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sBitx DE sold out

 

People,
The sBitx run of the developer's edition is now sold out. We have shipped more than 150 odd sets by now.?
The radio needed some upgrades and the switching regulator was upgraded to those who got the early ones with the linear regulator - the LM338.?
I have spent the last two weeks figuring out the power amplifier troubles. I think I understand the problem. It isn't the output matching. It is over-drive from the IRF510s. The drivers can potentially output 10 watts into the gates of the IRFZ24Ns (it is an almost exact replica of the uBitx power chain). It is the gates of the PA transistors that are blowing up due to over-drive from the drivers.?
I am working on an upgrade to combine that fix along with a real-time clock based on the DS1307 module.
I am working with our team to extensively test the PA upgrade that will be shipped to all the sBitx owners.
In the meantime, Anthony Goody, Steve, Bob have been sending in software upgrades frequently and I haven't had a time to pull them into the main branch. Real soon now.?
Frankly, I was pretty worried with the PAs blowing up. The rest could be fixed in the software. Hence, I was concentrating on the PA fix. I hope to present the upgrades this week.
Thanks to all the early adopters for their support to the sBitx. This has been a community affair and will continue to be owned and driven by all you great folks.

- f?
 

Ashhar,
Number 157? PA has not blown out yet (I do have the spares).? Is this still to be expected??
?
I was starting to look into a RTC upgrade also. the unit is from Adafruit PiRTC Precise DS3231 Real Time Clock for Raspberry Pi

Thank you for your hard work bringing the sBitx to life.
 

With the switching regulator, the thermal issue has been sorted out. Just keep the power under 20 watts on 40 and 80.


On Sun, Sep 25, 2022, 6:48 PM kc5kwz <jrbritton@...> wrote:
Ashhar,
Number 157? PA has not blown out yet (I do have the spares).? Is this still to be expected??
?
I was starting to look into a RTC upgrade also. the unit is from Adafruit PiRTC Precise DS3231 Real Time Clock for Raspberry Pi

Thank you for your hard work bringing the sBitx to life.

 

Until the PA-problems is fixed we can transform the sBitx to a usBitx !?

Remove both IRFZ24, remove C100 and C101, connect T6,6 to ground, find track T8,1 on pcb, cut track close to T8, connect a wire from T6,1 to PA-OUT.

Haven't tried yet but will do tomorrow.

de oz9ny, niels
 

¿ªÔÆÌåÓý

So your going to 5 watts out or what??? Say it ain't so!?

I don't think the wait for the solution will be long.

On 9/25/2022 5:29 PM, Niels Jalling wrote:
Until the PA-problems is fixed we can transform the sBitx to a usBitx !?

Remove both IRFZ24, remove C100 and C101, connect T6,6 to ground, find track T8,1 on pcb, cut track close to T8, connect a wire from T6,1 to PA-OUT.

Haven't tried yet but will do tomorrow.

de oz9ny, niels

Virus-free.
Mark Earnest
 

My finals now blow when attempting to set the bias, I¡¯m concerned I may have damaged something else as well. Is there anything in particular I should be checking?


--
KB3LYB
sBitx #077
 

When setting bias, set power supply current limit to 1 or 2 A. That will prevent blown finals.

Without transistors check if you get a smooth 0-5V variation with presets.

Raj

On 26/09/2022 4:22 PM, Mark Earnest via groups.io wrote:

My finals now blow when attempting to set the bias, I¡¯m concerned I may have damaged something else as well. Is there anything in particular I should be checking?


--
KB3LYB
sBitx #077
 

Was the DE version the only version available?

I see on?? there is still an order form for the fully assembled and the kit...are those unavailable now?? Or are they different than the DE version?

Mike
KF5DEY
 

The DE version was available with our without the Raspberry Pi and the display. Both are exactly the same minus the rpi and display.


On Fri, Sep 30, 2022, 8:30 AM Mike B <kf5dey@...> wrote:
Was the DE version the only version available?

I see on?? there is still an order form for the fully assembled and the kit...are those unavailable now?? Or are they different than the DE version?

Mike
KF5DEY

 

OK, now the page correctly displays the status, thanks

Mike

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