Re: [Discuss-gnuradio] DC on antenna

[Matt Ettus]

No.  Let me be clearer...

If you have a DBSRX Rev 2.0 board  (what most people have):
        Apply your bias voltage to the pin labeled "+" on J100 (the
                one closer to the SMA).  The other pin on J100
                is ground.
        Your bias voltage can be up to 30 V, and you can draw as
                much as 500 mA.


If you have a DBSRX Rev 2.1 board you have 2 choices:
        1)  Do the same as above.

        2)  If your desired bias voltage is 5.0V, you can instead
                simply short the 2 pins of J101 (NOT J100) together.
                Most GPS antennas can take 5V.  Ignore the silkscreen
                which says 6V.  You can draw about 200-300mA only.

J101 is only on rev 2.1 boards, not 2.0 boards.

Matt




Clark Pope wrote:
> Thanks, I see it on the board. But you mean short pins on J100, right?
> 
> 
>> From: Matt Ettus <address@hidden>
>> To: Clark Pope <address@hidden>
>> CC: address@hidden
>> Subject: Re: [Discuss-gnuradio] DC on antenna
>> Date: Sun, 12 Mar 2006 20:37:20 -0800
>>
>> Clark Pope wrote:
>> >
>> > Has anyone tried using the GPS antennas where you have to provide DC
>> > power over the antenna line with a USRP? Especially for the DBS board?
>> > Seems like there ought to be a way to get one of the DAC outputs
>> coupled
>> > into the RF to power a gps lna or switch elements, etc.
>>
>>
>> The dbsrx board has a header on it designed specifically to do this.
>> Just provide the voltage on J100, a 2 pin header.  If you have one of
>> the newer dbsrx boards, rev 2.1, just short the pins of J101, and you
>> will have 5V at the antenna port.
>>
>> Matt
> 
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