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Some time ago, I had to reload the OS and was using the default 'safe' calibration values.?
Today, I was doing some key-down rf out vs current testing today. Suddenly, it just went dark.? I wasn't running that much power, about 9w out on 40m.
I took a look inside, and noticed this.
I'm guessing that 'ooze' is not supposed to be there, so it looks like something exploded. What exactly is this little board? Is it part of the power supply system? I believe it is marked H11 on the main board.
When I power up the sbitx, my power supply voltage drops to about 4v, and shows 3-4 amps being drawn. So this is pretty weird.
?Everything?on the website?seems to point to v3 hardware?now. Is the v2 schematic available somewhere??
Thanks. Don
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That looks like maybe the small 5 volt power supply. If you unplug it and power on, is the current back down to a reasonable level?
Scotty
Some time ago, I had to reload the OS and was using the default 'safe' calibration values.?
Today, I was doing some key-down rf out vs current testing today. Suddenly, it just went dark.? I wasn't running that much power, about 9w out on 40m.
I took a look inside, and noticed this.
I'm guessing that 'ooze' is not supposed to be there, so it looks like something exploded. What exactly is this little board? Is it part of the power supply system? I believe it is marked H11 on the main board.
When I power up the sbitx, my power supply voltage drops to about 4v, and shows 3-4 amps being drawn. So this is pretty weird.
?Everything?on the website?seems to point to v3 hardware?now. Is the v2 schematic available somewhere??
Thanks. Don
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I pulled the board, and the unit is still bringing the supply voltage down and pulling the same current. Seems like something else failed and it took the 5v board with it. I don't see anything obvious?though. Sure hoping the Pi & touchscreen survived.
That looks like maybe the small 5 volt power supply. If you unplug it and power on, is the current back down to a reasonable level?
Scotty
Some time ago, I had to reload the OS and was using the default 'safe' calibration values.?
Today, I was doing some key-down rf out vs current testing today. Suddenly, it just went dark.? I wasn't running that much power, about 9w out on 40m.
I took a look inside, and noticed this.
I'm guessing that 'ooze' is not supposed to be there, so it looks like something exploded. What exactly is this little board? Is it part of the power supply system? I believe it is marked H11 on the main board.
When I power up the sbitx, my power supply voltage drops to about 4v, and shows 3-4 amps being drawn. So this is pretty weird.
?Everything?on the website?seems to point to v3 hardware?now. Is the v2 schematic available somewhere??
Thanks. Don
|
Don,
Dont assume the buck converter is blown. The gunk I see is
probably the glue on the preset to keep it from
changing during shipping. First suspect the finals and when you
fix it then see is the 5V is coming through.
Raj
On 04/03/2024 8:35 AM, dsay2001 wrote:
toggle quoted message
Show quoted text
Some time
ago, I had to reload the OS and was using the default 'safe'
calibration values.?
Today, I was
doing some key-down rf out vs current testing today. Suddenly,
it just went dark.? I wasn't running that much power, about 9w
out on 40m.
I took a look
inside, and noticed this.
I'm guessing
that 'ooze' is not supposed to be there, so it looks like
something exploded. What exactly is this little board? Is it
part of the power supply system? I believe it is marked H11 on
the main board.
When I power
up the sbitx, my power supply voltage drops to about 4v, and
shows 3-4 amps being drawn. So this is pretty weird.
?Everything?on
the website?seems to point to v3 hardware?now. Is the v2
schematic available somewhere??
Thanks.
Don
|
There’s a small potentiometer that adjusts voltage level. The ooze you see is glue to keep the voltage from wandering around like a student driver. It doesn’t look like anything exploded. Trust me, I have experience in that arena.
Jack, N6LN
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Thanks Raj. I know the finals were a problem, which is why I was running at pretty low power. I thought that when they?failed it just resulted in no rf out, not bringing the whole system down.
And I was curious if that was some kind of glue or sealer...
Don,
Dont assume the buck converter is blown. The gunk I see is
probably the glue on the preset to keep it from
changing during shipping. First suspect the finals and when you
fix it then see is the 5V is coming through.
Raj
On 04/03/2024 8:35 AM, dsay2001 wrote:
Some time
ago, I had to reload the OS and was using the default 'safe'
calibration values.?
Today, I was
doing some key-down rf out vs current testing today. Suddenly,
it just went dark.? I wasn't running that much power, about 9w
out on 40m.
I took a look
inside, and noticed this.
I'm guessing
that 'ooze' is not supposed to be there, so it looks like
something exploded. What exactly is this little board? Is it
part of the power supply system? I believe it is marked H11 on
the main board.
When I power
up the sbitx, my power supply voltage drops to about 4v, and
shows 3-4 amps being drawn. So this is pretty weird.
?Everything?on
the website?seems to point to v3 hardware?now. Is the v2
schematic available somewhere??
Thanks.
Don
|
Not sure, but I think when they fail they short out, & that's
why some form of current limiting is a good idea - could prevent a
burned-out board, especially with a LiPO battery.? Some of them
can deliver some hellish amperages.
Gerry Sherman
Sent by the Windows 11 Thunderbird
On 2024-03-03 21:58, dsay2001 wrote:
toggle quoted message
Show quoted text
Thanks Raj. I
know the finals were a problem, which is why I was running at
pretty low power. I thought that when they?failed it just
resulted in no rf out, not bringing the whole system down.
And I was
curious if that was some kind of glue or sealer...
Don,
Dont assume the buck converter is blown. The gunk I see
is probably the glue on the preset to keep it from
changing during shipping. First suspect the finals and
when you fix it then see is the 5V is coming through.
Raj
On 04/03/2024 8:35 AM, dsay2001 wrote:
Some
time ago, I had to reload the OS and was using the
default 'safe' calibration values.?
Today,
I was doing some key-down rf out vs current testing
today. Suddenly, it just went dark.? I wasn't running
that much power, about 9w out on 40m.
I
took a look inside, and noticed this.
I'm
guessing that 'ooze' is not supposed to be there, so
it looks like something exploded. What exactly is this
little board? Is it part of the power supply system? I
believe it is marked H11 on the main board.
When
I power up the sbitx, my power supply voltage drops to
about 4v, and shows 3-4 amps being drawn. So this is
pretty weird.
?Everything?on
the website?seems to point to v3 hardware?now. Is the
v2 schematic available somewhere??
Thanks.
Don
|
If you want to continue to use the device, do not remove or dirty the dried adhesive residue.
This is secured to the output voltage with which the RPI is nourished.
So the value of this output voltage is not freely adjustable!
(There is still something to learn in electronics)
--
Gyula HA3HZ
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There is no Electronic Current limit when nourished from the battery, so it does not protect from anything, especially not overcurrent.
Good protection is when we can adjust the voltage and electricity to the right value.
The right value is important, because if you set any one higher, there is no protection again.
I have the original V2 with IRFZ24N FETs and I actively use it from 12.5 V and 6.00 with the restriction.
Currently, there are nearly 2000 QSOs on 3 amateur bands that I have been using since mid -November.
--
Gyula HA3HZ
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I've been perusing the forum trying to find the replacement PA part number. I remember reading all of those messages, but thinking I was being careful and wouldn't need to do this.
Is the recommended part the IRF510? I also recall the suggestion to use mica insulators. Was there a resistor mod too?
On Mon, Mar 4, 2024 at 12:39?AM HA3HZ < gyula@...> wrote: There is no Electronic Current limit when nourished from the battery, so it does not protect from anything, especially not overcurrent.
Good protection is when we can adjust the voltage and electricity to the right value.
The right value is important, because if you set any one higher, there is no protection again.
I have the original V2 with IRFZ24N FETs and I actively use it from 12.5 V and 6.00 with the restriction.
Currently, there are nearly 2000 QSOs on 3 amateur bands that I have been using since mid -November.
--
Gyula HA3HZ
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DSAY2001,
The replacement parts will depend on if you want to change the PA in a v2 sbitx to the v3 version.? To do that, the PA is described in the attached document.
73
Evan
AC9TU
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Evan, thank you. That is exactly what I was looking for.
Don
On Mon, Mar 4, 2024 at 11:19?AM Evan Hand < elhandjr@...> wrote: DSAY2001,
The replacement parts will depend on if you want to change the PA in a v2 sbitx to the v3 version.? To do that, the PA is described in the attached document.
73
Evan
AC9TU
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Scotty R
Raj vu2zap
John Terrell, N6LN
HA3HZ