# Preowned engines, E unit buzzing? Prices?



## ftauss (Sep 18, 2012)

I was looking at a couple of "preowned" Lionel engines, a 2-6-4 and a 4-6-4. Frankly the Hudson was prettier with separate rails etc. But...

Both were rather reluctant to run on his test track. Forward or backward, They would run in reverse but not terribly convincingly. He's the only "factory authorized" dealer in the area and he says he had one of his techs look them over and he's going to have his other tech do a followup.

More disturbing was a fairly hideous buzz, loud enough to be distracting when operating. He says that's the E unit and that all older steamers tend to do that. Someone needs to tell my 2-4-2 because it runs pretty smoothly without a buzz.

I don't want to be a know it all out of the gate but that doesn't sound right to me. 

Also anyone got an idea on what those engines should be valued at, 2-6-4 looks to be all cast with a plain tender. Hudson has separate details and a whistle tender. Given they are returned to proper running condition he's asking $55 for the Adriatic and $130 for the Hudson.

Thanks!


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## Kwikster (Feb 22, 2012)

A couple things:

1) there were several versions of each type so a cab number would help, better yet pics if possible. 

2) The e-unit buzz is really normal for a non-electronic reverse unit. My 2026 pw steamer and my MPC era diesel both have it.

If he says "he had one of his techs look them over" and they don't want to function properly, the servicing is suspect IMHO. Likely need a thorough clean and lube.

Carl


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## klinger (Jan 2, 2011)

Most of my post war steamers have a buzz but run fine. The 2037 has a loud buzz, probably like what you are talking about, but does run fine. If you are going to spend the money, make sure the engine is running up to your standards though. As stated before, the tech's should be able to get it moving smoothly.


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## gunrunnerjohn (Nov 10, 2010)

There are also mods you can make to minimize or eliminate the E-Unit buzz.


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## Big Ed (Jun 16, 2009)

Both were rather reluctant to run on his test track. Forward or backward, They would run in reverse but not terribly convincingly. He's the only "factory authorized" dealer in the area and he says he had one of his techs look them over and he's going to have his other tech do a followup.


Sounds like his "techs" might need a little more training?

I would be hesitant on having work done by them, if they have it apart they should at least service it and clean it up.
It could be that their test track is messed up also? 

E units do buzz but.....More disturbing was a fairly hideous buzz, loud enough to be distracting when operating, Doesn't sound right.
As mentioned some buzz loud, but not enough to give you a headache when operating them.

Post the cab numbers. 
What John mentioned was an electronic e unit can be put in place of the e unit. No sound with them. Right John?


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## ftauss (Sep 18, 2012)

I guess my concern is wouldn't a new (refurbed maybe) unit not buzz if it is set up properly? I watched a video on cleaning E units, it doesn't look as if there is a lot to them. I'm not great with electricity yet, I know what all the bits and pieces are and can solder just not exactly how they all work together yet. The electronic E unit sounds interesting, it was among the first things I thought of but being new to this wasn't sure if they would work with the older analog engines. 

Is there a thread explaining this in more detail? I think I would make that my default solution for the problem, is this a straight swap meaning it fits into the same place on the motor frame? How much would they run, and where would I get one? Is this a mod a factory authorized shop would make or a DYI special?

Yes it worries me that the techs missed it. But the guy looked mortified and actually called the 2nd tech in front of me and asked him to come in Monday to look at the them and that he was working behind the first tech. And he is the only "factory authorized" repair station within driving distance.


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## Big Ed (Jun 16, 2009)

ftauss said:


> I guess my concern is wouldn't a new (refurbed maybe) unit not buzz if it is set up properly? I watched a video on cleaning E units, it doesn't look as if there is a lot to them. I'm not great with electricity yet, I know what all the bits and pieces are and can solder just not exactly how they all work together yet. The electronic E unit sounds interesting, it was among the first things I thought of but being new to this wasn't sure if they would work with the older analog engines.
> 
> Is there a thread explaining this in more detail? I think I would make that my default solution for the problem, is this a straight swap meaning it fits into the same place on the motor frame? How much would they run, and where would I get one? Is this a mod a factory authorized shop would make or a DYI special?
> 
> Yes it worries me that the techs missed it. But the guy looked mortified and actually called the 2nd tech in front of me and asked him to come in Monday to look at the them and that he was working behind the first tech. And he is the only "factory authorized" repair station within driving distance.



I think gunrunner or t man had a thread but I can't find it and have to go right now.

John should be able to help you whenever he logs back on.


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## AG216 (Sep 28, 2011)

you can stop the buzz in the e unit adding a diode bridge.
So basically the e unit will work using dc instead ac.
Some QSI electronic reverse unit are still available for single and double post war motor.
Check this
Talk with Art.
my 2 cents.
Andre.


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## gunrunnerjohn (Nov 10, 2010)

Dallee offers electronic reverse units for AC or DC motors, they might be a good choice if you want to go that way. The Model #400 is probably the one you'd want for an older AC motored locomotive.


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## BigAl56 (Dec 14, 2011)

If you are in to running Postwar, 1945-1969, engines the 'buzz sound is part of the charm.  The buzz is caused by the expansion and contraction of the coil because your AC power is reversing direction 60 times each second.

You can install a bridge rectifier to convert the AC to DC and that will eliminate the buzzing sound. I use bridge rectifiers all the time for crossing gates and semaphore signals to eliminate buzzing. Never installed one on an e-unit though. I kind of like the buzz. It takes me back to when I was 7 years old.


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## plandis (Oct 5, 2011)

areizman said:


> If you are in to running Postwar, 1945-1969, engines the 'buzz sound is part of the charm.  The buzz is caused by the expansion and contraction of the coil because your AC power is reversing direction 60 times each second.
> 
> You can install a bridge rectifier to convert the AC to DC and that will eliminate the buzzing sound. I use bridge rectifiers all the time for crossing gates and semaphore signals to eliminate buzzing. Never installed one on an e-unit though. I kind of like the buzz. It takes me back to when I was 7 years old.


have you ever burned up one of those AC soleniods powering it with DC?


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## BigAl56 (Dec 14, 2011)

None of my Lionel products have shown any ill effects. I had an MTH reproduction semaphore that I did burn out the coil running on DC. MTH must have used a poorer quality insulation on the wire.


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## gunrunnerjohn (Nov 10, 2010)

The only problem I've ever had with DC on an E-unit was that eventually it got magnetized and started sticking. A short shot of AC through the coil fixes that. 

One small issue, the coil will get hotter with DC than AC, since you won't have the inductance of the alternating current. I'd try a single diode on the E-Unit and just see if that's sufficient for it to hold at low voltage.


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## plandis (Oct 5, 2011)

degousing helps with the stickyness as John said but since a coil "Looks" like a very low resistance to DC (almost zero ohms), the proper way to limit the I2R losses (heat) would be to use a small resistance in series with the coil. this would also lead to lowering the gousing of the slug reducing the need to flash it with AC ocasionally.


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## gunrunnerjohn (Nov 10, 2010)

Since you're already converting to DC, I figure the diode will yield half the average current that AC would. It worked for a couple that I did the conversion on, and the E-Unit was totally silent.  I did stick a 220uF cap across them as well.


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## plandis (Oct 5, 2011)

I tried a single 1/2 wave on a crossing gate. darn thing buzzed just as bad. Must be a little C doing the trick.


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## gunrunnerjohn (Nov 10, 2010)

Yep, you need a cap to smooth things for half-wave. It also depends on the specific device, some don't react fast enough to need the cap.


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## BigAl56 (Dec 14, 2011)

Coils are usually not sensitive enough to require a capacitor. If you install a bridge rectifier you are converting to a DC signal but not halving the current. The coil will draw the same current it would if AC. The direction will just be in one direction and will cycle from 0 to your voltage 120 times per second.

Here is a diagram I found that explains it, albeit very techy.

http://www.google.com/imgres?q=rect...165&start=0&ndsp=24&ved=1t:429,r:11,s:0,i:107


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## gunrunnerjohn (Nov 10, 2010)

That's the reason I mentioned installing a simple diode and cap, less current and you don't need a high power dropping resistor that's just heating things up.


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## tjcruiser (Jan 10, 2010)

In the simplistic caveman approach, I tried this on one of my noisy e-units ...

I removed the plunger rod from the solenoid, and cleaned up its surface and the inside cylindrical surface of the solenoid. I then glued a small, round "craft-foam dot" to the top of the plunger, and reassembled everything. The foam "dot" was about 1/16" thick.

My caveman approach improved things significantly ... for this e-unit, at least!

TJ


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## gunrunnerjohn (Nov 10, 2010)

TJ, if you search for E-Unit buzzing, you'll find an old post somewhere where I described doing something similar. I put a rubber bumper at the top of the travel, that also made it a lot quieter. However, I suspect that cure won't work equally for all types, and it involves taking the E-Unit apart.


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## plandis (Oct 5, 2011)

areizman said:


> Coils are usually not sensitive enough to require a capacitor. If you install a bridge rectifier you are converting to a DC signal but not halving the current. The coil will draw the same current it would if AC. The direction will just be in one direction and will cycle from 0 to your voltage 120 times per second.
> 
> Here is a diagram I found that explains it, albeit very techy.
> 
> http://www.google.com/imgres?q=rect...165&start=0&ndsp=24&ved=1t:429,r:11,s:0,i:107


you must have gone to different electronic school than I did. if you put the same voltage of DC on the same coil as is normally powered by AC, the current (DC) Will be much higher. this is due to the inductive reactance (XL)of the coil when AC voltage applied. in the DC scenario, the inductive reactance is essentially zero. only the resistance of the wire winding limits the current flow. Now with the bridge you mention, yes, 120Hz is seen by the coil. this is superimposed on the DC voltage. you would be surprised by how much AC voltage is present at the output of the bridge rectifier.


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## tjcruiser (Jan 10, 2010)

gunrunnerjohn said:


> TJ, if you search for E-Unit buzzing, you'll find an old post somewhere where I described doing something similar. I put a rubber bumper at the top of the travel, that also made it a lot quieter. However, I suspect that cure won't work equally for all types, and it involves taking the E-Unit apart.


Now that you remind me, I think I "stole" the idea from you! Worked nicely on my e-unit!

 :thumbsup:

TJ


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## gunrunnerjohn (Nov 10, 2010)

It worked once for me, never tried it again. I happened to have that E-unit apart anyway, so it wasn't an extra burden to add the bumper.


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## servoguy (Jul 10, 2010)

The E unit buzz increases with the track voltage. If the loco is not well lubed or is pulling a long string of post war cars, the voltage will be high and the E unit will tend to buzz louder. If you listen carefully, the E unit buzz is louder with the loco in neutral than when it is running. The current draw of the loco reduces the voltage to the E unit.

The E unit will draw significantly more current on DC than on AC because on AC there is a component of the impedance that is L*2*pi*60*j where L is the coil inductance, 60 is the frequency in Hz, and j is square root of (-1). The impedance due to the coil inductance is orthogonal to the impedance due to the wire resistance so the two add as the sqrt of the sum of the squares.


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## BigAl56 (Dec 14, 2011)

I disagree. The current draw of the coil is the same weather ac or full wave rectified DC. The coil will not be running on true DC but one directional AC. Because the coil is being powered by a full wave rectified sign wave the equation above applies in both scenarios. If the coil was powered off of true non pulsing DC then the current draw is higher. I ran through this calculation 40 years ago when I was an engineer at Bally Pinball.


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## plandis (Oct 5, 2011)

there is physics and then there is bally physics!

.. so riddle me this:

what do you thin would happen to the current on an AC powered solenoid when you pull out the slug (or armature)? the same test on DC coil?

try it... you'll like it!


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## gunrunnerjohn (Nov 10, 2010)

I'd sure like to see how you came up with the same current for full wave rectified DC and AC from the same source.

Please be specific as to the calculations that allow you to arrive at this conclusion.

"One direction AC"? Is that a new term, because I sure have never heard of it! I agree that there'll be an AC component, but you still have DC. AC is when the waveform crosses zero, not when it changes amplitude, that's called ripple.


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## plandis (Oct 5, 2011)

I think he is referring to the bridge rectified waveform above the zero line. if that ripple were true sinusoidal (it's not), the average voltage would still be above the zero crossing -a dc component. average current would be higher due to the DC component -I think.

never could get those flippers to hit just right!!!


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## gunrunnerjohn (Nov 10, 2010)

Obviously, since a full wave rectified waveform is all above the zero line, the DC component is pretty high.  I'm going to take an old solenoid coil and do a simple test of AC and full wave DC, nothing like an empirical test.


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## servoguy (Jul 10, 2010)

Do you have a true RMS meter?


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## BigAl56 (Dec 14, 2011)

> The current draw of the coil is the same weather ac or full wave rectified DC


So why all the discussion about physics? And who said anything about pulling out an armature?

What I attempted to say is the current draw of a coil is the same regardless of the direction of current flow. If I connect ac from my Lionel transformer to the coil of the e-unit the current first flows through the coil in a positive direction. It increases gradually as the voltage changes from zero to the set V level then decreases to zero. The current then flows in reverse as the voltage changes to -V then decreasing again as the voltage returns to zero. This sequence occurs 60 times per second in North America. The average current through the coil is .707V/impedance. 

So now lets install a bridge rectifier and connect the e-unit coil to the dc output of the bridge. For convenience lets ignore the .7v drop of the diodes in the bridge. The voltage to the coil increases to +V then drops down to zero. However since we are now full wave rectifying the ac with the bridge the voltage increase again to +V, not in a reverse direction as it did in the first example. The direction being the same in both parts of the cycle will not effect the current draw of the coil. The formula .707V/impedance is the same with 120 positive pulses as it would be with 60 positive and 60 negative.

So how does all that differ from DC? If I were using an HO transformer, the output of that is closer to a pure DC. While there is some ripple for the most part there is no ramp up and down to +-V 120 times a second. The voltage stays relative constant at +V the entire time. Therefore we do not have to do a .707v reduction to determine average voltage and current.

So getting back to the buzz sound, running on DC eliminates the buzz because the coil is not expanding and contracting from the heat of the coil reversing 60 times a second. So while I do not save on amps if I Reverse the current flow I do save on noise and power which is why our pinball machines at Bally filliped and bumped much better on full wave DC than they did on traditional ac but I did not have to change the fuse value when I switched them to DC.


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## servoguy (Jul 10, 2010)

I doubt the noise is coming from the coil. More likely it is coming from the plunger as putting a small piece of rubber on the end of the plunger quiets it down.

If you really want to calculate the current through the inductor, you must expand the half wave rectified AC wave into a Fourier series and then calculate the current at each of the terms of the Fourier series. Summing up the resulting series of currents will then give the total current. The currents do not ad as scalars, but as vectors.

The DC term of the Fourier series will be the RMS of the AC wave form, or 0.707 of the peak of the AC wave form. To calculate the current for this DC term, it is only necessary to divide it by the coil resistance. For the other terms of the Fourier series, it is necessary to compute the coil impedance at the frequency of each term of the series. 

The coil inductance will be smaller with the plunger removed.


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## BigAl56 (Dec 14, 2011)

> If you really want to calculate the current through the inductor, you must expand the half wave rectified AC wave into a Fourier series and then calculate the current at each of the terms of the Fourier series. Summing up the resulting series of currents will then give the total current. The currents do not ad as scalars, but as vectors.


Whoa! Way too much math and physics for today!!!


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## gunrunnerjohn (Nov 10, 2010)

Right Bruce, and when you got done with all that math, I'll bet the full wave rectified DC draws more current through the coil.


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## servoguy (Jul 10, 2010)

I am sure it will. It is much easier to make a measurement.


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## gunrunnerjohn (Nov 10, 2010)

The test results are in. All measurements made with a Fluke 8012A True RMS meter for AC and the same meter for DC.

Running my 1033 at full bore (open circuit voltage 16.1 volts AC, I connected it to a Lionel two stage E-Unit. The reading for AC was .41 amps. I then inserted a bridge rectifier into the mix and measured the DC current, it was .62 amps. I also measured the AC input to the bridge rectifier, it was .63 amps, probably measurement error or resistance in the leads.

I think the myth that DC won't dissipate any more power than AC has been busted.


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## Big Ed (Jun 16, 2009)

I am sure glad you guys know what your talking about.

Sounds good to me.:dunno:


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## BigAl56 (Dec 14, 2011)

OK, I concede the point. I'm not going to deny the numbers, they are what they are but I do not comprehend how full wave DC draws more current than ac. Mathematically it should be the same.


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## gunrunnerjohn (Nov 10, 2010)

Not really. The current reversal of true AC has a much larger effect than the pulsating DC on the core. Much of the inductance is due to the changing of the magnetic field of the plunger. There is a higher apparent resistance with true AC.


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## plandis (Oct 5, 2011)

areizman said:


> OK, I concede the point. I'm not going to deny the numbers, they are what they are but I do not comprehend how full wave DC draws more current than ac. Mathematically it should be the same.


the reason it doesn't is mathematically, it is not the same!


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## plandis (Oct 5, 2011)

also, the .707 ratio ONLY applies to true sine wave. remember that the DC equivalent of the actual "work" produced buy an AC source is 63% or .63 peak. not .707! That figure is the "root-mean-squared (RMS) which is essentially the area under the curve -on a true sine wave only. So-when you flip the two halves over onto one side of the zero line, you no longer have a true sine wave above the zero crossing line. those two positive humps, when you look back at that google diagram posted, don't even resemble a sine wave.


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## gunrunnerjohn (Nov 10, 2010)

Correct, the bottom line is there is much less AC component, and it never reverses polarity. All of these factors increase the current draw through the coil. 

I decided not to tax my brain, 5 minutes on the bench was all I needed to verify it.


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## plandis (Oct 5, 2011)

Amen. I wish I had bench set up. someday I will.


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## gunrunnerjohn (Nov 10, 2010)

My bench is about 30 years old, I build it out of some pre-fab workbench legs and then just expanded from there. It's like an old pair of shoes, comfortable!


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## plandis (Oct 5, 2011)

gunrunnerjohn said:


> My bench is about 30 years old, I build it out of some pre-fab workbench legs and then just expanded from there. It's like an old pair of shoes, comfortable!


you've shown this before. I especially like the weenie mobile!


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## gunrunnerjohn (Nov 10, 2010)

The Weinermobile is a work in progress, it's going to be a TMCC controlled motorized unit with an on-demand singing of the Oscar Meyer Weiner song. I'm just waiting on the last parts, I'm getting it ready for the next modular show. I think kids young and old will identify with it. 

I'll have a thread on the construction when I get it wrapped up.


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## ftauss (Sep 18, 2012)

*That buzzing E unit was in a ...*

Baby Hudson # 685. It looks very nice, the tech said there was a bad solder joint casuing the problem. Seems to run good now and the buzzing is now tolerable. I did buy a Dallee electronic E unit, I may just put it up for now.

It has the whistle which my girl is gonna love. It's a little flaky but very loud and I suspect it's a solder issue, too. If it isn't I know were to ask. 

All in it was roughly $130.


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## tjcruiser (Jan 10, 2010)

gunrunnerjohn said:


> The Weinermobile is a work in progress ... I'll have a thread on the construction when I get it wrapped up.


With plenty of mustard, ketchup, and relish on hand! :thumbsup:


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## gunrunnerjohn (Nov 10, 2010)

Well, we will be serving hot dogs...


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## plandis (Oct 5, 2011)

gunrunnerjohn said:


> The Weinermobile is a work in progress, it's going to be a TMCC controlled motorized unit with an on-demand singing of the Oscar Meyer Weiner song. I'm just waiting on the last parts, I'm getting it ready for the next modular show. I think kids young and old will identify with it.
> 
> I'll have a thread on the construction when I get it wrapped up.


very cool. I've seen the real McCoy a few times out here. that will be fun to see when you get it done!!


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## plandis (Oct 5, 2011)

gunrunnerjohn said:


> Well, we will be serving hot dogs...


what brand I wonder...


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