"The phone is a remarkably complex, simple device, and very rarely ever needs repairs, once you fix them." - Dan/Panther
Started by RDub, October 28, 2016, 04:47:58 PM
Quote from: Ktownphoneco on October 28, 2016, 07:30:57 PMFirst of all, and correct me if I'm wrong, what you've described is actually placing a direct short across the microphone input circuit of either a sound card, or an on board sound circuit built into the motherboard (MB). I'm no computer expert, but I rather doubt that sound cards, add-on or built into the motherboard, were designed to accept a direct short.
Quote from: Ktownphoneco on October 29, 2016, 10:12:44 AMAs I understand it, the microphone circuit associated with a sound card, or the onboard sound circuitry, is designed to produce somewhere around 10mV to power the microphone inserted into the jack. I suppose that isn't a lot of voltage to short out, but I would imagine it's important to remove the male jack as soon as the dial test is completed, rather than leaving it plugged into the mic jack while the graph is analyzed. However without comparing the results of the same dial connected to an actual dial testing instrument, how do you establish that the results obtained through a PC, using the Audacity software are accurate ? I can carve out a handle on a 2"x 4" piece of lumber, and use it as a baseball bat, but my accuracy when hitting the ball will be way out of whack. As I see it, using a software program designed to analyze audio through a properly working microphone, isn't the same as asking it to measure the speed and duration of a series of short circuits. If the results can't be gauged or compared against the results achieved through a proper piece of equipment designed and calibrated for the specific purpose of measuring the speed and break / make ratio of a pair of pulse springs, the accuracy of those readings can't be confirmed.But if you feel it works, and your happy with the situation, then use it by all means. But I'm still not convinced. However, out of curiosity, I'll do this when I have a few minutes to spare.I have an old computer in my shop that has either a sound card, or sound circuit built into the motherboard, ( I just can't remember which ), and I really don't care one way or the other, whether or not the test damages the sound circuit.(1) I'll download the Audacity software and install it on the old computer.(2) Make up a microphone jack with cord and alligator clips on the 2 conductors.(3) Select an "un-serviced" Western Electric dial in good shape, and which appears to be operating well.(4) Test it on the Sage 930-A, and record the results.(5) Then connect the same dial to my old computer, and record the results obtained using the PC and the Audacity software.(6) Then post the results of the comparison tests conducted using both methods.Who knows, maybe I'll only manage to shoot myself in the foot.By the way, Sage telecommunications test sets get obsolete fairly fast, and they can be purchased off eBay fairly cheap. I bought mine for $95.00 plus shipping. The thing one needs to know is if the 930-A set has the add-on card for the tests that the purchaser wants to perform. Pulse speeds and break / make testing and DTMF frequency tests with the 930-A requires "Option Card - 01". There are approximately 31 Option Cards for this unit. The instrument itself, operates on either 48Volts DC, or 115 or 240 Volts AC, but not both.Results to follow when I have time to do the comparison tests.Jeff