PixelRadio, a DiY FM Transmitter with RDS RadioText

[munu]

Sorry if this was asked before but there are like 43 pages in this thread. As you can see from the picture I am still working on the board. Terrible soldering (ordered some flux because the solder puddled up high on the soldering iron). My question is regarding the housing, though. There are no guides to put the board in. The board is also a couple of mm to large to squeeze it in (you can see how the housing is actually bending). I have some 'stand off screws' to elevate the board but the fact that it doesn't fit into the housing suggest I am doing something wrong.

board.png

Never mind, I see there is a groove at the very bottom of the case...

[rayhjr]

Sorry if this was asked before but there are like 43 pages in this thread. As you can see from the picture I am still working on the board. Terrible soldering (ordered some flux because the solder puddled up high on the soldering iron). My question is regarding the housing, though. There are no guides to put the board in. The board is also a couple of mm to large to squeeze it in (you can see how the housing is actually bending). I have some 'stand off screws' to elevate the board but the fact that it doesn't fit into the housing suggest I am doing something wrong.

board.png

Never mind, I see there is a groove at the very bottom of the case...

Hey, don't feel bad. If that is the only mistake you make, your GOOD!

[Kev7274]

Mono mode disables the FM pilot tone and reduces RF bandwidth (better S/N). This improves reception of weak signals and is the main reason the feature exists.

But if you need stereo audio then there might be an easy remedy. For example, perhaps this issue is interference from an adjacent FM broadcaster or dirty RF source. Try tuning to other unused areas of the FM dial. Also try moving the receiver to other test locations that provide better reception. In some situations merely changing antenna position may help.

- Thomas

Re-flowed those those parts I saw,didn't see a U8 on the board or in the BOM,unless I overlooked it,and it didn't make a difference. I did however notice that when my hand or finger was near or touching the L7 jumper wire,there was almost complete silence on Stereo mode.

[munu]

I just be doing something wrong but I am not sure what. C3, the cap in the upper middle is a lot smaller than what the PCB indicates. But it is 100uF/16V from what I can read. Also C10 (lower right) is a lot smaller than the reference image shows. It's a bit confusing because C10 is supposed to be 0.01uF/50V and the other 3 around it are supposed to be 0.01uF/50V so they should be larger. Is C10 just oversized in the reference image (something like 63V or higher)?

20230128_082807.png

[rayhjr]

C-10 is .01 uF 50V and C-4,C-5 and C-11 are .1 uF 50V so yes C-10 is larger.
20230128_155505.jpg
And C-3 is 100uF 16V
20230128_155513.jpg
You are not doing anything wrong. I don't want to speak for Thomas but I assume he made changes and for whatever reason the Gerber files were not updated to reflect the changes or something entirely different, but if you stick to the parts list you should be OK.

[Wacamoe]

That voltage drop across R1 is valid, but are you sure the resistor value is correct? The expected 470 ohm might have been stuffed with the wrong value, such as 4.7K or 47K. Or maybe a bad solder connection on it. Eyeballs are often the best tool for the job, so check the color code. If unsure then lift one side and measure the resistor value with an ohmmeter.

Sounds like you are measuring the voltage across R2, which will always be zero (MOSFET gates do not draw current). Instead, your meter needs one lead on ground, the other on R2 (check both ends). You should see a bit over 3V on both ends of R2 when the LED is enabled.


Yes, reflow U1 pin 28 (at PCB socket pad and module pad), R1, R2, and Q1. Use solder flux (or fresh solder) to ensure good reflow.

Still not working? Post clear close-up photos of the top and bottom of the board around the R1,R2, Q1, LED1 region. Someone here might spot something.


- Thomas

I stopped working on it for a bit, and decided to work on another one of the boards that I bought (bought multiples of everything) and I had the same result. The color bands were hard to read and I'm PRETTY sure you were spot on that the R1 resistor was incorrect. Waiting for Amazon to ship me some (comparatively overpriced) replacements of the correct ones. Desoldering it was a pain, but I think my board is ready for it. If not....well I have 2 more spares.....

Thanks again - stay tuned.

[Wacamoe]

Ok @ThomasLED more LED light woes - I remade a new build again on another board, but this time, the LED is staying on regardless of any input being in the jack. Thoughts?

[ThomasLED]

I remade a new build again on another board, but this time, the LED is staying on regardless of any input being in the jack. Thoughts?

Need more info:

1. Does your browser (Firefox, Chrome, Edge) connect to PixelRadio?
2. While connected via the browser: Does the LED turn off when you enable the "Test Tone" Feature?

- Thomas

[Wacamoe]

1. Yes!
2. Yes as well.

[ThomasLED]

If the LED turns off when the test tone feature is working then all is good.

- Thomas