Diy kit ,Air band receiver,High sensitivity aviation radio

Uusi A1. Koottu ja koteloitu, testattu ja toimiva laite. Alignment & Adjustment:
Aligning the Aviation receiver consists of nothing more than adjusting the slug in the local-oscillator coil (L6) for the center of the desired tuning range, and peaking the IF transformer (T1). The receiver can be calibrated using a VHF RF signal generator, frequency counter, or another VHF receiver by setting R1 to its mid-position; remember that you want to set the local-oscillator frequency 10.7-MHz higher than the desired signal or range to be received.

Then, using a non-metallic alignment tool--a metal tool of any kind will drastically detune the coil, making alignment almost impossible--adjust the Local Oscillator coil L6 until you hear aircraft or aircraft communications. If you find that you're receiving a lot of FM broadcase stations, then you have adjusted the slug too far down into the coil. Turn it back until it is a bit higher than the coil form and try again. Once you're receiving aircraft or airport frequencies, adjust T1 for the best reception. Typically, T1 is adjusted 2-3 turns from the top of the shield can. If you don't have any signal-reference equipment or alignment, and are not yet hearing airplanes, your best bet is to pack-up the receiver and the necessary alignment tools, and head for the nearest airport! If the airport has no control tower, visit a general aviation center on the airport grounds, and ask which are the most active frequencies. Then adjust L6 and R1 until you hear the action. It should be obvious that alignment will test your patience if you do not live near a large airport.
Stretching L1, L3, and L5 at the antenna input will provide greater sensitivity if you have problems receiving a signal. Also, as mentioned before, ensure that L1, L3, and L5 are mounted a *little* bit above the pcb.
A ground-service operator or private pilot may be willing to give you a brief test transmission on the 122.8 Unicom frequency. And if your airport has ATIS transmissions you can get a steady test signal as soon as you are within line-of-sight of its antenna. (See the explanation of Unicom and ATIS down the bottom of this document). It is best to align the receiver right there at your local airport.