I immediately grabbed some tools and started making. While I'm sure this gap will allow all kinds of dust into the workings, it also means any light shining behind the buttons will leak out around them. They are suspended in a little plastic collar that allows them to float in the bezel with a gap about 1mm wide around the sides of the button. I took the radio faceplate apart and found that the buttons have lots of space around them. You have to feel around on the front of the radio and hope you don't bump the 'set' button in the middle or whack either of the volume or squelch controls too hard. The two complaints I have about the radio so far are that the interface buttons are all very small, which makes operating the radio while driving a little difficult, and that the tiny buttons are not backlit, which makes finding them at night next to impossible.
I wanted the dual radio feature which makes it easy to operate on one channel while checking other things on the other channel. Alternatively, I checked the receiver's clock display over time to verify reasonable adjustment of TC02 after cleaning.I recently purchased an Yaesu FT-8800R 144/430 MHz dual band FM transceiver.
The service manual specification for TC02 adjustment is 5.996544 MHz at nearby test point TP09.
Similar application of contact cleaner and trimmer wiggling brought the receiver instantly back to life. This was caused by a dirty trimmer TC02, in another shield box on the PLL circuit board. The second failure was more complete: no audio and no information on the lighted display. Lacking a counter, I found it adequate simply to return the cleaned trimmer approximately to its original position and to verify the result by tuning WWV in a sideband mode. The service manual specification for TC01 after warmup is 18 MHz (within 20 Hz) at nearby test point TP14. This was caused by a dirty trimmer TC01 in a shield box on the PLL circuit board, accessible by removing the top cover of the receiver. The first failure involved a flashing frequency display in addition to no receiver audio. It is extracted from my note in November, 2006 QST magazine. This comment is for those who have blank or flashing FRG-8800 displays. I used my GPS reference to be sure alignment was done OK.Īnd this is the result: a perfectly working receiver: Here you have some pictures of the cleaned unit, ready for alignment:Īlignment was mostly OK, just some Hertzs out in some oscillators. I also replaced the four display light bulbs, as there was one bad, one dim and two with too much brightness. So I decided it was time to clean the unit, removing knobs to clean them sepparately. Here you have a very small video (sorry about the lousy quality): Putting the PCB back got me a pretty hot working receiver :-)!!!. I fixed it as follows, scrapping and adding some wire and solder on each crack:
The mods seem somewhat complex I guess they are worth more than I have paid for the unit :-) I took some detailed pictures of the added PCBs:Īs you can see, there are a couple IF filters in one PCB, a couple relays in another one and, I guess, a new detector on the third. So I went back to head scratching until I found that pulling the PCB a bit generated some better reception. Now AM was received faintly and SSB needed about 0.2V to be heard. So I put back the PCB, hoping for the best. could this be the cause of the SSB deafness?. I found it was a PCB corner and it had a trace on it. While turning the unit to check lower side, I heard some noise inside. I polished the cans, dusted it out and started troubleshooting.ĪM sort of worked but SSB was completely deaf. I took the covers out to find some oxide in metal cans but mostly a clean receiver. Well, I knew it was in unworking condition and, really, it didn't work on arrival.
You can check what I am talking about here: It is a heavily modified unit (called Broadcast Monitor Receiver 2) and there is NO VHF converter, but an extra module with balanced audio and IF output on its place, along some other PCBs and other internal mods.
It is a Yaesu FRG-8800 receiver which suppossedly came with the VHF converter. But this time I have fixed a rig for my collection. Lately I spend most of my hobby time fixing rigs for other people.