My FM10A and its poor quality

[mcnugget540]

I recently bought and assembled a FM10A and i can hear the music playing but its really bad quality, i was playign a CD thru my DVD player and i could hear it on 91.3,.5,.7, and .9 but 91.7 was the best but still really fuzzy... someone help please

[jay]

You were probably tuned to 91.7 that would explain why it sounded the best. Was the stereo indicator on your receiver lit when you were on 91.7?

Their are several common reasons for hearing your station above and below your operating frequency.

1)IF bandwidth of the receiver. A lot of receiver's have bandwidths which are wider than the actual transmitted signal to compensate for a not so perfectly alligned tuner.

2) Strong FM signals themselves will tend to "bleed over" a few channel spaces. You may have noticed this yourself while tuning through the band. That's why it is important have at least two channels empty above and below your frequency to ensure you don't cause interference to your immediate neighbor's reception.

Situations like this are why I strongly recommend a frequency counter for precise tuning of the transmitter, okay it will be difficult to exactly tune it since the stereo pilot is shifting the frequency up and down a few kHz.

3) Excessively high modulation levels. There is no limiter in the FM10A to ensure that your audio stays within 100% modulation. If you set your FM10A's audio levels to sound as loud as the big commercial stations, they are too high. When set properly, sadly, you're audio will be about half the loudness of the big commercial stations.

The fuzzy noise could be caused by excessively high audio levels, and or frequencies above 15kHz interfering with the stereo subcarrier system, and or just adding extra noise into the audio spectrum.

[mcnugget540]

yes i didnt mind the 91.3.5.7.9 thing as much as i minded the fuzziness, how can i fix it?

[lwsweb]

In my experience, turning down the audio entering the transmitter (either externally or using the potentiometers inside the unit) helps a lot (like the first reply mentions). When I did this to my 10A, the audio went from sounding fuzzy to sounding crystal-clear!