Wiring the primary is straightforward, but the *isolation* of these connections is where your matching box will earn its keep in rejecting the noise from your house.
Here is the exact way to wire the primary terminals:
## The Primary Connections
The 8-turn primary has two ends. Because this is a magnetically coupled air-core transformer, there is no absolute "positive" or "negative" polarity you have to worry about.
1. Terminal 1 (Active Element): Connect one end of the primary coil to the lead coming from your 35-foot suspended wire. 2. Terminal 2 (Counterpoise): Connect the other end of the primary coil to the lead attached to the metal roof.
## The Golden Rule: Absolute Isolation
For this design to successfully block the noise from your switching power supplies and LED bulbs, the primary circuit must remain completely galvanically isolated from the secondary circuit and the radio chassis.
By keeping the primary winding electrically floating, the local electrostatic noise picked up by the massive metal roof cannot flow directly into the receiver's ground plane. The only thing that passes from the primary to the secondary is the alternating magnetic field of the RF signal itself.
## Physical Routing in the Box
Since your secondary tap wires are running to the rotary switches on the front/top panel, try to route the two primary leads out the *opposite* side or end of the box to their respective binding posts. Keeping the primary feed wires physically separated from the secondary switch wiring prevents them from acting like a capacitor and bypassing the transformer coupling.
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