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[Discuss-gnuradio] DBSRX Modification and Antenna Bias Question
From: |
Eric Cottrell |
Subject: |
[Discuss-gnuradio] DBSRX Modification and Antenna Bias Question |
Date: |
Wed, 11 Jul 2007 18:33:10 -0400 (EDT) |
Hello,
The question: What is the maximum voltage I can put into the antenna bias
connection?
The possible mod or configuration jumper:
I have a WR-LNA-3500 preamplifier that can be powered by coax or a coaxial
power connector. There is a diode to prevent backfeeding power through the
receiver port if the coaxial power connector is used. There is no shunt
resistor to prevent diode leakage current from building up a voltage on the
receiver port. I measure 13.2 volts on my high impedance DVM at the receiver
port with the preamplifier powered.
In looking at the schematic of the DBSRX I noticed there is no real DC path to
ground when DC Bias is not used. Would there be any problem to either jumper
the DC Bias connector when not used or to add a high value shunt resistor
across the DC Bias connector to keep any DC levels down? I assume the choke
will keep most of the RF on the proper side.
73 Eric
- [Discuss-gnuradio] DBSRX Modification and Antenna Bias Question,
Eric Cottrell <=