Author Topic: RDS encoder connection  (Read 4667 times)

Hoggins!

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RDS encoder connection
« on: July 24, 2011, 09:28:09 pm »
Hello Jan,

I already have one of your PIRA32 RDS encoder. Great device ! Currently, it is hooked on an FM transmitter with MPX output and RDS input.

I'm planning to use it with a couple of FM transmitter / stereo coder from [removed by admin], but I have a problem, regarding the manual you provided for the PIRA32 : on page 8, you say that the loopthrough mode is not recommended, and is to be used only if there is no other option. With these devices, that is the schema I'll have to use.

Can you explain quickly why you don't recommend the loopthrough mode ?

Thanks in advance,

Hoggins!

Jan

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Re: RDS encoder connection
« Reply #1 on: July 24, 2011, 10:10:38 pm »
The manual says "It is recommended not to use this mode if any of the other connections are possible."
The reason is strictly general - to reduce a number of components in the MPX path. This does not mean that loopthrough mode is not recommended at all. If there's no other option, there's nothing to solve.

Hoggins!

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Re: RDS encoder connection
« Reply #2 on: July 24, 2011, 10:20:53 pm »
Thanks !

But, digging more in their products, I discovered an option board that could upgrade their FM transmitters and allow for RDS input.
Knowing the quality of their products, I was doubtful that there would not be such an option.

But, just in case, thanks for the tip !

Hoggins!

Jan

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Re: RDS encoder connection
« Reply #3 on: July 25, 2011, 08:40:20 am »
In the case the transmitter allows at least the loopthrough connection (i.e. it has MPX input, not only L and R inputs like most of poor quality BH1415 based Chinese kits), paying for any optional board has no sense in my opinion as quality of this solution does not sound better to me than using the loopthrough mode.

When using real top grade equipment, for example providing 90 dB S/N and (real, not paper-like!) 70 dB stereo separation, the loopthrough mode may cause some MPX signal quality reduction regardless of the RDS encoder model as in this case the MPX coaxial cable alone can be a problem if it is longer than say 0.5 m. It is not a random that top parameters are reached only if stereo encoder and FM exciter are placed securely in the same housing and RDS input provided separately has real sense.