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  1. BITX20
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sbitx v2 power output

 

I updated the software in my v2 today. Then I decided to run the tx power calibration, just to understand how that works. To my surprise, I can't get more than 12w on 7 Mhz, even with the drive set to 100. My rf power meter is not a lab instrument, but I think its?pretty close. And the swr & power meters on the sbitx aren't showing me anything.

When I first got the unit about a month ago, I tried ssb on 40m. It was during the day, so I wasn't surprised when I didn't make a contact. At that point, I didn't check the power, but I think I was running at 50%.

So, does the current build that I pulled today include the tx mod? I didn't make the hardware modification, so I wonder if I damaged the fets.
 

ALC is designed not to overdrive the final stage.
In the forum topic where the publication was made, it is described what you should do next.
A link is provided where the description of what to do is found.
This should definitely be done. It's not enough to just do part of it. But it is also written there.

If you haven't already checked the screws that attach the FETs to the heatsink, do it now.
It happens that during the transport these have become loose and therefore they are not clamped to the cooling fin.
So, if you have a good and solid hardware, you can modify the firmware and load the device.
You charge the device with this setting, but there was a delivery in between.
Even though the manufacturer has tested this, it may change by the time it reaches you.
--
Gyula HA3HZ
 

The screws were and are tight.
I'm not sure which forum post you're referring to...I found one about 'for testers only', 'death by calibration'.

For now, I'm going to reload the original software.

Don

On Thu, May 18, 2023 at 11:48?PM HA3HZ <gyula@...> wrote:
ALC is designed not to overdrive the final stage.
In the forum topic where the publication was made, it is described what you should do next.
A link is provided where the description of what to do is found.
This should definitely be done. It's not enough to just do part of it. But it is also written there.

If you haven't already checked the screws that attach the FETs to the heatsink, do it now.
It happens that during the transport these have become loose and therefore they are not clamped to the cooling fin.
So, if you have a good and solid hardware, you can modify the firmware and load the device.
You charge the device with this setting, but there was a delivery in between.
Even though the manufacturer has tested this, it may change by the time it reaches you.
--
Gyula HA3HZ

 

Well, I can't go back to the original software. It seems that Win32DiskImager did not properly image the contents of the sd card that came with my sBitx. I am in the process of installing the V2.1 image that Farhan posted. I know I have to recalibrate the tx levels, and that's OK. But this question remains unanswered...

To safely use v2.1 of the software, do I have to make the hardware mod with Q10 and?pin 36 of the Pi connector?

Thanks.
Don?

On Sat, May 20, 2023 at 8:53?PM dsay2001 via <don.sayler=[email protected]> wrote:
The screws were and are tight.
I'm not sure which forum post you're referring to...I found one about 'for testers only', 'death by calibration'.

For now, I'm going to reload the original software.

Don

On Thu, May 18, 2023 at 11:48?PM HA3HZ <gyula@...> wrote:
ALC is designed not to overdrive the final stage.
In the forum topic where the publication was made, it is described what you should do next.
A link is provided where the description of what to do is found.
This should definitely be done. It's not enough to just do part of it. But it is also written there.

If you haven't already checked the screws that attach the FETs to the heatsink, do it now.
It happens that during the transport these have become loose and therefore they are not clamped to the cooling fin.
So, if you have a good and solid hardware, you can modify the firmware and load the device.
You charge the device with this setting, but there was a delivery in between.
Even though the manufacturer has tested this, it may change by the time it reaches you.
--
Gyula HA3HZ

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