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Re: Homebrew spectral analyzer
Hello,
?
Having finished my power supply, I return to my SimpleSA assembly.
I am at the same point as before and ask the same questions on the WIFI screen:
With version 11 I have an option in the main menu? "Sweep LOW" and the curve is displayed well. (on the pc with wifi application )
With version 15 I also have the option "Sweep LOW" but the curve is not displayed. (on the pc with wifi application)!
Also, shouldn¡¯t there be an extra "Sweep HIGH" option in the menu with version 15? It doesn¡¯t exist.
Strangely the SAW filter curve works.
Is it safe that version 15 is validated, works correctly with? and? the? display curves are good with the WIFI. The main display on the screen is good, but no curve. The WIFI.cpp seem to be the same on version 11 and 15?? Is it normal? I think something is missing??? Dave or other? people have a version 15 that works correctly in WIFI display, please let me know and/ or indicate if there has been a change.
Even to put their version in zip online
Thank's for your help |
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Re: Homebrew power supply
hello,
I simply used the software "front-facing designer" and printed in maximum HD quality with a laser.
So I took the dimensions relative to my front side, put the various holes (potentiometer, fuses, etc)
I then printed an example to serve as a template for drilling and cutting.
Then used a self-adhesive sheet printed in HD and then match and implant.
I¡¯ll do the same for my spectrum analyzer. cdt |
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Re: Homebrew power supply
Hello,
So, after several hours of work on the plate and assembly, I finally finished my power supply. 3 outputs? 5v, 12v? and a 0-25v variable with current limiter. Given the time spent on and the various parts purchases, this may not be worth the effort compared to any done or used purchase on some sites. Well, the pleasure is in having done it with his hands. lol.
I will now also finish my spectrum analyzer. I had further delayed work on the power supply.
Look and tell me...I think it's nice cdt |
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Re: Homebrew power supply
Hello,
Today I put the 3 integrated circuits.
The power supply? works fine and I can adjust the output? supply through the potentiometer.
I am limited to 25v max as my IC power supply design is limited to 25v. That should be enough for me and I don¡¯t take the risk of grilling them (Reminder no indication of the type of circuit, so I can¡¯t look at the datasheet)
Now I have a question for power ground and earth. (Recall there are 2 power supplies)
My enclosure is automatically connected to the ground via the mains supply cord. (Green/ yellow wire) Now what is the rule for "-" power supplies.?
Must they be connected together and "floating" in relation to the earth or imperatively connected between them AND the earth of office. Is it a matter of safety and/ or avoiding loops??
Here, where it gets a little tricky, is that the display to visualize the amps must be on the loop of the "-" power supply. (See picture)
thank's for your return cdt ?
? |
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Re: Homebrew power supply
Hello,
What news on the advancement of the supply power
The hardest part for me is done. 95% of the mecanic is done.
For the electronics:
On the PCB I made changes to the power supply of the 3 integrated circuits to prevent them from grilling with too high voltage. The circuits have no indication. In theory TL081.
For the ballast I added a transistor, so 2*2N3055. Lol, they are 50 years old and come from my first amplifiers.
I didn¡¯t put the 3300?F capacitor on. I found in my stock a PCB with 2*6800?F, and it fits very well.
You will see that I added a small 12v 3A power supply.
This will allow to have an additional 12v output and also 5v with addition of a regulator. Will also be used to power the V/A display and possibly for a fan if the 2n3055 heats up.
I have provided multi-turn potentiometers for adjustments.
This day, test in flywheel assembly of the power supply. (Without circuits) , all voltages are OK and well filtered.
More tests to follow.
cdt |
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Homebrew power supply
Hello,
Good morning,
I kind of left out the spectrum analyzer. I had a little time, so I started making my lab supply.
Everything starts with a cheap Kit (8€) and a recovery toric -transformer.
The kit has some faults. I will make some modifications. Not all??
See this site:??
For the transfomer, I completely cleared the secondary.
I made the ratio volts/ spire to reel secondary at my convenience.
I will also add a volt/amp display and multi-turn buttons.
There will also be 2 fixed outputs of 12 and 5 v 1A.
The power supply must provide a minimum of 0 -->30 V, 3 A (or more?) I will double the output ballast as well. change also capacitor ++Big!
The front is done, it¡¯s mechanical, but not equipped enough for it LOL Some work to do. Ha!! Less mechanics, but welding. Some picture + design of front panel cdt |
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Re: Homebrew spectral analyzer
On Sun, Jun 11, 2023 at 02:01 AM, Gerard wrote:
yes,I haven't seen your screenshot in SAHi mode, so I'm not sure if you have a problem. and,a very accurate value may require careful debugging, but I simply replaced it with 50R,because I think it is impossible to achieve a constant impedance for reception in such a wide bandwidth,a resistor is the most suitable. see the impedance of the RX can be seen in the AN427 documentation? |
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Re: Homebrew spectral analyzer
Hello,
Very good job. If you roll up the messages a little, you will see that an inductance was not shunted on the modules SI4432. (At least on this model)
 On other equivalent modules, Gyula sent me the modification. The previous ones no longer seem to be manufactured cdt |
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Re: Homebrew spectral analyzer
The issue with SAHi seems to have been solved, I don't know if there are still hidden issues, here is the screen I tested
Finally, A total of two modifications(both of which are indispensable.)
1.Modify the matching component parameters of RX
I changed the inductor to resistor, but I looked at other people's module pictures (e.g. #1999) and it was strange to see that they were using inductors in their modules, and Erik's module-specific modification instructions didn't mention that, so I guessed that the inductors in their pictures should be the initial parameters of the module,I don't know about those modules, but they are generally for a specific frequency, such as 433M 2.Add the filtering of CLK I'm using an active crystal, and I think I might not need filtering if I use TCXO (clipping sine wave). In addition, when I change some settings, the screen switching is very strange, for example, I set REF output or change the sweep range, the screen at this time is different from the dbm value I see on the screen after double-clicking, so I recorded a video, I don't know if this is in line with the code logic? Or am I missing something again? |
Gerard
