A Front-panel view of my FT-817.

One of the interesting features of the FT-817 is that many of the "conventional" calibration settings that would have, in the past, been done using manual adjustments of coils, capacitors, and potentiometers, are done via "software."

This explains the existence of the "Soft Calibration" menu in the FT-817's firmware.  This menu is reached by turning off the radio, holding down the A, B, and C keys simultaneously (which may be difficult to do if you have large fingers...) and turning the power on.  When you are done adjusting values,the F key must be pressed to save these parameters to the radio's EEPROM.  If this is not done, any changes made will simply be lost.

WARNING:
It is NOT recommended that you modify any of the parameters in this menu unless you know exactly what you are doing.

It should go without saying that you should record each of the 76 "soft calibration" parameters before doing anything else.  Using Simon Brown's FT-817 Commander you can save and retrieve these calibration values by using the Tools->Calibration menu (reachable by hitting ALT-C) and SAVING them.  (If you have more than one FT-817, make sure you don't inadvertently load the calibration factors for a different radio, for each unit is different.)

A word of warning:  Be careful if you "tune" past item number 17, the FT-817's voltmeter may become uncalibrated if you save the parameters.  If you turn off the FT-817 (and do not press the F key to "save" the modified parameters) then any changes you make will not be saved.

What follows is a list of each of the 76 parameters, followed by a description of what they (are believed to) do.  If you believe that you have more detailed information as to what any of these parameters do, please let me know.
 

Menu  No.	Name	Description
01	HF1RXG	IF gain setting for HF band 1 (0.1-<2.5 MHz.)  This adjustment sets a bias current into D1063 in the 1st IF.  This changes the attenuation of this stage and has an effect on AGC, S-Meter, and noise blanker operation as well as having an effect on the "apparent" sensitivity of the FT-817.  Lower numbers = greater attenuation (which equals higher gain - but not necessarily greater sensitivity.)
02	HF2RXG	The same as HF1RXG, except that it adjusts the IF gain setting for HF band 2 (2.5-<10.5 MHz.)
03	HF3RXG	The same as HF1RXG, except that it adjusts the IF gain setting for HF band 3 (10.5-<33.0 MHz.)
04	50MRXG	The same as HF1RXG, except that it adjusts the IF gain setting for "50 MHz" band (33.0-56.0 MHz.)
05	VHFRXG	The same as HF1RXG, except that it adjusts the IF gain setting for "VHF" (108.0-154.0 MHz.)
06	UHFRXG	The same as HF1RXG, except that it adjusts the IF gain setting for UHF (420.0-470.0 MHz.)
07	SSB-S9	This adjusts the amount of signal required for an S-9 reading in the AM/SSB/CW modes on all bands.
08	SSB-FS	This sets the amount of signal required for a full-scale reading in the AM/SSB/CW modes on all bands.
09	FM-S1	This sets the amount of signal required for an S-1 reading in the FM mode.  (Does not apply to WFM in the FM broadcast band.)
10	FM-FS	This sets the amount of signal required for a full-scale reading in the FM mode.  (Does not apply to WFM in the FM broadcast band.)
11	DISC-L	This sets the lower threshold for the "Discriminator Center" detection in the FM-N and FM modes.  This threshold is typically set for 3 KHz below the display frequency.  (Does not apply to WFM in the FM broadcast band.)
12	DISC-H	This sets the upper threshold for the "Discriminator Center" detection in the FM-N and FM modes.  This threshold is typically set for 3 KHz above the display frequency.  (Does not apply to WFM in the FM broadcast band.)
13	FM-TH1	This is believed to set the "bottom end" of the squelch range threshold.
14	FM-TH2	This is believed to adjust the amount of hysteresis in the squelch response.
15	FM-TI1	The precise function is unknown, but it appears to affect how the squelch operates in the presence of a received signal.  (Possibly an adjustment for a squelch time constant.)
16	FM-TI2	The precise function is unknown, but it appears to affect how the squelch operates in the presence of a received signal.  (Possibly an adjustment for a squelch time constant.)
17	VCC	This sets permits calibration of the voltmeter.  The voltmeter will display a voltage equal to 1/10th the displayed calibration value whenever the voltage being applied to the radio (at that moment of "calibration") is applied.  (See calibration info on this page for information on adjustment.)  The actual calibration value used to calculate the displayed battery voltage is stored in the EEPROM at memory location 0x53.
18	HF1-IC	This sets the maximum amount of current that the radio can draw when transmitting in the HF1 band (0.1-<2.5 MHz.)  This is overcurrent protection for the radio's finals and is measured by monitoring the voltage drop across one of the windings of T1035.  Higher values = higher current.
19	HF2-IC	The same as HF1-IC except that it applies to the HF band 2.
20	HF3-IC	The same as HF1-IC except that it applies to the HF band 3.
21	50M-IC	The same as HF1-IC except that it applies to the 50 MHz band.
22	VHF-IC	The same as HF1-IC except that it applies to the VHF band.
23	UHF-IC	The same as HF1-IC except that it applies to the UHF band.
24	HF1-HI	This sets the RF output power in the HI power setting for HF Band 1 (5 watts.)  Lower value = Lower power.
25	HF1-L3	This sets the RF output power in the L3 power setting for HF Band 1 (2.5 watts.)
26	HF1-L2	This sets the RF output power in the L2 power setting for HF Band 1 (1 watt.)
27	HF1-L1	This sets the RF output power in the L1 power setting for HF Band 1 (0.5 watts.)
28	HF2-HI	Same as HF1-HI except for HF Band 2.
29	HF2-L3	Same as HF1-L3 except for HF Band 2.
30	HF2-L2	Same as HF1-L2 except for HF Band 2.
31	HF2-L1	Same as HF1-L1 except for HF Band 2.
32	HF3-HI	Same as HF1-HI except for HF Band 3.
33	HF3-L3	Same as HF1-L3 except for HF Band 3.
34	HF3-L2	Same as HF1-L2 except for HF Band 3.
35	HF3-L1	Same as HF1-L1 except for HF Band 3.
36	50M-HI	Same as HF1-HI except for the 50 MHz Band.
37	50M-L3	Same as HF1-L3 except for the 50 MHz Band.
38	50M-L2	Same as HF1-L2 except for the 50 MHz Band.
39	50M-L1	Same as HF1-L1 except for the 50 MHz Band.
40	VHF-HI	Same as HF1-HI except for the VHF Band.
41	VHF-L3	Same as HF1-L3 except for the VHF Band.
42	VHF-L2	Same as HF1-L2 except for the VHF Band.
43	VHF-L1	Same as HF1-L1 except for the VHF Band.
44	UHF-HI	Same as HF1-HI except for the UHF Band.
45	UHF-L3	Same as HF1-L3 except for the UHF Band.
46	UHF-L2	Same as HF1-L2 except for the UHF Band.
47	UHF-L1	Same as HF1-L1 except for the UHF Band.
48	HF1TXG	This sets the gain of the transmit IF for HF Band 1.  This is done by adjusting bias current on D1017.  Lower value = Lower TX IF gain.
49	HF2TXG	This is the same as HF1TXG except for HF Band 2.
50	HF3TXG	This is the same as HF1TXG except for HF Band 3.
51	50MTXG	This is the same as HF1TXG except for the 50 MHz Band.
52	VHFTXG	This is the same as HF1TXG except for the VHF Band.
53	UHFTXG	This is the same as HF1TXG except for UHF Band.
54	HF1POM	This calibrates the RF Power meter for HF Band 1.
55	HF2POM	This calibrates the RF Power meter for HF Band 2.
56	HF3POM	This calibrates the RF Power meter for HF Band 3.
57	50MPOM	This calibrates the RF Power meter for 50 MHz band.
58	VHFPOM	This calibrates the RF Power meter for VHF Band.
59	UHFPOM	This calibrates the RF Power meter for UHF Band.
60	ALC1-M	This is believed to be a no-signal calibration setting for the ALC Meter.
61	ALC-M	This is believed to be a signal-reference calibration setting for the ALC meter.
62	HF1-RV	This adjusts the sensitivity of the reverse-power detector for purposes of VSWR protection for HF Band 1.  The higher the number, the less sensitive the '817 appears to be in response to high-VSWR (i.e. higher power under high VSWR conditions.)
63	HF2-RV	The same as HF1-RV, except for HF Band 2.
64	HF3-RV	The same as HF1-RV, except for HF Band 3.
65	50M-RV	The same as HF1-RV, except for the 50 MHz Band.
66	VHF-RV	The same as HF1-RV, except for the VHF Band.
67	UHF-RV	The same as HF1-RV, except for the UHF Band.
68	CW-CAR	This sets the level of the keyed CW carrier.  Lower value = Lower power
69	AM-CAR	This sets the level of the AM carrier.  This is typically set for a carrier level 6db below that of the peak power output.  Lower value = Lower Power
70	DEV-W	This adjusts the gain to the Frequency modulator in the "Normal" FM transit mode to adjust the clipped (peak) deviation level - typically +- 5 KHz.  (Note:  This is not the same as FM-MIC gain and should not be treated as such!)  Lower value = Lower peak deviation.
71	DEV-N	This adjusts the gain to the Frequency modulator in the "Narrow" FM transmit mode to adjust the clipped (peak) deviation level - typically +- 2.5 KHz.  (Note:  This is not the same as FM-MIC gain and should not be treated as such!)  Lower value = Lower peak deviation.
72	M-MTR	This calibrates the sensitivity of the MOD meter.
73	CTCSS	This sets the amount of deviation provided by the CTCSS (subaudible) tone - typically +-700 Hz or so.  Lower value = Lower deviation.
74	DCS	This sets the amount of deviation provided by the DCS (Digital Coded Squelch) code - typically +-700 Hz or so.  Lower value = Lower deviation.
75	LSB-CP	This sets the center of the passband of the SSB filter in the LSB mode for both receive and transmit.
76	USB-CP	This sets the center of the passband of the SSB filter in the USB mode for both receive and transmit.

Making use of these calibration factors:

Please read the following warning:

Before doing any of the following, it is again strongly suggested that you record each of the 76 parameters in the radio, as shipped from the factory, so that you can (at least) restore the radio to its original operation condition - unless you do something idiotic like blow the finals by running too much power.


Note that it takes some specialized test equipment to properly derive these values should they be lost due to negligence or stupidity.

The calibration values of every radio are different - even ones with adjacent serial numbers!

Any "modifications" and the risks and consequences of those modifications are done at the risk of the user.  YOU HAVE BEEN WARNED!!!

Accessibility to the various calibration parameters allows one to do some "modification" and experimentation to the '817 - without even opening the case or heating up a soldering iron.  Better yet, these modifications are completely reversible - provided that you recorded the original values and didn't blow something up.

What are some examples of what can be done with this information?  Here are a but a few possibilities:

• Provide reasonably accurate absolute signal strength readings using the FM and FM-N modes.  As described in the Repeater Coverage Analysis page, the FM S-meter can be made to cover a large dynamic range and this may be done by manipulating the FM-S1, FM-FS, and the RXG parameters for the appropriate band(s).  The result is that a direct reading of signal strength (in microvolts and/or dbm) may be calculated.
• The receiver "sensitivity" can be adjusted.  By using the RXG setting for the appropriate band, the "apparent" sensitivity of the receiver may be adjusted.  Because this adjustment is done in the first IF, it also affects the way the AGC operates - and thus the S-Meter - as well as the efficacy of the noise blanker to some extent.  It should be remembered that the limiting factor of the receiver's sensitivity is related more with the noise figure of the front end and not this parameter.  What it can do is adjust how the AGC responds (or doesn't) to signals.
• Is the scanner not stopping on-channel?  It may be possible to adjust the values of the DISC-L and DISC-H parameters.  These are used in the FM and FM-N (but not WFM) modes to determine if the signal is properly center-tuned.  Factory specs defines a "tuned" reading if it is within +- 3KHz of the display frequency - but this could be narrowed a bit.  Keep in mind that modulation of the signal (or noise from it being weak) will affect the accuracy and repeatability of the way the radio detects center tuning.
• Not a lot is known about the four FM- parameters.  It appears that the FM-TH1 affects how the radio's squelch responds (at least in the FM mode) to no-signal conditions.  This parameter appears to allow you to set the "open/close" squelch point when there is no signal present.  The FM-TH2 parameter seems to affect hysteresis - that is, the "width" of the threshold between the squelch opening and closing:  The squelch should always take more signal to open it than close it again.  Without hysteresis, the squelch would "chatter" (open and close quickly) on weak, fluttery signals.  The function of the two FM-TI parameters is not known precisely - but it appears as though they affect the time constant of the squelch (i.e. how fast it opens/closes with various signals.  More investigation is warranted.)
• The adjustment/operation of the "-IC" parameters (#'s 18-23) is covered on the "FT-817 Bugs,  Manual Errata..." page.  Needless to say, adjustment of these parameters (as well as the TXG and power level controls can allow one to get more than the original 5 watts out of the radio.  Please refer to the aforementioned link for the hazards of this sort of operation.  Warning:  It is possible to damage the finals in the radio if the proper calibration procedure is not followed!
• Parameters 24-47 are what set the output power levels on the various bands.  It should go without saying that the -IC parameters (#'s 18-23) are designed to protect the finals in the radio, and the various drive and output capabilities of the amplifier stages (and the power supply voltage!) will also limit how much RF power can be output by the radio. Warning:  It is possible to damage the finals in the radio if the proper calibration procedure is not followed!
• It is also possible to set "Custom" power levels.  For example, if you want the L3 power level to be 2 watts instead of 2.5 watts, you can set it there.  The L1 setting typically allows power to be adjusted down to 0.2 watts or so.  It is possible that appropriate adjustment of the TXG (#'s 48-53) and POM (#'s54-59) may allow setting of the '817 to even lower power levels (to drive a transverter or power amplifier) provided that one is prepared to sacrifice the ability to output a full 5 watts.  (But remember - these are soft parameters - you can always change them back!)
• You cannot use the AM-CAR parameter to get more peak RF output out of the radio in the AM mode.  If you try, you may get more carrier power, but you will not be able to put as much modulation on it and it will either start to distort, or sound "quieter" (because 100% modulation cannot be achieved) or both.  In any full-carrier DSB AM transmitter, the carrier must be set to 25% of the peak output power.  (I'm writing this because I just know that some CBer will try it to get more power...  and probably won't believe me anyway...)
• The DEV-W and DEV-N parameters set the amount of attainable peak deviation (set by the clipper) in the FM and FM-N modes respectively.  When set properly, no matter how loud you scream into the microphone or where you set the microphone gain, the deviation will not exceed the set level (nominally +-5 KHz for FM and +-2.5 KHz for FM-N.)  For proper operation, a "normal" speaking voice should hit the clipper often - but not sound distorted or badly compressed.  The FM-Mic gain setting should be used to set the level such that the person talking is plenty loud, but not so loud that normal room acoustics and noises are heard in the background.  Note that the same person may talk quietly in his ham shack, but nearly shout into the microphone when driving their car, so just one setting of the FM-Mic gain may not cover both situations ideally.
• If the "noise" in your receiver on you FT-817 sounds vastly different between USB and LSB and the person on the other end of the QSO reports that your transmitted signal sounds different in USB than LSB, then it could be that the LSB-CP and/or USB-CP parameters are not set properly for your filter.  The stock SSB filter in the FT-817 seems to have quite a wide manufacturing tolerance (as compared to much more expensive filters) and it is possible that adjustment of these parameters according to the service manual could mitigate the situation.  If the filter is non-symmetrical, then this probably won't help...  Keep in mind that this parameter will affect both transmit and receive audio quality.

While you are here, take a look at these other pages at this site:

Updated (With software version 2.0x) - Circuit and software description of the PIC-based PSK31 MedFER Transmitter.  (Note that FSK31 operation is also possible!) - Operation via a 1200 baud serial port is now possible, and the intermod has been greatly reduced!

"Optimizing the 'Simple Beacon' Transmitter" by Mark Mallory -  This article originally appeared in the Western Update (#59, September, 1988).  This is the original article describing a high-efficiency Class-E LowFER transmitter.

The "CT" LowFER Beacon Archive - Some pictures/info about the "CT" LowFER beacon of the late 1980's.  (Includes QSLs and sounds from some other beacons of the time.)

A Line-Synchronous noise blanker for VLF/LF/MF use - This blanker produces very little intermod, compared to many others...

"QRSS and You..." - Using absurdly low-speed CW for "communications"

Using your computer to ambush unsuspecting NDBs - A brief description of how Spectran may be used when trying to receive NDBs.

Any comments or questions?  Send mail to:  ka7oei@arrl.net