NOTE:
	Files ending with BTT are named this way to tell the unit to burn the bootloader 
	as well as the main program. Very old firmware will not recognize the BTT extension.
	If the unit does not update then change the .BTT extension to .BIN
	
  TFB-xxx.BIN is for the FB transmitter only
  THD-xxx.BIN is for all other ZHD capable transmitters only
  ZMT-xxx.BIN is for the small ZMT and ZMT48 transmitters and hand held ZMT style plug on
  HH-xxx.BIN  is for the full sized hand held 
  CL-xxx.BIN  is for the new wide band camera link and new IFB200s
  LNK-xxx.BIN is for the the older camera link and IFB200 (not wide band)
  ZM4-xxx.BIN is for the the ZMT 4 transmitter


-------------------------------------------------------------------------
----------------------- ZMT4 version history ----------------------------
-------------------------------------------------------------------------

4.71 Jun 19 2026
	Forced new transmit filter to On

4.70A May 27 2026
	Added new High Pass Filter (using ADC chip) that should be quieter
	Added new transmit filter to help receivers decode better
	
4.67 May 12 2026
	Removed TV_MIN / MAX screens from SETUP menu

4.66 May 11 2026
	Fixed some screen issues
	Do not allow record when no FAT32 file system present

4.64 May 8 2026
	Added new transmit filter for better range especially when using DCIRX and QRX400 receiver
	Added experimental audio High Pass filter (high precision, low noise)

4.61 Aug 11 2025
	Allowed a REMOTE STANDBY command to reboot the transmitter into standby mode
	(must use camera link version CL-401 or greater for this to work)

4.60 Feb 12 2025
	For ZMT4s sold after Nov 15 2025: 
	Fixed noise in 48V that could cause buzzing or popping in some microphones
	Bootloader V75 could help with crashing when formatting a card as well.


4.59 Jun 20 2024
	Added QUIET 48V screen in Factory menu - turn this on to quiet down 48V supply at low battery voltages (reduces battery life a little bit when in 48V mode)

4.58 Apr 22 2024
	Fixed LCD Timer: (DISPLAY DIM) to always allow screen to go dark in LOCK screen unless specifically set to "ALWAYS_ON"
	Fixed LCD Timer: was always timing out at 5 seconds regardless of the setting in the DISPLAY DIM page
	Fixed LOCK screen security issue when TC JAM screen pops up

4.57 Apr 5 2024
	Fixed problem with battery being jumpy when coming out of Remote Standby Mode
	Do not allow more than 10mW transmit power for Japan units

4.56 Mar 15
	Fixed: Was not displaying Japan-style indexed freqs 
	Added decimal point in Zaxnet RX FREQ page

4.55 Mar 5 2024
	Allowed lock screen to remain on indefinitely if OLED DIMMER setting is set to OFF

4.54 Feb 28 2024
	Fixed IFB RX FREQ screen
	No longer force Tx Audio Phase invert to false (allow user to choose it in factory menu)
	When Phantom Power is in 48V mode (greater than 5V) we shut down at 3.3V instead of 3.16 now to prevent noise
	Reduced Linear regulator voltage in 48V mode from 44V to 43V to reduce noise 

 -------------------------- 2024 ----------------------
4.49E Jan 23 WARNING IFB FREQ SCREEN NO LONGER WORKS
	Added Japan frequency list (125kHz steps) 
	Note: TVCHAN min and max freq need to both be set to Block 70 to trigger Japan mode (806MHz and 809.7MHz)
	
4.49D Sep 28
	Added support for 850MHZ Japan version

4.49 Sep 11
	Made lithium ION battery top of meter 4V instead of 4.2V

4.48 Sep 6 2023
	Fixed problem when removing SD card: the display still said "REC"

4.47 Aug 5 2023
	Added ZAXNET TX audio support (experimental)

4.46 Jul 25 (also 4.45A)
	Fixed problems formatting newer 4GB transcend cards 

4.45 Apr 4 2023
	Prevented remote control of frequency from allowing out of range freq choices

4.44 Apr 3 2023
	Fixed remote transport mode 

4.43 Mar 7 2023  (REMOTE TRANSPORT DOES NOT WORK)
	FIXED: In the LOCK screen, when no card was inserted, the screen could be quickly exited by pressing CARD+MENU and then MENU.

4.42 Jan 24 2023 (REMOTE TRANSPORT DOES NOT WORK)
	Zaxnet remote transport mode fix

4.41 Nov 21 
	Made sure 5V mic voltage is turned on in products that do not have phantom power

4.40 Nov 4
	Made changing of powered modes look for a unit code change to act like older transmitters
	when changing power modes using an IFB100's front panel 
	(Changing the unit code on the IFB front panel will now immediately change the 
	power mode of the ZMT4 to the current mode the IFB is set to.
	Previously you had to change the IFB's unit code and then change the power mode
	to get the new power mode to be sent).

4.39 Nov 1
	Added LOCK DIFFICULTY screen in SETUP menu. This changes the 
	number of times MENU+UP has to be pressed to exit in LOCK screen

4.38 Nov 1
	Don't allow MENU key to prevent going into lock mode on bootup
	Removed: TX AUDIO PHASE INVERT setting to be remembered after a power cycle

4.37B Oct 27
	Allowed TX AUDIO PHASE INVERT setting to be remembered after a power cycle

4.37 Oct 27
	Lots of changes to remote power control (merged from LA5 build)
	Brought back check of unit code when performing power control / wake commands
	Sport4: Prevented 48volt routines from possibly interfering with STEREO/MONO switch 
	Sport4: Removed 48V phantom related menus since it ha no phantom power
	Sport4: Added TX power status text on right side of home screen

4.36 Oct 26
	Bring back check of unit code when performing power control / wake commands

4.35 Oct 20 2022
	Made sure mute switch mode cannot get stuck on

	Added "SPORT MODE" in factory menu when set to 1, 
	these settings are always forced on power up:

    (phantom power setting no longer shows up in home menu)
     PhantomPower    = PHANTOM = "5 Volts"
     UserTxPower     = "TX POWER: 50mW" (or 100mW)  max power 
     lockmode        = "KEY_LOCK_ON_BOOT: LOCKED"
     TxDisable       = "TX DISABLE: NORMAL TX MODE"
     TXformat        = "TX FORMAT: STEREO"
     standby         = "STANDBY_BOOT_MODE = REMOTE STANDBY"
     MuteSwitchMode  = MUTE SWITCH DISABLED

     // force normal Zaxnet RX mode
     disable IFB RX to TX mode
     disable IFB pulse mode
     force IFB mode to "ZAXNET_MODE: 1 RX"

     "ADC_IMPEDANCE: 10K (DEFAULT)"

4.34 Sep 14 2022
	Went back to looking at unit code to determine if a unit should come out of standby
	Fixed display not dimming down to a single packet counter when in standby mode 
	Limited power selector to only two values on ZMT FLEX (10mW and 50mW)
	This contains bootloader v67 if .BIN file is renamed to a .BTT extension
	which helps with formatting Transcend cards

4.33 Jun 27
	Fixed TX NAME only being 7 characters 

4.32 Jun 13
	v60 bootloader which fixes a problem with formatting some SD cards

4.30 Jun 2
	prevented SPORT model from forcing TC SOURCE to IFB all the time on boot up

4.28 May 6 2022
	Added "ALL FREQS" mode to allow the 608-614 band in factory menu

4.27 May 2 2022
	Fixed lower case track names (from Nova) causing problems

4.26 Apr 25 22
	Fixed digital gain setting in ADC to proper unity (was 2dB off)

4.25 Feb 28 22
	Added MUTE SWITCH feature to AUDIO menu (press UP key to mute audio in home screen or Lock screen)
	and double click to latch the mute state.

4.24 Feb 11 22
	Allow last character in TXname to be edited
	Standby mode can power down if battery runs low now 
	Ignore unit code on TC packets when waking up from standby mode
	Fixed spy4 battery ADC not working on power up in standby mode

4.22 Jan 19 2022  ------------------------ 2022 -----------------------
	Fixed TX Name from possibly having old chars after it from a longer name

4.21 Dec 17 21
	Fixed corrupted settings when receiving txName from Nova

	Added .metadata_never_index file to SD card 
	so MACs will allow card ejection  this requires burning the bootloader
	To burn the bootloader rename the .BIN file to .BTT. That will tell 
	the unit to burn both the main program and the bootloader

4.20 Dec 8 21 DO NOT USE!
	Added support for receiving transmitter name from Nova over zaxnet

4.19 Dec 6 21
	Added ALLOW 608-614 screen for Roger

4.17 Sep 23 2021
	Fixed WakeUp from Standby when using a Nomad

4.14 Aug 12 
	Reduced noise floor at high gain settings

4.12 Jun 19
	Always allow recording in low power mode now	
	Attempted fix for some units not seeing card properly

4.11 Jun 7 (Warning: This version may not see the SD card properly)
	Allow recording while in low power mode (but not in standby mode)

4.10 May 26 (Warning: This version may not see the SD card properly)
	Slowed down processor speed to save power
	User can speed it back up in the DSP_SPEED page in the FACTORY menu (press MENU after changing it to save the setting)

4.06 May 3 
	We now reboot after waking up from low power mode to insure audio is reset properly

4.05 Apr 27 2021
	Added ADC Impedance screen to Audio menu
	Lower impedance settings tend to reduce the noise floor but 
	also reduces low frequency audio response

4.04 Apr 22 2021
	Fixed applying 5V to mic when unit is set to Zero Volt Phantom setting
	
4.02 Apr 14
	Forced impedance of main input to 20k all the time

4.01 Mar 8
	Reduced the noise floor of NeverClip
	Added ADC Impedance Mode screen

4.02 Apr 14
	Improved low frequency audio response

4.01 Mar 8
	Reduced the noise floor of NeverClip

4.00 Mar 6
	Fixed lock screen problem where turning off the LCD stopped the unit from transmitting	



