Fixing an old lionel #66 whistle controller

Lots of luck. If you want to control B & C terminals on

the ZW, it would be easier to build a circuit using switches and

diodes for the horn.The old 167 controller will do the same

thing and Greenberg's book does have drawing.

The #66 does have a classic look but it is sure dated with 3 buttons

and 4 terminals.

Pa, that's what drew it to me, was the look...I don't know why.

I asked the same question a while back and didn't get much that was useful - most of the responses related to the 167 controller, which uses a different rectifier. Here's the link:

https://ogrforum.com/d...nt/12129988001929078

Yup, saw that thread. I figured the rectifier disc would be the same as my ZWs but it's not...perhaps the simple principle is the same. Oh, I paid $5 for mine...cheap.
I tried it the other day whn my son and I were playing trains and it would reverse the trains no problem, but nothing else....probably a bad rec, but I'm going to pop the top again and double check the contacts.

BTW- I like how they marked the 2 inner terminals on yours red for reference...nice{if it's correct}.

I looked in the Lionel service manual the last time the subject of repairing external whistle controllers came up.

According to Lionel, it is common for the choke coil to develop a short. The choke creates a voltage drop, I don't think the whistle control can work with a bad one.
I think later external whistle controls had a circuit breaker added to protect the choke.

http://pictures.olsenstoy.com/searchcd31.htm?itm=705

CW

Thanks for that info - I'll check the choke coil, if the #66 has one (the link relates to the 167; I'll have to look to see if the 66 has the same type of choke coil). Do you happen to know the correct resistance value for that coil? I'm not sure if I have a meter that will actually measure impedance as opposed to resistance. I also see that the standard coil on the 167 produces an excessive voltage drop with a twin-motor locomotive, and they recommend removing laminations from the coil if you're going to use it with a twin-motor engine. This is getting complicated. I can't remember what engines I used to test the #66. I'm pretty sure one was a Standard Gauge steamer with an air whistle and the other was a diesel with can motors. 

And I'm very glad to see that Olsen's has their website problem sorted out and the diagrams are back on line. 

Burlington Route:

 Actually, Lionel didn't paint the terminals red - I did. I keep a bottle of red nail polish handy whenever I'm doing wiring. All my center rail drop wires under the layout get a dab, as do the hot terminals of accessories, LTC illuminated lockons, etc. It helps me avoid mistakes. 

I've had #66 whistle controls apart. As I recall, there is a choke in there. By nature, a choke will have very little DC resistance, so I don't think you can check the choke with a standard VOM. I will leave that discussion to someone with formal schooling in this area.

Any diode used to fix a ZW should work in the #66.The choke is used to compensate

for the higher voltage from the transformer when the horn button is not operated and

does not effect operation unless open. The 2 resistors should be about 1-5 ohms each. If you measure the resistance between the 2 outside terminals, there should

be zero ohms. If you press either horn button, there should be about 1 ohm with the moving train button and twice the resistance with the non moving train button.

If all this checks out, all that is left is the diode.

The circuit shown on Pg 388 top right of Greenberg's book should

be the same as the #66 with the addition of a second resistor in

series with the resistor shown in the drawing and shorted out by

the right hand button on thr #66.

The #66 is like the #167 without the extra contacts that

put rectified DC on the track to pull up the whistle relay.

The #66 controller has another button to connect a 10 ohm

resister across the track to increase the DC offset to help

the whistle work when the train is not running. The #66, like

the #167, was designed to work with the Z and R transformers

that have a higher output voltage. Even replacing the disc rectifer

with a diode will not correct the problems of electronic horns working

with the low load current drawn by can motors used today.