more likely to have read K&R (highly recommended).

I was quite serious about that back pocket thing.
If I have a difficult algorithm to work on, I code it tight so I can see
as much of the work at one time as possible.  Preferably so it all fits
on one side of a sheet of typing paper.  Better yet, half of one side.
Then pull it out at odd times during the day, jot notes when new insights come.
Works for me.

Didn't anybody have any comments about on how better to compute SWR? 

Jerry, KE7ER


On Sun, May 6, 2018 at 05:31 pm, Jack Purdum wrote:
Braces or brackets? Braces mark statement/function blocks while brackets are most often used with array sizes. The old K&R style was to leave the opening brace on the same line as the expression block, and then align the closing brace with the expression block start. I think that was done to get more lines on the screen when a 25 line display was common. Today, most seem to place the opening brace on its own line. If the block spans more than a page, the latest IDE shows the opening expression.

You can also use Ctrl-T to format your code to a common C coding style.
 

Re: SWR

K9HZ <bill@...>
 

BTW I’m using the MCP3202… SPI and dual channel with Sample and Hold…

 

 

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 Jerry Gaffke via Groups.Io
Sent: Sunday, May 6, 2018 9:39 PM
To: BITX20@groups.io
Subject: Re: [BITX20] SWR

 

Here's the datasheet:
    http://www.ti.com/lit/ds/symlink/ads1015.pdf
Pages 20-23 are of interest.
Looks to me like it is on the order of 10 bytes transferred via the i2c bus for each ADC read,
since we have to switch channels between reads to choose forward vs reflected power.
At 100 khz, that's 10us * 10 * 8bits/byte = 800 us.
That's an order of magnitude slower than reading the Nano's ADC using a an analogRead() call, around 100us.

It is possible to speed the i2c bus up from 100 khz to 400 khz,
But we can speed up the Nano ADC reads by a factor of 5, fiddling with the ADC clock prescaler.

So using the Nano's ADC is much faster than using this i2c ADC chip
Now if you found a good SPI ADC chip, that might be a different story.

Jerry


Virus-free. www.avg.com

Re: SWR

K9HZ <bill@...>
 

If you are only reading one variable, it’s much better to use the Nano’s A/D.  There is no syncing to do… just let it run continuously and read whats ever in the register.

 

 

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 Jerry Gaffke via Groups.Io
Sent: Sunday, May 6, 2018 9:39 PM
To: BITX20@groups.io
Subject: Re: [BITX20] SWR

 

Here's the datasheet:
    http://www.ti.com/lit/ds/symlink/ads1015.pdf
Pages 20-23 are of interest.
Looks to me like it is on the order of 10 bytes transferred via the i2c bus for each ADC read,
since we have to switch channels between reads to choose forward vs reflected power.
At 100 khz, that's 10us * 10 * 8bits/byte = 800 us.
That's an order of magnitude slower than reading the Nano's ADC using a an analogRead() call, around 100us.

It is possible to speed the i2c bus up from 100 khz to 400 khz,
But we can speed up the Nano ADC reads by a factor of 5, fiddling with the ADC clock prescaler.

So using the Nano's ADC is much faster than using this i2c ADC chip
Now if you found a good SPI ADC chip, that might be a different story.

Jerry


Virus-free. www.avg.com

Re: uBitx relay pinouts

Joe Puma
 

I thought if you tap before the roofing filter you can get a viewable bandwidth as much as the SDR receiver you’re using at a time, for a RTL-SDR thats 2MHz. I do this on my Yaesu.

 

I haven’t done this mod yet, heck I havnt even built my ubitx, waiting to buy a case so I don’t know where you were tapping and if it was after the roofing filter you would get a 15Khz signal if I’m correct?

 

 

Joe,

KD2NFC

 

 

Architecture The µBITX uses upconversion to the first IF of 45 MHz. This eliminates the need for a large number of band pass filters, keeping the design simple and virtually image free. The roofing filter at 45 MHz is 15 KHz wide. The signal is then down-converted to 12 MHz where a low ripple SSB filter with 8 crystals is used to provide a sparkling audio.

 

 

Sent from Mail for Windows 10

 


From: BITX20@groups.io <BITX20@groups.io> on behalf of Gregory Keys <Kg4gek@...>
Sent: Sunday, May 6, 2018 9:14:22 PM
To: BITX20@groups.io
Subject: Re: [BITX20] uBitx relay pinouts
 
Figured it out.
 I have been running my uBitx with KD8CEC's firmware and have been particularly happy with his SDR adaptation. However, it really bugged me that I could only see a very small amount of bandwidth at a time when using the tap off of the IF.
So, I added my upconverter inside the ubitx, put in a 5 volt power supply for it, and tapped the antenna directly on the output of K3. The end result is seen below. The first pic shows what I saw using the IF tap, a very small portion of the 80meter band around the tuned frequency. The second shows the entire 40 meter band! In order to do this, only one change was needed on the SDR software, in the external radio settings there is an option to run sharing the antenna rather than using the IF.
KG4GEK
Greg


Screenshot-2018-05-03-225437.png
Screenshot-2018-05-06-210043.png


On Sun, May 6, 2018 at 7:01 PM Dexter N Muir <dexy@...> wrote:

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

steve@...
 

Is it too late to sign up for one of each boards?

Steve
VE7GOY

Re: SWR

Jerry Gaffke
 

Here's the datasheet:
    http://www.ti.com/lit/ds/symlink/ads1015.pdf
Pages 20-23 are of interest.
Looks to me like it is on the order of 10 bytes transferred via the i2c bus for each ADC read,
since we have to switch channels between reads to choose forward vs reflected power.
At 100 khz, that's 10us * 10 * 8bits/byte = 800 us.
That's an order of magnitude slower than reading the Nano's ADC using a an analogRead() call, around 100us.

It is possible to speed the i2c bus up from 100 khz to 400 khz,
But we can speed up the Nano ADC reads by a factor of 5, fiddling with the ADC clock prescaler.

So using the Nano's ADC is much faster than using this i2c ADC chip
Now if you found a good SPI ADC chip, that might be a different story.

Jerry

Re: ND6T AGC implementation for uBIT-X

Tim Gorman
 

I made this point earlier. If you are tuning for minimum reverse power
you actually don't have to do any computation. Just output the reading
from the adc, be it an adafruit ads1015 or an AD8307. If the reading is
going down then so is the reverse power. Minimum load on the nano.

tim ab0wr

On Sun, 06 May 2018 17:26:55 -0700
"Kees T" <windy10605@...> wrote:

So what would be the minimum compute requirement on an existing
Nano ? Maybe read 2 analog inputs directly from 2 AD8307s  with only
a scaling factor for Stockton Bridge coupler loss. Multiply that by
1dBm per 25mV (linear spec for the AD8307) and you have the Forward
and Reflected power in dBm into a 50 ohm load.  Look up the "power"
in Watts or tape a small chart on the bottom of the uBITX.

73 Kees K5BCQ

Re: ND6T AGC implementation for uBIT-X

Tim Gorman
 

Jerry,

Do you have a portable antenna that is flat from 3500khz to 4000khz? Go
from one end of the band to the other and see if you are getting
reverse power at any point.

I don't put a unit in my go box that I question whether it is operating
or not. If operation is questionable then it isn't a unit you want to
depend upon in the field.

tim ab0wr

On Sun, 06 May 2018 17:24:55 -0700
"Jerry Gaffke via Groups.Io" <jgaffke=yahoo.com@groups.io> wrote:

There are times when I'd like to know if the rig is working. 

On Sun, May 6, 2018 at 04:59 pm, Tim Gorman wrote:


Forward power, and using it to calculate SWR, tells you more about
how your rig is operating then about the match to the antenna.

Re: ND6T AGC implementation for uBIT-X

Tim Gorman
 

How often in a portable operation do you connect to an antenna that has
*no* reverse power? An antenna that is perfectly flat on all
frequencies?

If you are using a tuner it's pretty simple to see if the
rig is putting out any power. Just tune away from what you think is a
perfect match.

I measure PA current to actually tell if the rig is working. Using an
i2c current sensor.

tim ab0wr



On Sun, 6 May 2018 20:38:36 -0400
"Vince Vielhaber" <vev@...> wrote:

If you're only looking at reflected power and it's flat you don't
know if you have a good swr or the radio isn't putting out. Now if
you're also looking at forward power, the mystery is solved.

Vince.



On 05/06/2018 07:59 PM, Tim Gorman wrote:
A simple measure of reverse power will tell you if the antenna is
working ok.

Re: ND6T AGC implementation for uBIT-X

Tim Gorman
 

That's basically what I am using. Except an LED won't read clear down
to zero reverse power.

tim ab0wr

On Sun, 6 May 2018 19:14:46 -0500
"K9HZ" <@Doc_Bill> wrote:

I guess then to take it a step further, all you need is the reverse
line section, a diode, a couple of RF blocking capacitors, a
resistor, and an LED. LED blinks when there is reverse power. You
could make that for less than $1.


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!

Re: SWR

Tim Gorman
 

Why is the i2c so much slower? When using the adafruit ads1015 the
entire analog to digital conversion is completely off-loaded from the
nano. All you have to do is read the registers in the ads1015. There is
a small amount of overhead in the i2c communication protocol but it
isn't significant from what I can see.

It isn't a matter of how fast the analog to digital conversion can be
done because you don't have to read the voltage repetitively as fast as
you can. You can't adjust a tuner faster than the nano can read it from
an i2c adc.

There was an earlier thread where it was argued that off-loading
everything you could from the nano to an attached processor provided
more cycles for things the nano *has* to accomplish. I would think that
would surely include doing analog-to-digital conversion.

tim ab0wr

On Sun, 6 May 2018 15:24:42 -0500
"AA9GG" <paul.aa9gg@...> wrote:

I agree the I2C would be a lot slower. You are better off using the
ADC inputs directly and let it "free-run" (I use ADC6 and ADC7).
That way when you need to access the data, it's just a quick check of
the "conversion complete flag" and grab the data from the registers.

On Sun, May 6, 2018 at 2:35 PM, K9HZ <@Doc_Bill> wrote:

We must use different libraries. I send out the start conversion
word to the part address… and away it goes. Then sometime later,
I poll to see if conversion is ready/ do a read at the same time
(because you get one or the other for free). If the data isn’t
ready, throw away what you got back and go do something else. If
you test every quarter-second, you would always get the data and
the ready bit set TRUE. Then update the display. Again, the time
it takes to do the A/D conversion isn’t important off-board as long
as both power readings are congruent and ready together at some
point. The reads can be executed whenever convenient as not to
interfere with keying, CAT commands, etc. without using interrupts.



With all this said, I support using a couple of caps and doing
something really easy. Maybe it works perfectly.





*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 <http://www.villagrandpiton.com/>

*Like us on Facebook! **[image: facebook icon]*
<https://www.facebook.com/VillaGrandPiton/>



Moderator – North American QRO Group at Groups.IO.



email: @Doc_Bill





*From:* BITX20@groups.io [mailto:BITX20@groups.io] *On Behalf Of
*Jerry Gaffke via Groups.Io
*Sent:* Sunday, May 6, 2018 1:54 PM
*To:* BITX20@groups.io
*Subject:* Re: [BITX20] SWR



You said
> goes on about its business for a while
That's not correct, unless you add some code to handle i2c transmit
and receive in
interrupt routines. That's some code most of us would prefer to
avoid.

We currently do blocking IO on I2C reads and writes.
Just clocking all those I2C bits around at 100khz takes
considerably more time than doing the embedded ADC reads.

I'm assuming we are mostly concerned about delaying other
operations, such as sensing the keyer.

If all you are worried about is how synchronous the two samples are,
then yes the 2 channel ADC chip on the I2C bus would be better,
even if we stick with the blocking code on i2c access.
Me, I'll try out a couple big caps first.

Jerry

On Sun, May 6, 2018 at 10:50 am, K9HZ wrote:

“Actually, reading values from an A/D over the I2C bus will take
more time than just reading from the Nano's embedded ADC. “



Yes, but in this case, taking more time is ok… because the Arduino
commands the A/D to perform its function, goes on about its
business for a while…the digitization happens independently of the
Arduino processing, and the data will be waiting for you want to go
get it. There is no real demand on when the data needs to be
available, it’s more a demand of being synchronized (so it’s
statistically better to get the average of 5 good numbers rather
than 50 marginal numbers). And (for me the best part) you really
can employ an A/D with synchronized S/H for good coordinated
forward and reverse power.



I really don’t think anyone here (other than me) will ever do it
this way. Just indicating reverse power by some cheap method is
probably fine for tuning an antenna.





<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient>
Virus-free. www.avg.com
<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient>
<#m_7015192241025951502_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>


Off topic: Duwayne on QSO Today

Ashhar Farhan
 

I think that this one deserves an exception. I hope the moderators agree :

DuWayne, KV4QB, our fellow here in the group. He is an amazing homebrewer who has done some really original work. We met online a few years ago on the Minima llist. 

He has been featured on the QSO Today. His story is inspiring and educational for me. 


- f

Re: ND6T AGC implementation for uBIT-X

Gene Nitschke <genenitschke@...>
 

Kees,


Thanks.  Found the files.   I have done a lot of SMT so looking forward to the boards to play with.

SWR/Wattmeter would be great especially if small enough to integrate in the uBitX box.


Thanks for all your hard work, and i am sure the entire group, appreciates it.


Thanks again,

Gene N2IJF




From: BITX20@groups.io <BITX20@groups.io> on behalf of Kees T <windy10605@...>
Sent: Sunday, May 6, 2018 6:59 PM
To: BITX20@groups.io
Subject: Re: [BITX20] ND6T AGC implementation for uBIT-X
 
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: ND6T AGC implementation for uBIT-X

Paul Littleton
 

I would like to obtain both the AGC and Click kits. 

Thanks

73, Paul, KA5BIW 

Re: uBitx relay pinouts

Gregory Keys
 

Figured it out.
 I have been running my uBitx with KD8CEC's firmware and have been particularly happy with his SDR adaptation. However, it really bugged me that I could only see a very small amount of bandwidth at a time when using the tap off of the IF.
So, I added my upconverter inside the ubitx, put in a 5 volt power supply for it, and tapped the antenna directly on the output of K3. The end result is seen below. The first pic shows what I saw using the IF tap, a very small portion of the 80meter band around the tuned frequency. The second shows the entire 40 meter band! In order to do this, only one change was needed on the SDR software, in the external radio settings there is an option to run sharing the antenna rather than using the IF.
KG4GEK
Greg


Screenshot-2018-05-03-225437.png
Screenshot-2018-05-06-210043.png


On Sun, May 6, 2018 at 7:01 PM Dexter N Muir <dexy@...> wrote:

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

Vince Vielhaber
 

If you're only looking at reflected power and it's flat you don't know if you have a good swr or the radio isn't putting out. Now if you're also looking at forward power, the mystery is solved.

Vince.

On 05/06/2018 07:59 PM, Tim Gorman wrote:
A simple measure of reverse power will tell you if the antenna is
working ok.