[aprssig] Re: New Exam Question Pool
jimlux at earthlink.net
Sat Mar 11 13:16:31 CST 2006
This is a fine example of an extremely poorly written question. Let's look
at it more detail:
What item is required along with your normal radio for sending
automatic location reports?
OK.. "item" is singular, and the way the the question is worded it implies
that you need only that one item to add to the normal radio.
What's "normal radio"? most radios these days don't include a digital
modem (for the Bell 202 tones), nor any processing to do the link level
protocol (HDLC and X.25), nor the application protocol (APRS). Sure, there
are a few (<5) models commmercially sold that include some or all of this,
but the vast majority of radios out there (after all, the question doesn't
say VHF/UHF FM radios, so it includes all those HF rigs)
I'd say that the correct answer is more like "a computer with a GPS and modem"
If you allow the poor wording to mean "what of the following could be used
with a radio and other equipment to send automatic position reports", any
of the answers would work. Sailors used speed and compass heading for
centuries to establish position. And, of course, time stations like WWV
(and the BBC) made longitude determination much simpler. The Broadcast FM
subcarrier receiver is a bit more of a reach, but for many years, GPS
differential corrections were broadcast on FM subcarriers, so a suitable
subcarrier receiver was an essential part of a precision GPS setup.
And, of course, if you had a voice parrot in your car that you loaded with
the interstate number and exit you were at, that was set up to squawk every
minute, it would be automatic reporting of position.
All in all, not a very well worded question, nor answers.
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