I know Dale Manquen commented on this earlier under Legacy Failures March 03, 2008 (see below), but I just wanted to vouch for the fact that the Legacy 990 Command Base is sensitive to the quality and exclusivity of the earth grounding that it's power pack gets in order to operate optimally. I found that the best results are achieved when the 990 power pack is connected directly into an earth grounded wall socket of its own (even sans a surge protector between it and the outlet). It does not perform as well when connected to a power strip that is shared with other things (like transformers providing track power) or on its own extension cord off a shared power strip.
The symptom that led me to first hand discover the Legacy system’s earth ground quality sensitivity was that a Lionel AF B&O 0-6-0 which I recently converted to TMCC and a previously converted SHS SF F7 would hesitate/stammer and their directional LED (when run fwd or rev) flicker when passing at slow speeds over a particular 15" piece of straight S-Trax in front of my control panel (beneath which are also a lot of wires stemming from my main power distribution board. I use a star topology, not bus loops to run power out to the tracks, etc). I cleaned the tracks, replaced that piece of track and at least 2 pieces on either side of it, and checked for proper power lead connections (the neighboring section of track), but to no avail. However, when I held my hand or a small tablet of paper vertically along the inside edge of the roadbed as if to shield the passing engine from something everything was fine - - no hesitation, no flickering. That led me to believe it was an electromagnetic disturbance, radio frequency interference, or signal strength related not physical connection problem. Also, a classic 930 AF illuminated caboose (with clean wheels) ran through the same section without a single flicker of its light bulb. When I removed the 990 power pack from the power stip that it was on (shared along with transformers) and instead plugged the power pack into an outlet of its own, all TMCC engine hesitation and flickering LED problems went away.
The range and connection strength of my Cab2 and 990 command base (already with a Hawking HAI7SIP antenna) also improved. I can now walk farther away from the layout (even with my back toward the layout) before the red Cab2 LED comes on. ====================================================
Dale Manquen Posted March 03, 2008 10:04 PM Hide Post The earth ground or electric panel ground MUST NOT BE CONNECTED TO TRACK COMMON. It carries half of the TMCC signal, and the track carries the other half. Shorting the two together will kill the TMCC signal!
Be certain that you have a good earth ground connection from the safety ground pin on the Legacy power supply to earth ground. The safety ground pin is the path over which the TMCC signal gets from the Command Base to the earth ground. Use a short direct connection to the wall outlet - no long coiled extension cords.
I'm having excellent results with my legacy system for the past 4 weeks since I installed it. I have a dedicated 18 gauge solid wire running from the power box ground on the water heater. I put a cheater ground plug on the power pack and pluged it into a power strip. I have the seperate wire connected to the brass ground strap on the cheater. This works super. I developed the idea afew years back when I started with my command base and cab 1. Has been faultless eversince I went with the seperate ground wire.
The power strip my Legacy base power-pack was originally plugged into had 9 transformers plugged into it (including two 30B's, a 19B and a 12B) either directly or via another power strip. Also since many of you probably run 3-rail, which uses both outside rails for the command base signal, you get a more complete "halo" effect or closed loop envelope of signal around your engines. I run two rails which makes for a more signal strength sensitive sitution.
