Re: any hints on replacing V2 board with V3 ????
Sure Gyula, ? original finals in the V2 were an issue. ?Had an initial failure running FT-8 on 10m at about 50% power. ? At the time the power supply was a 30A non current limited unit. ?I replaced the finals with original FET version twice and failed them trying to set bias. ?Upon the last failure I got a current limited supply per your comments and used the IRF 510s.?
V2 board has been stable running the IRF 510s and a current limited power supply set to about 6A. ?
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Re: any hints on replacing V2 board with V3 ????
On Tue, Sep 24, 2024 at 03:57 AM, Michael Saladino wrote:
I replaced my V2 with a V3 board.?? Moved the Pi4 over and used the new SD card.? Works great except for the V3 SWR not really reading.? I replaced the finals ( 4th time ) in my old V2 board with the IRF 510's and installed an old Pi 3B on it and now have a second sBitx that works great also!
Michael,
could you tell the forum readers why the final stage fets had to be replaced 4 times?
What antenna, what power supply did you use and in what modes did you use the device so that this could happen?
We want to learn from others' descriptions to avoid similar stories.
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Gyula HA3HZ
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Re: any hints on replacing V2 board with V3 ????
I replaced my V2 with a V3 board.?? Moved the Pi4 over and used the new SD card.? Works great except for the V3 SWR not really reading.? I replaced the finals ( 4th time ) in my old V2 board with the IRF 510's and installed an old Pi 3B on it and now have a second sBitx that works great also!
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Re: Anyone running V2 code on DE
Thanks Evan. I'll keep working at it!
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Mike KB2ML
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Re: Anyone running V2 code on DE
Hello Mike.?
There is an error in the final formula. The correct formula is
New Scale = Current Scale * (power setting/100 * desired max power)/Measured power
formula
Sorry for the error in copying the formula. The spreadsheet in the thread was correct.
73
Evan
AC9TU
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Re: Anyone running V2 code on DE
Evan, I decided to try to level the max power output on my sbitxDE by adjusting the values in hw_settings.ini. I followed your example and built a spreadsheet. Following your example calculations I can't get to the values you got, and in fact my new values go up where yours go down.
Where did that final new scale value come from?
This is one column from a spreadsheet I built to take measurements and calculate new hardware_settings values.
band (meters) 80
desired max power (watts) 10
drive setting 20
measured V peak 34
calculated power (V peak + .6)^2 / 100) 12.0
hardware_settings.ini 0.00255477
new hardware_settings.ini 0.01529234 <= my calculated value seems to be going the wrong way
--
Mike KB2ML
Evans Example:
Power level set for 20
Desired full power of 35 watts
Measured value of 10 watts
Starting value from hardware.ini scale=0.00255477
New Scale = Current Scale * Measured power / (power setting/100 * desired max power)
New Scale = 0.00255477 * 10 /( 0.2 * 35)
New scale = 0.001788339
Note above that the power level was too high, so the Scale value must go down. I set up a spreadsheet to adjust all bands in one restart since you need to restart the sbitx program between Scale changes.
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hey Charudatt,
?
I have clean simple 6 meter code you might want to look at...
?
writen on the raspi pico and a sh1107 1.3 oled.? it has alot to it . contact me a n4cnr.ham@... I figure if we team up and make bot a 2m and 6 meter set of kits we can make this a great project. I have started working on a vfo board.?? ?
I also have rit on a encoder working ... I have alot of functionality to explain
?
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Re: any hints on replacing V2 board with V3 ????
Bill,
?
Here is link to the TVS diodes,
?
Joel
N6ALT
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Re: any hints on replacing V2 board with V3 ????
Hey Bill,
?
One other thing I forgot to mention, you will have to move your Raspberry Pi over from the V2 board to the V3 board but that's easy, just four screws, also make sure to install the SD card that comes with your new V3 board in the Raspberry Pi, don't use the the V2 SD card on the V3 board.
?
Joel
N6ALT
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Re: any hints on replacing V2 board with V3 ????
tnx Joel , that sound like my plan...
? ? what are the specs on the diodes used for clamping..????
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On 9/23/2024 10:25 AM, Joel Caulkins/N6ALT wrote: Hi Bill,
To answer your question, just take the V2 board out and install the V3 board in it's place. They are basically identical boards, the V3 board having IRF510s for finals instead of the original IRFZ24Ns. The V3 board also has the clamping diodes across the gates of the IRF510s to protect them from voltage spikes blowing them up, other than that there isn't much difference. I upgraded my V2 board to a V3, I then modified my V2 board and i keep it as a spare but have never needed it.
Joel
N6ALT
--
link to my QRZ listing
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Re: any hints on replacing V2 board with V3 ????
Hi Bill,
?
To answer your question, just take the V2 board out and install the V3 board in it's place. They are basically identical boards, the V3 board having IRF510s for finals instead of the original IRFZ24Ns. The V3 board also has the clamping diodes across the gates of the IRF510s to protect them from voltage spikes blowing them up, other than that there isn't much difference. I upgraded my V2 board to a V3, I then modified my V2 board and i keep it as a spare but have never needed it.
?
Joel
N6ALT
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Gyula, good catch!? I do have XT65s, I've just labeled them incorrectly in the schematic. But you are right in that I have them flipped, that's a quick fix.? Thanks!
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On Mon, Sep 23, 2024 at 02:53 AM, Jeff Duce wrote:
Let me know if I've made any major mistakes here.? I figure I'll make a short run of boards to test and verify I didn't mess up the board design.? If that's all good, then I'll run do a larger order and put them up for sale on the etsy page.? Downside is that
this process could take a month or so.?
?
Jeff
Jeff,
?I know this connector as XT60, but that's a minor problem. The bigger one is that there is a 10A fuse at the input that connects to the radio, while it can be seen on the opposite side in the conceptual drawing. So I see this as a faulty design, the pcb needs
to be rearranged a bit. In the conceptual drawing, the left side is the input from the power supply, the right side is connected to the radio.
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Gyula HA3HZ
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any hints on replacing V2 board with V3 ????
expecting a board ( to get current ) ..... got tired of having to pay attention to all the conversations on mods....
guess I'm 50% appliance operator & DXer.
so you have any hints? , should be easy//
bill
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On 7/23/2023 1:35 PM, Evan Hand wrote: Hi Steve,
I agree that changing to the aluminum nitride insulators should remove any issue with the heat on the finals.? I do not see a fan as required at this time.? My comments pointed out that the full scope of the thermal process needs to be addressed, not just the insulators.
Looking at your thermal pictures, it appears that you have a DE without all of the mods to the PA completed.? I also noted that Q13 is much warmer than the other three pre-driver transistors. You might want to look into that before a failure.
Just suggestions.
73
Evan
AC9TU
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It would be interesting to incorporate a small UHF antenna directly into the sBitx, when and if it will support the band.
With a dedicated antenna socket, it could offer "off band" communications to repeaters between DX sessions, without a second device, antenna, battery et c.
Inside the box it would be impossible, but maybe a folded dipole arrangement could be envisioned "beside"...
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Re: Advice and Opinions on the next iteration of the sBitx
sorry if already suggested, I guess I should have read the previous threads before...
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Well, you just need four contacts, but I see your point.
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On Mon, Sep 23, 2024 at 02:53 AM, Jeff Duce wrote:
Let me know if I've made any major mistakes here.? I figure I'll make a short run of boards to test and verify I didn't mess up the board design.? If that's all good, then I'll run do a larger order and put them up for sale on the etsy page.? Downside is that this process could take a month or so.?
?
Jeff
Jeff,
?I know this connector as XT60, but that's a minor problem. The bigger one is that there is a 10A fuse at the input that connects to the radio, while it can be seen on the opposite side in the conceptual drawing. So I see this as a faulty design, the pcb needs to be rearranged a bit. In the conceptual drawing, the left side is the input from the power supply, the right side is connected to the radio.
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Gyula HA3HZ
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If you are going to operate UHF or higher, you might be interested in a satellite tracking program.? GPREDICT is available for Windows or Linux on x86 processors.? I don't know about the Pi or Macs.
Gerry Sherman
Sent by the Windows 11 Thunderbird
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Looks pretty nice to me!!!? ? Gordon KX4Z
On Sun, Sep 22, 2024 at 8:53?PM Jeff Duce via <jefe_de_estado= [email protected]> wrote:
So here's the latest.? My thought is that this would more or less replace the existing plug on the radio.? Can't really do that inside the radio without a lot of effort.? Here you would just plug in the board into the existing plug, which means you can now
only plug power into the board. The enclosure would have some sort of lid, but I haven't drawn it yet.? It uses a single existing screw from the bottom of the case to keep it from getting torqued too much when you unplug.? The box would need to be 3D printed,
it's a bit awkard and needs way more support that I'd like, but it's pretty small, so shouldn't be too bad.
From Left to right:? F1 would be a 10A fuse. D1 is a TVS diode to filter out fast high voltage transients (ESD protection).? The middle section (C1 to D3) is a crowbar overvolt circuit.? When voltage is below 16v, no current goes through these devices.? The
gate to the SCR is at 0V, so nothing happens.? When voltage is above 16v, the zener D2 allows voltage to pass, which turns on the gate on the SCR.? The SCR then creates a high current short to ground, which then pops the fuse.? Caps and ferrite for filtering
so you don't induce a current and pop the fuse from RF. Next section is reverse polarity protection.? After some going back and forth, I've picked a mosfet that is very low Rds, (1.6mOhm).? If power is connected with the correct voltage, it passes the current
with only a maximum power loss of 0.16w.? If polarity is reversed, Vgs will be 0v, and the mosfet won't turn on, no voltage at the output.
So you get ESD, overvolt, overcurrent, reverse polarity protection with no voltage drop at very low power loss.?
Let me know if I've made any major mistakes here.? I figure I'll make a short run of boards to test and verify I didn't mess up the board design.? If that's all good, then I'll run do a larger order and put them up for sale on the etsy page.? Downside is that
this process could take a month or so.?
Jeff
Andy,
if you have already brought up the topic here, I will answer here, although the title of the topic does not indicate this. I, who am only a radio user and cannot code, am told by others that it is not too late to learn. The sBitx developers settled on Discord
because many other devices are discussed in this forum. Besides, you also know that the direct answer option is given there, not here. In this way, developers can immediately find the questions that concern them and can answer them. So it is not so easy to
distinguish between the two servers, because each has advantages and disadvantages, you just have to consider them.
Just as no two people are the same, no two thoughts are the same. You can be confrontational and you can come to an agreement.
It is not necessary for everyone to go there, anyone who is interested in the matter and has an idea to share can do so.
--
Gyula HA3HZ
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So here's the latest.? My thought is that this would more or less replace the existing plug on the radio.? Can't really do that inside the radio without a lot of effort.? Here you would just plug in the board into the existing plug, which means you can now
only plug power into the board. The enclosure would have some sort of lid, but I haven't drawn it yet.? It uses a single existing screw from the bottom of the case to keep it from getting torqued too much when you unplug.? The box would need to be 3D printed,
it's a bit awkard and needs way more support that I'd like, but it's pretty small, so shouldn't be too bad.
From Left to right:? F1 would be a 10A fuse. D1 is a TVS diode to filter out fast high voltage transients (ESD protection).? The middle section (C1 to D3) is a crowbar overvolt circuit.? When voltage is below 16v, no current goes through these devices.? The
gate to the SCR is at 0V, so nothing happens.? When voltage is above 16v, the zener D2 allows voltage to pass, which turns on the gate on the SCR.? The SCR then creates a high current short to ground, which then pops the fuse.? Caps and ferrite for filtering
so you don't induce a current and pop the fuse from RF. Next section is reverse polarity protection.? After some going back and forth, I've picked a mosfet that is very low Rds, (1.6mOhm).? If power is connected with the correct voltage, it passes the current
with only a maximum power loss of 0.16w.? If polarity is reversed, Vgs will be 0v, and the mosfet won't turn on, no voltage at the output.
So you get ESD, overvolt, overcurrent, reverse polarity protection with no voltage drop at very low power loss.?
Let me know if I've made any major mistakes here.? I figure I'll make a short run of boards to test and verify I didn't mess up the board design.? If that's all good, then I'll run do a larger order and put them up for sale on the etsy page.? Downside is that
this process could take a month or so.?
Jeff
toggle quoted message
Show quoted text
Andy,
if you have already brought up the topic here, I will answer here, although the title of the topic does not indicate this. I, who am only a radio user and cannot code, am told by others that it is not too late to learn. The sBitx developers settled on Discord
because many other devices are discussed in this forum. Besides, you also know that the direct answer option is given there, not here. In this way, developers can immediately find the questions that concern them and can answer them. So it is not so easy to
distinguish between the two servers, because each has advantages and disadvantages, you just have to consider them.
Just as no two people are the same, no two thoughts are the same. You can be confrontational and you can come to an agreement.
It is not necessary for everyone to go there, anyone who is interested in the matter and has an idea to share can do so.
--
Gyula HA3HZ
|
HA3HZ
Joel Caulkins/N6ALT