I have a few problems with this.
1 - It has bad selection bias. Amateurs who are already on satellites and who use S-band downlinks are the ones who don't have problems with interference. If they had interference, they wouldn't be on those bands. Additionally, people currently on satellites tend to be those with lots of space for big dishes. The point here is to open this up to people who won't, and would have more interference problems, since they live in denser areas and can't put up big dishes with lots of directional gain.
2 - Anecdotal "evidence" is pointless, especially since it is 5 years old. WiFi is a lot more popular now than it was 5 years ago.
3 - Could you justify putting up an X million dollar satellite that uses a band which is questionable at best, just because some complainers who don't actually volunteer to do anything say that it works for them?
4 - Why should we have to justify why we're not using a band? As we agreed at the SD meeting, we are looking at providing _services_ and the best way to do that, not how to best make use of old hardware, which wouldn't be usable anyway. X-band is usable too. Why isn't anyone asking us to justify not using it?
Matt
Jim Sanford wrote:
Team: The kind of rational technical argument we should be prepared to answer. . . .
73, Jim
-------- Original Message -------- Subject: [amsat-bb] Re: S band downlink on P3E Date: Thu, 7 Sep 2006 17:40:39 -0400 From: Jeff Griffin [email protected] Reply-To: Jeff Griffin [email protected] To: [email protected] References: 01b401c6d28f$cc51d870$1001a8c0@RAFPavillion 050e01c6d2ac$e29ff720$6401a8c0@KO4MA
Ok guy's, how about a test ? Why not everyone who is mode L/S capable get on AO-51 between September 11, and September 18th and post all results here? Or have another mode V/S session for the L band challenged? All we need is degree(s) of elevation worked, type of antenna, and rx environment, and quality of rx signal received. This should tell us what we want to know. I don't think there is a problem, as I worked up to 10 stations a pass last mode V/S session , and didn't hear anyone complain....
73 Jeff kb2m
----- Original Message ----- From: "Andrew Glasbrenner" [email protected] To: "Rick Fletcher" [email protected]; "'AMSAT'" [email protected] Sent: Thursday, September 07, 2006 2:38 PM Subject: [amsat-bb] Re: S band downlink on P3E
Rick,
I am in _TOTAL_ agreement. I live in the suburbs of Tampa/St. Pete and never had an interference problem on my 3 foot dish. I have used the same dish to log well over a dozen WiFi access points in that immediate neighborhood. With properly designed equipment, all that trash on 2.4 ghz goes away with some elevation. What won't work is helixes with multiple sidelobes, and surplus dishes that let one whole polarity of noise right thru the back.
Everyone knows I'm a big supporter of AMSAT, but I gotta call it as I see it. It makes me think of "bait and switch" to collect money for a project featuring such a popular mode and then drop it.
The loss of Mode B on AO-40 caused a lot of the hardcore AO-10/AO-13 types to walk away, and that was tough to overcome. Now that we have, and we have people wanting S band, we leave them behind too. Even if it's a sound engineering decision (and that hasn't been proven to me) it's a horrid marketing decision. Bad mojo for a organization that lives on the donations of it's members.
Sorry if this causes any pain to those involved with Eagle, but I needed to get it off my chest.
73, Drew KO4MA AMSAT LM 2332
While AO-40 was still alive and I was working it from deep within "Silicon Valley", an area blanketed by WiFi, 2.4GHz cordless phones, etc., I discovered that a parabolic dish with a properly positioned and designed patch feed (slightly under-illuminating the dish and having no significant side-lobes) would bring in AO-40's S-band downlink very nicely and cleanly.
Of course, other feed or antenna types such as helical antennas/feeds were useless in that environment.
I have to admit that I don't buy the "too noisy" argument.
73,
Rick KG6IAL
Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Via the Eagle mailing list courtesy of AMSAT-NA [email protected] http://amsat.org/mailman/listinfo/eagle