Quite so, Dom.
Pre-launch predictions were way-off on AO-40 ground station requirements. We were told all one needed was a 16-turn helix and a downconvertor such as the "Drake". I found that the 24-inch BBQ with bare Drake was deaf.
But when I used a 33-inch offset feed dish (solen from my ku-band sat-TV) coupled with a good preamp before my unmodified Drake...I could copy the beacon out to squints of 49-degrees. That tranlates as nearly 5 s-units SNR for low squint angles (<10). I did spend a little more than the average BBQ dish user (I purchased the MKU-232 from db6nt for ~ $245, but made the system). I bought three Drakes in 1998 for $100 and modified one to 435 MHz IF. The other I received at 123 MHz totally unmodified. I gave the third as a door prize at a local hamfest.
My dish cost me $159 (for the 1-meter dish I had to buy for my TV system since I stold the 33-inch for ham radio). I built my own 5-turn helix for under $20. Everything else was left over from AO-10/13: FT-847, M2 UHF yagi, 2m yagi.
For mode-L, I bought a 45-element loop-yagi ($125) and DEMI 144/1268 Tx conv. ($450). There is the Yaesu B5400 and coax cables, etc. etc. ...but not counting that. You should guess what my 2m-eme station cost? So I have a lot of cash tied up in eme/sat ham radio (~ $10K), but not everyone need duplicate what I do.
To summarize, my mode-US station came real close to performing like my AO-10 mode-B station (in many ways it was superior).
Well I am glad that Amsat-DL chose to keep mode-L and S on P3E. You know my opinion regarding Eagle...disappointment. But I will reserve judgement till the day it is in orbit and operational...then ask me!
73's Ed - KL7UW
At 11:43 AM 9/8/2006 +0200, i8cvs wrote:
----- Original Message ----- From: "Jim Sanford" wb4gcs@amsat.org To: amsat-bb@amsat.org Sent: Friday, September 08, 2006 3:40 AM Subject: [amsat-bb] S-band on Eagle
Ladies and gentlemen:
As one of you commented this evening, AO-40 wasn't exactly a rock crusher on S-band. It worked, and adequately, at least on CW, but was not great.
Hi James, WB4GCS
Not true ! If one of us commented that AO40 was not great and only was usable at least on CW it means that his own station was not adeguate for it and not the satellite was responsible and one non able to fly swallow does not make a summer. By the experience of users majority the S-band downlink of AO40 was great and the best ever made by AMSAT
As I reflect on my personal AO-40 experiences, I now understand that there are 2 reasons for my disappointment. Local noise was one, and transponder distortion was another --
If local noise was a problem for you it was not a problem for the world wide majority of S-downlink users
Distorsion is not completely true ! Warbling and not distorsion was only present when RUDAK was operating so another swallow that not make a summer.
Thanks again and very 73,
Jim
James A. Sanford, PE Eagle Project Manager wb4gcs@amsat.org
Best 73" de
i8CVS Domenico
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73's, Ed - KL7UW ========================================= http://www.qsl.net/al7eb - BP40iq 144-EME: FT-847, mgf-1801/1402, 4xM2-xpol-20, 170w 432-EME: FT-847, mgf-1402, 1x21-ele (18.6 dBi), 60w =========================================