Receiver input protection

Discussions related to schematic capture, PCB layout, signal integrity, and RF development
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grosseman
Posts: 1
Joined: Mon Apr 25, 2016 10:12 am

Receiver input protection

Post by grosseman »

Hello guys,

I am planning to utilize the Blade for some ham stuff like spectrum anayzing, digital modes etc. But I'm very hesitant to connecting the RX input straight into my radio club's HF antenna installation. I'm imagining bad stuff will happen to the Blade if there's any stray capacitance and whatnot built up on those antennas when I plug it in.. or is my worry unfounded? Is the protection already built into the circuitry enough for this sort of usage? If not, is there any sort of circuit you could build to provide adequate protection? I've read about using bleeder resistors to ward off static buildup, would that be sufficient?

Regards
bglod
Posts: 201
Joined: Thu Jun 18, 2015 6:10 pm

Re: Receiver input protection

Post by bglod »

We do have some ESD protection on the front end, and the LMS6002d can be exposed to signals up to +23 dBm before it is damaged. The ADC saturates at about -13 dBm, making signals above that level useless. If you you want to be totally safe, you can put a limiter and/or attenuator on the RX port. MiniCircuits makes some really nice connectorized components for this, but feel free to use any brand of your choosing.
Electrical Engineer
Nuand, LLC.
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