Thanks to the generous replies here, I have worked through a couple bugs on the way to getting this used DK16 system running here, and I think I have just one issue remaining.

There is a KSTU and a K4RCU in the base unit (there is no expansion unit) to support standard devices.

When I hook up a standard phone to one of the standard ports I have wired (at station 18 and 19), I hear a steady tone, but it's not a good imitation of the CO office dialtone. Another post here notes that standard devices get intercom dialtone, so the pitch or quality of the tone doesn't trouble me too much, but it won't let me dial. The LCD display records my keypresses, but there is no dialing, no line ringing and no connection.

The only programming I have done is Prog 90, 92, 03, 81 and 87. I entered all the default values for Prog 03.

Can any of you pros nail it down from what I've said?

My first thought would be a bad K4RCU card. That is the DTMF Receiver card for analog stations to break dial tone. If you don't have another one, it will be hard to troubleshoot.

After you programmed Code 92 into program 03, did you cycle the power? You have to do that system reset everytime you make a change in prog. 03.

Go ahead....reset it now and see if it works.

Dan

Well another point to ponder is that the voltages given out by the Toshiba unit is usually 24 volts. In the old days, some Single-line devices could not work at such a low voltage since a normal Telco line would be at about 48volts.

There are no voltage boosters for the DK16s though, unless you use the RSTU cards which accepts R48S.

Ditto Voyager, can't tell you how many times I have had to tell an experienced tech to cycle the power after changing 03!

MrEngineer, I checked voltage at the MDF, and it was around 48V, so that cause can be eliminated.

Dan & Breed, I was wondering myself afterward if I cycled power -- it was a rush visit. That sure would be nicer than replacing the K4RCU! But unless anyone has anything to add, I'll take that as the next reasonable step if cycling power doesn't take care of it.

See if you can dial out using pulse instead on tone this will tell you if your DTMF is bad

I ran back out there and cycled power, and still got the same results.

But wait! I was looking again at the manual, at Program 03. I think when I programmed that I entered all the defaults. But though the default for slot 03 is code 31 (KSTU installed), the default for slot 00 is code 91 (common control with no K4RCU) rather than 92 (common control with K4RCU). I would have thought that if the base configuration included a KSTU, it would have also included a K4RCU, but maybe not.

Would code 91 for slot 00 produce the behavior I experienced: dialing does not break dial tone?

I guess I would rather make a newbie mistake here than try to come up with a K4RCU on short notice!

Yes. Also in Prog. 31 make sure LED 17 is turned on for these ports.

Steve, your interesting post appeared while I was writing my last one. If Program 03 turns out not to have been my problem, spare me another long hunt through the manual: what program(s) do I need to change to pulse dialing? And again, if pulse dialing works, I can reasonably conclude that the K4RCU is a likely culprit?

Just a few programs to check.
pgm 00 = 92
pgm 03 slot 13=31
pgm 12 digit 9 = 4secs.
pgm 30 led 11 = off

Can you call internally to station 10 or 11?
Can you call the analog stations from a digital station?
Do they ring or voice annouce?
If you call them and pickup...can you hear the other end?
Clip your buttset on the pins and listen....what do you hear?

If you haven't a DTMF to swap with I'd suggest to default the system again and start over......that's what Tech support always said to do! JK Seriously might be a good idea.
Make sure the K4RCU is in correctly and securely...reseat it.
Same thing with your KSTU.
Last thing check your amp cable.

Hope these help.

I mean try putting your butt set to pulse or the standard phone you are using to pulse, program 03 is going to be your problem, set it to 92 , cycle the power and I bet you will be goood

A piece of good news: setting Program 03 slot 00 to code 92 resulted in the standard phone being able to break the dial tone.

Here's the next problem (!): I can now start dialing, but can't finish. Whether in tone or pulse dialing, after I dial a second digit I get a twice-per second beep.

Regarding some other items on your checklists:
Prog 31: LED 17=On -- OK
Prog 03: slot 03=31 -- OK
Prog 12: digit 9=4s -- OK
Prog 30: LED 11=Off -- OK

Can you call internally to station 10 or 11? Yes
Can you call the analog stations from a digital station? Yes
Do they ring or voice annouce? Ring
If you call them and pickup...can you hear the other end? Yes

How do I get over this next bump?

Alternatively, if I were to start over and reinitialize the basic programs (90, 92, and 03) correctly this time, can I expect normal basic functionality from a standard phone on a standard port? I.e. go off hook, get dial tone, and dial out?

sound like it is restricted, check program 48

Also check progs 16, 40, and 41. Or as Steve said, check prog 48.

Could also be a bad KSTU since you said that the dialtone sounded funny.

the DK-16's intercom dial tone sounds different ,not like regular dial tone, I think that is what he was talking about

After dialing the line access code do you get dial tone? If not check programs 16, 40, and 41. If you do check 48. Just as suggested above

I am so stupid. Ha ha

And if you need to modify the restricted digits, you'h have to go to Program 46

A belated reply and resolution on this last problem. It was simply pure inexperience with some fundamentals on this system.

In short, I didn't know that I needed to dial a CO line access code (701-708) from a standard phone. This was true even after I set up Program 32 Automatic Preference so that the digital phones automatically access a CO line.

Thanks, Breed, for the mention of the line access code. That eventually set the right bells ringing in my head.