Here is a look at the outside of the Tech 7 Ampac 760.
Alton Junction
In the interest of salvaging a tiny shred of meaningfulness from this train wreck:
Billwiz, if you are at all handy, some of these potentiometer-based controls don't have the stops built mechanically into the actual pot, but use external plastic stubs that bear on something, perhaps in the plastic handle.
If you're comfortable with a little disassembly, and you can't or don't want to get your money back (or a partial refund from ) your seller -- both of which you have a strong claim on, if he implied or sold you the pack as serviceable -- you can take the knob off or look at the pot inside to identify what is broken to let the knob go around and around.
Depending on how the potentiometer is made internally, it might work just fine electrically without 'shorting' in the non-scale 60 degrees of rotation, in which case you could make a stop glued to the knob with a couple of blocks or posts glued to the case to arrest rotation, and gin up some appropriate friction arrangement to hold the knob in intermediate position if its action is loose or floppy.
You could of course easily remove and replace the pot with something compatible -- use a multimeter to determine resistance at zero and full, and get something electrically compatible from a source like Mouser. You'd need to know or learn electrical soldering, but that is a valuable modeling skill in its own right.
As I recall, the MRC case screws are a 'security' type, either Allen hexes or Torx-style with a pin in the center. Any of the eBay or Harbor Freight 'security bit' sets for replaceable-bit screwdrivers will contain the appropriate bit to get these out.
gmpullman Billwiz All of them have a limit when you turn the handle (maybe 300 degrees?). From MRC: Key Features: Accutec Technology™ provides smoother performance and helps maintain the extra power when climbing grades or running over poor track conditions Proportional Tracking Control an innovative system of control that yields the most responsive, realistic model train operation Automatic Circuit Protector automatically disconnects power to the track to protect your equipment if overload occurs Main Line Direction Switch throw the switch to reverse direction of the loco More Powerful than others in its class with power to pull heavy loads and operate accessories Pilot Indicator Light shows power is being delivered to the track Advanced Slow Speed Circuitry so your loco can crawl and couple easily Fixed A.C. Terminals for powering switch machines, lights and other accessories 300 Degree Speed Control uses 300 degree throttle for an extended range of control {my bolding} Looks like Bill was pretty close afterall. To the Nth degree. Thanks, Bill. Regards, Ed
Billwiz All of them have a limit when you turn the handle (maybe 300 degrees?).
From MRC:
Key Features:
{my bolding}
Looks like Bill was pretty close afterall. To the Nth degree. Thanks, Bill.
Regards, Ed
hey what about that? Please let my wife know I got something right!
Lastspikemike Just posting the correct information. No criticism was made nor intended.
Just posting the correct information. No criticism was made nor intended.
Lastspikemike I'm really not sure what the points of these other posts were after I confirmed the actual facts.
I'm really not sure what the points of these other posts were after I confirmed the actual facts.
LastspikemikeLooking again I'd say the range of the throttle knob is closer to 330 degrees.
BillwizCompletely uncalled for attack on another poster.
Yes, completely uncalled for, but it is what Mike does. At least he did not personally insult me this time.
It is all he does, it is his only act, and the only ability he likes to show off. He certainly does not like to show off his model trains. This is a model train forum, remember?
As long as the moderators continue to allow it, we will need to put up with it.
I apologize to all for my estimation being off by 10% and all the confusion that must have caused.
I like showing off my model trains. Maybe someday Mike will do the same, and he can drop this tiresome dispute-baiting and enjoy himself.
-Photograph by Kevin Parson
CSX Robert"About 270 degrees" is not specific information.
I guess I should have said "About 3/4 of a turn" instead of using the degrees to equal 75% of a full rotation. I can see how that could confuse some people that have a hard time visualizing "Knob Spin Increments", or KSI factors.
Anyway, on my layout, 300 degrees (give or take a few) is still about 3/4 of a turn. I think my response to the OP was OK to answer his question.
If nothing else, I did get a couple new additional screen-shots for my ever-growing "Things Mike Has Actually Posted" file before he goes back and edits them all for content. Maybe someday I will compile it all into a yearbook or something.
-Kevin
Living the dream.
BillwizAll of them have a limit when you turn the handle (maybe 300 degrees?).
LastspikemikeYou should try to be more accurate when posting specific information.
"About 270 degrees" is not specific information.
Lastspikemike SeeYou190 BlazmoIntoWowee Should I be returning this? Yes. The throttle should sweep about 270 degrees with positive stops at both ends of rotation. -Kevin Far more than 270 degrees. More like 300 degrees or perhaps more as noted by another poster. You should try to be more accurate when posting specific information. Especially when you don't have an MRC 760 to look at, although the MRC photo of their own unit is pretty clear.
SeeYou190 BlazmoIntoWowee Should I be returning this? Yes. The throttle should sweep about 270 degrees with positive stops at both ends of rotation. -Kevin
BlazmoIntoWowee Should I be returning this?
Yes.
The throttle should sweep about 270 degrees with positive stops at both ends of rotation.
Far more than 270 degrees. More like 300 degrees or perhaps more as noted by another poster.
You should try to be more accurate when posting specific information. Especially when you don't have an MRC 760 to look at, although the MRC photo of their own unit is pretty clear.
Mike
Completely uncalled for attack on another poster. I said 300 degrees as a guess, I did not put a protractor on any of my MRC powerpacks. Kevin said @270. You know what? We've already decided that the powerpack was broken - it should stop (270, 285, 300 or whatever degrees). The OP should return it and get his money back. Everyone has agreed to this. Your post was pretty much an attack on Kevin (again). Please stop doing this. Kevin has always given helpful info in his posts.
BlazmoIntoWoweeShould I be returning this?
MRC does not say in the Tech 7 Amoac 760 manual whether it uses a pot or an encoder for the speed control. But every MRC throttle I have ever seen has stops at the minimum and maximum positions.
The manual indicates if the unit is in warranty you can send it back with $15 to cover shipping and handling. You would need proof of original purchse, which I doubt you'd get from an eBay sale. My advice is that you try them using the contact information in the manual:
(732) 225-6360
rrtech@modelrectifier.com
Model Rectifier Corporation, Parts & Service, 80 Newfield Avenue, Edison, NJ 08837-3817
BlazmoIntoWowee Hey folks i picked up a Tech 7 Ampac 760 from eBay as my first power pack. The throttle goes allll the way round and round, which seems wrong to me, but like I said, first power pack. Should I be returning this?
Hey folks
i picked up a Tech 7 Ampac 760 from eBay as my first power pack. The throttle goes allll the way round and round, which seems wrong to me, but like I said, first power pack. Should I be returning this?
Honestly, I do not know as I do not have this powerpack. However, I have at least 5 MRC powerpacks. All of them have a limit when you turn the handle (maybe 300 degrees?). Perhaps yours is faulty. I would check with MRC quickly, then return it.