PCS-Electronics

If it helps, there is a "bodge cap" on the back of the board (across earth and what seems to trace back to pin 7 of the atmel). If I lift this, the tone increases in volume. The primary frequency measured at this point is 48 Khz.

I've removed the card from the PC and it's running on a linear bench PSU.

Once the transmitter is running, I've even disconnected the USB feed, but the tone is still apparent.

Disabling stereo on the unit and feeding an external multiplexed signal in results in the same tone being present.

I've ...

Thanks for the info.

I'm running the unit on an external, linear bench PSU. The problem was also apparent when running on the PC PSU.

It is frequency dependent. 91.7 is clean, 92.5 has the tone.

I've checked the frequency and it's around 9 Khz (half 19 Khz?)

Any suggestions where I might check ...

Thanks Marco.

I'm think I'm being a bit slow but it's not clear to me which component to remove referencing your PDF.

Here's an annotated picture of the components I think your PDF refers to - which letter should I remove?
(I did try B but it had no effect).


http://s8.postimg.org/g28djogc5/PCI3 ...

Hi,

I'm experiencing the same issue on my V1 PCI3K unit discussed in the thread "PCI MAX 3000+ v2 high pitch tone" http://www.pcs-electronics.com/phpBB2/viewtopic.php?t=2597

The tone is only apparent on certain frequencies, as detailed in the other thread - 92.50 is bad, 91.7 is OK.

I removed ...

Thanks Marko.

I'd like to feed an externally generated mpx signal into my PCI MAX 3000. Can someone please recommend the best point? Ideally I'd like the option of keeping the internal RDS encoder.

I notice my unit is about 3 Khz low in frequency. What is the recommended approach to allowing the frequency to be ...