Handcrafted indoor digital TV (DVB-T) antenna by Svetoslav Stoyanov (LZ5UG)
Instead of an Introduction
As my high school teacher Nikola Lazarov at the technical school on Shipka Street used to say: „VHF propagation is purely God’s work!“
Why God’s work? Because with a direct line of sight, the signal comes through effortlessly. When obstacles block the path, you are forced to deal with interference waves.
These superimposed waves create distinct Spatial Minima and Maxima. Signals arrive at your antenna either in-phase (maximum signal strength) or out-of-phase (complete signal cancellation). Due to complex urban surroundings, the sweet spot might pop up a meter or two away in the most unexpected corner of the room.
Step-by-Step Positioning Guide
- Face the TV toward you: Never attempt to find an antenna position without watching the signal meter on screen in real time!
- If automatic scanning yields zero channels:
- Switch to Manual Channel Scan mode. For Sofia and surrounding regions, local multiplexes broadcast on channels 23, 40, 52, and 64.
- Select a specific channel number for your local broadcast area.
- Slowly move the antenna around the designated area (or where your spouse permitted it to sit). Move it not just horizontally, but vertically up and down — the peak signal might actually be sitting near floor level!
Field Example: In the village of Bistritsa (near Sofia), optimal reception was found 10 cm above the window sill. Placing the antenna directly on the sill resulted in absolute zero signal strength and quality!
Finding the Compromise Spot
Repeat the manual test for all other regional broadcast channels to find a single compromise position. Shifting the antenna by just 1–2 cm can drop a channel or cause heavy video stuttering.
Fine-tuning can easily take up to two hours, so take your time. You can do plenty of quick chores in 5 minutes, but finding a sweet spot for a tricky TV signal isn’t one of them.
If you fail to get results even with my custom passive antenna (pictured above), don’t rush out to buy a giant outdoor antenna. Outdoor units suffer from the same interference wave physics, and your mounting choices on the roof are severely limited by chimneys and poles.
With direct line of sight, no tricks are needed — from Ovcha Kupel in Sofia, my unamplified indoor antenna easily pulls in channels 41 and 57 broadcast directly from Mount Botev (over 140 km away).
Pure God’s work… then again, cable and satellite providers have mouths to feed too!
Svetoslav Stoyanov (LZ5UG)
