PaØpga 1 yaesu frg-7700 survival guide.
2 paØpga specifications frequency range: audio output: 150 khz - 30 mhz in 30 bands 1.5 watts ( 8 ohms, 10% thd) modes: speaker impedance: am, ssb (usb, lsb), cw, fm 8 ohms 4 - 16 ohms for external speaker or headphone sensitivity: am ssb/cw fm 0.15 - 0.3mhz 30 µv 3 µv/500 ohm - 0.3 - 2mhz 25 µv 2 µ...
PaØpga 3 frg-7700 survival guide this is a survival guide for the frg-7700, one of the most versatile receivers from yaesu. With the help of this guide your frog can survive the next 20 years and more. This guide is in the true boatanchor tradition, a collection of known faults and their solution, a...
4 paØpga manuals: copies of the user manual and the service manual can be obtained from the fox-tango website, by far the best website for all classic yaesu equipment. If you want to work on your frg-7700, it is a must to have the manuals and schematics. See: http://www.Foxtango.Org the manuals are ...
PaØpga 5 rotate the dial to the “0” position and check the voltage, it will be around 2.4 volts. The manual says between 1.5 and 2.0 volts, but none of the four receivers i tested were in that range. All of them had higher values from 2.25 – 3.1 volt and are working fine, so i let it at that. For al...
6 paØpga be careful: remove the powercord first!! The lamp of the vfo is mounted in a small reflector that is very close to the soldering side of the receiving board and this lamp is always “glued” to the grommet from the heat of the lamp, so changing is very difficult. To get access, you have to di...
PaØpga 7 if your display goes weak, you can solve the problem temporarly by removing the orange filter in the display window. Your frog has then a very bright green display, that will again last for years. I tried it, but was not happy with the look of it, it was no frog anymore, so i put the filter...
8 paØpga.
PaØpga 9.
10 paØpga.
PaØpga 11 a frg-7700 adventure ( a resurrection story of a frg-7700) i had a recently a receiver with a bad displaydriver, and obtained another from internet as spare, with a defect. Well, as things go, this rx had also a display problem, the previous owner told me that he had used the receiving and...
12 paØpga with some wires, so i measured the connections and found a broken trace. To repair the board, it was necessary to take the pll board out of the receiver. While i was at it i measured all diodes and inspected the rest of the board very carefully. All seemed ok. After studying the schematic,...
PaØpga 13 the s-meter was also not functioning properly, and after taking it out, i saw that the movement was just a block of rust. I cleaned it as far as possible, but the needle stuck every now and then, so i suspected a broken movement, or the coil out of his bearings. While i had the meter out, ...
14 paØpga i then build in the vfo a small circuit with a vhf varicap that was on hand (bb 209), and a small ceramic condenser (12pf) over the existing variabele condenser. The tune voltage is hf decoupled by a 10k resistor and a 22n condenser. I soldered everything spider-style to the tuning condens...
PaØpga 15 8) change c94 and c95 (all 10nf) in 1nf, for a lower load of t09 and t10. 9) remove r85 (4k7) for a better q of t09. If step 8 and 9 is done, you have to re-align t09 and t10 for maximum signal. 10) change c89, c101, c111 and c117 (all 10nf) to 560pf, to lessen the load on t08,t10, t11 and...
