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/v ... 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 the RDS board with no effect. I have tried a 470uF capacitor across the GND and 5V lines on the RDS pin header, no change.
The tone is apparent when installed in a PC or running standalone on a bench PSU.
Is there a similar resolution for a V1 board to the one published for the V2 board?
If it helps trace board revision, my software is "PCI3K v1.1 02/10".
Thanks,
Max.
PCI MAX 3000+ v1 high pitch tone
Moderators: Sir Nigel, Nina, pcs, 5r, phpBB2 - Administrators
Go ahead and apply the same fix, I think the capacitor is in the same position.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
I have checked the schematic of the old V1 from 2009, the old v1 did not use PWM to set power so if you have a problem it is caused by something else.
I would disconnect audio input and if the problem dissapears than use USB audio instead.
It could also be a noisy power supply in your PC. If this is the case using external power supply would probably help.
I would disconnect audio input and if the problem dissapears than use USB audio instead.
It could also be a noisy power supply in your PC. If this is the case using external power supply would probably help.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
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 next?
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 next?
It is hard to say, probably coming from your PC and creating a beat tone with another signal, could even be coming from sound card or motherboard.
Probably a very unfortunate combination of several factors.
Experiment a bit, you can even take the card out, it does not need to be inside PC actually.
Probably a very unfortunate combination of several factors.
Experiment a bit, you can even take the card out, it does not need to be inside PC actually.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
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 monitored the signal at a distance and the tone is there.
Is it possible to obtain a circuit diagram? Where is the best place to probe the audio input into the VCO?
Any other recommendations welcome.
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 monitored the signal at a distance and the tone is there.
Is it possible to obtain a circuit diagram? Where is the best place to probe the audio input into the VCO?
Any other recommendations welcome.
Hi,
in that case the board could be broken, if its still under warranty we'll replace it for free.
If not you can still send it and we'll have a look at it.
in that case the board could be broken, if its still under warranty we'll replace it for free.
If not you can still send it and we'll have a look at it.
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128