My Father'n Law and I are working on his large HO scale basement layout. For his steam engines on the main lines he is using a PFM-II. We have encountered a problem. When there are more than two blocks active at once the sound no longer works. The engine will still function, just no sound. This is a challenge because we have to constantly turn blocks on and off so that only two blocks are active as any steam engine travels on the mains. Is there anyone out there who has experience with the PFM-I & II and encountered a problem like this? If so, how did you solve it. BTW.... DCC is not an option for us because the layout is 80% finished and with over 40 engines in our library we simply cannot afford all the decoders and change out the old high-draw electric motors (most of our engines are 10+ years old).
Chris, I suspect many, such as myself have read this thread but haven't replied because we haven't had the experience you are talking about. I know the one thought I had is that going more than two blocks shouldn't affect it, unless something is drawing power from the other blocks. What I suggest is that you post this question in several different forums. I have done this when I have known I was asking an obscure question. Even posting to 4 or 5 different forums concerning one thread brought only two responses in all, but if they are the right two.... hey... what more can you ask for. You might include in your post a request for a forum some one can suggest to you where you are likely to receive an answer. I am think Yahoo! Groups here, where an electronic rail roading group might exist and I don't know about it. [ 07. January 2003, 18:37: Message edited by: rsn48 ]
I don't know of a yahoo group for PFM. Come to think of it, I havn't seem much on line regarding PFM at all. When questions do come up, invarable there is a reply like "Why bother, get DCC it's better" and that gets old quick doesn't it? So, anyone know a good on-line resource for PFM questions?
Here are two responses I received from people concerning your problem in another forum; hope one of them is helpful: Rick; The completion status of a layout has nothing to do with the ability to use DCC, it can be wired just like another throttle into a block control system. So if the cab control uses DPDT switches to select the throttle, cab A can be the PFM unit, and cab B can be DCC. Many clubs did this to transition to DCC. The PFM systems are museum pieces. Over the years, there have been several automatic block control systems in the magazines, but they would cost more to implement that DCC, including 40 decoders and 40 DSX sound decoders. The Digitrax DH163 series of decoders, which are rated at 1.5A continuous, and 2.0 amps peak, will not have any problem with almost any HO locomotive. Tony's is a good source for information, and decent prices, but shipping to BC may not be practical. http://www.dcctrains.com/index.html Robert Hundman, Editor / Publisher of Mainline Modeler may be able to direct you to someone who can assist, as he used to be involved with PFM. http://www.mainlinemodeler.com/ Good luck. Nigel Don Gibson this is a good one. Soundtraxx and a fellow in Eureka (PBL?) make Analogue Throttles (with sound via the tracks) which are an updated version of the PFM system. They are Digitized sound vs. Tape loops. They are magnificent - also pricey ... but then, so was the PFM. Basically, the AC sound waves are imposed on the track voltage DC, and picked up from the rails by a loudspeaker with a small capacitor blocking the 12v. DC. It sounds to me like the 'Sound' is being weakened by either resistance in the block system or weak amplifier output to the 'throttle' section, or both. All you can do is check ALL your throttle and block connections for 'cold solder' joints by re-soldering them. If that solves it, wonderful! Paying an engineer to check your complete system @$75hr will still leave you with major outlay AND a antiquated mechanical tape loop system (That is the only one of PFM's I am aware of) that is essentially non-repairable. An ADVANTAGE to the Analogue sound transmission (vs. DCC) is the lower frequencies (sound) can run to speakers under table. Above the table sound is limited to about 500 Hz - (near the center of a piano). With DCC the sound is generated from the modules inside the engine, and it's physically impossible to get any low frequencies from the cavity that small.
