Recently a friend gifted me a Lionel 6-18018 (Vintage 1992, #4501, 2-8-2 Southern RR Mikado) Based on provided instructions, This Locomotive and Tender utilizes a Lionel 5906 controller (included in the box) to activate the Bell.
The Lionel 6-18018 (Vintage 1992, #4501 is of the Lionel LLC - Richard Kughn/Neil Young era and is a conventionally controlled Locomotive (i.e., variable voltage Transformer).
I have a KW Transformer that is deemed compatible with the Lionel 5906 Sound activation Button for sounding the Bell.
I have attached, for reference, selected sections of the O&M Instructions included with the #4501 Mikado, these provide wiring detail for adding the 5906 Sound Activation Button. (Figure 5 for “AC Transformers with built-in Whistle Actuator”.)
It is my understanding, based on previous Forum “Posts”:
- Activating the Whistle control on the KW “adds a negative DC bias to the center rail, the sound activation the button (5906) adds a positive DC bias to the center rail.”
Based on the O&M wiring instructions (attached) I added the 5906 Button to the KW circuit and, using a Fluke 115 Digital VOM, set to DC, verified the expected DC bias polarity. (The Red test lead of the Fluke connected to the center rail and Black lead connected to the outer (common) rail. The result:
- As expected, Activating the Whistle control on the KW “adds a negative DC bias to the center rail, the sound activation the button (5906) adds a positive DC bias to the center rail.
After the above verifications, I placed the Locomotive and Tender on the track. However, I did not get the expected results.
- Results: KW activates the bell and the 5906 button activates the bell. No whistle activation.
I removed the 5906 Button from the circuit and connected only the KW to the track and verified again with the Fluke 115 connected to the center and outside rails that activating the whistle control on the KW adds a negative DC bias to the center rail. I placed the Locomotive and Tender on the track.
- Results: Activating the Whistle control sounds the Bell (versus the whistle).
Without going into detail, I tried various wiring configurations (eg., reverse wiring of the 5906 button etc.) but never achieving the expected results. (If interested, I can also post those wiring configurations and results - although never the desired result.)
The only and very unconventional configuration that achieved the desired result was wiring the 5906 Button in the circuit as instructed and reversing the “A” and “U” terminations at the KW. This in effect reversed the anode and cathode orientation of the diode in the KW and the diodes in the 5906. However, it connects “A” (power) to the common “outside” rails and “U” (common) to the “center” rails.
(At one time I found a schematic of the 5906 Posted on the OGR Forum. However, I have not been successful in recent searches to find this Posting/circuit.)
I did find a “Posting” that states “The Sound Activation Button uses six diodes in one direction and one diode in the other direction.
As a “double check” I verified the KW diode orientation based on the Lionel Service Manual by visual inspection and manually tracing wiring. For reference, I have attached page 1 of the Lionel KW Service Manual that I used which provides a schematic of the KW whistle control when activated.
(As a sidebar, several years ago I replaced the original KW rectifier with a NTE5994 Stud mount rectifier rated 600 V max and 40 A max – overkill I know.) Based on my “double check”, the diode orientation is per the KW Service Manual.
Out of curiosity, I unboxed my original Lionel 671 Turbine and Tender. (Santa brought the 671 and KW at the same time.) The whistle operated as expected with A to center rail and U to outside rail. Subsequently, I reversed the A/U connections at the KW. The whistle of the 671 sounded as expected (i.e., the 671 was not “A” and “U” orientation selective as is the 4501 Mikado).
It appears the 4501 Mikado of the Lionel LLC - Richard Kughn/Neil Young era electronic design is sensitive to DC positive/negative orientation but are not consistent with previous Lionel Transformers.
I have another steam locomotive of the Lionel-FunDimension era that has a motor driven whistle. I modified the wiring (switched wires) in the tender to make it compatible with the KW (i.e., It would not respond to the KW unless I swapped A and U Connections at the track. Therefore, to keep the KW and Service Manual schematic consistent, I modified the wiring in the tender).
I am open to more test configurations if desired. Please let me know.
My goal is to understand and resolve this puzzle electrically and technically.
How do I overcome the seemingly puzzled wiring related to the 4501 Mikado???
Thanks for your support.
