hello everyone, I’m looking at buying a PFM sound system and was wondering if an LTM module is required for every locomotive you install a sound unit in.
Thanks
Andrew
Isn’t PFM sound a stand alone unit, with speakers around the layout to provide the sound? No speakers in the engines? It’s really old tech, used cassette tapes for individual sounds. I could be wrong, but I haven’t heard of them for quite a while. A friend of mine had one quite some time ago.
Bob Boudreau
I’m not sure what an ‘LTM’ modue is, but the PFM sound system requires speakers installed in engines or cars, since the PFM sound is picked up via the rails.
It is a series of tape loops fed into an amplifier that superimposes sound onto the rails.
Speakers must have bi polar capacitors (110 mfd or 2-220mfd) to block the DCand a power pak capable of pure DC (to not produce hum).
PBL made a Solid State version for $900 but was discontinued.
http://www.p-b-l.com/PBL2002/main-ns.html
Yes each engine requires an LTM and a tender speaker. There is an add on reverb unit and a printed circuit card that directs the bass to an under layout woofer as bass is non directional. Crank that baby up and people will be jumping out of their chairs upstairs! Believe me I know. You also need to paint the back of a driver and use a template to clear sections to create the chuff. Basically a capacitor loads and discharges each time an insulated area is followed by contact with the driver. Becasue it superimposes a high ffequensy sound and an ac signal for the capacitor it can’t be used with electronic signal circuits or DCC. The 3 continuous loop tapes have four sounds on each. It has been a while since I have run mine but they are a free swinging bell and an air ringer, coupling, low wheel speed, medium and high, single and crosscompound air compressors, generator, blower and a couple of others. The unit has five whsitle switchs for low off and high and a rotating knob to raise the pitch through five steps. Basically any whsitle that you have a sound of can be reproduced. you can also vary the steam sound of the whistle. Anyone who has heard one for the first time usually heads for a window to watch the train go by. The console also has a doppler effect knob and a few other goodies. Nothing in DCC has the quantity or quality of the choices at the average cost per engine since most of it is actual recordings of a bunch of choices. Cost per engine is les than fifteen dollars in todays market.
Yes, the LTM needs to be installed in each engine if you want that engine to chuff, ring the bell and whistle. PFM sold individual components such as the wiper, capicitor and coil so you could build you own LTM. I still have one of the PFM sound units along with several of the components, but it does not offer the same advantages as DCC sound does now.
[#ditto] For that matter you don’t even need the PFM parts. You can get the same capacitor, choke from any electronic store. You can make with wiper with any springy metal. I’ve got one locomotive that uses a paperclip for the wiper. Or if you use an axle cam the wiper that comes with it will work much better anyway.
But it still sounds better… I had three but just sold the old yuck one (mark II) on ebay. I am real hopeful for the next DCC sound encarnation (24 bit dual or quad sampling). There were just two mini-sounds on ebay last week.