Jeff Liebermann wrote:
26 KHz seems a rather odd horizontal frequency. Any hints as to what
equipment is the monitor installed, whether it's NTSC, SECAM, PAL,
TTL, VESA, or HDMI, and what you are trying to accomplish?

Some old Arcade games used EGA monitors running at 25kHz and 60Hz refresh rate to produce 512x384 or 512x768 interlaced. 26kHz fits within the sync limits of these monitors and results in 400 active lines (or 800 interlaced).