Of course. If your preamp has a D.C. Blocking capacitor at the output, you can usually extract the D.C. by simply putting a small RF choke on the output pin. You MUST have a blocking cap. Generally, for narrow band use, it's not fussy. ARR suggested a 1 mH RFC. Try it. Bias T's get fancy only if you want broad frequency coverage.
Ed Krome K9EK Sent from my iPhone
On Nov 26, 2017, at 3:02 PM, Scott [email protected] wrote:
Hi everyone.
The schematic makes me think "yes", but I wanted to check before making a purchase.
Normally a bias-tee is used to inject a DC voltage onto your coax to power a pre-amp. Since some pre-amps aren't powered off the coax, but rather from a separate pair of pins, I was wondering if you can use a bias-tee AT THE PRE-AMP to extract the DC voltage off our coax for connection to those external power pins on the pre-amp?
Running a separate cable to power the pre-amp is not the end of the world, but it would be convenient if I could turn on the bias voltage available on the Airspy or RTL-SDR and then extract it up at the antenna to power a pre-amp.
Thanks for any recommendations!
-Scott, K4KDR _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb