View Single Post
  #11   Spotlight this post!  
Unread 07-07-2010, 10:32
billbo911's Avatar
billbo911 billbo911 is offline
I prefer you give a perfect effort.
AKA: That's "Mr. Bill"
FRC #2073 (EagleForce)
Team Role: Mentor
 
Join Date: Mar 2005
Rookie Year: 2005
Location: Elk Grove, Ca.
Posts: 2,372
billbo911 has a reputation beyond reputebillbo911 has a reputation beyond reputebillbo911 has a reputation beyond reputebillbo911 has a reputation beyond reputebillbo911 has a reputation beyond reputebillbo911 has a reputation beyond reputebillbo911 has a reputation beyond reputebillbo911 has a reputation beyond reputebillbo911 has a reputation beyond reputebillbo911 has a reputation beyond reputebillbo911 has a reputation beyond repute
Re: Hi-Fi Stereo FM Transmitter

Quote:
Originally Posted by Al Skierkiewicz View Post
Bill,
Does the transmitter light a stereo light on a receiver very close to the transmitter? If not, this is usually an indication that the 19 kHz pilot carrier is not functioning..... It may indicate that the 38 kHz crystal is defective.
Quote:
Originally Posted by Don Rotolo View Post
Try a half-wave counterpoise: If your antenna goes 38" in one direction, connect a wire to Ground (right where it first hits the board) and run it 38" in the the other direction. The best signal will be at a right angle to that "dipole".

It's cheap and quick, and could double your signal strength or better.

But try what Al said: If you can't get stereo from 6" away, there's a fault. I have built $25 FM kits which worked at 150 feet, no problem.
It looks like I will be dragging the scope out of storage and actually using it for the first time in over a year. I know the calibration is suspect on it, but that won't matter for this troubleshooting exercise. If the signal from the crystal isn't there, then I will know the cause.

Don, I was thinking the same thing. In fact, I have a dipole antenna from a stereo receiver I was going to try just for kicks.

I'll let you know what I figure out.
__________________
CalGames 2009 Autonomous Champion Award winner
Sacramento 2010 Creativity in Design winner, Sacramento 2010 Quarter finalist
2011 Sacramento Finalist, 2011 Madtown Engineering Inspiration Award.
2012 Sacramento Semi-Finals, 2012 Sacramento Innovation in Control Award, 2012 SVR Judges Award.
2012 CalGames Autonomous Challenge Award winner ($$$).
2014 2X Rockwell Automation: Innovation in Control Award (CVR and SAC). Curie Division Gracious Professionalism Award.
2014 Capital City Classic Winner AND Runner Up. Madtown Throwdown: Runner up.
2015 Innovation in Control Award, Sacramento.
2016 Chezy Champs Finalist, 2016 MTTD Finalist
Reply With Quote