Im using the 74LS47 chip, bought from jameco,
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_47790_-1

I can't get an output on the a-e pins that go to the 7 segment cathode display. The most I get is 0.07 V when low and 0.14 V when suppose to be high. I tried a few combinations with the LT , BI/RIO , RBI pins without getting an output voltage on my voltmeter.
[testing the chip i have 5v going to Vcc and 0 to ground, inputs A-> D i play with putting from 5v to 0v. I moitor the outputs of pins a-e and get .07 to .14 V]

(just noticed the output might be open collector, what does that mean for me?)

Datasheets
http://www.jameco.com/Jameco/Products/ProdDS/47790TI.pdf
http://www.jameco.com/Jameco/Products/ProdDS/47790.pdf

 

"Open collector" means that it can sink current, but cannot source current.

In order to see the output voltage change, you will need to use a resistor between the output and the supply voltage.