The Goal
Channel 21 carries 50.1 and 50.2 — ABC and CW — from WNTI in Watertown. From Navan (east Ottawa) this is a fringe signal. The ridge along Navan Road gives slightly better long-distance reception than surrounding terrain, but WNTI is still a stretch. A purpose-built single-channel Yagi offers the best possible gain for one target frequency.
The design uses K7MEM's VHF/UHF Yagi calculator with a low-loss homemade coaxial balun at the feed point. A "single cut" Yagi uses one length of aluminium rod for all elements — each cut precisely for 506 MHz.
Construction Gallery
34 photos documenting the build from raw aluminium through final assembly. The boom is non-conductive wood so elements mount directly without insulating bushings.
Build Notes
Balun: A homemade coaxial choke presents high impedance to common-mode current, preventing the coax shield from acting as part of the antenna. Seal with self-amalgamating tape.
Aiming: Point the director end (shortest element) at the target. Use OTADVR's OTA Map for the exact magnetic bearing to WNTI.
Result: With good atmospheric conditions — temperature inversions in late spring through early autumn — 50.1 and 50.2 come in cleanly.