Back in the 1970’s when MPC first came out with whistles (8206 Steamer),
and horns (mostly in dummy GP-20 units), they required the use of a special
activator botton that rarely worked correctly, and often burned itself out.
I have since had a new sound unit put in my 8206, but I have a group of these dummy GP units that have these horn units in them.
any ideas out there on how to get these horn units to work???
Ken
Every Lionel that I’ve known of has used a DC offset to activate the horn or whistle. This is what postwar transformers did, and what modern transformers still do. Lionel does make a control button for transformers that don’t have any sort of horn or whistle control built in.
My best suggestion is for you to try this. If your horn or whistle still doesn’t work, reverse the wires to the track and try again.
My modern power - CAB-1 & Powermasters in Conventional, RS-1 & MW transformers, also MRC 027 packs, all activate the MPC sounds quite well below about 80/85% power. Above this, it seems the DC signal weakens and the sounds fade off some.
I’ll have to try it on the new CW-80 currently powering the Polar Express!
The sound of the MPC Geep horns is quite nostalgic to me(I was only about 11 at the time) - the LI & SF GP-20’s for example. We already had lots of postwar equipment in 1973/1974, and this was the “new” sound system on the block and we used it a lot on the “Carpet Centrals” of the day. I never really cared for the MPC electronic steam whistle that I first heard on the 8206 NYC baby Hudson(loved the Baldwin Discs, though!). By the time we took delivery of the very similar 8603 C&O baby Hudson, the whistle feature was gone, & it was back to S-O-S only.
We used older 250 watt ZW’s for the MPC horns back then, they worked fairly well too, using the original circuitry only. Our activation buttons gave up quite early due to the strings of postwar cars we loaded up behind the Geeps.
Carefully seperating the controller halves, I found the diodes to be woefully inadequate for O gauge loads, even on an intermittent basis. I think they were about 1/2 amp or so. The other issue was the copper contact strips that made up the make-break switch action were too easily distorted with repeated firm press