[Kindle Fire Q&A, Help & Troubleshooting] noober22:
Actually, this question is the most likely addressed to the ROM developers, but I can't post there. So... hasn't anyone seen into the Kindle WLAN config file named 'TQS_S_2.6.ini' when working on Kindle ROMs?

I'm looking for a way to increase the WiFi range a bit without grilling the radio module. Can I just update the fields FEM1_TXBiPReferencePDvoltage_2_4G and FEM1_TxBiPReferencePower_2_4G? As far as I understood:

The .ini file is the result of Texas Instruments WL1270B calibrating, a process the integrator—either Jorjin (https://www.ifixit.com/Teardown/Kindle+Fire+Teardown/7099#s30229) or Amazon itself—performed once as soon as the chip revision is chosen and maybe (I'm not sure) the specific antenna is connected. The 'TxBiPReference' prefix itself tells us so: it stands for 'the reference Transmitter, Built in Production'.

The .ini file then is being put in a ROM (in mine, CM10.1.2-otter built on 2013 Jul 11, it's in /system/etc/wifi/), as a hardcoded set of parameters, suitable for the radio module (Jorjin WG7310) / the tablet (Kindle Fire). A WLAN driver reads the parameters on loading and send them back into the chip to apply.

One can change the file to make the driver set the chip into an unintended mode.

FEM1_TXBiPReferencePDvoltage_2_4G is 0177, it means 0x177 or 375 mV.

FEM1_TxBiPReferencePower_2_4G is 80, it means 0x80/8=128/8=16 dB according to a comment in the .ini file. Though no suffix is defined, I guess in fact it's dBm, in other words the power is ~40 milliwatts.

And I'm not sure I got all correct. For instance, is it really 'TQS_S_2.6.ini' where the settings for the driver are stored and loaded from? Some sources mention converting the .ini file into an NVS bin file (?—Dunno what's this).

The rest is an absolute mystery to me. I have faced some radio units before, but they were UHF / GSM (AT-based) ones, never 802.11.

What does FEM stand for? Front-end module? Why FEM1 then? (I've seen FEM0 prefix in some .ini files for other devices: https://e2e.ti.com/support/wireless_connectivity/wilink_wifi_bluetooth/f/307/t/127647).

Does PDVoltage stand for 'powered device voltage', in other words, the voltage of the module ('device') when it's in active ('powered') state as opposed to inactive (sleeping, power-saving) state?

Why the voltage at all? UHF transmitters, for instance, had a setting for output power only. I guess, the higher power, the greater voltage, but what is the relation?

What if I just change FEM1_TxBiPReferencePower_2_4G to a0 (20dBm/100mW)? Would the module just start working on the maximal power allowed by ETSI? Or it would burn out?

I see a family of parameters, named 'Power Limits' (the pattern is FEM1_TxPerRatePowerLimits_2_4G_condition, where condition is 'Normal', 'Degraded' or 'Extreme'). The value consists of 6 numbers which should correspond to some 6 data rates. I can calculate that the limits are (for normal battery state) from 14 to 20 milliwatts. How it goes together with FEM1_TxBiPReferencePower_2_4G?

So, if anyone has answers to the questions or just a ready config file for increasing WiFi range, it would be great :)

Disclaimer. Yes, I know that such changes can be harmful for the device as well as for people. And yes, I'm well aware that in most countries there are laws limiting the power.