# Question re AF Turnouts



## BrokeCurmudgeon (Feb 8, 2016)

A question for all those gurus of all things American Flyer. What, if any, is the difference between a 720 and a 720A Turnout? I know that the 720A was a later release after the 5 digit numbering scheme was introduced. Are there any internal or operational differences? Thanks


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## cramden (Oct 13, 2015)

Operationally there isn't any difference between the 720 and the 720A. The difference is in the bases, the 720 base conforms to the tracks whereas the 720A is a rectangle base. The other difference is the lamp housing was changed in the way the red/green colors are displayed inside the housing. If I remember the 720A uses a simpler red/green set-up to display the switch position vs. the 720. Both have the two train switch for multi-train use.


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## mopac (Feb 24, 2011)

Broke, isn't it great to have people here that know this AF stuff? Very helpful.


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## flyernut (Oct 31, 2010)

cramden said:


> Operationally there isn't any difference between the 720 and the 720A. The difference is in the bases, the 720 base conforms to the tracks whereas the 720A is a rectangle base. The other difference is the lamp housing was changed in the way the red/green colors are displayed inside the housing. If I remember the 720A uses a simpler red/green set-up to display the switch position vs. the 720. Both have the two train switch for multi-train use.


I'm working on a pair of turn-outs that were made in 55, and for the life of me, when in regular train operation, the siding is dead, while the straight is powered. Looking at the underside, the switch is different from earlier models of the 720A. I wonder if Gilbert decided to make that siding dead in either regular or 2 train operation. There's just no way power can get to the siding as there's no contact for it.. Both turn-outs are the same.. Maybe I'm missing something??


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## cramden (Oct 13, 2015)

I'm trying to remember where I read something about odd ball 720A switches. I believe it had to do with the reverse loop problem but I can't be sure. There was something about if you looked at the rails there was an extra cut in the track. Let me see if I can come up with something definite. Look at the topside of the switch with a "normal" one to compare. What is different underneath? No switch for two train operation? Maybe post a pic if possible.


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## cramden (Oct 13, 2015)

Is it possible the contacts were removed at some point?


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## flyernut (Oct 31, 2010)

cramden said:


> Is it possible the contacts were removed at some point?


They were never there, by the looks of them. I'll get a picture up soon, comparing the 2.


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## flyernut (Oct 31, 2010)

As promised,here's the picture of the 2 turn-outs. The one on top works as it should, but the one on the bottom when switched to straight in regular operation the siding will be dead. The wiring on the bottom if you study it, will do the same thing as the one on top, with less wiring. Can't figure this one out, I'll have to check continuity through-out.


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## mopac (Feb 24, 2011)

I can't help. I do not know the turnouts much. But you are saying in regular operation
straight and siding should always be live?


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## flyernut (Oct 31, 2010)

mopac said:


> I can't help. I do not know the turnouts much. But you are saying in regular operation
> straight and siding should always be live?


Most of my turn-outs will stay live in both turn and straight. However, I do have some turn-outs that will deaden the siding in regular operation. This may be a design change in later turn-outs.


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## cramden (Oct 13, 2015)

That's sure strange, but it looks factory. I'm still looking to find that info I read about. I could be wrong on the extra rail gap but there are later switches that have an extra tie molded in the plastic. Most have five but there are a small reported number that had an extra tie. Have you tried applying power and verifying that with normal operation you don't have power to both tracks?


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## BrokeCurmudgeon (Feb 8, 2016)

flyernut said:


> Most of my turn-outs will stay live in both turn and straight. However, I do have some turn-outs that will deaden the siding in regular operation. This may be a design change in later turn-outs.


I like the spur track to be dead until I switch it so that I can park a second locomotive on the spur in a “dead” state while running another on the main line. Of course this is only on my test track layout. On a proper layout my preference would be different.:laugh:


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## mopac (Feb 24, 2011)

Broke, I agree. I would want the siding dead unless turnout is turned to siding. But that is what the "2 train" switch is for. If I am right when bell is to "2 train" siding is dead unless
turnout is set for siding and straight is dead when turnout is set to siding. LOL, something like that.

I found out if you don't have the lock-on on the correct side of turnout, it doesn't work right.


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## BrokeCurmudgeon (Feb 8, 2016)

mopac said:


> Broke, I agree. I would want the siding dead unless turnout is turned to siding. But that is what the "2 train" switch is for. If I am right when bell is to "2 train" siding is dead unless
> turnout is set for siding and straight is dead when turnout is set to siding. LOL, something like that.
> 
> I found out if you don't have the lock-on on the correct side of turnout, it doesn't work right.


Sorry for being so ignorant but what is a 2 train switch?:smilie_auslachen:


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## mopac (Feb 24, 2011)

Its that bell looking switch on top of your turnout. Its a slide switch. Get your your
magnifier glass out. One end of slide says regular operation and the other side of slide
says 2 train.


Its on manual or remote turnouts.

Bell set to 2 train, power is routed to which direction the turnout is set to and the other route is dead.


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## BrokeCurmudgeon (Feb 8, 2016)

mopac said:


> Its that bell looking switch on top of your turnout. Its a slide switch. Get your your
> magnifier glass out. One end of slide says regular operation and the other side of slide
> says 2 train.
> 
> ...


 Of course! I knew that. I was lost thinking about controlling multiable trains in DCC. It is tough getting old.....:hah:


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## cramden (Oct 13, 2015)

mopac said:


> Broke, I agree. I would want the siding dead unless turnout is turned to siding. But that is what the "2 train" switch is for. If I am right when bell is to "2 train" siding is dead unless
> turnout is set for siding and straight is dead when turnout is set to siding. LOL, something like that.
> 
> I found out if you don't have the lock-on on the correct side of turnout, it doesn't work right.[/QU
> You got it mopac, and yes the lock on has to be on the track on the point side of the switch or you defeat the 2 train operation.


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## mopac (Feb 24, 2011)

cramden, I was perplexed on that till I figured out why my straight route was never dead. 
LOL.

Broke, maybe I didn't use correct terms. Didn't mean to throw you.


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## cramden (Oct 13, 2015)

Another thing to remember about the 2 train setting is unless the switch is being used for a siding or a spur you must set all the switches to 2 train. So 1 pair has both set to reg. or 2 train and so on with more pairs, otherwise your passing track will still get power.


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## AmFlyer (Mar 16, 2012)

A couple of things to add. The controller box for the 1946 720 turnouts did not have a spring "return to center" feature for the controller levers.
The 1955 turnouts may be part of a small run of turnouts specially made for reverse loop use. I recall a presentation on this some years ago by a Gilbert collector. I unfortunately do not recall the differences. I would think all that would be needed is a gap in the rails to eliminate the need for fiber pins but this turnout could have been part of that run.


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## AmFlyer (Mar 16, 2012)

The 2 Train feature of the turnouts is more effective when using 2 transformers if the Base Posts are not connected together. When I started using the the MRC O-27 DualPower in place of my 19B's I had to add fiber pins at 2 locations in the track plan. This was because the DualPower has a common Base Post for both throttles.


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## mopac (Feb 24, 2011)

AmFlyer, I have seen on ebay a control unit for reverse loop. Somewhere in the $40
some range.


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## AmFlyer (Mar 16, 2012)

Is it the Gilbert 695 Reverse Loop kit or a new product?


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## mopac (Feb 24, 2011)

Only seen it once and I think it was Gilbert.

I am not a fan of 3 rail track but reverse loops are no problem with it. I hear.


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## AmFlyer (Mar 16, 2012)

If a layout has reverse loops it can be a lot more interesting to operate. Here is a picture of a modern reverse loop controller for AC operation. I have 4 of these on my layout. With these the operator needs do nothing, one cannot even tell the train went through a reverse loop.


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## mopac (Feb 24, 2011)

I have a reverse loop controller for my HO with DCC. It is a board also and you are
correct, operator does nothing and you can not tell polarity has been changed.

I only have one but I can see me getting more. Mine are only 20 something each or you
can get a board that will do 4 and its about 50.

I have the 4 board but it also can be used as power distribution for 4 sections with circuit breakers.
That's what I use it for.

If one circuit breaker blows the other 3 keep running. Easier to find problem area.


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## AmFlyer (Mar 16, 2012)

The DCC boards are similar, work the same and are less expensive. The market for DCC is much larger than for the AC boards. The large heat sink is visible, I recall the AC boards are rated for 10A. About $45.


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## mopac (Feb 24, 2011)

I saw that large heat sink. My new flyonel UP diesel has 2 fairly large ceramic heat
sinks mounted on top of loco frame. They do get warm. I guess that is to dissipate
heat from changing AC to DC for the can motors. The shell has some kind of chrome
tape on underside of shell over the heat sinks so that it doesn't melt the shell. Shell
is very close to the heat sinks. Hope the tape works.


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## BrokeCurmudgeon (Feb 8, 2016)

A good description on making reverse loops work. http://www.portlines.com/Adobe/AF RVS LOOP HANDBOOK.pdf


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## mopac (Feb 24, 2011)

That is real good Broke. I need to save that. An automatic reverser is the way to go.
Otherwise you should stop engine in the reverse section and start throwing switches.
It can be done manually but a real pain to me.


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## BrokeCurmudgeon (Feb 8, 2016)

After thinking about I think that I will place a reverse look in my test track that is rapidly becoming a real AF layout.:hah::hah::hah:


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## AmFlyer (Mar 16, 2012)

That link is the best I have seen describing 2 rail reverse loops. A long time ago I earned a degree in EE so I am not put off by electronic complexity. However I still spent the $45 to get the Auto Reverser boards, the layout operates sooo much better with them, especially with multiple reverse loops. Remember if a turntable is incorporated it is also a reverse loop.
Broke, I think you will like the layout better with the reverse loop. The only problem is you will soon want a second one so the trains do not need to be backed through the single reverse loop.


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## mopac (Feb 24, 2011)

I had not thought about a reverse loop on my future layout. Maybe I should. Its a great way to turn a train. Like you said you should incorporate 2 for continuous running.

Broke, 2 loops would take up a lot of real estate.

You really would not need 2. A reverse loop could be tied to an oval.


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## BrokeCurmudgeon (Feb 8, 2016)

This is my problem!:laugh: It all started out by buying a 21160 on line. Not much of a locomotive and so so as a display on a shelf. Now after buying 7 more various AF locomotives to rebuild, I needed a test track. But wait! Now I need a good layout with Grargrave tracks and Turnouts. My wife is losing what patience that she had. She said it was the trains or her. I will surely miss her. :smokin:


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## mopac (Feb 24, 2011)

Broke, you are too funny. No wife but I went overboard this year and I am backing myself off. I do have other projects around the house I need to do and I have let them go.
After the projects are done I will return to running trains. I need to get these projects done so if I die the kids can sell the house for the most money. Fun is over for awhile.


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## AmFlyer (Mar 16, 2012)

AF reverse loops do take up a lot of real estate. If incorporating 2 it is best to stack them. Of course then the grade between them takes up a lot of space. Alternatively a long oval with an "X" in the middle works as two reverse loops.
For HO and N there is a lot of DCC compatible electronics like the Reverse loop controller combined with 4 Block Power Controllers on one board for $20. To get the same in "S" it cost $45 for the A/C RLC, $100 for the Lionel LCS BPC2, $30 for the interconnecting cable. Then there is the wireless interface, oh well, enough.


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## BrokeCurmudgeon (Feb 8, 2016)

AmFlyer said:


> AF reverse loops do take up a lot of real estate. If incorporating 2 it is best to stack them. Of course then the grade between them takes up a lot of space. Alternatively a long oval with an "X" in the middle works as two reverse loops.
> For HO and N there is a lot of DCC compatible electronics like the Reverse loop controller combined with 4 Block Power Controllers on one board for $20. To get the same in "S" it cost $45 for the A/C RLC, $100 for the Lionel LCS BPC2, $30 for the interconnecting cable. Then there is the wireless interface, oh well, enough.


AmFlyer, I truly enjoy your posts! It is not hard to tell that you are an EE. Way back in 1964-65, Uncle Sam and the USAF gave me to about one year of electronics schooling. It started my career in the Telecommunications industry. I only wish that I could remember all the theory that they pounded into my scull! Anyway, I like the way you attack the problems in this hobby!:appl:


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## AmFlyer (Mar 16, 2012)

To be clear, I was educated as an EE, I do not make a living in that field. That is likely to the world's greater good.
Using GarGraves track opens up a lot of possibilities for the layout. If it is flex track it is also a lot more time consuming to get it right.


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## cramden (Oct 13, 2015)

I got curious so went checking some of my switches. What I found was one with shiny metal plates and one with black painted plates. The black plate one is dated 5-53 and has the same set up as the one flyernut posted.






The shiny plate one is dated 1-50 and has the double brass tab. I connected power to the switch track at the point end and observed the following, On reg. setting on the switch with one brass tab there is power on the straight and power to both tracks when switched to the diverging track. On two train setting there is power only to the switched track with the other track dead. The other switch with the two brass tab set up has the same results when power is applied as the first switch. Maybe the single tab was a cost saving on later production switches. Another way to tell the difference is looking at the top of the switch. The single brass strip has 1 rivet between the "V" near the button whereas the two brass tab switch has a rivet between each set of tracks instead of near the button. What looks like it won't work actually does. It would be interesting if anyone gets different results.


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