This Heathkit Frequency Modulation Tuner operates on the super regenerative principle and covers the new FM Band 88-108 Megacycles. It is 110v 60 cy power transformer operated. The tuning coils are ready assembled to the tuning condenser and the IF transformer is assembled and aligned the tuning condenser is also aligned and set for peak performance and the trimmers are soldered to prevent misalignment during assembly. The tuner incorporates the latest type vernier slide rule dial. The dial cable is special long wearing nylon for years of service. As this unit is power transformer operated, it can safely be attached to AC - DC type receivers for amplification without danger.

The newer types of insulated resistors have a higher wattage rating: The 1/4 watt size is now rated at 1/2 watt and these are used in this kit.

Resistors and potentiometers have a tolerance rating of plus or minus 20 % unless otherwise stated. Therefore, a one megohm unit may test between 800,000 and 1,200,000 ohms. The Heathkit circuits are designed to accommodate these variations.

In connecting the tuner to an amplifier, be certain that the grounded side of the tuner is connected to the grounded side of the amplifier. The usual connecting cable is a single shielded wire and the grounded side is the shield. The tuner may be connected to the phonograph or FM connection of any radio. The connecting plug depends on the type of radio and should be obtained from the radio dealer. For local stations, a single wire approximately 3 feet long can be connected to one of the antenna terminals but for distant reception an FM dipole antenna is recommended with connections. On single wire, try each post and use one with best results.

The table below lists the voltages measured between the chassis and tube socket contact. Measurements were taken with 1,000 ohms per volt volt meter normal variation of plus or minus 15 % are to be expected due to line voltage variations.

FM 1 FM TUNER PARTS LIST