FlightAware Discussions

Anyone know the value of L14 on ProStick+?

I recently replaced the SMA connector on a blue FlightAware ProStick+ and when applying the hot air, didn’t protect the surrounding components adequately - big mistake! In the process, the L14 inductor near the connector decided to take leave of the device and sprout wings, never to be seen anywhere near my workbench again. Highlighted in the photo below, L14 appears to be the first component after the SMA connector, and I think is part of the matching circuit on the input of the Skyworks LNA.

By any chance, does anyone know the value of L14 ?

edited to correct typo

I think it is 8.2nH, but not 100% sure - let me ask someone who knows what they’re talking about :wink:

Suggest you look at the datasheet for the Skyworks LNA IC. The test circuits are often published and usually copied by the user.

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Thank you!! That was going to be my starting value to try since it’s used on the evaluation board for the lna, although I also didn’t want to presume that that was the value chosen in the FlightAware design.

Thank you for your help!!

The Skyworks uses 0603 size 8.2nH inductor on their demo board. We use 0402. If you use the part listed on Skyworks datasheet. It is possible that it won’t fit.

MLG1005S8N2HT000 This is the part we use for L14. You can buy it from mouser. If not go for RF inductor with 0402 package, with mininal SRF(self resonant frequency) to be at least 3.6GHz, max DC Resistance 0.4ohm and minimum Quality factor 8 (>10 @100MHz, >27@300MHz and >30@500MHz).

6 Likes

Wow!! Many thanks for the actual part number and specifications.
I’ve always been impressed with FlightAware’s customer service but this is above and beyond.
Thank you again!!