Re: sBITX transmit problem - low analog drive signal?
#sBitx
Thanks for the reply.
Yes to both.
--
? 73
??? Bob? KD8CGH
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Re: sBITX transmit problem - low analog drive signal?
#sBitx
Bob, Some parts if the manual are outdated. But there being no output is weird. Do you have an oscilloscope or an RF probe in the shack? - f
On Tue, Aug 9, 2022, 6:52 PM Bob Benedict, KD8CGH < rkayakr@...> wrote: Trying again with this lack of RF out in CW and digital and appears to need overdriven in SSB to get RF output. (/g/BITX20/message/94533). I wonder if the drive signal is being reduced or not properly amplified? There appears to be ten divisions on drive spectrum scope scale. The operating manual suggests mic gain be adjusted to span 6 in SSB. As you can see from the attached images for SSB with audio at about 6 divisions there is no output. When driven hard there is output. The generated CW signal, like the moderate SSB signal produces no output.
Moderate SSB, no output
Loud audio in, RF output
CW, no RF output - same result with digital modes
--
? 73
??? Bob? KD8CGH
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Re: SBitx Transmitter Active Indicator
#sBitx
I have used this method before with other transceivers with good results.? I just wound a few turns of magnet wire through a clip-on ferrite, soldered to an LED, and clipped it to the antenna in use.? It's not pretty or sophisticated, but it works great.
"If it's stupid but it works, it's not stupid"
73
N1EDC
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sBITX transmit problem - low analog drive signal?
#sBitx
Trying again with this lack of RF out in CW and digital and appears to need overdriven in SSB to get RF output. ( /g/BITX20/message/94533). I wonder if the drive signal is being reduced or not properly amplified? There appears to be ten divisions on drive spectrum scope scale. The operating manual suggests mic gain be adjusted to span 6 in SSB. As you can see from the attached images for SSB with audio at about 6 divisions there is no output. When driven hard there is output. The generated CW signal, like the moderate SSB signal produces no output. Moderate SSB, no output  Loud audio in, RF output  CW, no RF output - same result with digital modes  -- ? 73 ??? Bob? KD8CGH
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Again...easy does it on the adjusting screw...
Jack, W8TEE
On Tuesday, August 9, 2022 at 08:05:08 AM EDT, Anthony Good <anthony.good@...> wrote:
Just found these on The Amazon and ordered them to play with:
(No promotion or endorsement of Amazon implied. ?I can just get these next day from them¡)
Ok understood... I have a few of the below in the parts bin so could potentially modify my sbitx to use this instead... slight overkill though... ;)
On Tue, 9 Aug 2022 at 12:24, Ashhar Farhan < farhanbox@...> wrote: Peter, At present we use an LM33, linear regulator to drop 13.8v to 5v. This takes almost 1.5A current on rx. With this mod, the radio is running cool and the current draw is less than 0.5A. - f What is the purpose of this mod or what is the issue... not quite following ....
See attachment !
On 09/08/2022 4:32 PM, Ashhar Farhan wrote:
Those are the ones. Any idea of the chip used?
MP2307 is the chip Raj ![]()
On 09/08/2022 12:49 PM, Ashhar Farhan wrote:
I swear I had sent an email on this an hour ago... Anyway, I replaced replaced the LM338 with a switching regulator. This one was very inexpensive, less than a dollar. It is also very efficient and small. Unfortunately, I dont know what it is called! I am attaching the pictures. There is a tiny pot on it that controls the output voltage. I added a 22 ohms, fat resistor to the output pins and adjusted the output to 5.4v. Then I took out the LM338 and installed this. The ground is a thick and very short connection to a mounting hole (I used desoldering braid). The input and output is wired to the LM338's pcb holes. I am running this for a while before declaring victory. If someone can identify the chip and the regulator, I will be grateful.
--
Jack, W8TEE
|
I have replaced the LM338. Remember to set the output voltage before mounting!
de oz9ny, niels
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There is also a set of resistors on the back that you can short to set it to 5v. I will try that as well.
Farhan:
We used one of those in the another project. The voltage is adjusted with a small Phillips head screw driver. Just be aware that it is very easy to torque the set screw right off the board. It could be the batch we bought were more fragile than most, but slow and easy should be the approach to the adjustment.
Jack, W8TEE
On Tuesday, August 9, 2022 at 03:19:51 AM EDT, Ashhar Farhan < farhanbox@...> wrote:
I swear I had sent an email on this an hour ago... Anyway, I replaced replaced the LM338 with a switching regulator. This one was very inexpensive, less than a dollar. It is also very efficient and small. Unfortunately, I dont know what it is called! I am attaching the pictures. There is a tiny pot on it that controls the output voltage. I added a 22 ohms, fat resistor to the output pins and adjusted the output to 5.4v. Then I took out the LM338 and installed this. The ground is a thick and very short connection to a mounting hole (I used desoldering braid). The input and output is wired to the LM338's pcb holes. I am running this for a while before declaring victory. If someone can identify the chip and the regulator, I will be grateful. - f
--
Jack, W8TEE
|
Farhan:
We used one of those in the another project. The voltage is adjusted with a small Phillips head screw driver. Just be aware that it is very easy to torque the set screw right off the board. It could be the batch we bought were more fragile than most, but slow and easy should be the approach to the adjustment.
Jack, W8TEE
On Tuesday, August 9, 2022 at 03:19:51 AM EDT, Ashhar Farhan <farhanbox@...> wrote:
I swear I had sent an email on this an hour ago... Anyway, I replaced replaced the LM338 with a switching regulator. This one was very inexpensive, less than a dollar. It is also very efficient and small. Unfortunately, I dont know what it is called! I am attaching the pictures. There is a tiny pot on it that controls the output voltage. I added a 22 ohms, fat resistor to the output pins and adjusted the output to 5.4v. Then I took out the LM338 and installed this. The ground is a thick and very short connection to a mounting hole (I used desoldering braid). The input and output is wired to the LM338's pcb holes. I am running this for a while before declaring victory. If someone can identify the chip and the regulator, I will be grateful. - f
-- Jack, W8TEE
|
Same chip!
On 09/08/2022 5:34 PM, Anthony Good
wrote:
toggle quoted message
Show quoted text
Just found these on The Amazon and ordered them to play with:
(No promotion or endorsement of Amazon implied. ?I
can just get these next day from them¡)
Ok understood... I have
a few of the below in the parts bin so could potentially
modify my sbitx to use this instead... slight overkill
though... ;)
On Tue, 9 Aug 2022 at
12:24, Ashhar Farhan < farhanbox@...>
wrote:
Peter,
At present we use an LM33,
linear regulator to drop 13.8v to 5v. This takes
almost 1.5A current on rx.
With this mod, the radio is
running cool and the current draw is less than
0.5A.
- f
What is the purpose of
this mod or what is the issue... not quite
following ....
See attachment !
On 09/08/2022 4:32 PM,
Ashhar Farhan wrote:
Those are the
ones. Any idea of the chip used?
MP2307 is the chip
Raj
![]()
On 09/08/2022
12:49 PM, Ashhar Farhan wrote:
I
swear I had sent an email on
this an hour ago...
Anyway,
I replaced replaced the
LM338 with a switching
regulator. This one was
very inexpensive, less
than a dollar. It is also
very efficient and small.
Unfortunately, I dont know
what it is called!
I
am attaching the pictures.
There is a tiny pot on it
that controls the output
voltage. I added a 22
ohms, fat resistor to the
output pins and adjusted
the output to 5.4v. Then I
took out the LM338 and
installed this. The ground
is a thick and very short
connection to a mounting
hole (I used desoldering
braid). The input and
output is wired to the
LM338's pcb holes.
I
am running this for a
while before declaring
victory.
If
someone can identify the
chip and the regulator, I
will be grateful.
|
Re: SBitx Transmitter Active Indicator
#sBitx
Hi All,
Thanks for your suggestions. ?I did think about paralleling across the relay coil. ?Adding a few milliamperes of load to the ULN2003A driving the RXRelay should not overload the device but I do not know the actual load of the coil. ? ?Does anyone know the coil loading? ?Without doubt, adding the LED to the coil is the simplest addition if it doesn¡¯t break stuff.
Again, thank you very much for your suggestions. ?I¡¯ll report my findings.
Cheers, Scott
|
Just found these on The Amazon and ordered them to play with:
(No promotion or endorsement of Amazon implied. ?I can just get these next day from them¡)
toggle quoted message
Show quoted text
Ok understood... I have a few of the below in the parts bin so could potentially modify my sbitx to use this instead... slight overkill though... ;)
On Tue, 9 Aug 2022 at 12:24, Ashhar Farhan < farhanbox@...> wrote: Peter, At present we use an LM33, linear regulator to drop 13.8v to 5v. This takes almost 1.5A current on rx. With this mod, the radio is running cool and the current draw is less than 0.5A. - f What is the purpose of this mod or what is the issue... not quite following ....
See attachment !
On 09/08/2022 4:32 PM, Ashhar Farhan wrote:
Those are the ones. Any idea of the chip used?
MP2307 is the chip Raj ![]()
On 09/08/2022 12:49 PM, Ashhar Farhan wrote:
I swear I had sent an email on this an hour ago... Anyway, I replaced replaced the LM338 with a switching regulator. This one was very inexpensive, less than a dollar. It is also very efficient and small. Unfortunately, I dont know what it is called! I am attaching the pictures. There is a tiny pot on it that controls the output voltage. I added a 22 ohms, fat resistor to the output pins and adjusted the output to 5.4v. Then I took out the LM338 and installed this. The ground is a thick and very short connection to a mounting hole (I used desoldering braid). The input and output is wired to the LM338's pcb holes. I am running this for a while before declaring victory. If someone can identify the chip and the regulator, I will be grateful.
|
Re: #sbitx user interface layout changes proposla
#sBitx
Hi Ashhar,
1) I tend to agree. ?Much more potential to add functionality to the waterfall.
2) Agreed.
3) Agreed. ?I have a few other thoughts:
a) Change the band buttons to two band buttons, BAND UP and BAND DOWN. ?(I¡¯m thinking like the Yaesu FT-817/818, Elecraft K1, KX3, etc.)
b) Have it so repeatedly pressing the MODE button will cycle through the modes, and have it wrap-around the list when coming to the end.
c) Have pushing the VFO encoder cycle through the tuning Steps.
d) Add 1 Mhz as a tuning STEP.
e) Eventually add acceleration to the VFO control so the faster you spin, the higher the step rate.
f) On CW, change the LOW and HIGH buttons to CENTER and BW (bandwidth). ?Low and High works well with voice and digital modes, but I find as a CW op that center and bandwidth controls are more useful.
g) In CW mode, have volume control pushes cycle the focus between the AUDIO, CENTER, and BW buttons, perhaps also WPM. ?There may be focus-cycling algorithms optimal for other modes.
4) Is there currently a way to change the center frequency of the waterfall? ?I find with lower SPANs the monitored bandwidth can easily go off the right of the waterfall.
5) Any way in GTK to make the cursor disappear on a touch screen button push? ?I find the cursor tends to get in the way of the button text which is a pain with buttons that show settings.
I¡¯d be happy to work on some of these as I continue to get familiar with the code.
73 Goody
toggle quoted message
Show quoted text
1. Increasingly, a vertical spectrum and waterfall display makes sense to me. We can stream the text being? decoded against each frequency. Much like the CW skimmer et al. 2. The on-display keyboard. The current keyboard is too small for actual touch typing. Should we keep it such that on a button, it overlays the bottom area and then vanishes when done? That way we will get more real-estate to put other things in. 3. I seem to mostly use the bandswitches, mode and audio control. Should others also be hidden to be on-demand? These will clear up the screen for more interesting things like a signal browser, etc. Let's slug it out. - f??
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Ok understood... I have a few of the below in the parts bin so could potentially modify my sbitx to use this instead... slight overkill though... ;)
On Tue, 9 Aug 2022 at 12:24, Ashhar Farhan < farhanbox@...> wrote: Peter, At present we use an LM33, linear regulator to drop 13.8v to 5v. This takes almost 1.5A current on rx. With this mod, the radio is running cool and the current draw is less than 0.5A. - f What is the purpose of this mod or what is the issue... not quite following ....
See attachment !
On 09/08/2022 4:32 PM, Ashhar Farhan
wrote:
Those are the ones. Any idea of the chip used?
MP2307 is the chip
Raj
![]()
On 09/08/2022 12:49 PM, Ashhar Farhan wrote:
I swear I had sent an email on this an
hour ago...
Anyway, I replaced replaced the LM338
with a switching regulator. This one was very
inexpensive, less than a dollar. It is also very
efficient and small. Unfortunately, I dont know what
it is called!
I am attaching the pictures. There is a
tiny pot on it that controls the output voltage. I
added a 22 ohms, fat resistor to the output pins and
adjusted the output to 5.4v. Then I took out the LM338
and installed this. The ground is a thick and very
short connection to a mounting hole (I used
desoldering braid). The input and output is wired to
the LM338's pcb holes.
I am running this for a while before
declaring victory.
If someone can identify the chip and the
regulator, I will be grateful.
|
Peter, At present we use an LM33, linear regulator to drop 13.8v to 5v. This takes almost 1.5A current on rx. With this mod, the radio is running cool and the current draw is less than 0.5A. - f
What is the purpose of this mod or what is the issue... not quite following ....
See attachment !
On 09/08/2022 4:32 PM, Ashhar Farhan
wrote:
Those are the ones. Any idea of the chip used?
MP2307 is the chip
Raj
![]()
On 09/08/2022 12:49 PM, Ashhar Farhan wrote:
I swear I had sent an email on this an
hour ago...
Anyway, I replaced replaced the LM338
with a switching regulator. This one was very
inexpensive, less than a dollar. It is also very
efficient and small. Unfortunately, I dont know what
it is called!
I am attaching the pictures. There is a
tiny pot on it that controls the output voltage. I
added a 22 ohms, fat resistor to the output pins and
adjusted the output to 5.4v. Then I took out the LM338
and installed this. The ground is a thick and very
short connection to a mounting hole (I used
desoldering braid). The input and output is wired to
the LM338's pcb holes.
I am running this for a while before
declaring victory.
If someone can identify the chip and the
regulator, I will be grateful.
|
What is the purpose of this mod or what is the issue... not quite following ....
See attachment !
On 09/08/2022 4:32 PM, Ashhar Farhan
wrote:
Those are the ones. Any idea of the chip used?
MP2307 is the chip
Raj
![]()
On 09/08/2022 12:49 PM, Ashhar Farhan wrote:
I swear I had sent an email on this an
hour ago...
Anyway, I replaced replaced the LM338
with a switching regulator. This one was very
inexpensive, less than a dollar. It is also very
efficient and small. Unfortunately, I dont know what
it is called!
I am attaching the pictures. There is a
tiny pot on it that controls the output voltage. I
added a 22 ohms, fat resistor to the output pins and
adjusted the output to 5.4v. Then I took out the LM338
and installed this. The ground is a thick and very
short connection to a mounting hole (I used
desoldering braid). The input and output is wired to
the LM338's pcb holes.
I am running this for a while before
declaring victory.
If someone can identify the chip and the
regulator, I will be grateful.
|
Raj, I have measured the switching frequency to be exactly 250 khz. The attached datasheet is saying 380 khz or something like that.
See attachment !
On 09/08/2022 4:32 PM, Ashhar Farhan
wrote:
Those are the ones. Any idea of the chip used?
MP2307 is the chip
Raj
![]()
On 09/08/2022 12:49 PM, Ashhar Farhan wrote:
I swear I had sent an email on this an
hour ago...
Anyway, I replaced replaced the LM338
with a switching regulator. This one was very
inexpensive, less than a dollar. It is also very
efficient and small. Unfortunately, I dont know what
it is called!
I am attaching the pictures. There is a
tiny pot on it that controls the output voltage. I
added a 22 ohms, fat resistor to the output pins and
adjusted the output to 5.4v. Then I took out the LM338
and installed this. The ground is a thick and very
short connection to a mounting hole (I used
desoldering braid). The input and output is wired to
the LM338's pcb holes.
I am running this for a while before
declaring victory.
If someone can identify the chip and the
regulator, I will be grateful.
|
See attachment !
On 09/08/2022 4:32 PM, Ashhar Farhan
wrote:
toggle quoted message
Show quoted text
Those are the ones. Any idea of the chip used?
MP2307 is the chip
Raj
On 09/08/2022 12:49 PM, Ashhar Farhan wrote:
I swear I had sent an email on this an
hour ago...
Anyway, I replaced replaced the LM338
with a switching regulator. This one was very
inexpensive, less than a dollar. It is also very
efficient and small. Unfortunately, I dont know what
it is called!
I am attaching the pictures. There is a
tiny pot on it that controls the output voltage. I
added a 22 ohms, fat resistor to the output pins and
adjusted the output to 5.4v. Then I took out the LM338
and installed this. The ground is a thick and very
short connection to a mounting hole (I used
desoldering braid). The input and output is wired to
the LM338's pcb holes.
I am running this for a while before
declaring victory.
If someone can identify the chip and the
regulator, I will be grateful.
|
Diagram is attached. (Pasted)
Raj
On 09/08/2022 4:32 PM, Ashhar Farhan
wrote:
toggle quoted message
Show quoted text
Those are the ones. Any idea of the chip used?
MP2307 is the chip
Raj
On 09/08/2022 12:49 PM, Ashhar Farhan wrote:
I swear I had sent an email on this an
hour ago...
Anyway, I replaced replaced the LM338
with a switching regulator. This one was very
inexpensive, less than a dollar. It is also very
efficient and small. Unfortunately, I dont know what
it is called!
I am attaching the pictures. There is a
tiny pot on it that controls the output voltage. I
added a 22 ohms, fat resistor to the output pins and
adjusted the output to 5.4v. Then I took out the LM338
and installed this. The ground is a thick and very
short connection to a mounting hole (I used
desoldering braid). The input and output is wired to
the LM338's pcb holes.
I am running this for a while before
declaring victory.
If someone can identify the chip and the
regulator, I will be grateful.
|
Those are the ones. Any idea of the chip used?
MP2307 is the chip
Raj
On 09/08/2022 12:49 PM, Ashhar Farhan
wrote:
I swear I had sent an email on this an hour ago...
Anyway, I replaced replaced the LM338 with a
switching regulator. This one was very inexpensive, less than
a dollar. It is also very efficient and small. Unfortunately,
I dont know what it is called!
I am attaching the pictures. There is a tiny pot
on it that controls the output voltage. I added a 22 ohms, fat
resistor to the output pins and adjusted the output to 5.4v.
Then I took out the LM338 and installed this. The ground is a
thick and very short connection to a mounting hole (I used
desoldering braid). The input and output is wired to the
LM338's pcb holes.
I am running this for a while before declaring
victory.
If someone can identify the chip and the
regulator, I will be grateful.
|
Bob Benedict, KD8CGH
Raj vu2zap
