Distinctions Between a/c

I've been wondering for awhile how to tell two sets of a/c apart visually:

How you visually spot the difference between a CRJ100 and a CRJ200?

How about a Dash8 100 and a Dash8 200?

Between the Dash 8-100 and Dash 8-200s, the 100 series has 1 "fin" on the belly of the fuselage and the 200 series has 2 "fins". I don't know what the "fins" are called or their purpose (stablizer, radio antenna)?

100 series: http://www.jetphotos.net/viewphoto.php?id=6456717
200 series: http://www.jetphotos.net/viewphoto.php?id=6046470


Between the set of CRJs, there is no distinct visual difference besides a loss of/extra window due to different cabin configurations.

thanks - I never noticed that before

there is another difference between the -100 and -200 dashes. the engines are different. the shaft horse power of the -200 engines is the same as that of the -300s. that is why the -200 can carry more, but also has a higher operating cost. i don't remember what the actual numbers are, will try to jog my memory though...

I think the 'fins' are radio antennas.

Quote:

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Originally Posted by heeshung

I think the 'fins' are radio antennas.

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Yes, you are indeed right...they can be for VHF or UHF equipment. Also it can vary based on what avionics is installed. So using the number of antennas for identifying equipment isn't very accurate.