Hello and thank you for reading this post.
First and foremost although I've dabbled with electronics over the years (mainly digital and a bit of analogue) I am TOTALLY green with RF so excuse me if my use of terminology is quite a bit off.
I'm struggling with a HA11211 based FM/AM tuner section of a micro component system that refuses to drive the signal strength and tuning led's. Radio broadcast reception on FM and AM works fine with no apparent issues (weakness of signals, clarity, tuning problems etc). The problem here is solely with driving the 5 led signal strength meter and tuning meter (3 led's left centre right).
My understanding of the 11211 so far is that the signal strength level is fed out through pin 9 (in my case) to a BA695 pin 3 (3 led tuning IC) and a LB1416 Pin 3 (5 led driver).
Interestingly touching pin 8 with a length of wire does (besides inducing a lot of other radio stations on the audio) raise the voltage of the 11211's Pin 9 to about 1.4v and the signal strength meter hits 2-3 led's so this leads me to believe that the 11211 may not be behaving correctly. I replaced the HA11211, BA695 and LB1416, tested all supporting resistors but all symptoms persist. Its as though the 11211 is not receiving a strong enough signal in the first place from the earlier IF stages (even though I must admit the audio levels sound perfectly fine). Could the Ceramic Filter be filtering fine but over attenuating the signal? Is this a typical symptom of a failing CF or should I be looking elseware (earlier IF stages?). Or maybe am I'm getting this all wrong?
Thank you
First and foremost although I've dabbled with electronics over the years (mainly digital and a bit of analogue) I am TOTALLY green with RF so excuse me if my use of terminology is quite a bit off.
I'm struggling with a HA11211 based FM/AM tuner section of a micro component system that refuses to drive the signal strength and tuning led's. Radio broadcast reception on FM and AM works fine with no apparent issues (weakness of signals, clarity, tuning problems etc). The problem here is solely with driving the 5 led signal strength meter and tuning meter (3 led's left centre right).
My understanding of the 11211 so far is that the signal strength level is fed out through pin 9 (in my case) to a BA695 pin 3 (3 led tuning IC) and a LB1416 Pin 3 (5 led driver).
Interestingly touching pin 8 with a length of wire does (besides inducing a lot of other radio stations on the audio) raise the voltage of the 11211's Pin 9 to about 1.4v and the signal strength meter hits 2-3 led's so this leads me to believe that the 11211 may not be behaving correctly. I replaced the HA11211, BA695 and LB1416, tested all supporting resistors but all symptoms persist. Its as though the 11211 is not receiving a strong enough signal in the first place from the earlier IF stages (even though I must admit the audio levels sound perfectly fine). Could the Ceramic Filter be filtering fine but over attenuating the signal? Is this a typical symptom of a failing CF or should I be looking elseware (earlier IF stages?). Or maybe am I'm getting this all wrong?
Thank you