I've posted the schematic and assembly drawing for the U-band receiver test fixture on the U-band receiver page in EaglePedia just above the receiver fabrication section. This PCB was made to test a way to tune the matching networks for the narrow-band SAW filters. I also added a new second mixer and IF amplifier so that changes to reduce thermal dissipation in revision B of the receiver can be tested. Note that the average DC power consumed by first IF amplifier, second mixer and second IF amplifier drops from 870 mW to 370 mW. The circuit should exceed the specifications in the recently-revised U-band receiver requiremnts document.
73,
John KD6OZH
John,
Why not put the new 10 MHz reference on the test PCB too? We might as well test as much as we can with that board.
73,
Juan
-----Original Message----- From: John B. Stephensen [mailto:kd6ozh@comcast.net] Sent: Sunday, August 19, 2007 5:34 PM To: juan-rivera@sbcglobal.net; Bill Ress; Jim Sanford (wb4gcs); Dick Jannson Cc: 'AMSAT Eagle' Subject: Info on U-band receiver changes
I've posted the schematic and assembly drawing for the U-band receiver test fixture on the U-band receiver page in EaglePedia just above the receiver fabrication section. This PCB was made to test a way to tune the matching networks for the narrow-band SAW filters. I also added a new second mixer and IF amplifier so that changes to reduce thermal dissipation in revision B
of the receiver can be tested. Note that the average DC power consumed by first IF amplifier, second mixer and second IF amplifier drops from 870 mW to 370 mW. The circuit should exceed the specifications in the recently-revised U-band receiver requiremnts document.
73,
John KD6OZH
participants (2)
-
John B. Stephensen -
Juan Rivera