PS3 F3A - Can it mate with a PS2 F7A?

Sure.  My son and I have lashed up PS2 and PS3 regularly.  Should not be an issue.

Ron

So MTH has made a few different styles of F-units. On some the other A or B unit has a slave board. I think they only did this with the PS2 versions.

You should be able to run them together as a consist if you program them in the remote correctly, but if the PS3 unit has any wires or electrical connectors on the rear, do not connect them to any wires on the PS2 units.  When run as a MU consist (or lashup as the remote calls it) the F3A “leader” won’t control the other F7A. Each locomotive is programmed by the remote to know it’s position and then responds to direction changes independently.

When programming the consist, the remote asks you to specify the direction that each locomotive is facing.

I would not connect the "trailer unit" to the F3 PS3 unit. I think the slave boards are different in PS2 & PS3.  MTH did produce PS3 slave units for a couple of years.

@Alan P,

All of the above are generally correct but it may not be clear to you from them what the options have been over the years.  Here is a summary:

1. Oldest Versions -- Trailing units (called slave units) were connected to the units in front of them via wired tethers.  Units of similar vintage having tethers, i.e. same or similar production year, both having PS2, or both having PS3, should be connectable, but those that are very different from each other in age or version of DCS probably won't be.
2. More Recent Versions -- Trailing units and those in front of them are not connected electrically.  Each unit has it's own DCS transceiver.  These are programmed and can be controlled separately but are most often organized as a "lash-up', which allows DCS to control them together as if they are one engine.   
3. Also Possible -- Comments above in this thread seem to indicate that some versions were marketed that can accommodate either of these situations.  I have never seen one with this feature, but they may exist.  If these exist you should use only one of the methods to control them, and not try to use both at the same time.

Let us know how this turns out for you.

Mike

If the OPs description of what he has is correct and the MTH Products website is accurate in their description, these are the combinations the OP should be able to run.

Hi guys, first, thank you!

I should have added that I use a CAB-1L/legacy powermaster setup on my little layout. No DCS. Ron's helpful schematic gets at what I was trying to do - two powered As, tethered, master PS3 and slave PS2. Ideally they automatically recognize each other and I get directional control and lighting of the pair. Based on what you've told me, I think I'm not going to try that.

Best,

Alan P

No DCS... Yeah, now you CAN'T run them together.

@Ron045 posted:

No DCS... Yeah, now you CAN'T run them together.

In addition to Ron's observation even if you did have DCS you would not be able to tether a PS3 to a PS2 engine.

Without DCS, you will need to run them in conventional through the PowerMaster (see manual).  You will be able to run your 20-2550-1 ABA set in ABA, AB, and AA, and you can pull the dummy B-unit behind your 20-21462-1 A-unit in an AB.  But without DCS you can not "lash-up" the 20-2550 powered A with the 20-21462 powered A for smooth command control operation.

That does not mean the two powered A-units can not be run together in conventional.  Put both on the same track facing the same direction but several inches apart.  Then run them in conventional.  If their speeds are fairly close, you can run them together.  If one is noticeably faster than the other, then there will be stress on the engines possibly damaging them.  If they don't move then that probably means their forward/reverse functions are out of sync and you just may have damaged your traction tires.

Have fun.

If it were in a command environment, you’d have to use them together as a “lash up” you would not be able to plug them together.

Got it, thanks again. I think I may swap the shells between my PS3 F3 and the PS2 F7 master. That way I get the cigar/lightning AA combo I want, with both units PS2, powered, with directional lighting. I'll also have a PS3 lightning F7 that can make an AB with either the cigar or lightning dummy Bs. I 'm aiming for an early-60s look which is why I like mixing the two paint schemes.

Best,

Alan P

So I was able to do some live testing just now. I don't yet have my "new" PS2 F7 yet, but I do have a B&M PS2 F3 that's about the same age and has the wired tether jack. I put it on the track with my NYC PS3 F3, which has no tether but DOES have switches to control startup direction. As Mellow Hudson Mike and Ron suggest above, with both motor and headlight switches set to R, it moves in sync with the older F3 despite having no physical connection. The motor and gearing specs must have remained constant over the years, I guess, as the speeds seemed to match perfectly.