Jose - If it is similar to the HP two way GPS power splitter, then the MMIC is a voltage regulator used to deliver 3 volts to the amplifier transistor. In my splitter the MMIC died, so, not having another, I cut it out and soldered in a wire from the 5 volt input to the 3 volt output and then the splitter worked fine again. The 30 ma may be OK, as the antenna has to let the receiver know that it is OK, and it does that by exceeding a current threshold on the 5 volts delivered by the receiver. I doubt if the transistor draws nearly as much. Check the output lead on the active device to see if you have 3 volts on it. From your picture it appears it is the tab that goes to the output filter. 73 - Mike
Mike B. Feher, N4FS 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jose Manuel Sent: Monday, July 21, 2008 1:34 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] HP58504A antenna Hello all, I´d like to repair a HP58504A antenna that don´t deliver any output signal. The current is about 30 mA ( I think too high), and the transistor (unknown type) and the MMIC (uPC2749TB), seems to be with correct voltage. Does anyone have any experience or data about this antenna? I took an inside photo: http://www.ea1px.es/HP58504A.jpg Can the transistor be identified by the color code? Thanks in advance, José, EA1PX _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
