[GreenKeys] dial dwell time adjustment success / 101C modem operation question
Keith Lueck
kwlueck at swbell.net
Mon Feb 18 19:45:07 EST 2019
Hi all -
I pulled apart the CCU on my ASR33, and removed the dial. I studied the mechanism, and saw how the dwell time might be adjusted by bending a strip of metal that acts as a cam follower. Before doing that, I noticed that the contacts were dirty, and there was a lot of smutz all around them (looked like debris from contact arcing to me), so, I tried cleaning the contacts with a strip of paper moistened with DeOxit. I got a lot of black stuff off the contacts, but I found doing so made the dwell time even shorter (on the order of 15-20 msec, down from 28 msec). So, I went ahead and carefully tried to bend the cam follower. I got the dwell time up to 40 msec, and that made my telephone line simulator happy! Dialing out was now successful. Not satisfied with that (the dwell time is supposed to be 40-60 msec) I tried bending it a bit more, and I got no contact opening at all. I bent it back a bit and got back to 40 msec, and decided to leave well enough alone...
So now, I can call the 33, and the 101C will answer and provide the answer carrier. However, when I dial out from the 33 to another phone, and I answer the phone, I don't hear the originate carrier from the 33 (I don't have another modem yet). Does anyone know if the 101C should provide an originate carrier immediately, or does it wait for the answering modem to provide its answer carrier? Reading over the BSP, it's not clear to me, and I haven't tried to decipher that detail by looking at the schematics. Thought one of you all might know.
Thanks,
Keith
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