KrakenSDR Powered Off - Incident Power Limit at Antenna Port

I’m trying to install a KrakenSDR in my vehicle alongside a 5, 25, or 50 W mobile VHF/UHF Ham radio installation. I’m understandably concerned about coupled power from transmitting in near proximity to the Kraken’s DF array killing the SDR. The FAQ recommends also disconnecting antennas from the Kraken when in proximity to powerful transmitters like mobile Ham radios and not only turning it off before transmitting, but it doesn’t give a reason other than that it may trip the ESD protection. If the Kraken can withstand more than +10 dBm in the off state, that would significantly improve integration alongside VHF/UHF Ham Radios. What do the board designers or community think about the safe RF input power level to the antenna ports when the Kraken is powered off? Is it truly only +10 dBm still?

I understand when in use the maximum safe input power level to an antenna port on the Kraken is +10 dBm. When powered off, what is done to the antenna ports and can it withstand more power then when powered on, why or why not? If it can, what is the limit while powered off. I was really hoping to install this device alongside my Ham radio and not have to disconnect antennas by hand to operate without hurting my Kraken. Now it’s looking like I would have to spend $250 on isolation switches controlled by 5V or 12V to protect it without unscrewing the antennas. If I could just turn it off and have it be ok in proximity to my transmitter though, that would be great to know.

I did take some external measurements of my kraken for the state of the antenna ports in various power conditions to learn more about htis. When powered off the DC resistance of an antenna port is basically an open circuit (> 20 M Ohms). When powered on but not using that antenna port/RTLSDR, the DC resistance is roughly 115 Ohms. When using a port, the resistance is roughly 115 Ohms.

The fact that the ports become open circuits when the Kraken is powered off lead me to believe it can withstand more input power. Would the board designers be able to provide any more information on this. For something intended to be installed in a vehicle and used by people similar to Ham operators, +10dBm even in the off state is very limiting when existing alongside VHF/UHF Ham radios.

I’m not an expert on what the Kraken can actually handle in terms of being overloaded, but it seems to me that if the Kraken is powered off… it won’t get damaged unless you plug a transmitter directly into one of the antenna inputs or something crazy like that.

I suppose you could get a RF Millivoltmeter and measure how much actual power is at the Kraken antenna ends when transmitting from other radios, and run the radio at the lowest power possible to keep it at a minimum.

I’ve operated a 50 watt radio from the same vehicle, with the Kraken antennas still on, but not with the Kraken powered on. No issues.

However, I’ve found that the antenna I use for the 50 watt radio does interfere with the DOA estimation (as I expected it would), so I wind up folding the extra antenna down or just taking it off while using the Kraken… but that’s me.

I’ve resorted to using a HT in the vehicle on low power to prevent both issues… overload and/or another external antenna messing with the Kraken’s ability to get a accurate direction on the desired signal.

When powered down operating at HT power levels next to the Kraken will be fine.