Jim Currie suggested that I do a tutorial on the use of a VOM meter some time ago. This is essentially copy of that tutorial that was posted elsewhere over two years ago. His thinking is that every modeler needs this tool, and should know how to use it. A VOM meter is indispensable for use during wiring and troubleshooting layouts and accessories. This meter is an electrical device used to measure Volts, Ohms and Milliamps, thus the name, VOM. There are two types of these meters, one is analog where the value of what you’re measuring is shown by the position of a needle on a dial face, and the other has a digital readout. I have an analog meter that is probably a good 50 years old and still works, but finding one is difficult nowadays, so we’ll talk about the digital type.

Let’s spend a little time discussing what is it that we’re actually measuring. Volts are the amount of electrical potential between two points, kind of like the amount of water behind a dam, the higher the water, the more potential there is. There is AC volts and DC volts. AC is what you get out of the wall socket in your house and can only be created by a generator. Current flows back and forth 50 or 60 times a second. DC volts are what you get out of a battery or a power pack that has change AC into DC. Current flows only in one direction in this case. There is another tutorial on power packs here that you might want to read. Voltage by itself can do nothing. You can frequently measure voltage between yourself and a water pipe, but it is normally harmless. Notice I said “normally”. If you measure a few volts between you and the pipe, that’s what’s know as “pick-up”, if you measure a lot higher, say 110, don’t touch the pipe, that’s not a good thing. What is required is current, measured in amps, to get any work done. Think of this as the water pressure that flows through the pipes leaving the dam. Resistance, measured in ohms, is the ability to oppose the forces of electrical current. This would be the same as when the water pressure hits a restriction or narrowing in a pipe, lowering the water pressure. Or in our case, lowering the amount of current that flows. There is a relationship between these and can be expressed in a formula: Voltage equals Current times Resistance, or, E = I x R. If you know any two values, you can calculate the other one using this basic electrical formula. “E” is used to denote voltage and stands for “Electromotive force”, “I” stands for current and “R” for resistance. Power is the Voltage multiplied by the Current, or P = E x I, and cannot be measured using a VOM.
A basic meter looks like these:
   
You can purchase an inexpensive meter for under $10US, and up to a couple of hundred dollars for a very sophisticated instrument. The one on the left I paid about $3 for on sale at Harbor Freight, the other two were about $40-50 purchased at an electronic supply house. There is no need to spend more than that. Some meters can also measure things like capacitance or even temperature. Simple meters now days have the ability to check transistors. Features and accuracy are depended on the individual model. Some are designed for more rugged use than others. For instance, if I were to drop my $3 meter, I’d just leave it and sweep it up with the trash, but my $50 meter has a rubber cradle to keep dropping damage to a minimum. Analog meters are also very sensitive to abuse as well. All meters are set up about the same. There’s an on/off switch somewhere, holes at the bottom for probes, a digital readout and a large switch used to set the meter to select what you are measuring. Make sure the meter is set for the measurement you’re about to take and at least the highest value you expect to see. Remember, the numbers on the meter selection switch represents the highest value that can be read in that switch position. Also, make sure the two probes are in the correct holes for what it is you are measuring. You can damage the meter, or blow an internal fuse, if you have it set for 20 mA and you are measuring 2 amps or if you’re measuring voltage and the meter is set to measure resistance. Each meter is different in some respect. The meter on the right is self-seeking in that you can just set it for what it is you’re measuring and it will seek the proper scale for the value. To me these types of meters are confusing. The smaller meter does not measure AC current and has limited range positions.

Measuring Volts:
When wiring up anything, it’s the wires that bring the voltage to wherever it’s needed. In our case, the wires go from the power pack to the rails (maybe through a control or switch panel), then to the loco’s motor. If you don’t have voltage, you don’t have anything. When testing, I always start at the farthest point. If I don’t have voltage there then I check the power pack. If I have voltage at the source, then I can work back in either direction to locate the point where I have voltage on one side, but not the other. In the case of rail wiring, it’s necessary to move both probes as you go since there is no common connection (or grounds) in DC rail systems. When measuring DC voltage, there is polarity, the red probe goes to plus, the black to minus. If they are reversed, the meter will read a minus (-) in front of the value. Remember, if you don’t have a load, you will read the same voltage all along the line, that can change when you add a loco or a light somewhere.
   
Measuring Current:
There is no current on an open circuit. Once you add a load, or some resistance in the circuit, you will generate current. The lower in resistance the load is, the higher the current. The higher the voltage, the higher the current will be for the same load. That’s why when you increase the voltage from the power pack; the current increases and the train will run faster. Current is always measured in series with the load, that is, you must connect the meter in line with one of the power wires. Remove one wire from the power pack; connect one probe to the power pack, the other to the wire you just disconnected. Set the meter to the highest current setting. On some meters that will require moving the positive probe to a different probe hole. There may be a fuse in the lower settings while a setting of 10A or more usually aren’t fused. If for instance you want to find out how much current your new loco draws at slow speed, adjust the power pack to the setting you want and put the loco on the track. Turn on the power pack and read the meter, if it’s too small a number, you may have to lower the meter setting. If the meter value keeps changing as the loco goes from one section of track to another, that’s a good indication that you have some rewiring to do. It could mean that a rail joiner is not making good electrical connection or that you need to add a new voltage drop to the rail section that is affected. Undersized wire will cause these problems as well. As you increase the speed setting on your power pack, the current will increase as well. If you have a lamp connected to your power pack, as you increase the voltage, or speed setting, the lamp will get brighter and the current will increase. The total current at the power pack is equal to the sum of all the currents required by all the loads you have. Let’s say you have two locos and at the 50% speed setting, they each draw .250 amps, and you add four lights, each drawing 50 mA, or .05 amps. Your total current draw will be 700 mA or .7 amps. You have to check the label on the power pack to see what the maximum output is. Some are rated in amps, others in watts, or power. If you exceed the rating, one of two things will happen. The unit will shut down until the load is removed and or the power pack it reset, or on some cheaper units, the voltage will drop to compensated for the increased current and it will heat up. Some have thermal overload protection, but the ones that don’t can be damaged this way, so whatever you power pack is like, it’s best to know how much current it can safely deliver and how much your equipment is loading it.
   
Measuring continuity:
Continuity is basically when you have an electrical connection from one point to another, or a “short”. For instance, of you have an open or loose rail joiner, you most likely won’t have continuity along your rails. Continuity is essential to complete a circuit and for current to flow. Frequently, when troubleshooting wiring, it is easier to use the resistance setting on the meter to test continuity, which should appear as a short. One word of caution, do not measure anything on the ohms scales with power on. It is best to just disconnect the wiring to the power pack. Many meters have a continuity setting that is denoted by a musical note next to the switch position. With the meter set for that, the meter will buzz whenever the two probes are touched together. If your meter doesn’t have that, then use the lowest setting for ohms. A short will then show as “0” and an open circuit as a “1” on the left.
To test for a short between the rails, connect one probe to one rail and the other probe to the other rail. If the power pack is disconnected, you should see an open circuit. Note that if you have some lamps in the circuit or have the power pack still connected, you will see some resistance, but you shouldn’t see a short circuit.
To test for an open circuit to your rails, connect one probe to the end of the wire that went to the power pack, and touch the other probe to the closest rail where the other end of the wire is connected. You should see a short. Run the probe down the rail and you should see a short all along the rail. If at any point the meter shows an open or high resistance, you have located a problem area. If you have a switch or control panel in the circuit, you’ll have to be sure the switches are in the right position. You should repeat the process with the other wire and rail.
   
Measuring resistance:
Everything that uses electricity has resistance. For the most part, you shouldn’t care. If you know the voltage and current ratings of things, you can calculate the resistance. On the other hand, if you know the resistance and the voltage, you can calculate the current. If for instance you have a 5 volt lamp that you want to use in a 12 volt circuit, you need to know either it’s current rating or it’s resistance so you can put a voltage-dropping (or current-limiting) resistor is series with it so as not to damage the lamp. Set the meter to one of the ohms scales, in this case a lower one. Touch each probe to one of the lamp contacts or wires and read the meter. Let’s say it reads 50 ohms. Using the formula above, you can calculate that it takes .100 amps, or 100mA to light. You’ve got to use a series resistor with a value that will drop 7 volts across the resistor and the remaining 5 volts across the lamp. Using that same formula, you can determine that you need a 70-ohm resistor, or a standard 75-ohm resistor. In this case, a one-watt resistor would be necessary. You can use the resistance scales to check continuity as described above. This is a good way to do it since it can show when you have a connection, but a poor or high-resistance one. If you’re checking continuity on your rails and you’re getting 0, or a short, then your OK, if you see a higher number like 100 or 1000 ohms, you can have either a poor solder joint, a corroded rail joiner or even a dirty track.
   

Hi all

I recently purchased a Bachmann Spectrum 2-6-6-2 and I noticed that my front set of wheels need a bit more weight. Oh, it climbs fine, but you can see the boiler rising up and the wheels sometimes actually break contact with the rail.

I have some weight ready to go, but I cannot for the life of me figure out how to open this bad boy. I have the explosion right here next to me even now, and I cannot see where I need to start to get into the boiler.

If anyone has this engine and has a tip or trick, let me know! I love how this guy pulls, but can't help but think that it would be even better with just a skosh.

Thanks,

George

I keep seeing comments about people dreading having to ballast their tracks, or, from people who've tried and not had success, what a crummy task it is.  What follows is my procedure for ballasting - there are others that work as well, but this one uses tools and materials which are cheap and readily available.
The choice of ballast is up to you - I use Woodland Scenics Fine Ballast on much of my HO scale layout, but used real limestone "fines" on much of the upper level.

To ballast your track, I find that a small paper cup (such as those kitchen or bathroom Dixie cups) gives you great control over where the ballast goes. I usually move the cup along the centre of the track, tapping it as I go, to keep the ballast flowing. Less than you need is better than too much, although a soft 1/2" brush is useful for pushing around the excess or levelling what's in place. Then go back and do both roadbed shoulders in turn. Use the brush to level and re-arrange things as required, making sure to keep the ballast away from the throwbar area and the flangeways of the guardrails.  When using the brush, drag it over the ballast with the handle almost parallel to the track - this gives more control over where the ballast goes.  If you use the brush as you would a paintbrush, the ballast will scatter when the bent bristles flex.

To remove stray ballast from the tie tops, lightly grasp the metal ferrule of the brush between the thumb and forefingers of one hand, laying the handle across the rail tops, then, as you move the brush along the tracks, lightly and rapidly tap the brush handle with the fingers of your free hand. The stray ballast will "magically" bounce off the ties and into place between them.

If you're also ballasting turnouts, make sure to keep the level of the ballast below the tops of the ties, and don't place any ballast between the ties surrounding the throw bar.

To avoid gluing the points to the ties, place two drops of plastic-compatible oil atop each tie over which the point rails move, one next to each point rail, then flip the points back-and-forth several times to spread the oil. Parking the points in mid-throw will also help to ensure that they don't get glued to the stock rails, either.

You can mist the contoured ballast using either water and alcohol, or water with a few drops of dish detergent added. Either should work, although I prefer the detergent, as it's cheaper and works just as well. (I save my alcohol - not the denatured kind -  for a nice drink after I've completed the ballasting.)     Use a sprayer that will allow you to spray a fine mist. To avoid having the force of the spray dislodge loose ballast all over the landscape, aim the first few spritzes upward, letting the droplets fall like rain. Once the surface has been wetted, you'll be able to spray it directly. Make sure to thoroughly wet the ballast right down to the base. Not doing so is probably the main reason that many people have trouble getting a decent-looking and durable ballasting job.

To apply the glue/water mixture (white glue works just as well as matte medium and is way cheaper, especially if you buy it by the gallon. Those who claim that white glue dries shiny are not using sufficient wetting agent. The proportions should be about 50/50 water/glue, although a little heavier on the water will still work well).  To apply the glue mixture, don't ruin a perfectly good spray bottle (and while doing so cover your rails and anything else nearby in glue, too):  instead, use a dropper. An eyedropper will work, but a plastic squeeze bottle with a small nozzle will be much faster. Simply move along the track, as quickly as necessary, allowing the glue mixture to drip onto the ballast (or ties - you won't see it once it dries). You should be able to see it being drawn into the ballast, due to the wetting agent. I usually do the area between the rails first, then the sides in turn. The glue mixture will spread throughout the ballast and down to the roadbed, so make sure to apply enough to allow this to occur. The result will be ballast bonded solidly in place, yet with the appearance of loose, individual pieces.

Where I have scenic areas adjacent to, but below the level of the track, I also apply the basic ground cover, which also helps to soak up the excess glue that spreads out from the ballast line.  If you're applying ballast (or ground cover) to steeply sloped areas, use a suitable-width brush to apply undiluted white glue to the slope before applying the ballast or ground foam, which will help to hold everything in place while you apply the wetting agent and the dilute white glue (these steps help to bond the top layers of material to those in contact with the unthinned glue, and also help to draw that glue up into the top layers).  In the photo below, the ballast, sub-ballast, and rock fill, along with the trackside weeds, was all applied and secured in the same step.

   

The pictures below show the sequence of operations to ballast your track.

First, add the ballast.  Here it's been generously applied from a paper cup...

   

Here's the ballast after it's been groomed....

   

The area has been sprayed liberally with wet water.....

   

Don't be stingy with the glue/water mixture either:

   

   


When it's dry (it may take several days), the ballast will appear loose, but will withstand most non-contact vacuuming...

   

Wayne

OK, this may be a bit self-promoting, but by golly, I’m proud of the fact that my wife has her book published and I want to tell you about it. About 15 years ago, she started on a book about her early life, growing up in a large, very poor family with an alcoholic father in upstate New York. The book is called, “Mama’s Diamonds”. She finished it and put it away, where it sat for 11 years until I was able to convince her that it was worthy of getting published and offering to help her take that last step. From Sept. through Nov. last year, we did the final edit together. Our oldest son (aka: “Hobbs” on the old Gauge) designed the cover while I put the book in its final form for printing. It was released for publication in Dec. Although there’s a steam engine on the cover, the book is not about trains. If you look, there is a single light in the baggage car, and that’s significant to the story.

You can preview the book at her publisher’s site: http://www.lulu.com/content/4942425 If you click on the “>” above the cover you can read several pages of two of the chapters, plus a poem she wrote that is also significant to the book. We are waiting to see if some of the booksellers like Amazon.com and Borders pick it up, we should know sometime in Feb. But in the meantime, the book is available from either the publisher or us. The list price of the book is $21.95, but I’m going to make a special offer to members of this forum that they should find hard to refuse. Send us a check in the amount of $18.00US and we will send you a personally autographed copy by the author. No sales tax and we pay the shipping to the continental US. Just PM me and I will send you our address and who to make the check or money order out to. We will only charge the difference in shipping to countries other than the US. I can let you know what that will be when I PM you back so you can decide if it’s worth it. Amazon will surely discount the book, but they’ll charge for shipping, and their books won’t be personally autographed either.

Oh, before anyone asks, Emcie Day is her pen name, or nom de plum, and is derived from the her first two initials, M and C. Look, you don’t argue with some crazy writer who wants anonymity. Just so you know, all the stories in the book are true, some are funny when you see what the kids go through to help make ends meet, then there are a few parts that will tug at your heartstrings. I love the book, but I also love the woman who wrote it, so I’m kind of biased. You’ll have to decide for yourself.

if you think you have bad working conductions how bout 30 inch coal .

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In the essence of bringing something fresh to the new forum rather than bringing over all my old stuff, may I introduce you to what will someday be Scorpion Bend.
I most certainly have nowhere near the amount of space that some of you do and I my funding department is meager at best. Despite these two limitations, I've rather conservatively stepped off into the shallows and begun construction on our first, serious, G scale layout! I say serious because I've done G scale before but it's never amounted to anything more than an oval around the Christmas tree!

While this is still going to start out as a glorified dog bone around a pine tree, it will help get my foot in the door for future expansion. The railroad will also begin life as a DC system but later switch over to battery power. Let's take a look at the backyard.
Front and center, I envision a simple dogbone loop around the pine tree. It will then extend back to the wall turning right to the town of Saguaro (Phase 2). To the left, it will hug the wall all the way around behind the shed to bulge out from the left wall at Needle junction (Phase 3).



To the left of Needle Junction, the track will again cling to the wall behind some Oleanders and then pop out into Pine falls (Phase 4). In this area, I plan to build up a large mountain against the fence and have some sort of a waterfall cascading down into a pool at the bottom with the track running through the mountain and across the pool on a long girder bridge. Imagination is required when looking at the picture!



The next thing we did was picked out a starter train. I know.... we bought the train before the track was even installed. Doesn't everybody do it that way? Here you can see my two little engineers testing it out. The older boy runs it very realistically. However, the younger one likes to see how many G's it'll pull around corners .



Next step was deciding how the railroad would be constructed. We knew that we wanted it up off the ground (above the level of the yard) and so discussed some kind of containment and backfill. I started looking into RR ties and discovered they were priced atrociously. Later that week, my whole family was riding the train at McCormick RR park in Scottsdale, AZ when I happened to glance into a back corner and saw piles and piles of treated, 4x4, RR ties. The next day, I inquired and was told that they were changing over to a composite ties and I could help myself to as many as I could carry off... new or used! BINGO!!!! JACKPOT!!!! Several days later, I took my truck and trailer back and loaded up until my tires all looked squishy! I figure I got about 400 in that trip.





I know it doesn't look like much but 400, treated, 4x4, RR ties is a pretty heavy load for a half ton and a lightweight trailer!!!!!

I've now dug a trench down about 12" (except where there's roots), buried the 4x4's end down, side by side, leaving approximately 18" above ground. I've then tied them together with some pallet banding strap to make things a little stronger and unify it as a whole.



Since I don’t have any fancy tools, I was cutting each 4x4 with my chain saw until it crapped out. Now I need to take it apart and do some saw maintenance (spark plug, sharpen the chain, etc. etc. etc.). Since my saw was now out of commission, I figured I could use some exercise and used my hand saw for a while. That took a REALLY LOOOOOOOOONG time. My wife felt sorry for me and approved the purchase of a new toy! Now it's coming along MUCH faster!!!!



At this point, some friends of mine voiced concern for my tree. It was their opinion that what I was doing was... going to kill it . I love the tree, as shade is very important here in Phoenix. However, my wife hates it because it grows straight up for about 12' and then takes off at an angle over the neighbors wall. Likewise, the neighbor hates it because it hovers over his yard and drops pine needles all over his golf course lawn. With that said, if the tree lives... great! If it dies, by the by.
When I installed the ties, or rather when I dug the trench, I severed very few roots. Most were left intact and I cut the ties at random lengths to sit above the roots and maintain a somewhat uniform height above ground. Some of the RR ties are only buried by an inch or two, others go down in between the roots up to 15".



I completed the majority of this project early summer before it got hot and I have not noticed any change in the tree during the last 5 months. True, I have not added the fill yet. I have asked several nurseries about what I have been doing and have of course gotten the the whole range of answers from, "Ain't gonna hurt it" to, "Oh yeh, certain death." In hopes of minimizing my impact, I think I will still fill but only half as much as I had previously planned.

After some further thought, I've decided to cut the 4x4's down 8" to only 10" above ground. Since the ground slopes up towards the tree naturally, this should not impact the tree much as I won't be piling new dirt up against the trunk, just adding about 6" above the roots in an 8' diameter circle. Cutting the 4x4's down will also significantly reduce the amount of fill I will need to bring in. To keep the track a little higher, there is talk of putting it on a trestle around the tree now to maintain the 18" above ground. Anybody got a template for a G scale trestle?



Today, my two boys and I laid out our track for a test fit and ran our first train. Why is it that the track never goes together like it’s been drawn? I drew it up in AutoCAD to exact dimensions and for some reason, it’s way off. Regardless, I took some installation liberties and made it fit! Some of my joints aren’t butt to butt and it’s driving me nuts but it will do for now.





Keep in mind that ALL of the track will be raised with fill by another 8-10”. This is just to give me a rough idea of how things will lay out. Since my layout will probably change and evolve, I’m going to use treated 4x4’s for the subroadbed and screw the track to that as opposed to a concrete roadbed.

Like I said, this is a first for me. I've done lots of layouts but never one outside or in G scale. If you see that I'm making other glaring mistakes (such as possibly killing the trees ) please speak up! I've located some free fill and also some free boulders so it seems more exercise will be the next step!

I built it about 1 year ago for a teamtrack on my N scale microlayout.
It was made using barbecue sticks and .030 " styrene sheet
It was weathered with a very diluted wash of India ink.
That's my 1st scratchbuilding project and I had a good time doing it.
The wood planks were made by lightly scribing the 2 styrene sheets with an Xacto blade

Jacques

I'm looking to elevate one cruved track from 0" to about 4" to meet with a bridge over other tracks. I have about 20 feet to work with and have been looking into the Woodland Scenics 2% Incline Set (#ST1410). It's made of white foam in a zig-zag design which allows it to be very flexible (I would assume). The set comes in eight 2' sections and will raise the track to 4" in 16 feet. It looks good on the internet but I was wondering if any of you out there have use one of these incline sets yet. If so, how do you like it? Did it install easily and does it form a smooth grade? They're only about $20 so I thought it might be worth buying rather than messing around with other metahonds I've used in the past, which were a pain in the A$$. Any advice or info would be appreciated.

Thanks,
Kevin

I want to add Sound to some of my HO steam locomotives and I would like to have a nice tiny wire connector between the locomotive and tender so they can be unpluged and boxed to transport. BLI and PCM have a nice little 7 and 8 wire plug with a receptacle that is very small but they are not available that I'm aware of.
I have searched the web with no luck. Does anyone know where I could by these? it would be nice if you could get them with 6 inch leads on either side of the connector like the trailer wiring plugs from the auto parts store.
Thanks
Charlie

Don't know whether this will help anyone or not, but

WHYY Arts is running The Daylight: Most Beautiful Train tonight (1-17-09) at 10 PM Eastern