Newbe wondering about transformers and power

I’m new to this and was wondering about power requirements. Is there a standard of sorts for “X” feet of track you need “Y” transformers? I’m guessing there is a limit to the amount of track footage one transformer can run, or, am I off base? Also, does anyone recommend a particular transformer brand?
Thanks
ISRDUDE[?]

There is no formula for power to length of track. The length of track has nothing to do with power needs. The lose of power with the length of track is caused by resistance in the rail and rail jointers and no amount of power can really over come this. This is why DDC systems have bus wires with feed to the track every few feet.
Your main concern is how many locomoitives you plan to run at one time and how much current they draw. Todays modern locos do not pull much current as the locos of the pass. I can remember locomotives pulling 1 amp now it is about a tenth of that.
Remember all those accessories draw power to. I use a old power pack that I picked up for $1 at a train show to run most of my lights and switch machines.
As for good brands I lean toward MRC. I have three of them and like them. I have not had any experaince lately with other brands so I can’t compare them.
With my Tech II packs I run from 1 to 3 locos on a train and have never run short of power.

Suggest that, regardless of system, if you are building a permanent installation, you run #12 or 10 solid wires (insulated) as bus bars and feed your track from them about every 3’, using #18 or 20 solid drop wires soldered to the rails and the bus bars. If you are operating straight dc (not DDC) you can do these bus bar feeds independently so that they can be switched on and off or between sources. Far more reliable than relying on the rail with all its connections and higher electrical resistance. I’m sure there are magazine articles and relatively inexpensive books that will tell you in detail how to do this, particularly how to solder to the rail so it’s not damaged.

Isrdude,

There IS a voltage drop on long DC run’s but that’s only beyound 30 or 50 feet; the advise you’re getting in the above posts are good (A few years ago I found a spec buried in one of Lionel’s books requiring one connection every 12 ft on center, but I’ve haven’t seen anthing like that in HO).

Rick Selby’s book "Basic Wiring for Model Railroaders’ has been a good guide for my use as someone who is getting back into the hobby after many years and I’m sure it can be helpful to you. It’s available elsewhere on this web site.

HTH

Mark

What scale? How many trains? How long is your main line? Do you have big yard(s)? How big is the layout?