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RSP1A Bias -T

Posted: Wed Mar 07, 2018 5:15 pm
by mattltm
Is there a point on the RSP1A PCB that I can pick up the switched 5v that feeds the Bias-T and is there a component that I can remove to prevent the 5V being fed up the coax?

I want to experiment with using the Bias-T function to switch some outboard modules without having to tap it from the antenna connector.

Re: RSP1A Bias -T

Posted: Thu Mar 08, 2018 1:27 am
by IQbert
I haven't looked at the schematic, but typically a voltage is added to an RF line through an RF Choke/inductor. Remove that, and tap into the non-RF side. Good luck.

Re: RSP1A Bias -T

Posted: Thu Mar 08, 2018 6:26 am
by mattltm
IS the schematic publicly available? I've had a quick Google search but can't find anything.

Re: RSP1A Bias -T

Posted: Fri Mar 09, 2018 6:19 pm
by DF1KZ
Yes, there is a component you can remove - its an inductor on the pcb near the antenna plug. You remove it on your own risk. Your warranty will be void.
You can also use an external DC-block, a capacitor in series (depending on your lowest frequency 100nF-470nF, ceramic).
Imho there is no circuit drawing of RSP1A available but you can find pictures of the pcb.


Re: RSP1A Bias -T

Posted: Mon Apr 02, 2018 4:53 pm
by mattltm
IQbert, I would love to reply to your PM but can't because I am not allowed to send any messages yet!

Please PM me your email address and I will send you what you need.