zed_zed said:
73's !
Do you guys know, what's going wrong when this receiver doesn't make a sound exept a quiet schhhhhhh from the speaker ? I just got it for a good price, and now...i'm searching who's the component in the main unit (maybe somewhere else ?) making this icom so quiet...!
The antenna and it's connection are fine, that's all i can say for the moment
:0(
Thanks.
Do you have a signal generator and an oscilloscope?
If not, I would suggest the following:
1. Tune the receiver to a strong FM broadcast station.
2. As you tune through the FM band, watch the S-meter. Does it move? If it moves, try different demodulator settings (AM, FM, FM Narrow, SSB, etc). Does the meter move on all of them? Do you get any audio (it might be distorted; that is OK for the moment) on any other demod settings? Does the noise in the speaker increase when you go to CW?
3. If you have another receiver which tunes to 10.7 MHz, connect it to the IF (SDU) output of the R-7000. Can you hear the FM stations when tuning the R-7000?
If the S-Meter does not move, and you don't get any output on any demodulator settings, the problem is probably in the RF or Synthesizer area. This makes troubleshooting without test equipment a little tougher. One crude way to determine if there is a RF problem is to scratch the antenna connector on the antenna input connector of the R-7000. If you hear crackle in the speaker, the problem is most likely in the synthesizer.
If there is no crackle, tune the R-7000 trough its range and scratch the antenna every 100 MHz or so (I don't remember the exact band limits on the RF filtering on the receiver). If you can hear a crackle on some frequencies but not on others, the problem is most likely in one of the RF filter / amplifier stages. If there is no crackle on any frequencies, the problem is probably caused by a faulty synthesizer. I don't have the R-7000 service manual, so I am walking on thin ice here. However, I think the first point to check in the synthesizer would be the combined Lock signal. This is the "ANDed" Lock from all phase locked loops in the receiver (this signal is sent to the processor as a Status signal). If it is off, the next step would be to check which of the Lock inputs is off. That would point to the faulty phase locked loop. The bad thing is that troubleshooting a phase locked loop without test equipment is very tough. The first step would be to get a service manual for the receiver, and familiarize yourself with the frequency plan, and the location of all the building blocks. The next step is to get some test equipment (it doesn't matter if it is old or crude - anything is better than nothing), or at least another receiver which tunes from about 10 MHz to a few hundred MHz..
Let me know if I can help you in any way. If so, I will give you my email address, and we will see what can be done.
Good Luck,
steve_s
