Re: The sBitx Release on www.vu2ese.com
Will the SBITX software start and run on a Pi 4, 8 GB by itself, in other words ?the Pi isn¡¯t connected to the SBITX boards? My kit has been shipped, but I thought I would familiarize myself with the SBITX software while I wait for it. I successfully burned the image from the vu2ese.com website onto a 32 GB MicroSD card and the Pi 4 will boot from it. When I click on the SBITX icon, Fldigi starts in another browser tab and a window flashes briefly in the middle of the screen. I can open the Fldigi tab and close it, but I can¡¯t get the SBITX window to stay open. Thanks.
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Stephen, KO4CVU
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Scott, I had posted in the linuxhams group that has members who develop the hamlib. The question was "what is the minimal set of commands that a net rigctl should implement?" So far I havent got any reply.? We should have a way where we kill the fldigi when we choose the digital mode.
These are tradeoffs, the fldigi takes time to wake up. So if it is not prelaunched, quickly flipping between modes will be difficult. On the other hand, fldigi automatically takes over and hangs onto the audio devices, preventing other apps to take over the same.
If there are any pulseaudio gurus here, we can perhaps do a better job with easier virtual devices. - f
Hi Ashhar,
I think I figured most of it out.? Only one external application can access audio at a time.? I did not notice that fldigi automatically launched when sBitx is launched.? I closed fldigi and launched wjstx and partial success.? CAT control is still funky, when it works it seems to only allow sbitx to external app control and not the other way round.? That worries me a bit for automated transmissions, etc., but I have a much better understanding of how audio is used in the RPI.? I'm going to download the RPI version of JS8Call and try to set it up like wjstx and fldigi.? We'll see.
So far I am really pleased.? Looking forward to updates and bug fixes as they become available.? I imagine you will have one for things like the audio "tap" and others in the near future.
Cheers, Scott?
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Hi Ashhar,
I think I figured most of it out.? Only one external application can access audio at a time.? I did not notice that fldigi automatically launched when sBitx is launched.? I closed fldigi and launched wjstx and partial success.? CAT control is still funky, when it works it seems to only allow sbitx to external app control and not the other way round.? That worries me a bit for automated transmissions, etc., but I have a much better understanding of how audio is used in the RPI.? I'm going to download the RPI version of JS8Call and try to set it up like wjstx and fldigi.? We'll see.
So far I am really pleased.? Looking forward to updates and bug fixes as they become available.? I imagine you will have one for things like the audio "tap" and others in the near future.
Cheers, Scott?
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Re: Turn off WiFi on your sBitx
OK. I was a little too fast. I did the test without the top cover. When the top cover is in place the sound is there but the frequency is lower than before.
When the WiFi signal is low the the WiFi -transmitter raises the signal power.
Tomorrow I will build another LM380 amplifier and try placing it away from the WiFi section.
/niels
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Re: sBitx antenna-first warning
Semiconductor devices die from either too much power leading to thermal damage, or higher voltage leading to voltage damage, or too much current leading to some other damage.?
It¡¯s not magical why they get destroyed. ?It¡¯s easy to explain why Q90 could be destroyed in earlier designs; too much reverse voltage.?
The impedance presented to the semiconductor devices by the combinations of passive devices between them and relatively free space (TraTransformers, inductors, capacitors, multiple multiple multiple) ?should remain relatively constant at any power level. ? The passive devices don¡¯t really care what power level (within their limits), they simply run around the Smith chart
Depending on what impedance they present to the RF power being potentially delivered by the semiconductors through drain voltage and current changes, some set of instantaneous voltages and currents (at radio frequency) will be developed. ? ??
At low power, the variations in the voltage and current Of the semiconductors ?is very much likely less. ?Hence, less ?chance of exceeding one of their ratings.?
I don¡¯t think the semiconductor die can tell what the SWR is¡ª only what voltage drops in current flows are happening. ?And from knowing where you are on the Smith chart those should be predictable. ??
I hope that makes some sense.?
Gordon.?
toggle quoted message
Show quoted text
On Aug 4, 2022, at 08:49, Jack, W8TEE via groups.io <jjpurdum@...> wrote:
?
On Wednesday, August 3, 2022 at 01:45:51 PM EDT, Ashhar Farhan <farhanbox@...> wrote:
Jack, How much voltage were you running on the drains? - f
We've tested the T41 with its 510s to 40W and nothing fried. 80-40-20M all can deliver about 25W without much effort. 15M is about 20W and 10M drops to about 13W. Like I said, it is what it is...
Jack, W8TEE
On Wednesday, August 3, 2022 at 01:14:06 PM EDT, Jerry Gaffke via <jgaffke= [email protected]> wrote:
The IRF510 can work dependably, Allison reports years of success with HF amps at 40W push-pull, surviving everything from accidental open antenna connections to dead shorts. In posts to this forum from several years ago, Allison went into plenty of detail. She even used them on 6m at several hundred watts (with bunches of them in parallel). The QSX amp from qrp-labs uses IRF510's in push-pull, does a consistent 10W from 3 to 30mhz. ? Clean and linear even when operating from 12v, tolerates any antenna condition. A product of collaboration between Hans and Allison.? ?Cost of $26 USD for the kit, a steal. If I were building a rig like the sBitx from scratch, I would start with that amp for a PA, perhaps add PIN diode TR switching with the HV supplied by rectified RF. HFsignals could steal that PA design for the sBitx-v2, give Hans $5 for every unit if feeling guilty. Using the IRF510 for RF power amps takes careful design.? Especially heat sinking, as the IRF510 is not very good at getting heat from the die to the TO220 tab.? The IRF510 prefers more like 24vdc for higher power and reduced distortion. Improper design can blow the gate due to exceeding Vgs max spec momentarily Needs more drive than an RD16HHF1 to get similar power levels due to moderately high gate capacitance. However, Vds max is much higher for the IRF510 than it is for the RD16HHF1, so for cases of high Vds the IRF510 would survive a high SWR better than the RD16HHF1. Allison was of the opinion that moving to the RD16HHF1 on the uBitx would not help much. Reading from?? "The power amplifier of Figure 6 is a conventional power chain, probably a little sub-optimal. Two stages of pre-driver amplification with metal 2N2222As boost the signal level from -15 dBm to a little above 100 mW" For "sub-optimal" we could substitute "inexpensive".? One necessary change if wanting somewhat even power output all the way up to 30mhz would be an additional stage of amplification.? Gong from -15 dBm to +20 dBm (100mW) in two stages of 2N2222's is 35 dB of gain, or 17.5 dB per stage.? That's pushing it,? Though as we saw on the uBitx, optimizing a power amp is complicated, especially when doing it for a low budget product.? If NFET's seem too hard to use and just too dang complicated, an 807 or 6146 should do fine with any SWR when operating at 40W.? ?;-) Names could be shorter 80 years ago, they didn't have 10 gazillion different electronic parts to keep track of. Jerry, KE7ER On Wed, Aug 3, 2022 at 09:29 AM, Ashhar Farhan wrote:
The RD16HHF1s are no longer in production. There are some really good parts from Nexperia. They have no easy names like 807 or 6146. They have names like AFT05MP70. Why have short names when you can make up names that can't fit on the package?
- f
--
Jack, W8TEE
-- Jack, W8TEE
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Re: QR code and KD8CEC Memory Manager, "Error- data file is short"
Hmmm. Strange. Worked for me last week and I have a badly messed up eeprom. I assume you entered your call sign in with the memory manager? The backup is stored by call sign.?
sorrry, no other suggestions. ?
73
Mark
AJ6CU
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Interesting.? When I adjust frequency at the wsjtx it changes on wsjtx screen but not the sBitx display.? However, when I change the frequency on the sbitx, it does change the wsjtx screen.? I can live with that but no audio makes it to the wsjtx program.? Hmm...
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I though the wsjtx was already configured to work with hamlib. The ft8 on the sbitx doesnt use the wsjtx. To use that, you have to set the mode to Digital (not ft8) and then use wsjtx through NET rigctrl of hamlib. Let me try it out here. - f
Hi Ashhar,
Just got my sBitx.? Awesome!? You deserve many "pats on the back" and profits.? Thank you for making such a nice product.
A few notes:
- Please program the tap to force volume control as discussed above.
- Native sBitx display on DS1 monitor is working great.? No need to move it to other display(s).
- Second (and/or third) monitor is scalable for third party applications.
- Consider providing Micro HDMI panel mount to right side above RPI penetrations.
Questions:
- I can't seem to get CAT control to work for WJSTX, WSPR mode.? Hamlib NET was programmed but not functional.? What should it be?
- What should the programming be for the Input and Output audio settings?
Maybe I am doing this all wrong so I will reread the Operating instructions but I am assuming that the external programs can work with sBitx and suppling WJST-X will work the radio but I must be missing something.
Again, thanks for a great design!
Cheers, Scott
?
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Re: sBitx PA Power Supply
The irfz24N cant run at a higher voltage. Nor is the PA power line isolated from the 12v supply line (unlike the ubitx)
Can the sBitx PA be run at a higher voltage like on the uBitx? If so, are there board connections for this? Or would it require major surgery on the PCB?
Thanks Max?
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Re: Turn off WiFi on your sBitx
I tried that as well, it didn't fix it.
On Thu, Aug 4, 2022, 3:12 PM Niels Jalling < niels@...> wrote: Hi
I may have solved the WiFi noise.
After having seen several schematics for LM380 I discovered that all of them have a 100nF cap in series with a 2.7ohm? from pin 8 to ground. This was not on the sBitx schematics.
Dismantling the sBitx again and study the pcb. No cap and resistor.
I didn't have 2.7ohm but 4.7ohm parallel with 10ohm gives 3.2ohm. I gave it a try.
And result was no strange noise with WiFi connected and no noise when disconnected from my net.
73 de oz9ny, niels
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Hi Ashhar, Just got my sBitx.? Awesome!? You deserve many "pats on the back" and profits.? Thank you for making such a nice product. A few notes:
- Please program the tap to force volume control as discussed above.
- Native sBitx display on DS1 monitor is working great.? No need to move it to other display(s).
- Second (and/or third) monitor is scalable for third party applications.
- Consider providing Micro HDMI panel mount to right side above RPI penetrations.
Questions:
- I can't seem to get CAT control to work for WJSTX, WSPR mode.? Hamlib NET was programmed but not functional.? What should it be?
- What should the programming be for the Input and Output audio settings?
Maybe I am doing this all wrong so I will reread the Operating instructions but I am assuming that the external programs can work with sBitx and suppling WJST-X will work the radio but I must be missing something. Again, thanks for a great design! Cheers, Scott  ?
|
Can the sBitx PA be run at a higher voltage like on the uBitx? If so, are there board connections for this? Or would it require major surgery on the PCB?
Thanks Max?
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Re: sBitx antenna-first warning
On Wednesday, August 3, 2022 at 01:45:51 PM EDT, Ashhar Farhan <farhanbox@...> wrote:
Jack, How much voltage were you running on the drains? - f
We've tested the T41 with its 510s to 40W and nothing fried. 80-40-20M all can deliver about 25W without much effort. 15M is about 20W and 10M drops to about 13W. Like I said, it is what it is...
Jack, W8TEE
On Wednesday, August 3, 2022 at 01:14:06 PM EDT, Jerry Gaffke via <jgaffke= [email protected]> wrote:
The IRF510 can work dependably, Allison reports years of success with HF amps at 40W push-pull, surviving everything from accidental open antenna connections to dead shorts. In posts to this forum from several years ago, Allison went into plenty of detail. She even used them on 6m at several hundred watts (with bunches of them in parallel). The QSX amp from qrp-labs uses IRF510's in push-pull, does a consistent 10W from 3 to 30mhz. ? Clean and linear even when operating from 12v, tolerates any antenna condition. A product of collaboration between Hans and Allison.? ?Cost of $26 USD for the kit, a steal. If I were building a rig like the sBitx from scratch, I would start with that amp for a PA, perhaps add PIN diode TR switching with the HV supplied by rectified RF. HFsignals could steal that PA design for the sBitx-v2, give Hans $5 for every unit if feeling guilty. Using the IRF510 for RF power amps takes careful design.? Especially heat sinking, as the IRF510 is not very good at getting heat from the die to the TO220 tab.? The IRF510 prefers more like 24vdc for higher power and reduced distortion. Improper design can blow the gate due to exceeding Vgs max spec momentarily Needs more drive than an RD16HHF1 to get similar power levels due to moderately high gate capacitance. However, Vds max is much higher for the IRF510 than it is for the RD16HHF1, so for cases of high Vds the IRF510 would survive a high SWR better than the RD16HHF1. Allison was of the opinion that moving to the RD16HHF1 on the uBitx would not help much. Reading from?? "The power amplifier of Figure 6 is a conventional power chain, probably a little sub-optimal. Two stages of pre-driver amplification with metal 2N2222As boost the signal level from -15 dBm to a little above 100 mW" For "sub-optimal" we could substitute "inexpensive".? One necessary change if wanting somewhat even power output all the way up to 30mhz would be an additional stage of amplification.? Gong from -15 dBm to +20 dBm (100mW) in two stages of 2N2222's is 35 dB of gain, or 17.5 dB per stage.? That's pushing it,? Though as we saw on the uBitx, optimizing a power amp is complicated, especially when doing it for a low budget product.? If NFET's seem too hard to use and just too dang complicated, an 807 or 6146 should do fine with any SWR when operating at 40W.? ?;-) Names could be shorter 80 years ago, they didn't have 10 gazillion different electronic parts to keep track of. Jerry, KE7ER On Wed, Aug 3, 2022 at 09:29 AM, Ashhar Farhan wrote:
The RD16HHF1s are no longer in production. There are some really good parts from Nexperia. They have no easy names like 807 or 6146. They have names like AFT05MP70. Why have short names when you can make up names that can't fit on the package?
- f
--
Jack, W8TEE
--
Jack, W8TEE
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Re: The Daylight Again - An All analog radio
I bought them off amazon!
I like this. This reminds me of waiting for the next article by W7ZOI or Doug DeMaw. I built a SW converter using a universal breadboard once. It was just a pcb with squares. I need some to pickup some pads for another Manhattan type build.?
?Where did you find the deep drawn box? I picked up two years ago at a hamfest that were made by Hamtronics for repeater modules. I haven¡¯t seen anything like that in years. I have my Bitx40 in one.
73s John N4HNO?
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Re: The Daylight Again - An All analog radio
I like this. This reminds me of waiting for the next article by W7ZOI or Doug DeMaw. I built a SW converter using a universal breadboard once. It was just a pcb with squares. I need some to pickup some pads for another Manhattan type build.?
?Where did you find the deep drawn box? I picked up two years ago at a hamfest that were made by Hamtronics for repeater modules. I haven¡¯t seen anything like that in years. I have my Bitx40 in one.
73s John N4HNO?
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I find that Elecraft's tap method for controls is easy and useful.
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? 73
??? Bob? KD8CGH
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Re: Turn off WiFi on your sBitx
Hi
I may have solved the WiFi noise.
After having seen several schematics for LM380 I discovered that all of them have a 100nF cap in series with a 2.7ohm? from pin 8 to ground. This was not on the sBitx schematics.
Dismantling the sBitx again and study the pcb. No cap and resistor.
I didn't have 2.7ohm but 4.7ohm parallel with 10ohm gives 3.2ohm. I gave it a try.
And result was no strange noise with WiFi connected and no noise when disconnected from my net.
73 de oz9ny, niels
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Re: Turn off WiFi on your sBitx
Farhan, try adding a square inch of copper PCB tight against the top of the LM380, earthed. The RF could be getting direct into the silicon die.
Ian McCrum, MI5AFL
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Re: Turn off WiFi on your sBitx
The LM380 takes the earphone out from the codec. If you plug in earphones, the LM380 is cut off. There is no buzz in the earphones, but the buzz in the LM380 continues eve though it is not connected to the ear out of the codec. The LM380 is possibly picking it up from the wifi radio that is directly under it, on the raspberry pi. - f
Interesting. ? Perhaps it is being demodulates before that? ? Where in the line does it first manifest?
Gordon ? I have to report failure with the current attempt at eliminating the burp from the LM380. I tried putting a 2.2ohms in series with 0.1uf across the speaker as a snubber. I added a bypass on pin 1. I put a 0.1uf across the input I loaded down the input to 220 ohms. None produced any difference. It is incredible that 2.4 GHz signal of about 1 mw is getting inside an audio IC. Maybe the microwave homebrewers should use LM380 instead of expensive GaAs FETs. I will still chipping away at this interesting problem. - f We are early adopters because of the confidence we have in you!? Looking forward to getting mine on Monday!
On Tue, Aug 2, 2022 at 10:09 PM Ashhar Farhan < farhanbox@...> wrote: It is tough and frustrating to be an "early adopter". I thank you all for taking the plunge, Respect!
The joys of mass production and finding little bitty problems. ? ?We have the same thing in drug product production and vaccine production of course.... only when you make a lot of some thing do you start to find a little bitty unexpected issues.?
We have the incredible advantage of having Ashhar right on top of everything!! ? My first Heathkit had horrible key clicks and I think I spent a year shipping it back-and-forth Benton Harbor (from earning money vacuuming the house ) before I learned enough to fix it myself. ?
Gordon ? Bob, Thats the LM380 having some kind of oscillations. I will have a fix for the quickly. The sound goes away if you turn the wifi off. Right click on the wifi icon and select Wifi off. - f On Wed, Aug 3, 2022, 2:46 AM Bob Losee KO9V < Loseeunc@...> wrote: I¡¯m having the same sounds¡ anywhere from 4 to 8 sounds then a several second pause, then starts again. ? Changing audio level makes no difference. I¡¯ve never tried transmitting¡ just listened to WWV across town from me and it is a clean stable receiver.? Tried logging in to my wifi but I still have two red X characters over the wifi symbol Bob, KO9V, Serial Number 20 On Aug 1, 2022, at 1:57 PM, Niels Jalling <niels@...> wrote:
?When I powered up my new sBitx I heard repeating noise from the loudspeaker. I knew I had seen the problem mentioned somewhere.
Found it on youtube:
Follow the description to turn off the WiFi and the noise goes away.
73 de oz9ny, niels
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Bob Benedict, KD8CGH
