Re: [RCSE] Re: TX RF output? Long!

2006-03-10 Thread Jon Stone
From: Doug McLaren [EMAIL PROTECTED] Of course it's a real phenomenon. The technical term is `desense'. http://users3.ev1.net/~medcalf/ztx/desense.html It's also called the near-far problem. Imagine trying to hear a whisper across a crowded room. Nearby louder voices drowned out the

RE: [RCSE] Re: TX RF output? Long!

2006-03-10 Thread Rob Davis
@airage.com Subject: Re: [RCSE] Re: TX RF output? Long! From: Doug McLaren [EMAIL PROTECTED] Of course it's a real phenomenon. The technical term is `desense'. http://users3.ev1.net/~medcalf/ztx/desense.html It's also called the near-far problem. Imagine trying to hear a whisper across

Re: [RCSE] Re: TX RF output? Long!

2006-03-10 Thread Rick Eckel
Hmm. Of course this is true when all are speaking in the same frequency range. But how about if all the other conversations are being held above 20khz or below 20hz?? Does sheer power on other frequencies swamp the front end of a receiver? Shouldn't we see more evidence of this at the

RE: [RCSE] Re: TX RF output? Long!

2006-03-10 Thread lomcovak
] Re: TX RF output? Long! From: Doug McLaren [EMAIL PROTECTED] Of course it's a real phenomenon. The technical term is `desense'. http://users3.ev1.net/~medcalf/ztx/desense.html It's also called the near-far problem. Imagine trying to hear a whisper across a crowded room

Re: [RCSE] Re: TX RF output? Long!

2006-03-10 Thread Bill Swingle
A PCM signal is no better than PPM. The only benefit would have been if the PCM Rx went into fail safe. Obviously could have been quite helpful. If it did go into failsafe. Bill Swingle Janesville, CA RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe

Re: [RCSE] Re: TX RF output? Long!

2006-03-10 Thread Doug McLaren
On Fri, Mar 10, 2006 at 11:08:42AM -0500, Rick Eckel wrote: | Hmm. Of course this is true when all are speaking in the same | frequency range. But how about if all the other conversations are | being held above 20khz or below 20hz?? Yes, whispered voices aren't the best analogy, as they

Re: [RCSE] Re: TX RF output? Long!

2006-03-10 Thread tony estep
From: Rick Eckel [EMAIL PROTECTED] But how about if all the other conversations are being held above 20khz or below 20hz?? Does sheer power on other frequencies swamp the front end of a receiver? Shouldn't we see more evidence of this at the launch area? === Up or

Re: [RCSE] Re: TX RF output? Long!

2006-03-10 Thread Martin Usher
Imagine trying to hear a whisper across a crowded room. Nearby louder voices drowned out the one familiar voice you are trying to hear. All radio receivers face the same issues. (Jon Stone) This is where the magic of the newer receivers comes into play. Like any other radio they also have a

Re: [RCSE] Re: TX RF output? Long!

2006-03-10 Thread lomcovak
As it would have Bill...if indeed a PCMm RX was employed, as the communications protocol would have been different (except in the unlikely case the offending TX was identical and on the same frequency). A PCM RX would immediately have gone into hold, and then would have either returned to

Re: [RCSE] Re: TX RF output? Long!

2006-03-10 Thread tony estep
From: Doug McLaren [EMAIL PROTECTED] For desense to occur, the signals don't even have to be in the same band. For example, in my car the FM radio (88-108 MHz) signal gets noticibly quieter when I transmit on my 144 MHZ ham radio. Same thing happens in my

Re: [RCSE] Re: TX RF output? and urban legends

2006-03-09 Thread tony estep
From: [EMAIL PROTECTED]The above is of course only a guess...Yep. Perhaps some of the engineers in the group could provide some factual info.

RE: [RCSE] Re: TX RF output? and urban legends

2006-03-09 Thread John Diniz
: [RCSE] Re: TX RF output? and urban legends From: [EMAIL PROTECTED] The above is of course only a guess...Yep. Perhaps some of the engineers in the group could provide some factual info.

Re: [RCSE] Re: TX RF output? and urban legends

2006-03-09 Thread lomcovak
Actually Tony, what I stated are actual...heaven forbid...facts, as I prefer to speak from a position of first-hand knowledge and experience rather than hearsay. The anecdotal evidence put forth by John D. is a great real-world indicator of how prevelant this problem can be. I have personally

Re: [RCSE] Re: TX RF output? and urban legends

2006-03-09 Thread tony estep
- Original Message From: [EMAIL PROTECTED] Cc: Soaring@airage.com Actually Tony, what I stated are actual...heaven forbid...facts, as I prefer to speak from a position of first-hand knowledge and experience rather than hearsay. == Yep. The guesswork Gordy was referring

Re: [RCSE] Re: TX RF output? Long!

2006-03-09 Thread tony estep
- Original Message From: EXT-McCleave, Howard R [EMAIL PROTECTED] I was flying at about 50 feet of altitude along the tree line at the west end of the field when the plane did an immediate vertical dive into the ground with no possibility of recovery. When I walked out to get the

Re: [RCSE] Re: TX RF output? Long!

2006-03-09 Thread Doug McLaren
On Thu, Mar 09, 2006 at 10:28:37AM -0600, EXT-McCleave, Howard R wrote: ! What do you think experts, is swamping a real phenomenon or did | he have a lousy TX?? Plane's gone but I would still be interested to | know what y'all think. Of course it's a real phenomenon. The technical term is

Re: [RCSE] Re: TX RF output?]

2006-03-08 Thread Martin Usher
What a novel and smart suggestion. Makes one wonder how many TX's out there have never experienced a tune-up... They don't have any moving parts. Older radios may have parts like descrete coils (sometimes with slugs) that can can change their size slightly over time (mechanical, maybe due to

RE: [RCSE] Re: TX RF output?]

2006-03-08 Thread John Diniz
Message- From: Martin Usher [mailto:[EMAIL PROTECTED] Sent: Wednesday, March 08, 2006 4:01 PM To: soaring@airage.com Subject: Re: [RCSE] Re: TX RF output?] What a novel and smart suggestion. Makes one wonder how many TX's out there have never experienced a tune-up... They don't have any moving

Re: [RCSE] Re: TX RF output?]

2006-03-08 Thread Simon Van Leeuwen
You might consider asking a repair depot about how many TX's come in that are indeed emanating into adjacent channels. Secondly, RX's have interfered with each other in dual installations causing a loss of range, which on some installations has been severe. Using isolation techniques, the

Re: [RCSE] Re: TX RF output?]

2006-03-08 Thread Jeff Steifel
Actually without being as smart as some of you I can still disagree with this. Most radios do get out of alignment. I have been on the receiving end of splatter. A tuneup couldn't hurt. Receivers do emit RF. An ESL member has come up with a way of tracking a receiver based on its emission. He