Jim,
I tried the lowest profile ones I could find, I had to remove the MCU one because it comes in contact with the crystal on the board below it, all the other ones I was able to leave in place. Do we need them anyway? Farhan says no. I think a better solution would be to fit a quiet fan in the case close to the Raspberry Pi. Either way, only time will tell.
Joel
N6ALT
|
What was the purpose in forming another group?? There is years worth of info on groups.io so what will Discord offer....?
|
Re: What is the actual status of the sBitx V2
Dave,
After receiving the Sbitx_v2, I read a few posts about loose screws. I have verified these issues on my own.
I fixed what I experienced without it causing me any problems. ? I wrote about it here: /g/BITX20/message/101717
The May 4th message is for those who received the device before that date. They had to do things as instructed.
As far as I know, for deliveries after this date, this is done by the manufacturer, which is confirmed by paper.
So, if someone is bothered by the possibility of a mechanical error in shipping, you can fix it with a little manual work.
In the same way, the firmware is not final, so it is necessary to ensure that the device is up-to-date.
RPi driven trx is a promising development option.
--
Gyula HA3HZ
|
Re: What is the actual status of the sBitx V2
Jack, thanks much for your comments!
Well, as anyone should be able to tell I would really like to buy
the V2 and I agree that it is reasonably priced based upon the
hardware and features.? I think it would make a terrific portable
rig, and I've been expecting somebody to come out with a high
performance self-contained FT8 rig for a long time.
The ease with which people say the heat sink inserts can be pulled
out, and Ashhar's comment about the majority of returned units
having detached heatsinks, still concerns me though.? I think I will
wait until that issue gets resolved one way or the other ... either
fixed or proven to be a non-issue.
Thanks again es take care,
Dave?? AB7E
On 5/29/2023 10:57 AM, John Terrell,
N6LN wrote:
toggle quoted message
Show quoted text
Dave, I’ve probably had more experience changing finals and
working with their heat sinks both for the DE and theV2 than
most out here. I don’t think that most blown finals are because
of heat sink issues. I use heat conductive paste anyway but I
have no evidence that it’s necessary. The heat sink warms nicely
and that’s a god sign. In my view the only way heat transfer
could improve would be with direct metal contact without mica
and of course that’s not practical.
In my experience finals are blown by inadvertent over driving
and the V2 has some protection now against that. Follow the
calibration instructions and take the time to tweak the
hw_settings.ini file. It’s important. After that my V2 works
nicely.?
If you take into account the cost of a Raspberry Pi 4 and a 7
inch DSI touch screen the radio is really very reasonably
priced, IMHO.
See my message #102663.
Have fun!
Jack
N6LN
|
Hi,
I’m installing a Raspberry Pi 4 in the Sbitx v2 that I bought recently at the Hamvention. ?Can anyone tell me whether there is enough clearance to place those tiny stick-on heat sinks on the cpu and memory chip? ?Are they even needed?
Thanks
Jim
va3kv
|
Re: What is the actual status of the sBitx V2
Dave, I’ve probably had more experience changing finals and working with their heat sinks both for the DE and theV2 than most out here. I don’t think that most blown finals are because of heat sink issues. I use heat conductive paste anyway but I have no evidence that it’s necessary. The heat sink warms nicely and that’s a god sign. In my view the only way heat transfer could improve would be with direct metal contact without mica and of course that’s not practical.
In my experience finals are blown by inadvertent over driving and the V2 has some protection now against that. Follow the calibration instructions and take the time to tweak the hw_settings.ini file. It’s important. After that my V2 works nicely.?
If you take into account the cost of a Raspberry Pi 4 and a 7 inch DSI touch screen the radio is really very reasonably priced, IMHO.
See my message #102663.
Have fun!
Jack
N6LN
|
Just a reminder we now have a Discord. We have almost 70 people in there now.?
|
Re: SD card burning with latest software build
#sbitx_v2
Thanks!!
73,
Dave?? AB7E
On 5/29/2023 10:44 AM, HA3HZ wrote:
toggle quoted message
Show quoted text
Dave,
Feel free to use a larger SD card for continuous use. Currently,
9GB of the 32GB or 64GB is used.
--
Gyula HA3HZ
|
Re: SD card burning with latest software build
#sbitx_v2
Dave,
Feel free to use a larger SD card for continuous use. Currently, 9GB of the 32GB or 64GB is used.
--
Gyula HA3HZ
|
Re: What is the actual status of the sBitx V2
I would say that yes, you should strongly consider a different mechanism for securing the PA transistors to the heat sink.? You mentioned elsewhere that you have had 20-25 failures out of 500 shipped units.? That is far from being a trivial failure rate. Given that lots of users here have stated they are keeping the output power well below the rated 40 watts because of the publicized problems, I could imagine that the overall failure rate might be higher if they were not doing that.
I think it's reasonable to expect that the software issues will get fixed ... but a hardware problem like this sounds like a design issue that should not go unresolved.
73 es take care,
Dave?? AB7E
toggle quoted message
Show quoted text
On 5/27/2023 5:07 PM, Ashhar Farhan wrote: Dave,
We are seeing reports of loose screws turning up, boxes dented, bnc connectors bent. We have taken these up with the DHL.
As for the PAs blowing up, as a part of our testing process, we operate it at 40 watts for a full minute and 15 seconds with open load. The heatsinks is clamped with m3 screws using a torque wrench.
As the boards that blew up were return we are finding that the heatsink clamps were invariably loose, this could happen only in transit. Perhaps we need a different and failsafe way to clamp these.
- f
|
Re: SD card burning with latest software build
#sbitx_v2
Please excuse me if this is a dumb question ... I'm a total noob
when it comes to the RPi.? But is there a reason why simply using a
64 GB card isn't advisable?? The cost differential is minor.
Thanks much,
Dave?? AB7E
On 5/29/2023 4:04 AM, HA3HZ wrote:
toggle quoted message
Show quoted text
If someone is having
trouble because they cannot copy the image to a 32GB SD card,
because there is a few bits less space on the card. I recommend the
following:
?
The solution may be
to first copy the image to a larger, for example 64GB uSD card
(use balenaEtcher prg).
You start the RPi with the 64 GB
card, then copy it back to the 32 GB card with the SD Card
Copier program.
To the card you couldn't copy to
because there wasn't enough space.
This is the simplest solution.
You don't need shrink, you don't
need linux os. By the way, the sbitx_v2 image takes up about 9
GB of space.
?
Yes, I tried it and
it works.
--
Gyula HA3HZ
|
On Mon, May 29, 2023 at 08:55 AM, loopMasta wrote:
I get 12v at the cathodes of? D30 and D31 ???
To check Q29, I would verify that the gate is close to the input voltage to the sBitx when receiving and close to zero when transmitting.
Q29 gate is 0v
LoopMasta, The voltages you listed do not make sense.? A zero volt on the Drain of Q28 and 12 volts on the diodes would mean that L27 is open.? Can you verify that there is continuity across L27? At the same time, you state that there are 0 volts on the Q29 gate when receiving.? That means that Q23 is shorted or grounded.? This would turn off Q28 and allow the drain to rise to 12 volts. Your issue is that the Pin Diodes are not turning on to let the RF through to the receiver.? When the diodes are on, the voltage on the cathode (banded) end should be zero volts to turn on the diode.? When the diode is in forward conduction mode, it allows the RF signal through.
| Sbitx T/R switch truth table |
? |
| ? |
? |
? |
? |
| ? |
Receiving |
Transmitting |
? |
| Q22 |
Off |
On |
? |
| Q23 |
Off |
On |
? |
| Q28 |
On |
Off |
? |
| Q29 |
On |
Off |
? |
| ? |
? |
? |
? |
| When On the drain should be close to the source voltage |
| When Off, the drain should be much higher than the source voltage |
| The Gate voltage needs to be higher than 2.5 volts to turn on the MOSFET |
Check that the TX signal is at 0 when receiving and that the Q23 drain is at 12 volts,? 73 Evan AC9TU
|
Re: Smoother tuning on the uBitx v6 (or other radios with plastic knobs)
Using Felt thats not thick enough, just double or triple up layers. TenTec did that for the Corsair and possibly other? radios. Cheers Barry ? Sent from for Windows ?
toggle quoted message
Show quoted text
From: Tom DentonSent: Monday, May 29, 2023 12:35 AM To: BITX20@groups.ioSubject: Re: [BITX20] Smoother tuning on the uBitx v6 (or other radios with plastic knobs) ? I'll bet that knob costs a little more than $10. ?
I've heard about felt on the back of tuning knobs. I tried it on my K-1, but I didn't have a thick enough piece and didn't really want to cut the shaft shorter.
Tom
|
I will have a chart for you in two days. - f
On Sun, May 28, 2023 at 05:00 PM, Evan Hand wrote:
Hi Evan. Thanks for your answer.
I do not have a V2, so I can not give you actual voltage or oscilloscope waveforms.? Reviewing the schematic and interpreting from my V1 De, I would check that the TX signal changes from close to zero volts while receiving and close to 3.3 volts when transmitting.? That can be measured on the gate of Q22.?
The TX signal is 0v on rx
Using the same process, I would verify that the drain of Q28 is close to zero when receiving and at the HV value when transmitting.? Note that the HV value depends on the power out of the finals.? The minimum should be the supplied voltage to the sBitx (nominal of 12 volts).
Q28 drain is 0v
I would also verify that the two pin diodes' banded ends (cathodes of? D30 and D31) have close to zero when receiving.
I get 12v at the cathodes of? D30 and D31 ???
To check Q29, I would verify that the gate is close to the input voltage to the sBitx when receiving and close to zero when transmitting.
Q29 gate is 0v
You should see the same signal at the BNC input of your signal generator on both sides of C212.? You can trace the signal through the PIN diode switches.
I am not seeing my signal after D31 !!!
|
On Sun, May 28, 2023 at 05:00 PM, Evan Hand wrote: Hi Evan. Thanks for your answer.
I do not have a V2, so I can not give you actual voltage or oscilloscope waveforms.? Reviewing the schematic and interpreting from my V1 De, I would check that the TX signal changes from close to zero volts while receiving and close to 3.3 volts when transmitting.? That can be measured on the gate of Q22.?
The TX signal is 0v on rx
Using the same process, I would verify that the drain of Q28 is close to zero when receiving and at the HV value when transmitting.? Note that the HV value depends on the power out of the finals.? The minimum should be the supplied voltage to the sBitx (nominal of 12 volts).
Q28 drain is 0v
I would also verify that the two pin diodes' banded ends (cathodes of? D30 and D31) have close to zero when receiving.
I get 12v at the cathodes of? D30 and D31 ???
To check Q29, I would verify that the gate is close to the input voltage to the sBitx when receiving and close to zero when transmitting.
Q29 gate is 0v
You should see the same signal at the BNC input of your signal generator on both sides of C212.? You can trace the signal through the PIN diode switches.
I am not seeing my signal after D31 !!!
|
Hi All,
I’d vote for a short press of the tuning encoder to execute tuning lock leaving the long press for something else.
A dial lock indicator would be nice.?
Cheers, Scott
|
Re: What is the actual status of the sBitx V2
It is a bond that cannot be disassembled under the influence of heat.
The thread is a releasable joint, another thing.
And it is precisely the female thread that must be fixed so that it does not release the heatsink when the amplifier stage heats up.
I stick with the longer screw that attaches to the heatsink.
--
Gyula HA3HZ
|
Re: SD card burning with latest software build
#sbitx_v2
If someone is having trouble because they cannot copy the image to a 32GB SD card, because there is a few bits less space on the card. I recommend the following:
?
The solution may be to first copy the image to a larger, for example 64GB uSD card (use balenaEtcher prg).
You start the RPi with the 64 GB card, then copy it back to the 32 GB card with the SD Card Copier program.
To the card you couldn't copy to because there wasn't enough space. This is the simplest solution.
You don't need shrink, you don't need linux os. By the way, the sbitx_v2 image takes up about 9 GB of space.
?
Yes, I tried it and it works.
-- Gyula HA3HZ
|
Re: SD card burning with latest software build
#sbitx_v2
Yes, renaming the? unzipped file is enough. - f
On Mon, May 29, 2023, 4:00 PM Petr Ourednik < indians@...> wrote: Hi,
when I unzipped the latest soft for V2 I realized that there is no extension in the file name.
I expected .img or .iso file.
Is it ok to just rename it with .img to be burned correctly on SD card please?
Thanks,
-P #5
|
SD card burning with latest software build
#sbitx_v2
Hi,
when I unzipped the latest soft for V2 I realized that there is no extension in the file name.
I expected .img or .iso file.
Is it ok to just rename it with .img to be burned correctly on SD card please?
Thanks,
-P #5
|
Joel Caulkins/N6ALT
Jim K5KKB Steeb
HA3HZ
John Terrell, N6LN
Bart Grubbs
Stefan Beck