It will be a multi-stage effort. First, I have to do the reverse engineering, then obtain a prototype PCB and assemble and test a unit to see if I actually got it right. Once it's functional with a prototype PCB, then I can build some of them.
I am a bit confused by what seems to be conflicting information. The info from the engineer says that the ground and U wiring should be 2-4 inches apart, yet there is discussion of aluminum tape and foil under the roadbed or plywood which would seem to me to be inside the recommended 2 inches. I am just about to secure the roadbed etc and not certain if I should run aluminum tape under the roadbed? Does Dale's power booster eliminate the need for this ?
Responses are appreciated.
GREG in Wisconsin
Putting copper/aluminum tape under the track to enhance the earth ground portion of the TMCC signal is not a good idea. Lionel’s CTO group were the ones recommending the 2+” separation between the earth ground and outside rail ( U connection) portions of the TMCC signal. Dale’s / GRJ TMCC booster will definitely help Lionel engines with blinking engine head lights which is an indication of poor TMCC signal strength.
Bob D
A man who should know, he's working on one of the largest O-gauge layouts you'll ever see. 
Stackm746 posted:I am a bit confused by what seems to be conflicting information. The info from the engineer says that the ground and U wiring should be 2-4 inches apart, yet there is discussion of aluminum tape and foil under the roadbed or plywood which would seem to me to be inside the recommended 2 inches. I am just about to secure the roadbed etc and not certain if I should run aluminum tape under the roadbed? Does Dale's power booster eliminate the need for this ?
Responses are appreciated.
GREG in Wisconsin
I was under the impression the blinking light problem occurs when running a locomotive under elevated track. The engine stops and the front light starts blinking because it is recieving too much signal. The signal generated by the top track is a circle that mixes with the signal on the lower track effectively increasing frequency and confusing the engine so it shuts down. To stop the elevated track signal from propagating below the track either a foil (NJ High Railers used copper foil) or a wire running along side the track (I think only one side is needed and the wire can be coated) connected to 'earth ground' stops the signal from propagating below the track and mixing with the signal on the lower track. There was an article in the OGR magazine written a few years ago by the HJ High Railers addressing this issue and their recommendations on alleviating it.
The blinking for poor signal strength can happen whenever you have low TMCC signals, under elevated tracks is just one example of potential trouble spots.
Joe Fauty posted:Stackm746 posted:I am a bit confused by what seems to be conflicting information. The info from the engineer says that the ground and U wiring should be 2-4 inches apart, yet there is discussion of aluminum tape and foil under the roadbed or plywood which would seem to me to be inside the recommended 2 inches. I am just about to secure the roadbed etc and not certain if I should run aluminum tape under the roadbed? Does Dale's power booster eliminate the need for this ?
Responses are appreciated.
GREG in Wisconsin
I was under the impression the blinking light problem occurs when running a locomotive under elevated track. The engine stops and the front light starts blinking because it is recieving too much signal. The signal generated by the top track is a circle that mixes with the signal on the lower track effectively increasing frequency and confusing the engine so it shuts down. To stop the elevated track signal from propagating below the track either a foil (NJ High Railers used copper foil) or a wire running along side the track (I think only one side is needed and the wire can be coated) connected to 'earth ground' stops the signal from propagating below the track and mixing with the signal on the lower track. There was an article in the OGR magazine written a few years ago by the HJ High Railers addressing this issue and their recommendations on alleviating it.
At the NJ-hi railers, I have been removing the foil that was put under the track years ago. The electrical team has been installing telephone poles where we run a ground wire on for the locations which we have a weak signal. When telephone poles are not appropriate in the scenery, we will run a wire ~ 2" away from the outside rail on the layout. The main thing to remember is to try to keep the "U" terminal wiring (outside Rail connection), ~2" away from any earth ground connection like you have in 110V power cables and water pipes. When you have the U terminal wiring to close to earth ground, especially parallel runs, capacitance shorting effect comes into play, reducing the overall TMCC signal.
After making sure the basic wiring is correct and you still have an issue, the Dale M/GRJ booster works wonders.
Bob D
NJ- Hi Railers
I have a few questions regarding extending the antenna in an engine. Should the wire be a "solid" wire or a "stranded" wire? What is the best gauge wire to use for this purpose? Can I just splice the new wire into the existing antenna wire? Thanks.
Extending the antenna with wire works but I found using 1/2” copper tape works better. There is approximately a 25% signal improvement using the copper tape. If you use the copper tape or wire, make sure to also use silicone adhesive to secure the wire/tape to the body of the engine. You can find the copper tape on e bay.
It makes no difference what kind of wire you use, and as Bob says, the area will help, so copper tape works well. Since I have a bunch of the old stock Lionel copper tape antennas, I tend to use those until I run out of them.
There is a very small (1x11/2x3/8) 12V RF preamplifier that provides 16db of gain at the TMCC track signal frequency. Inserting this preamp between the loco antenna and the TMCC decoder RF input might resolve the low signal issues that many of us have experienced. I plan to try this.
BOB WALKER posted:There is a very small (1x11/2x3/8) 12V RF preamplifier that provides 16db of gain at the TMCC track signal frequency. Inserting this preamp between the loco antenna and the TMCC decoder RF input might resolve the low signal issues that many of us have experienced. I plan to try this.
Can you provide further information on the RF preamp
thanks
Thanks for the help. One more question, how do you connect the antenna to the copper tape? Solder?
Newt posted:Thanks for the help. One more question, how do you connect the antenna to the copper tape? Solder?
Solder is definitely the best way
For sure solder!
Stackm746 posted:I am a bit confused by what seems to be conflicting information. The info from the engineer says that the ground and U wiring should be 2-4 inches apart, yet there is discussion of aluminum tape and foil under the roadbed or plywood which would seem to me to be inside the recommended 2 inches. I am just about to secure the roadbed etc and not certain if I should run aluminum tape under the roadbed? Does Dale's power booster eliminate the need for this ?
Responses are appreciated.
GREG in Wisconsin
I think the foil or sheet aluminum came about from misinformation about what the issue is under an overhead track or also maybe from the use of the term ground "plane". Both ideas are erroneous. Dale M tried to stamp out the word plane, but had little luck. It was too catchy. As stated above, the overhead track or tunnel screens the engine from the overhead signal provided by the house ground wiring in the room. The term is "ground wire" that is the third wire in the house wiring and is what Lionel uses as an antenna. No concept of a "plane" is involved.
The TMCC antenna system is the ground wire overhead and the outside rails of the track. The engine sits in the middle in the ideal situation. As also stated the antenna, the ground wire, and the U terminal, the outside rails, should be kept apart to avoid a capacitive effect from shorting the two together and reducing the signal strength.
I agree with Chuck, putting the earth ground under the track is the wrong way to go about it. As he stated, ideally the earth ground is above the level of the track a few inches as most TMCC antennas are near the top of the locomotives.
Thanks. I have a followup question. When my train room was built, I had the electrician run a separate ground wire from the actual earth ground. I also have a circuit for all the wall receptacles which goes around the room but at a level below the tracks. Finally, I have a 20 AMP isolated circuit that resides in the middle of the room that I am using to power the layout with 12 bricks and a ZW-L. For my ground wire, can I run it off the separate earth ground or should I connect it to either the circuit that goes around the room or the circuit that is powering the layout.
Thoughts and comments are appreciated.
GREG in Wisconsin.
IMO, the best place to connect any extra earth ground wire is right at the command base. For the TMCC Signal Booster I actually made a tether for the power brick that taps the earth ground off the outside of the barrel, that's my choice. You can also tap off pin-5 of the serial connector.
