It seems to me that a more reliable design would avoid relays to switch between the Gain and the Omni antennas. It would be better to use directional couplers that feed the signals from both antennas to the receivers. Relays have to be commanded and can fail. A coupler is doing it's thing all the time.
On Sep 23, 2006, at 1:47 PM, John B. Stephensen wrote:
I think that the L band receiver could be used for multiple purposes -- command, linear transponder uplink and digital transponder uplink. See the attached diagram.
73,
John KD6OZH
----- Original Message ----- From: "Rick Hambly (W2GPS)" w2gps@cnssys.com To: "'John B. Stephensen'" kd6ozh@comcast.net Cc: "'EAGLE'" eagle@amsat.org Sent: Saturday, September 23, 2006 16:15 UTC Subject: RE: [eagle] Re: IF switching
John,
We should have omni antennas for perigee commanding. That tends to work when all else fails.
Rick W2GPS AMSAT LM2232
-----Original Message----- From: eagle-bounces@amsat.org [mailto:eagle-bounces@amsat.org] On Behalf Of John B. Stephensen Sent: Saturday, September 23, 2006 12:10 PM To: Robert McGwier Cc: 'EAGLE' Subject: [eagle] Re: IF switching
Bob:
In Mirek's design there is an L-band receiver PCB and a command receiver or command detector PCB mounted in one module. The two connect via the 10.7 MHz
IF. Command detectors could be connected to both the U and L receivers.
Are you suggesting one L receiver connected to an omni antenna and used only
for the command link and a second L receiver connected to a gain antenna and
only used for the transponders? A smaller solution would be one L receiver with an antenna relay.
73,
John KD6OZH
----- Original Message ----- From: "Robert McGwier" rwmcgwier@comcast.net To: "Robert McGwier" rwmcgwier@comcast.net Cc: "'EAGLE'" eagle@amsat.org Sent: Saturday, September 23, 2006 04:25 UTC Subject: [eagle] Re: IF switching
Robert McGwier wrote:
Robert McGwier wrote:
The downlinks in Lyle's SDX block diagram are two-fold. S and V. The only change I would make for Eagle is to make both of them HELAPS. This might prevent both of them being used simultaneously as HELAPS but it might not. We might choose to do a "delay only" version of the HELAPS for the second transmitter.
I would like to suggest that we use Mirek's command receiver to feed the exact same command receive technology to be used for P3E and that is the SDR/FIQ channel on the IHU-3. The less work we have to repeat, the better. I believe we should have stand alone command receivers independent of the transponder antennas. I would like to hear from John
Errrrr. Uhhhh. We might need antennas. I meant independent of the transponder receiver antennas.
I am definitely going to bed now. Independent of the transponder RECEIVERS. That only took 3 times to get right.
and Mirek on this. Mirek's command receiver is nicely done.
Bob
-- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman "You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat." - Einstein
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Via the Eagle mailing list courtesy of AMSAT-NA Eagle@amsat.org http://amsat.org/mailman/listinfo/eagle <Transponder Architecture - L RX.pdf>
Via the Eagle mailing list courtesy of AMSAT-NA Eagle@amsat.org http://amsat.org/mailman/listinfo/eagle