The main features of this head include:
- Frequency control of COMM, NAV1 and NAV2.
- Setting of a standby frequency (lower row) that can be swapped with the active frequency (top row)
- Selectable simultaneous display of active NAV and COMM frequencies.
- Monitoring of station beacon tones through use of the "tone" switch.
- Dimmable incandescent frequency displays.
- Test feature that illuminates all 7 segments of all digits to identify any burnt out segments.
- DME data from NAV1 & NAV2 can be sent to the HSI's distance readout, selectable via a button next to the indicator.
Interfacing the incandescent displays with EPIC required eight transistors (to control the common of each digit) and seven opto-isolators (one for each of the digit segments). Since the 32 digit display module works by multiplexing LEDs, I also had to put a diode on each incandescent segment to prevent unwanted bleedthrough of current from any other illuminated filament segments. A variable voltage regulator delivers 15 to 26VDC to drive the filaments. All of this required a lot of work electrically, but I prefer the look of incandescent displays to LEDs. Special thanks goes to James Price for his great EPL code support for this control head.
The main countermeasure panel controls the dispensing of chaff, flare and jamming devices. It indicates how many of each countermeasure is available and can be set to dispense countermeasures either manually or automatically upon the detection of a threat. Pre-programmed dispensing configurations are also selectable.
The bottom panel provides for emergency communications, IFF Ident, and crypto key zeroizing.
In addition to this new control, a canopy jettison lever from an F-18 Hornet was installed along with a canopy open/close switch from an A-6 Intruder.
An F-111 avionics self-destruct panel was also installed, which was used in the real aircraft when the avionics suite was considered highly classified.
