This manual is downloaded from the FoxTango site, Yaesu. FRG HF Receiver. Survival Guide. Revision 2 march. If you want to work on your FRG, it is a must to have the manuals and schematics. See: The manuals are very informative and deal. The purpose of this manual is to provide the reader with information critical to the nance of the FRG general coverage communications receiver.
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PLL Reference oscillator Adjustment: Problems with this IC are almost always man-made, like a short during the change of the light bulb in manuxl VFO, see above or poking around in the set with the power cord attached.
The Xtal oscillator was working and at the good frequency. The receiver is very sensitive and stable, and has a pleasant audio. I found out afterwards that feg-7700 receiver was used on a sea-going yacht, and some spots were corroded from the salt water.
Service and User Manual – Yaesu FRG – Receiver — Download free service manuals
One of the things I missed on this receivers is a small RIT control or fine tuning, a very handy device when I am listening in on a net or rag chewing Hams.
Using the clock was no problem, but the switch could not change to the frequency mode, it still displayed the time. Yaesu uses a amber filter, to change the color in the style of all their equipment of the janual FTZD, FT This tube has a filament, and has in maunal long run the same problem as all tubes: It is possible to remove also R 10kbut the gain and noise of the 2 nd IF will raise janual high level, and can cause oscillations.
The 2k2 resistor is a trimmer!
If you check carefully, use the schematics and the very good circuit description in the handbook to make yourself familiar with the circuits used. These terms and conditions are subject to change at any time and without notice.
Later I found out that this particular receiver has been used in a yacht, and salt water spray left its corroding mark… If you have some weird display problems, check those diodes first, or the attached switches and transistors.
This explains the difference in frequency as you are listening to a ham net on a given frequency. If it is not possible to collect equipment myself, and pay cash, I am not interested, and can better save my money. The cores are not interchangeable, so do one at a time.
Removing the paint altogether from mabual sides is also a possibility, it can be done with thinner and rubbing with an old cloth, you have just to be careful with the front itself, the paint there is quick damaged. Try to make this adjustments very careful, often these voltages are too high, resulting in a loss of range or a failure to lock properly, with a high noise level as result. So, it seemed that the counter IC did at least something.
After modification the receiver is to re-align according the service manual, for the best results. MilliHenry, to form manuall DC path to unload antenna charges. I swapped the meter scale, and put the meter back. The manual says between 1.
Yaesu FRG-7700 Instruction Manual
The circuit design is ok, but can be improved. There is not much difference between the first and the last receivers, the mmanual thing I saw was a different coupling of the frequency scale to the dial mechanism.
The diode wires were very corroded, so I changed all three diodes.
One of my sets had a bad mode switch. The set and memory module is very stable, but some changes improve the receiver considerably: Service and User Mahual. A FRG with a memory unit has no problem with that, you tune in, push the Memory button and then Memory read.
A mode switch changes the display for frequency, clock, on-time, off-time and sleep function. With the help of this guide your Frog can survive the frh-7700 20 years and more.
I have seen all kinds of junky stuff on e-bay, that was tampered with and sold for high prices, to the chagrin of the new owner. Notify me of new comments via email. If the receiver is switched off, the display is off, however power to the IC is always on. Kenwood used the same IC in their R receiver, so that can be a source as well. After 46 working years I am retired now, so time is no issue.
Remove the power cord first!! The variable tuning range changes somewhat over the band: I have a credo here: If the end point of each Mhz range is getting lower at the high side of each band, a re-alignment of the first PLL is necessary, receiver receives not higher than or so on the analog scale If only the end points at the 5, 12, 20 and 29 Mhz bands are too low, a re-alignment of the second PLL is necessary. I checked and manaul the two PLL circuits, because they were way off the right tuning frg-770.
This is a survival guide for the FRG, one of the most versatile receivers from Yaesu. Troubles I have encountered so far: There is just one offset possible, so in SSB mode there is always a frequency difference between the carrier frequency and the displayed frequency of about 1. The covers are sprayed twice by Yaesu: This should not put too much strain on the power supply, because the current is minimal.
You agree not to post any material which is knowingly false, obscene, hateful, threatening, harassing or invasive of a person’s privacy. However, if you don’t manuaal either, skip this alignment, If you receive signals, this section is working.
The general alignment can be done as described in the manual, with the proper tools and equipment, it is a straightforward job. Is the set very unsensitive, check first the semiconductors in the circuit, or there can be resistor or condenser failure, that is much more likely than misalignment… Closely check for abnormalities burnt or cracked components, bad soldering joints, bad connectors and other trouble spots.
You can then tune around the frequency with the Memory fine knob. After rebuilding, I will try some modifications, to improve selectivity and test some ideas frg-7700 my own, like a clarifier, improve sensitivity for the AM bands and others. My command of the English language could be better, so I apologize for linguistic mistakes here and there. My experience with 4 of this receivers is that most of the failures I encountered, where man-made by amateurs who never read a handbook, but first plug in a soldering iron, and sell the set when the smoke has settled, and then often try it again with the next set coming their way….