MiniRds New version

[Marcel_TNT]

Hi Jan! I see in the pira shop at MiniRds kit "This item will be replaced by a new version in October/November 2011."
You still plan to release new version this month?
Can you give me please some detailes about it like new features... changelog!
I just sold my stereo pll to get a better one and the mini rds from pira with it also and i need new rds encoder so seeing this text i tought to myself to wait a little longer for this new version!

[Jan]

In this issue it is unfortunately not so important what I'm planning but when the new boards will be finished as their production has been passed on 3rd party company. As soon as I'll know exact date, I'll put it on the website.
This device named MicroRDS is based on MRDS1322, the feature list can be found it the datasheet http://pira.cz/rds/mrds1322.pdf. In short the device is completely smd, with integrated pilot tone amplifier, four communication modes including 400 kHz I2C and RS232 with selectable polarity and speed. All signals are available on 12-pin I/O connector.

[Marcel_TNT]

Good! Maybe it will be less noisy than the MiniRds.... The MiniRds worked fine for me.. never had problems with any receiver but that noise alwais bugged me, i had to set pilot level  lower but i still could not get rid of it entarely, even do i syncronised it with stereo encoder(pira version)   

[Jan]

Your last post is very incorrect. Noise in audio band is below -90 dB, that applies to all PIRA32, MiniRDS and MicroRDS. You can never hear any noise on the encoder's output. Several companies mount the minirds into their brand transmitters.

From what I read your FM equipment is probably not a professional product and you have never used any FM analyzer to set correct signal levels. Look for the problem there.

[Marcel_TNT]

I also tought that it was from my last exciter with 2 oscilators but i tested it on my curent exciter also and still noise and also same thing on your pira exciter with i builded several months ago... this is my curent exciter   http:[snip - no promotions please ]   the 15w version

[Jan]

An audible noise from the minirds unit is impossible by principle (the antialias and bandpass filter is passive). For example noise at 5 kHz is below -100 dB (referenced to the 75 kHz FM deviation). So there are another possible reasons:
1) Distortion in the exciter or
2) too high RDS signal level, that causes 1) and distortion in receiver or
3) individual unit failure? Can send you another unit if necessary.
Before you release any strong allegation an appropriately strong argument base must exist. How did you assured that the deviation caused by RDS is below 7.5 kHz as required by standards? In other words I hope you have tried to adjust the RDS level and you are not injecting the RDS signal to Left or Right audio input.

[Marcel_TNT]

Well, i never measured with any equipment... first i tought it was normal the noise because just like a stereo encoder some noise is normal to apear, you can't compare a mono exciter with a stereo one at blanck noise level! But i saw at a friend the pira32 rds and i noticed his blank was crystal clear on fm thats why i tought the noise could be eradicated by a more expensive rds(pira 32) and asked you about new model!
Aldo i also cannot compare my situation with of that of my friend because i don't know what pilot level he has from the pira 32... thats why i needed to be asured by you that Minirds is same at noise as pira32 rds.
I think most probable cause could be pilot level because if i raise it then the noise becomes louder and louder, and another thing is if i turn the receiver on mono mode then the noise is not audible no more!
In any case the mini rds does his job more than expected for that money it costs, not to mention the stereo encoder from your schematic... it takes the exciter to another level... all sounds can be hared, excelent separation and it doesen't cut off a thing!

[Jan]

If RDS noise varies with pilot level, then the noise surely does not come from the minirds. In my opinion both pilot and RDS injection is too high into the exciter. Hobby FM equipment is usually much sensitive than professional equipment, i.e. all modulation signals must be kept on low level to prevent overmodulation and distortion.

Some people are able to do things that one is amazed, for example connect RDS signal to audio Left or Right channel before stereo encoder or to a limiter and then wonder that it does not work as expected... 

[Marcel_TNT]

Very true, i also seen some crazy stuff done! I usualy do stuff by the law except for the sound (the input of the exciter) i alwais modified the input in my crazy desire to reach the loudness of sound of the legal radio stations from my country but how can one do batle with their sound processors of over 10.000 euro or more....  is true i made some progress but also lost some things in the sound and surton distortion apeared!
Another thing i wanted to ask you... i see you sell the rds ic programmed so i can build the MiniRds at home, but the MiniRds i purcesed from you had a Pic  not Mrds!

[Jan]

Yes, it is a pic based.

[Marcel_TNT]

So if i want to buy it programmed to build the MiniRds at home you will send my the pic or the mrds?

[Jan]

the mrds is pic + internal software

[Adam Eve]

Jan,

Since you have now developed a new RDS product will you be making the firmaware for the old one available for purchase as a .hex file for us homebrewers?

Maybe you could host it on a limited access basis?

OR maybe not! :-)

[Jan]

Due to exclusivity agreements signed with several manufacturers the software components distribution must stay under control for next years. There are companies that have invested a lot of resources into their RDS equipment based on the chip. Their investment must be protected as some competitors might start to produce similar device without any development costs, just copying existing design. That's unacceptable in fair business.

[radiowavesokc]

What is the RS-232 interface chip you have pictured on the MicroRDS encoder to interface with a computer?  Thanks.