Radio Data System (RDS) > P132, P164, P232(U) and P332 RDS Encoders

P132 Introducing Static on the FM Transmission

(1/2) > >>

Gordon_Waters:
Hi,

Just install the P132 and notice that there is now slight static / distortion of our transmission.
What would cause this ?
What can I do about it.

I have a encoder & transmitter  with single MPX connector so using it in loop mode
.


Thanks

Jan:
Did you adjust RDS level?

What's the RDS modulation level reading on your FM analyzer?

Gordon:
Hi,

Thanks for your reply.

I do not have a FM analyzer, so do not know. I guess I need to get hold of one and find out.

I Did turn it back form the 4000 to 3000, but didn't notice anything. Although I was not sre that this would achive anything.

Gordon

Jan:
Do you mean 4000 mV pp ?

In loopthrough mode, the RDS level should never exceed 350 mV pp ! (LEVEL=22)

For example:
assuming your FM transmitter requires 5000 mV pp for 75 kHz FM deviation
and desired RDS modulation level is 3 kHz,
the RDS level must be (3/75) * 5000 = 200 mV pp (LEVEL=13)

Gordon_Waters:
Thanks, With some testing I have dropped it back to 203mV. The static is certainly not as noticeable, but it's still there slightly.

It's like the station is not quite turned in.

Navigation

[0] Message Index

[#] Next page

Reply