Memory equipped FRG 7700 receivers include a backup feature which will hold the memory even when the unit is unplugged from the supply voltage. The backup feature requires three AA size penlight cells (not supplied), which should be installed as shown in Figure 1. Be absolutely certain to observe the proper polarity of the batteries during installation.
Battery consumption is extremely low. but we recommend that the backup batteries be replaced once per year. If you have not used the FRG 7700 for a long time, we recommend that you inspect the penlight cells to ensure that no leakage from the batteries has occurred. Damage caused by battery leakage or improper battery polarity is not covered by our warranty.
Figure 1
For best performance and safety, the FRG 7700 should be connected to a good earth ground. The ground lead should be a heavy gauge braided cable or wire, and should be connected to the terminal marked "E" on the rear panel of the receiver.
The antenna is an important part of your static: installation. Without a good antenna system, it u be difficult for you to take full advantage of your FRG 7700 receiver's many high performance features. For best reception, please follow the guidelines presented below regarding antenna installation.
(1) Low Frequency (LF) and Medium Frequency (MF) Reception (Below 2 MHz Exclusively)
Good all around reception will occur if a single long wire is connected to the BC terminal on the rear of the receiver. Insulate the wire at the far end, and at the point where it enters your house: ceramic insulators suitable for antenna installations are available from your Yeasu dealer. The wire itself may be either bare or insulated (plastic or vinyl covering on the wire), with the constraint that bare wire should not come in contact with trees or other obstructions.
In general, the antenna wire should be as long. high, and in the clear as possible. If these simple recommendations are followed. good reception will be easy to obtain.
(2) Shortwave (SW) Reception (Above 2 MHz Exclusively)
Maximum performance is secured in the shortw ave bands through the use of a resonant antenna having an impedance of 50 ohms at the design frequency. A center fed "dipole" antenna cut for the mostlistened to frequency will easily satisfy this requirement. Dipole antennas should be fed with coaxial cable, and suitable antenna kits are available form your Yaesu dealer.
However, the shortwave bands are quite wide, and no dipole antenna will be resonant throughout this entire frequency range. The best course of action, then, is to cut the legs of the dipole antenna to the longest (equal) lengths that your installation area will allow. This will provide an excellent listening system for your shortwave station.
Should you wish to cut your dipole antenna for optimum performance on a particular shortwave band, the formulas of interest are:
  Length (feet) = 468 frequency (MHz)
Length (meters) = 142.5/frequency (MHz).