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To keep the receiver ON while unattended
Ted's tip followed a request as how to keep the radio on, with no cable or PC connected, "It is necessary to pull the DTR (pin 4) and RTS (pin 7) lines high on the RS-232 Serial port. This can be a little tricky if it's necessary to unplug the serial cable. A breakout box with the proper connections installed between the receiver and serial cable should work; just don't unplug the breakout box.

It isn't be necessary to send periodic commands to the receiver. The receiver definitely 'goes to sleep' after 20 seconds if the serial cable is removed.

Icom doesn't use this feature, but you can force a remote reset of the receiver by pulling the DTR/RTS lines low and holding for 20 seconds, or so. This seems to work just as well as turning the front panel power switch off and back on. Perhaps the software developers on the list can incorporate this feature in their next releases."


Wideband Discriminator Output
This may be old news for some people, but what the heck. I was flipping through the PCR-1000 service manual, and noticed that the wideband FM discriminator output is available on the DSP connector. I haven't modified mine yet (other priority projects in the queue!), but I think I'm going to add a 3.5mm stereo jack somewhere in the housing, and put the NBFM discriminator output on one channel and the WFM discriminator output on the other. Since mine is connected to a soundcard, this would allow selecting whichever discriminator you like as input into programs such as ACARS, satellite demodulators, etc. My main reason for all this is to hook up my SCA decoder. The signal is available on pin 11 of J12, which is one of the connectors where the optional DSP unit connects to. This is straight off the detector chip (TA31136), so you might want to consider running it through an op-amp circuit with some settable gain, and make sure the input impedance is something the chip will be happy with. I haven't looked up the part yet, but when I get around to this, I'll post a schematic on my website. -- Chris, jcwren@jcwren.comon the PCR Mailing List. Thanks Chris!

Peter Andersson's setup to decode the Differential corrections transmissions for the Global Positioning System (DGPS) that are transmitted using MSK.

LF Reception
From Larry VA3LK, I have been experimenting with the PCR down in the area of 100 to 200 kHz. The radio works down here, it is not as sensitive as one would like, in fact it is not very good at all but it does work. Some issue for those who might be thinking of using the radio down this low. First, put a 52 ohm resistor on the BNC jack and sweep the range of frequencies you are interested in and make a note of the spruious signals that are all over the place in this area of the band. This will help you sort out the real and imaginary signals when you put an antenna on the radio. When you put an antenna on the radio, I use USB, Narrow, and put a modern spectrum analyser on the audio output. I happen to use Gram. This will let you see signals you can not hear in the audio. I was able to find several FSK teletype signals that I could not hear as well as several I could hear very well. The big thing was to figure out what are real signals as well as spurious signals inside the radio. Not a great radio down at this frequency but better than nothing and good enough to tune up a loop antenna and a preamp as well as a couple of filter sections. Good Luck

Larry adds, I now have a tuned loop which is very narrow band, only 1.5 to 2 kHz wide at the 3 dB points and this radio works very well with that front end selectivity.


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