The situation: I own several power packs from the 1970s, (Good ole MRC Gold Case ThrottlePacks). I want to hook them to my layout and run locos built in the 1990s. When I crack the throttle, these locos take off like a scalded cat. My question: what is going on and how do I solve this problem? ------------------ Clifton Chief Cook and Bottle Washer of the LaZ & E RR, (known locally as the Lazee Boy Lines)
Well, at the risk of being cited as a turn-coat, I have one acronym for you: DCC. I have been doing a lot of research on this and it clearly is the wave of the future...no more toggle switch blocks etc. Of course if you want to go with a power pack, then I suggest the MRC Tech 4, as the newest and possibly best designed. I don't know for sure though, because I haven't bought power packs since the late 80's. Good luck and Happy Modeling!! ------------------ The Santa Fe and Southwestern, Chief of the Southwest!!
lifton, I feel your pain, you ought to see the box full of those I have! Back then the motors needed a lot of grunt to start up, so the transformer started with 3 volts and went up to 13 to 18volts. Go to a radio supply store, (or TV, VCR, or even a Radio Shack) and get an audio volumn reostat. They cal them pots today, for potentiometer, but same thing. Wire this from your track to the OLD style power supply. Turn the pot to full wide open so you don't burn up the little nickle silver resistance wire. Now turn the power supply on and watch your gauge, as you increase the voltage, nothing will happen until the rotor touches the bit pot inside the power supply. then the needle on your gauge will show somewhere around 3 to 5 volts. STOP TWISTING THE ROTOR!!! Permanently mark where the rotor just makes contact. Now if your engine is running and you want to slow it down, twist the volumn control counter clockwise as if you were turning down the volumn, and your train will slow down to a crawl or stop. DO NOT TURN UP THE transformer until you have first turned up the volumn control all the way. That's the easiest way to salvage and use the old Tycos, LifeLike etc. This is also a way to run an accessory that only has a 1-1/2volt motor too. ------------------ Watash #982
I moved this topic here, as I feel it may get more coverage, as it is not scale-specific ------------------ Alan Curtis. Moderator. Member #12 The perfect combination - BNSF and N Scale! www.alancurtismodels.com Andersley Western Railroad Alan's American Gallery
Alan, I'm sorry I put this in the wrong spot. I should have realized this was a topic appropriate for the "Inspection Pit." I model in N-Scale and that's what drove me to the N-Scale page. You were correct to make the move. Watash, thanks for your comments. I read your stuff on this site and am impressed with the breadth of your knowledge. A tip of the engineer's hat to you. JCater, thanks for your input. I want to make the move to DCC. The only problems right now are cash and I'm working in N-Scale with locos needing decoders. But, I'm encouraged by the new lower-cost systems coming from Atlas and MRC. I think those will be perfect for my 2-foot by 4-foot N-Scale layout. ------------------ Clifton Chief Cook and Bottle Washer of the LaZ & E RR, (known locally as the Lazee Boy Lines)
I know exactly what you mean. I have a MRC tech II which is perfect, and a MRC Dualpack from 1984. The old pack gives my locomotives two speeds, breakneck and stop. You should have seen us trying to ease a Camelback into the station, like watching someone with a five-speed on a hill learning how to drive. The Tech II's may be getting long in the tooth, but they do their job well and are getting cheaper all the time! ------------------ Southern Serves the South!
<BLOCKQUOTE>quote:</font><HR>Originally posted by Clifton: Alan, I'm sorry I put this in the wrong spot. <HR></BLOCKQUOTE> Clifton, there is no such thing as a 'wrong place' on Trainboard I just thought it may get a wider audience here ------------------ Alan Curtis. Moderator. Member #12 The perfect combination - BNSF and N Scale! www.alancurtismodels.com Andersley Western Railroad Alan's American Gallery
SteveB, get 4 little alligater clips and two short pieces of #28/16 wire. One volumn control. Crimp or solder one clip to each end of both pieces of wire. (4 clips OK?) Now remove one wire from your power pack. With power off. Clip #1 to power pack , other end #2 clip to one terminal on volumn control. Clip #3 put on other terminal of volumn control. Clip #4 to wire you just removed from power pack. FIRST, turn volumn control all the way wide open (clockwise) to stop. NEXT, turn power pack throttle control all the way off (Counter-clockwise) to stop. NOW is the safe time to turn power on at power pack. The Camelback should not run. If it does not run, you are connecter and "set" correctly. OK, now you are ready for "the test". SLOWLY rotate the THROTTLE clockwise and be ready to stop rotating when the camelback starts to move; as it is moving rotate the VOLUMN control counter-clockwise to slow the cambel back down all the way to a stop. SLOWLY, rotate ONLY the volumn control and allow the camelback engine to creep along as you have never seen it before! You will be surprised! ------------------ Watash #982
Watash, Have you ALWAYS been brilliant?!? Maybe I can use my Tech II's the same way, at least until I'm ready to switch over to DC. Thanks for the great advise!! Happy Modeling!! John ------------------ The Santa Fe and Southwestern, Chief of the Southwest!!
Sorry JCater, I can't take credit for that, my dad really was brilliant. He showed me how to do that (back in 1936), before we ever bought our first power pack. He first had me take the carbon core out of used flashlight batteries, and make a carbon pile to run our first HO Strom Becker RockIsland Rocket on 6 volt. Then we (he) made a selenium rectifier to convert AC into DC and we re-wired the 6v motors to 12v. Then he scrapped some old radios, and showed me how to use them for a reostat to control the speed. I have grown up with that sort of thing, and he had a fully equipped machine shop in our basement. I now have my own in a workshop behind our home. Even though my mom always called me "son", I was never too handsome nor rich! But thanks for the compliment! ------------------ Watash #982 [This message has been edited by watash (edited 06 January 2001).]
Another possibly eaiser option would be to add a couple of resistors to the output of the transformer. I did this once in N scale and dont remember exactly what size I used, 200 ohm possibly. They are cheap though so you can experiement with them to get just the right effect..Mike
Hey Mike, I always thought a resister was when she said NO! I never dated a 200 pounder either. Did she resist? ------------------ Watash #982
A comment on the original question... Clifton said>>> The situation: I own several power packs from the 1970s, (Good ole MRC Gold Case ThrottlePacks). I want to hook them to my layout and run locos built in the 1990s. When I crack the throttle, these locos take off like a scalded cat. My question: what is going on and how do I solve this problem? <<< Resisters aside, if you are using 1970s packs that were not specifically designed for N scale, your locos WILL take off like a scalded cat! MRC had two distinct packs back then, one for HO and another for N. The rheostat was different. (Yes, they used rheostats up until the Tech II line.) A dropping resister will work, but I would seriously suggest buying a new pack(s). 1970s will still work with most HO, but not with the low draw motors in N scale. Yes, I still have one of the 1970s dual packs in operation on my HO road, but not for the mainline. It controls switching in two separate yards. I have dismantled it for a control panel and a hand held throttle. Roger Roger Hensley - rhensley@anderson.cioe.com == http://cid.railfan.net/eci_new.html == == East Central Indiana Railroad ==
Hey THANKS Roger, you just saved me some money! I still have a couple of old "N" scale power packs, so I can hook up one of those to an HO pack, and do the same thing as the volumn control. ------------------ Watash #982
Not exactly. I removed the rheostat assembly in each case and extended the wiring from it back to the basic power supply. The supply is tucked away on a shelf and one rheostat assembly is now mounted in a control panel and the other in a small Radio Shack project box. In both cases the power supply is still in use. To use the rheostat assembly with a different power supply should work, but remember that the N scale control is a different resistance than the HO. Try it and let me know how it works. It could be a nice low speed control. Roger
Well, it worked somewhat, not as well as the volumn control does. An engine running free still jerks into life when the "N" reostat first touches the resistance winding, runs or stops, on or off. (Same way my wife drives). The volumn control works on either power pack. I have not tried to run more than one engine at a time, so it might burn the little winding apart on the volumn control, I don't know, but it ran the only two diesels I have unpacked. I just use them for testing track, a Revel, and a Cox, both good runners though. My power pack is a 15 amp 12 volt selenium rectifier and also sets out of the way on a shelf. It has no problem running up to six steamers at a time, the most I ever ran on one train. two 4-8-8-4's on head end, one 4-8-8-4 and a 2-8-8-2 in about 50 cars back, and two 4-8-4's on rear end of 105 cars, counting a caboose. ------------------ Watash #982
Okay, a new question on the same topic: So, if I add a transistor throttle add-on (from the Kalmbach electronics book) to the fixed DC output, is that another way to solve my problem? BTW, I totally forgot that in the 1970s, MRC made different power packs for HO and N. These were originally purchased for HO equipment. That helps explain a big part of my troubles. Thanks to everyone who has responded up to this point for your help. I am learning a lot. ------------------ Clifton Chief Cook and Bottle Washer of the LaZ & E RR, (known locally as the Lazee Boy Lines)
Clifton asked...> Okay, a new question on the same topic: So, if I add a transistor throttle add-on (from the Kalmbach electronics book) to the fixed DC output, is that another way to solve my problem? <<< Yes. Roger
