Re: Farhan to give sBITX talk at FDIM
I was sort of listening to all of these while doing other things, but it seems to me that I was able to follow quite a lot of this, slides or no. I¡¯m blind, so that I was able to follow the presentations mostly says either 1) I have no idea what I¡¯m doing (not impossible), or 2) people do a good job of explaining without a lot of ¡°As you can see by this thing over here¡± kinds of explanations. Anyway, using a Pi to do a lot of the grunt work means more room for accessibility extensions, like things that talk and extra buttons in place of touch screen icons, or something. I suppose this means I should probably try to learn something useful and get going. ¡
Buddy Brannan, KB5ELV - Erie, PA
Email: buddy@...
Mobile: (814) 431-0962
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On May 24, 2021, at 10:15 AM, Shirley Dulcey KE1L <mark@...> wrote:
He's using a Raspberry Pi 4. That's four Cortex-A72 cores clocked at 1.5 GHz maximum out of the box, and it can be overclocked to 2 GHz if need be. Plenty of processing power, and the multiple cores mean that the user interface won't become unresponsive because of the CPU demands of the DSP. That's one flaw that the popular inexpensive DMR HTs all share; the SDR processing, the digital voice codec, and the user interface are all done by an STM32F405 processor, and limitations like their slow band scanning are caused by the heavy demands on that CPU.
Sustaining 1.5 GHz, let alone 2 GHz, for extended periods of time on multiple cores requires the addition of some way to cool the CPU; either a heat sink plus fan or a LARGE heat sink that is essentially the entire case for the board.
On Mon, May 24, 2021 at 9:52 AM Jack, W8TEE via groups.io <jjpurdum@...> wrote:
Hi Trystan:
My problem was that at the last moment I change from my house to Al's for the presentation. My office is in the basement and the extender I'm using started causing the Internet connection to drop out. Since that would be a disaster during my talk, Al let me set things up at his house. Things got a little confusing, but we muddled through.
I really enjoyed Ashar's talk as we are also working on an SDT. A couple of years ago, Al and I did a DSP board that connected to the uBITX, but it never really caught on. I think we made it too complex to add it to the uBITX. The new SDT will have mutlple boards with lots of "board real estate" and test points for experimenting. We will also do a book where each chapter will discuss a section of the rig, from antenna to earphones. Another thing we learned from the JackAl experience was NOT to use a resistive touch screen. Most QRP rigs do not have enough mass to activate a button without using the other hand to stabilize the rig. Ashar's rig uses capacitive touch...smart move! Also, he is using a large display where us "fat-finger people" can actually poke an individual button! And the RP has a mega-munch of memory and is clocked at 750mHz (I think?). Anyway, it was interesting to see what he's done with the uBITX in the SDT sandbox. I also admired the "cleanliness" of his code...good stuff!
Jack, W8TEE
On Monday, May 24, 2021, 3:54:59 AM EDT, Trystan G0KAY <trystandavies+nodirect@...> wrote:
Jack,
I really felt for you when you couldn't find your slides, then after you found them you couldn't share your screen. Then the summary table was all blacked out. Argh! Your talk was very good, thank you!
Unfortunately I missed Asher's talk as it was on too late for me, but plan to see it when they release the recording.
Trystan:
G0KAY
--
Jack, W8TEE
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Re: Sound card TNC free for a ham who needs it
The interface has been claimed via private email.
Chris?
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Re: Sound card TNC free for a ham who needs it
I don't see any replies. I'll take it.
John Norris K1CAG
2515 Solomon Lane Nashville TN 37207
On Sunday, May 23, 2021, 11:34:05 PM CDT, Christopher Miller <djmalak2k6@...> wrote:
Hello,
?I was gifted a v3 bitx by a ham when I was at my lowest. I want to buy another prebuilt sound card adapter Prewired for my Hf rig. This is only because I really do not have the skills to build cables. The kit itself is fine. You would have to build cables for your radio.
?I¡¯m willing to ship It to the first ham to email me from conus or Canada.?
kf4ftr
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Yeah. ?That what is inside the JackAl. ?
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On May 24, 2021, at 12:22 PM, jerry@... wrote:
?All,
?Has anybody played with this:
https://www.pjrc.com/diy-dsp-audio-filter-for-radio-hams/
?It's an audio filter with approximately 1 zillion features. ?I'd like to use it in my uBITXv6. ?Might strip everything out but the CW filter. ?I think it could also help with AGC - if the input can handle the range of signals.
?I like the idea of having the DSP at least help with AGC - because an AGC done totally before its input would reasonably cause the output to pump with strong out of band signals.
?Got a Teensy 3.6 on my desk right now.
?????????????????- Jerry KF6VB
--
¡_. _._
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Talk: The Magic Band by Don Field G3XTT - Tues 25th May 2021, 1900 UTC
#6meters
Talk: The Magic Band by Don Field G3XTT
Don Field G3XTT?will take us through the fascinating properties of the 6m Band which results in people calling it ¡°The Magic Band¡°.?The propagation properties of this band, as it is nestled between the HF bands and the VHF bands, give remarkable and often unexpected results.?These propagation properties attract enthusiasts who seek out these often unpredictable properties but with incredible results.
?
Don has also written the book,?¡°The Magic Bands¡±?which covers 6m and 4m. The book is available from the RSGB, Practical Wireless and Amazon.
?
Don Field G3XTT?is a well-known person in amateur radio, having been on the board of the RSGB, carried out DXpeditions, and is the editor of Practical Wireless.
?
We hope you can join us.
?
Tuesday 25th May 2021, 1900 UTC
?
This event is hosted on Zoom:??(Meeting ID: 773 073 0073 - no passcode)
Also, live-streaming on YouTube? (Bury Radio Society with Warrington Amateur Radio Club) Trystan G0KAY
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All,
Has anybody played with this:
It's an audio filter with approximately 1 zillion features. I'd like to use it in my uBITXv6. Might strip everything out but the CW filter. I think it could also help with AGC - if the input can handle the range of signals.
I like the idea of having the DSP at least help with AGC - because an AGC done totally before its input would reasonably cause the output to pump with strong out of band signals.
Got a Teensy 3.6 on my desk right now.
- Jerry KF6VB
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Re: Suggestions for a switching regulator
On a buck mode switcher, you are more concerned about? noise on the input, not the output. A 2A 5v switcher operating from 12v would be drawing about 5A from the 12v supply sometimes, 0A most of the time. The current through the inductor is pretty much constant. >? It was suggested to use a lower switching frequency so that the harmonics in the HF are weaker. With a 50khz switcher, you have a weak birdie every 50khz. WIth a 2mhz switcher, you have a strong birdie every 2mhz. Pick your poison. If you use a chip that can synchronize to an external clock, you could drive the switcher from one of the 8 outputs of a $2 Si5351C. Put them birdies anywhere you want. (It's of variable duty cycle, so there is some other hash.) With proper board layout, proper cap and inductor choices, chokes and bypass caps on input and output, perhaps some shielding, I doubt you would have much trouble with any of the IC's. But you need good documentation for that IC to make the proper choices. Jerry, KE7ER
?
On Mon, May 24, 2021 at 09:49 AM, Ashhar Farhan wrote:
Arv,
That is the best solution if you can :
1. Dissipate 2 A x (12-5)V = 14 watts continuously in a massive heatsink.
2. Be alright with a 20 watt power drain.
A straightforward LM338 takes care of this.
- f
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?
Farhan
?
A conventional (inexpensive) linear or switching regulator can be used
to drive a higher powered BJT or MOSFET pass transistor.? This also
provides a place (the base of that pass transistor) to add even more
filtering (4700 mfd in parallel with 0.1 mfd and 0.01 mfd).?
?
Arv
_._
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Re: Suggestions for a switching regulator
Arv, That is the best solution if you can : 1. Dissipate 2 A x (12-5)V = 14 watts continuously in a massive heatsink. 2. Be alright with a 20 watt power drain. A straightforward LM338 takes care of this. - f
Farhan
A conventional (inexpensive) linear or switching regulator can be used
to drive a higher powered BJT or MOSFET pass transistor.? This also
provides a place (the base of that pass transistor) to add even more
filtering (4700 mfd in parallel with 0.1 mfd and 0.01 mfd).?
Arv _._
On Mon, May 24, 2021 at 1:33 AM Ashhar Farhan < farhanbox@...> wrote: The LM2575 has just 1 A rating. we need 3A
On Mon, May 24, 2021 at 12:45 PM Cristian Radulescu via <criradul2001= [email protected]> wrote: Hi Ashhar,
I would suggest the LM2575 SMPS chip.
I used it many times and it seem quiet on SW bands and it will sustain 2-3 amps easily.
The schematics is simple and uses few components, a 330 microHenry inductor and a switching schotky diode (1N5819) apart from the in and out filtering capacitors.
73's de YO3IAZ, Cristian
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Re: Suggestions for a switching regulator
Farhan
A conventional (inexpensive) linear or switching regulator can be used
to drive a higher powered BJT or MOSFET pass transistor.? This also
provides a place (the base of that pass transistor) to add even more
filtering (4700 mfd in parallel with 0.1 mfd and 0.01 mfd).?
Arv _._
On Mon, May 24, 2021 at 1:33 AM Ashhar Farhan < farhanbox@...> wrote: The LM2575 has just 1 A rating. we need 3A
On Mon, May 24, 2021 at 12:45 PM Cristian Radulescu via <criradul2001= [email protected]> wrote: Hi Ashhar,
I would suggest the LM2575 SMPS chip.
I used it many times and it seem quiet on SW bands and it will sustain 2-3 amps easily.
The schematics is simple and uses few components, a 330 microHenry inductor and a switching schotky diode (1N5819) apart from the in and out filtering capacitors.
73's de YO3IAZ, Cristian
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Shaun G3ZSU
I was running my v3 on 160 m without a good matching antenna or harmonic filter and got the output transistors well too hot to touch, could smell them, had big heat sinks on.? I was very impressed with amount of heat and figured they got killed. After cool down, everything is fine.
Have had several mic elements give up the ghost and that gives almost no output. There are lot of things that can go bad. Usually my experience with the relays is that they get stuck on which gives different problems.
(OT) With a better antenna and high pass filter mine works very well on 160m.?
--
73
Dave
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Re: Suggestions for a switching regulator
Why not use the low current LM2575 to control a higher current pass transistor, perhaps a 3055, like we did in the 'old days' to build a power supply?
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Re: Suggestions for a switching regulator
Farhan
I know you specifically mentioned "switching" type supplies, but my
recommendation would be to use a linear regulator if possible.? Maybe
something like a 7810 followed by a 7805, if that is possible.? The
manufacturer's data sheets usually show the circuitry inside these,
allowing you to duplicate their circuits but with higher current capable
parts.? There are also 5A rated versions of these devices.
On Sun, May 23, 2021 at 11:22 PM Ashhar Farhan < farhanbox@...> wrote: It was suggested to use a lower switching frequency so that the harmonics in the HF are weaker. I will look at some 50 KHz parts. The transients need to b snubbed on the output and the input needs to be cleaned. I am wondering what kind of inductors will help. I will try with the FT37-43 (use what I have) and see if that works.
- f
On Mon, May 24, 2021 at 10:44 AM Ashhar Farhan via <farhanbox= [email protected]> wrote: Jerry, Terry, All good suggestions. Let me play with these.
I've built a lot of boards with switchers, but never
anything with radio gear on it.? It is done all the time though,
successfully.? I'm sure any cell phone has a few.
Here's an ap note from TI on this:
If you are building your own switcher, buy a chip from a mainstream?
manufacturer.? Being in the US, I would tend to look first at TI and Analog Devices,
though there certainly are other good sources.
A well documented part will have suggestions on board layout and
the proper choice of capacitors and inductors.? Read it carefully.
You might try corresponding with the manufacturer, asking for advice.
Your volumes will be relatively low, but the application engineers?
generally are happy to help.
For a radio, you want a switcher that operates at a constant frequency,
and at a frequency of your choosing.? A pin into the part can be supplied
with a clock of perhaps 500khz, telling the part when to switch.
The word "synchronous" in the world of switcher design means something?
else, and is not a requirement in your case.? It means that there are two FET's in your
buck mode switcher feeding the inductor.? Sometimes the high side FET
is on, connecting the power source to the inductor.? Other times the bottom side
FET is turned on, sourcing current from ground into the inductor.? In a "non-synchronous"?
switcher, that low side FET is typically just a schottky diode.? The diode is slightly
less efficient because it has a roughly 0.3v forward voltage drop, but that won't
make much difference for a 5v supply,
You definitely want a complete ground plane under it, follow the docuementation
on part placement and how to stitch up the ground plane.? Be aware of how
the switched currents are flowing.
You may want that ground plane to be on a different board than the radio.
Keep things physically small and the layout tight to reduce radiation.
For a buck mode switcher, it is switching the current coming in.
The current going out is fairly smooth if you have s sufficiently large inductor.
So pay special attention to selecting the capacitors at the input to the switcher,
and make sure they are placed very close to the FET switch.
Jerry, KE7ER
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Possibly no CAT because there is no USB driver.? A number of Microsoft 10.x users have indicated that the recent upgrades to 10.x have blocked
the USB driver that is used for CAT purposes.? Before blaming the hardware
or software I would try removing and then re-installing the USB driver,
particularly the driver for CH-340 USB devices.
If using a Linux system you can use "lsusb" to see what USB link is talking
to your Arduino.? I have no idea what the equivalent command would be
for Microsoft Windows.
Other possibility is that you have a bad case of "Schrodinger's CAT" virus.
Arv _._
On Sun, May 23, 2021 at 10:30 PM Evan Hand < elhandjr@...> wrote: On Sun, May 23, 2021, at 01:02 PM, Shaun Scannell wrote:
Not used my uBitX V6.1 for a? few weeks.? Today, It won't connect to Log4OM, or WSJT-X.? Device manager says USB No Driver loaded, but doesn't try to find one.? As a stand alone, receive is OK, but no transmit CW or SSB.? Before I start on the wrong thing, has anyone got any good idea's where to start please?
Shaun,
The only thing that CAT control and the lack of CW and SSB transmission would be the Nano.? I would suggest that you pull the Nano from the ?BITX and see if that will connect to the PC.? The Nano will get power from the USB port and should work as if the rest of the radio is there.? Of course, you will not get any of the audio signals, so you are just looking for the CAT control operations, not the full function of the software.
If the port and CAT functions do not work, then I would reflash the firmware in the Nano to see if that solves the issue.? Ashhar Farhan has a video on how to do that here:
My guess at this point is that something wiped out the Nano.
73
Evan
AC9TU
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Shaun,
Before replacing the IRF510s, do a voltage check on Q90.? That one is the most common culprit when both CW and SSB power output drops to less than a watt.? The values for the v4 power sections are the same for all versions.? It can be found by searching the files section for vu2zap in the Troubleshooting Folder.? Raj did the measurements and posted the spreadsheet.? Be sure to follow the instructions on the sheet: The power amp sections are measured by pressing the PTT and supplying no audio to the mic.
You can also do the bias test on the tuneup page of HFSignals:
If you can set the bias, the finals should be OK.
73
Evan
AC9TU
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Thank you to everyone.? There were 3 problems.??
First, Gyula, you were correct, I had upgraded Win10, and lost the Arduino drivers.??
Second, Thanks Evan, a re-flash of the Arduino got most things working again.
Third, Now almost no output. Nothing at all showing into a dummy load.? So I suspect I have managed to destroy the IRF510's.? Can hear a little by monitoring on another transceiver.? So have just ordered replacements.
Have no idea how this all happened, as it was 100% OK last time it was used.??
73, thanks for all the help.
Shaun G3ZSU
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Re: Suggestions for a switching regulator
On 2021-05-24 08:21, Gordon Gibby wrote: Great information, guys! Thank you for all this wisdom.
*** Indeed. I have a need for a 12V buck regulator in my "big linear" project. Had no idea it was so easy now. Just the switching regulator chip, an inductor, a fast diode and a couple capacitors. Wow. - Jerry KF6VB On May 24, 2021, at 09:42, Rafael Pinto [PU1OWL]
<rafaelgcpp@...> wrote: ?Farhan,
Ultimately I'd go to some of the big HF rigs service manuals and
check how they internally regulate the voltages.
The IC7300, for example, uses a TPS62110 from Texas Instruments, but
that is a 1.5A part. The FT991A uses some 7809, 7805 and linear
regulators.
Regards,
Rafael Links:
------
[1] /g/BITX20/message/88689
[2] /mt/83043300/243852
[3] /g/BITX20/post
[4] /g/BITX20/editsub/243852
[5] /g/BITX20/leave/10189903/243852/952924773/xyzzy
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Re: Farhan to give sBITX talk at FDIM
I don't think they do it automatically; you'd have to do it in the code, perhaps running the DSP in a separate thread or even as a separate program if that seems simpler. The library used by C code is glibc, of course, which is thread-safe.
Hi Shirley:
I haven't looked at the RP or its specs for a long time, and did not know it was running at that speed. I did notice during his talk that Farhan is using C for development, but there's a lot of Python code for the RP. Do you know if the C libraries automatically do threading for the UI?
Jack, W8TEE
On Monday, May 24, 2021, 10:15:55 AM EDT, Shirley Dulcey KE1L < mark@...> wrote:
He's using a Raspberry Pi 4. That's four Cortex-A72 cores clocked at 1.5 GHz maximum out of the box, and it can be overclocked to 2 GHz if need be. Plenty of processing power, and the multiple cores mean that the user interface won't become unresponsive because of the CPU demands of the DSP. That's one flaw that the popular inexpensive DMR HTs all share; the SDR processing, the digital voice codec, and the user interface are all done by an STM32F405 processor, and limitations like their slow band scanning are caused by the heavy demands on that CPU.
Sustaining 1.5 GHz, let alone 2 GHz, for extended periods of time on multiple cores requires the addition of some way to cool the CPU; either a heat sink plus fan or a LARGE heat sink that is essentially the entire case for the board.
Hi Trystan:
My problem was that at the last moment I change from my house to Al's for the presentation. My office is in the basement and the extender I'm using started causing the Internet connection to drop out. Since that would be a disaster during my talk, Al let me set things up at his house. Things got a little confusing, but we muddled through.
I really enjoyed Ashar's talk as we are also working on an SDT. A couple of years ago, Al and I did a DSP board that connected to the uBITX, but it never really caught on. I think we made it too complex to add it to the uBITX. The new SDT will have mutlple boards with lots of "board real estate" and test points for experimenting. We will also do a book where each chapter will discuss a section of the rig, from antenna to earphones. Another thing we learned from the JackAl experience was NOT to use a resistive touch screen. Most QRP rigs do not have enough mass to activate a button without using the other hand to stabilize the rig. Ashar's rig uses capacitive touch...smart move! Also, he is using a large display where us "fat-finger people" can actually poke an individual button! And the RP has a mega-munch of memory and is clocked at 750mHz (I think?). Anyway, it was interesting to see what he's done with the uBITX in the SDT sandbox. I also admired the "cleanliness" of his code...good stuff!
Jack, W8TEE
Jack, I really felt for you when you couldn't find your slides, then after you found them you couldn't share your screen. Then the summary table was all blacked out. Argh! Your talk was very good, thank you! Unfortunately I missed Asher's talk as it was on too late for me, but plan to see it when they release the recording. Trystan: G0KAY
--
Jack, W8TEE
--
Jack, W8TEE
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"Bugware 10" (the Pro version) also updated its supply of garbage
on my Lenovo W540.? This is a machine with 32 gig of RAM and a 1
terabyte SSD?? It took almost 4 hours to get the machine back into
working order.? At first, it wouldn't even accept my password and
refused to start.? Time to switch to Linux!? This isn't the first
time I've seen the hard drive pollution that MS ships.? It seems
that every alternate version is something best lost in space.
Gerry
Sent by the Thunderbird.
On 2021-05-24 10:01 a.m., Scott via
groups.io wrote:
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I've struggled with this exact problem and my advice would be to thoroughly?investigate
the COM port settings and leave the uBITX as is.? ?Even now, when
I have to restart the computer I sometimes have to restart WSJT-X
a few times or disconnect/connect? the USB cable to get things to
synch up.? ?Get your device manager open and display a window with
the com port settings beside a window of the Settings/Radio screen
in WSJT and check for any dissimilarities.
For reference, my WIn10 just got a lengthy update (which
completely knocked out my Bluetooth - ongoing) and here's my
working driver info;
Scott
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Re: Suggestions for a switching regulator
Great information, guys! Thank you for all this wisdom.?
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Show quoted text
On May 24, 2021, at 09:42, Rafael Pinto [PU1OWL] <rafaelgcpp@...> wrote:
?Farhan,
Ultimately I'd go to some of the big HF rigs service manuals and check how they internally regulate the voltages.
The IC7300, for example, uses a TPS62110 from Texas Instruments, but that is a 1.5A part. The FT991A uses some 7809, 7805 and linear regulators.
Regards,
Rafael
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MadRadioModder
Trystan G0KAY
_Dave_ AD0B
Shirley Dulcey KE1L