Hi Jason, I would ask for one test to be made regardless of degrees and that is turn on your AM car radio and drive through intersections where the static, from improperly grounded power transformers, etc. wipe out the AM signals. now turn around safely, tune in a FM signal, both of them from nearby stations,and listen to the difference in the quality of the signals received. Also take a AM portable radio and walk around some power poles and listen to the AM signals get wiped out. This says to not fly around power poles with transformers, etc. mounted on them. This will give some idea of what your receiver can hear while you are flying around. Also, don't fly around any shops where they are Arc welding. Thermals, Art
Jason Werner wrote: > Roy's friends are correct, in a "realistic" standpoint. > > FM's major advantage over AM is that slight modulations in amplitude of the > carrier wave do not change the data being sent. With AM, the amplitude > change IS the data being sent. All radio signals suffer from some amplitude > changes to the signal due to the atmosphere and physical interaction. > > The realistic standpoint is that we are working in a small environment. Our > distance is so short from transmitter to reciever, that the change is small. > The area has little time or ability to change the signal. Try this one day. > Drive close to the AM transmitting tower of your local station. Nice clear > signal. Drive 50 miles away. Static. Some more, some less. But when > close there is little if any static. Again, the distance is small resulting > in less decay of the signal. And BTW - that arc welder in the area, yes it > causes problems but again the Rx design will filter out that noise, just > like on Fm. > > Same with PCM. Many people claim that PCM results in less signal problems > than FM. Not true. From a carrier wave standpoint, the wave for both is > the same. The difference is how the Rx reacts to it. PCM allows a data > stream to be "self correcting" due to the data pattern. PPM (FM) does not > have that. Plus the microcomputer in the Rx has better smarts than a FM rx. > That is why the IPD reciever is nice. It is essentially a microcomputer to > process the incoming signal. Anyway, PCM is not "better" than FM...the part > that is better is the Rx design and the computer inside it. > > Jason Werner > > ----- Original Message ----- > From: "Roy G Biv" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Monday, May 06, 2002 10:19 AM > Subject: Re: [RCSE] ??? Radio Failure > > > > > >>No one today would use an AM receiver for our hobby. > > > > >That's a bold statement. It's not my primary radio, but I've been using > an > > >AM radio for years in both power planes and gliders with no problems. > > > > That =is= a bold statement, and possibly misinformed. > > > > I have two flying buddies with electronic engineering degrees; > > both say AM/FM itself makes no difference. Both fly AM and FM. > > I fly both AM and FM, and in last 10 years, only the FM sets > > have given me any real problems. Poorly engineered receivers > > =are= a real problem I have found. Some brands better than others. > > > > > > "It's not what we don't know that hurts us > > so much as what we know that ain't so." > > - Mark Twain > > > > > > > > > > > > > > _________________________________________________________________ > > Send and receive Hotmail on your mobile device: http://mobile.msn.com > > > > RCSE-List facilities provided by Model Airplane News. Send "subscribe" > and "unsubscribe" requests to [EMAIL PROTECTED] > > RCSE-List facilities provided by Model Airplane News. Send "subscribe" and >"unsubscribe" requests to [EMAIL PROTECTED] RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
