Automated packet deviation tester back on air.

To assist packet operators in Melbourne and surrounds to setup their packet stations with the correct 3.5 kHz deviation, an automated packet deviation tester has been set up by Paul Engler VK3XDE. This device reports the deviation and signal strength of all stations it hears.

To use the device, connect to VK3XDE-11 on 145.200 MHz. Issuing the Mheard command makes the device report the signal strength and deviation of all stations whose packets it is able to decode (whether they have connected to the device or not). Paul recommends issuing the MHeard command a couple of times to give the device several packets to sample.

If you are using the host mode version of WAPS, you will need to turn WICEN packet headers off using [F6] or the device will try and interpret the packet headers as part of the command.

The device may report erroneous readings under the following conditions:
* A badly distorted audio signal
* Badly off frequency
* A noisy signal
* Hum on the transmitter

Also, the signal strength range of the device is currently -108 to -87 dbm. (approximately .1 to 10 uV in 50 ohms) Signals below -108 dbm will not be decoded and signals above -87 dbm will be reported as -87 dbm. Paul reports that you will actually need a signal of about -100 dBm (approx 2.2 uV in 50 ohms) to be decoded reliably.

Of course, you need to be able to be heard by VK3XDE-11 (in Mt. Waverley) directly to use the device. If you connect via a digipeater, XDE-11 will report the deviation of the digipeater.

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