Panhandle Amateur Radio Club

Promoting Amateur Radio in the High Plains of Texas

Analog to Digital Link Info

Signal paths on the N5LTZ 443.650 analog repeater link to the W5JTC 444.300 digital repeater.

Step 1. A base, mobile or handheld radio within hearing range of the N5LTZ 443.650 repeater begins transmitting an FM radio signal on 448.650 mhz with a CTCSS tone of 88.5 hz.

Step 2. The FM signal is received by the N5LTZ repeater and re-transmitted to all stations within hearing range on 443.650 mhz Fm. All stations within range of the repeater listening on 443.650 mhz will hear this signal except the station inputting on 448.650.

Step 3. One of the radios hearing the re-transmitted signal is W5CEH’s radio that is connected to a WiresX interface that is connected to the W5JTC room which is also connected to the W5JTC 444.300 digital repeater.

Step 4. The signal heard by W5CEH’s radio is digitized and sent over the internet to every WiresX node in the world that is connected to the W5JTC room on the WiresX network.

Step 5. The signal entering the W5JTC room from the internet is re-transmitted as a C4FM digital signal on 444.300 mhz and received by all stations within repeater range with C4FM capable radio tuned to 444.300 mhz.

These are the steps the signal takes going from analog in to analog out and being digitized and sent over the internet to be re-transmitted as a digital signal which is decoded by a C4FM radio. There are several delays as the signal is digitized, sent over the internet, re-transmitted as a digital signal and finally decoded by a C4FM radio.

Step 6. A base, mobile or handheld radio within hearing range of the W5JTC 444.300 repeater begins transmitting a digital C4FM signal with an 88.5 CTCSS tone or a signal coming into the WiresX W5JTC room via the internet is re-transmitted as a C4FM radio signal on 444.300 mhz.

Step 7. The signal is decoded and heard by all C4FM capable radios within range of the W5JTC 444.300 digital repeater as well as all WiresX nodes connected to W5JTC.

Step 8. One of the nodes connected to the W5JTC room is the W5CEH node which receives the signal over the internet and re-transmits it as a FM radio signal on 448.650 with an 88.5 CTCSS tone.

Step 9. The FM signal from the W5CEH node is received by the N5LTZ 443.650 analog repeater and is re-transmitted on 443.650 which is heard by all radios within range of the N5LTZ repeater tuned to 443.650.

As you can see, a lot of planning and equipment is involved in what appears to be a simple link from analog to digital and back. Ten Thousand attaboys go out to Charlie W5CEH who made this link possible.

Dave WA5X

provided by Dave WA5X

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