Adjustments & Options


The adjustments page has 5 slider type adjustments, BACKLIGHT, ALARM, VOLUME, SQUELCH and TONE.


The BACKLIGHT adjustment controls the brightness of all parts of the screen. The screen can easily be seen in bright sunlight. When the InfraSignal Radio is battery operated, reducing the BACKLIGHT will increase the battery life.


The ALARM adjustment controls the alarm threshold. Its value is displayed on the sliding scale and also displayed numerically in red above the sliding scale. The value is also displayed at the top of the SIGNAL LEVEL bar graph on the mode pages. When the alarm is disabled, the red numerical value at the top of the SIGNAL LEVEL bar graph on the mode pages is replaced with two red dashes.


The VOLUME adjustment controls the volume of the speaker and the gray colored headphone output on the right side of the radio. When using the AUDIO ON VU METER mode, audio can be heard on the black colored infrasignal output jack, also on the right side of the radio. Please take note. This output is quite loud in the headphones. It is set to a fixed level for recording and is not controlled by the VOLUME adjustment.


The SQUELCH adjustment silences the speaker when the signal level drops below the adjusted squelch value. This eliminates all unnecessary noise from the speaker. The headphone output is not affected by the squelch adjustment.


About the TONE adjustment. All sounds at and below about 20 Hertz (cycles) cannot be heard by the human ear. In order to hear these sounds, i.e., infrasound, a higher frequency tone has to be added to the infrasound to increase it up to the audio frequency range. The infrasound modulation rate and amplitude are faithful preserved.


This tone adjustment is provided for the convenience and preference of the person monitoring the infrasound.


The OPTIONS page is where you set up the AGC (Automatic Gain Control) parameters and:

  • Turn the alarm function on / off;
  • Set the alarm volume;
  • Check the connectivity of the optional remote alarm;
  • Turn the remote alarm on / off;
  • Run the alarm test;
  • Run the scan 16 test signal test;
  • Run the sinewave test;
  • Run the frequency measurement test;
  • Calibrate the LCD;
  • Select language, English or Spanish;
  • Reset system default settings;
  • Read the user’s guide and the radio’s Serial Number.

CURRENT AGC SETTINGS, [window] This window displays the current AGC settings. This window also displays the text, DETECT PULSE AND SOUND ALARM when the detect pulse option is turned on.


NORMAL AGC, [button]  This is the setting for all general monitoring of infrasignals. NORMAL AGC returns all AGC functions to slow and also turns off the DETECT PULSE option.


FAST IMPULSE RESPONSE, [button and in window] This setting provides a faster response to a strong signal when it is first detected. This is a good setting to use when the signal is strong and intermittent.


SLOW IMPULSE RESPONSE, [button and in window] Is the normal setting.


DETECT PULSE, [button] Detect pulse is a special function designed specifically for use with the EMP sensor. It turns on an alarm function that responds to a fast pulse, sounds the alarm and saves the event to memory. In the event that power is lost during or after the pulse is detected, both events are saved to memory. When power is restored, (perhaps with a generator or backup battery) the alarm will sound and a message (in red letters) will appear on screen, saying “A pulse was detected before loss of power”. To protect this message from accidentally being reset, a special reset sequence is provided in the message.


FAST / SLOW DISCHARGE, [button and in window] This setting determines the rate of AGC discharge once the input signal decreases.


HOLD AGC LEVEL, [button] This setting delays the discharge function for a selectable amount of time determined by the 15 / 30 SECONDS setting.


15 / 30 SECONDS, [button] This setting determines the amount of time the HOLD AGC LEVEL holds the AGC level before allowing it to discharge.


FAST / SLOW AGC, [button] This setting determines the overall response of the AGC function. Slow AGC is normal and is modifiable by the other settings. Fast AGC disables all other AGC touch buttons except NORMAL AGC. *Fast AGC is only fast from an infrasignal point of view. It is very slow when compared to other higher frequency receiving equipment.


Transparent (ALARM IS ENABLED), [button] The alarm is turned on for all modes except the AUDIO ON VU METER, FREQUENCY MEASUREMENT and scope speeds 3 and 4.


ENABLE ALARM, [button] The alarm is presently turned off.


Transparent (ALARM IS DISABLED), [button] The alarm is presently turned off.


DISABLE ALARM, [button] The alarm is turned on for all modes except the AUDIO ON VU METER, FREQUENCY MEASUREMENT and scope speeds 3 and 4.


ALARM TEST, [button] When this button is touched, four things happen. The alarm will sound, the red light will flash, the ESPANOL button will change to ALARM 50% VOLUME and the SCAN 16 TEST SIGNAL button will change to a transparent (ALARM VOLUME IS AT 100%). While the alarm is sounding, the volume can be changed to 50% and back to 100% if desired. When the radio is turned off, then turned back on, the alarm volume setting will return to its default value, 100%.


RESERVED FOR EXTERNAL ALARM, [small window] When an optional alarm device is connected, this window will change to a button and display green text, EXT ALARM ENABLED. This is the default setting when the power is first turned on and the external alarm is connected. When the local alarm sounds, the external alarm will also sound. Touch the green EXT ALARM ENABLED button, it will change to display yellow text EXT ALARM DISABLED.


EXT ALARM DISABLED, [button] When the local alarm sounds, the external alarm will not sound.


USER GUIDE, [button] The user guide is written in both English and Spanish. It explains the use of all touch buttons used in the InfraSignal Radio. The user guide also provides step by step instructions for the 2 system level tests, i.e., SCAN 16 TEST INSTRUCTIONS and SINE WAVE TEST INSTRUCTIONS. Additional information such as FCC Part 15 test results, Patent status, Copyright information, Model number, Serial number, software and firmware versions, 50Hz / 60Hz Notch Filter information can be found on page 14 of the English language version only.


ESPANOL / ENGLISH, [button] This is the button to touch to switch languages from English to Spanish and vice versa. In addition to switching between two different languages, this button also resets adjustments, AGC settings, alarm activation and non-volatile memory to default values. This is very handy to reset the system when you want to return to default values. Switch to the other language, then switch back.


LCD CALIBRATION, [button] If you touch one button and an adjacent button response, chances are, the touch screen needs to be recalibrated. This doesn’t happen very often, almost never, but when it does, touch the LCD CALIBRATION button and follow the on-screen instructions.


There are a lot of selectable AGC settings when using the infrasignal modes, most of which will never be needed by most setups. Most of these AGC settings are designed to optimize reception performance for tape or digital recordings. An example would be when trying to record a strong signal that occurs in burst with long pauses (thinking elephants here). You would set the AGC by touching the FAST IMPULSE RESPONSE >> HOLD AGC LEVEL >> 15 / 30 SECONDS buttons to hold for about 15 seconds. Touch the 15 / 30 SECONDS button again to hold for about 30 seconds. You can monitor the signal by going to INFRASIGNAL ON CHART or the INFRASIGNAL ON SCOPE button. If the first strong signal burst is long enough in time, it will level off the AGC to the proper level so the next burst will be received with little or no distortion. If the first strong signal burst is not long enough in time, the AGC will hold a lower value but subsequent burst will add to that value until it reaches the proper level. This is assuming that the strong signal burst occur before the selected hold time runs out. If the hold time runs out and the AGC starts to discharge, the next strong burst will start to increase the AGC from that discharged point.