XXL wrote: ↑Mon Feb 15, 2021 8:53 pm Iv just got round to building sinus's originally posted RDS encoder from the start of this thread. Its making alot of noise. Like Ghost noises. If i try and filter it out, i loose RDS. Iv never had this issue with other rds encoders. what could it be ?

XXL

I have found that if you use a high quality (and short) connection between Audio and MPX paths like RG316 the noise seems to be reduced considerably!

sinus trouble wrote: ↑Mon Jan 17, 2022 12:54 am

XXL wrote: ↑Mon Feb 15, 2021 8:53 pm Iv just got round to building sinus's originally posted RDS encoder from the start of this thread. Its making alot of noise. Like Ghost noises. If i try and filter it out, i loose RDS. Iv never had this issue with other rds encoders. what could it be ?

XXL

I have found that if you use a high quality (and short) connection between Audio and MPX paths like RG316 the noise seems to be reduced considerably!

What is the noise though and where is it coming from ?

sinus trouble wrote: ↑Mon Jan 17, 2022 12:49 am Here are the Gerber Files!

Gerber SINUSRDS PCB.zip

i yust start draw 1/3 and have plant to add RS232 converter to usb...
on this pcb missing electrolytic capacitance in - out lm7805...

I suspect that the noise is comming from a harmonic of the 57Khz?

You have to remember that the carrier is 'Digitally' created and filtered! Complex micro controllers with much higher Bit Rates could possibly help? But that is not the aim of this Project!

I will measure the spectrum when i get time!

rigmo wrote: ↑Mon Jan 17, 2022 10:59 pmi yust start draw 1/3 and have plant to add RS232 converter to usb...

Hello Rigmo

I doubt that a USB/SERIAL adaptor will work? If you look back to my previous USB versus SERIAL measurements, There is a significant difference in voltage just to start with!

Also the data string is inverted, The SERIAL idols LOW and goes HIGH to initiate DATA WRITE

USB on the other hand idols HIGH and goes LOW to initiate DATA WRITE

It is possible to bypass Q3 and feed the USB direct to RB1 of the PIC. BUT! In order to keep this pin stable, This pin needs to be held HIGH by the pull up resistor (R12) when not receiving DATA

rigmo wrote: ↑Mon Jan 17, 2022 10:59 pm this pcb missing electrolytic capacitance in - out lm7805...

You can add them if you wish? However the whole circuit operates well below 20mA I doubt the LM78L05 would struggle to do the job as it is!

It's always a good policy to RF bypass voltage regulators as close to the pins of the IC as possible. This ensures that they stay stable, even with lots of RF around!

pls anyone to share hex file for pic 16f628???

Once you install the RDS software, Click the Question mark (?) at the top right of the page! All HEX files are included there!

Medley

Medley is spot on!

Download the link that i posted! All the info you need is there!

Medley2k wrote: ↑Mon Mar 14, 2022 9:27 pm Once you install the RDS software, Click the Question mark (?) at the top right of the page! All HEX files are included there!

Medley

thanks medley!!

another problem started when i connect rds with stereo encoder, signal of stereo disappear!!!!!when i put standalone stereo encoder is worked fine and when i put together with rds, rds is working and no stereo signal!!!Any ideas what happen with this ??????

Are you sure this is not an issue with the stereo coder? Have you tested the RDS with a driver then tested the stereo code with the driver separately?

I have built a few of these RDS boards and they have all been rock solid. I would test both the RDS and the stereo coder on a working driver separately as a first point and see what results you get.

Medley.

Level too high or need sync . Why no 1 of you post picture's

radium98 wrote: ↑Thu May 12, 2022 5:08 am Level too high or need sync . Why no 1 of you post picture's

i add photos of my set up!!!

Hello Steven30gr

Nice build by the way! Very neat and tidy!!

Generally it is not recommended to use both encoders together without some kind of system to synchronise the signals! However it should still work?

Levels are very important and i suspect this could be part of the problem?

To start with, Audio over modulation can cause your Stereo pilot to blink? So thats the first thing to keep in check!

Secondly, the Stereo pilot should be adjusted up until recognised by your Receiver! I would then advance it just a touch to be safe!

Finally, your RDS pilot should only be a fraction of the overall modulation! I cant remember the exact figure? But its something like 10% or less? Whacking up the level will not improve RDS!

Just to add! I am a big fan of those 'Quick Hookup leads' they are very handy! Screened cables between each MPX connection would not only improve noise! But also block most of the nasty signals leaking in!

The 19 kHz pilot tone should have a deviation of 7.5 kHz and the RDS should be 2 kHz. Do not vary from these levels. The 57kHz (the RDS signal) must be phase coherent with the 19 kHz pilot, to prevent "undesirable artifacts" according to CENELEC EN 50067:1998, which is the current specification for the system.

Most good answers. Up to 3.4 khz for rds system

Pleas can you chek it? I make fast smaller board.. i hope is good

Albert would be the man to confirm?

But it looks good to me Rigmo! Excellent work!