Minitor III Programming Stand - homebrew??

[aaknitt]

From the Batlabs Minitor III section:

Looking at the back of the programming base, the RJ-11 style plug has the contacts on the top of the jack. Label these contacts from left to right a,b,c,d. Inside the programming base 3 pins of 6 are used (they are labeled 1-6). a->3, b->1, c->5.

I noticed on the Universal Programming Interface schematic that the RJ-11 uses all four pins, but only three pins interface with the pager. Is the fourth pin (contact "d" from above) not used, or is it used by the programming stand itself?

I'm asking because I'm wondering if it's possible to go directly from the RJ-11 to the connector on the bottom of the pager using a "homebrew" programming stand, or is there circuitry in the programming stand that would preclude this?

Any advice would be great.

Thanks,

Andy

[n6fnp]

Hi,

Did you ever have any luck making a programming stand for a Minitor III pager? I
would like to do the same thing.

Do you know what pins on the bottom of the pager go to the interface unit?


-Thor

[aaknitt]

Thor,

I haven't tried it yet, mostly because I'm still unsure if there is some kind of level conversion done inside the programming stand. I'm doubtful that there is, but if there isn't, what is the purpose of the 1.5V line coming out of the UPI? Maybe it's used on a different pager, but not the Minitor III? I'm just not sure. As far as pinout, this is from the Batlabs Minitor page:

Looking at the back of the programming base, the RJ-11 style plug has the contacts on the top of the jack. Label these contacts from left to right a,b,c,d. Inside the programming base 3 pins of 6 are used (they are labeled 1-6). a->3, b->1, c->5.

If you find anything out please let me know!

Andy

[VE9MP]

The 1.5 V is used as activate "events" I know of FD's that have their pagers rigged into an alarm type system so when the tones go out that pin get 1.5V going in it which activates the alarm. I'm *very* doubtful it has a purpose when programming.

[KB2ZTX]

Well I think I can help you guys out. As I have always wanted to make one of these for myself, i tried it. Let me give you a few hints.

First off find 2 MIII or MIV broken chargers. You need a 3rd pin from the 2nd charger only. I took a 12" piece of phone cable with the connector on one end. First off, remove the center copper pin that goes to the old ground. Next move one of the single wide ones to the spot.

I next soldered the wires to pins 1, 3, and 5.

Went over to the compter and read and wrote both a MIII and a MIV. I'll try to bring my camera monday and take a few pics of what I mean, but it took me all of 10 minutes with all the parts. Pretty simple.

Hope this helps.

Jeff S.

[aaknitt]

Awesome, thanks guys! I'm going to go even more ghetto than using old chargers...I was thinking about bending some stiff wire to get the "spring" action and making my own "cradle". If I get it to work I'll post some pics...it won't be pretty though! That information also makes building the interface easier...I can just build the MAX232 level conversion part and not worry about the 1.5V power supply portion.

Thanks again,

Andy

[aaknitt]

Well I made a completely ghetto homebrew UPI and programming cradle and it works just fine. The UPI is on a breadboard and the programming cradle is three pieces of wire bent to make contact with the contacts on the bottom of the MIII. I have to hold the pager still while reading and writing the codeplug, but it works well. I didn't build the 1.5V supply portion of the UPI either. I don't have any web space or I would post a pic. Next steps are to get the circuit off of the breadboard and onto something more permanant, and to make a more elegant homemade programming cradle.

Thanks all!

Andy