Large Scale Central

Getting great range

Electronics Power and Sound
#1

I have today just finished an installation using the new RCS PnP-3AC with Phoenix P5 + P5T sound. This loco started out as an AC RS3 and is now a longer wheelbase NSW 40 class Alco diesel that is being kitbashed by a customer.
After a couple of less than satisfactory antenna placements I mounted the RCS RX-8 metal cased receiver on the back of the cab wall. I drilled a small hole through to the cab and mounted the AZARR 27 Lite antenna vertically up one corner and around the top of the roof.
I have just range tested the loco and I could reliably control the loco and blow the horn with out it dropping in and out, up to at least 300’. I couldn’t get any further away because I came up against an electrified fence for keeping horses away from the garden.
To say the least, I was astounded. The only other locos I have tested to get anywhere near that range were an USA F3 and an AC E8. Both of which allow an antenna to be stretched out up really high.

The really interesting part is I had no extra motor “noise” suppression components on the AC motor blocks. Just the suppression fitted by the factory.

I have a friend with an SD-45 that has reasonable range and shortly I will try the install method on it.
I will report back on what happens.

#2

X Axis, Y Axis, Z Axis?

or low ground plane with vertical mast? (like a broadcast AM tower?)

#3

Joe,
Could you please define X,Y & Z.

I mounted an AZARR, part vertically, part horizontally.

The point was to get the antenna as far away as possible from the PWM generator on the AC switches.
I did and it seems to work just fine.

#4

3 Axes = 3 dimensions in space.

X Axis runs east and west.
Y Axis runs north and south.
Z Axis runs up and down.

My theory: A vertically oriented antenna (Z Axis) recieves the strongest signal from a vertically oriented transmitting antenna. Similarly for the other two axes, but the ground plane (in this case the dirt you’re walking on) works best with a vertical antenna. (big example: AM broadcast towers.)

Since people point their transmitting antennas in many different directions, I’m just wondering if having parts of the antenna in all three axes is helping with reception.

You wrote “PWM generator on the AC switches”. Are you saying that the (battery) power going to the DC motors is pulse width modulated? I can see where that could generate RF noise.

Sincerely,

Joe Satnik

#5
Joe Satnik said:
3 Axes = 3 dimensions in space.

X Axis runs east and west.
Y Axis runs north and south.
Z Axis runs up and down.

My theory: A vertically oriented antenna (Z Axis) recieves the strongest signal from a vertically oriented transmitting antenna. Similarly for the other two axes, but the ground plane (in this case the dirt you’re walking on) works best with a vertical antenna. (big example: AM broadcast towers.)

Since people point their transmitting antennas in many different directions, I’m just wondering if having parts of the antenna in all three axes is helping with reception.

You wrote “PWM generator on the AC switches”. Are you saying that the (battery) power going to the DC motors is pulse width modulated? I can see where that could generate RF noise.

Sincerely,

Joe Satnik


X, Y & Z axes do not apply to us as everything is always moving.
However, vertical is always better.
Most locos have no room for a proper vertical antenna let alone a ground plane like how a car radio antenna works.

There are “null” points ( as in dead spots) on the radiated TX signal no matter what sort of TX. Moving the TX antenna around will change the “null” position relative to the RX antenna.

To the best of my knowledge all R/C ESC’s designed for on board use, have a pwm output which can affect the incoming signals. That sort of RFI is usually taken care of by proper suppression at the motor(s). The two axle AC motor blocks do have suppression built in that seems to work just fine in my testing of this particular loco.

I was talking about the small pcb mounted at right angles on the AC switch control pcb that is generating a weird form of pwm to power the lights and perhaps the smoke unit at low speed. That pwm generator is a cause of RFI that affects “through the air” range.

To be specific as to the range, I was 110 paces (of my 6’5" long legged frame) away and still holding a reliable signal around a house and through trees and bushes.

#6

Tony,

If you really want to be confused (like me), re-read your posts substituting “Alternating Current” whenever you see a stand alone “AC”.

What is ESC?

A null in one axis may not be a null in another. That’s the point in my first reply.

Has to do with the cosine of the angle between the transmitting and recieving antennae.

For simplicity, assume straight wires for antennae, no ground effects.

If both TX and RX antennae are parallel to each other (zero degrees), cos is 100 percent (best reception). Right angle to each other (90 degrees) cos is zero percent (null, no reception). Halfway in between (45 degrees) cos is about 70 percent (decent reception).

Now, assume you have 3 RX antennae, one on each of the X, Y and Z axes. Assume that you can add their signals together for the reciever.

No matter which direction you point the TX antenna, you will never have a null, as the cosine to at least one of the axes will be non-zero.

No matter which direction you point your 3 axes (additive) RX antennae cluster (eg, engine goes around a curve), you will never have a null, as the cosine between the TX antenna and at least one of the 3 RX antennae will be non-zero.

I’m guessing that your RX antenna bent in 3 axes is imitating the effects of the cluster described above. An experienced ham operator would know more.

That leaves signal degradation effects from distance and blockage (buildings, landscape, etc.). Since most operators want to have sight of the engine they are operating, blockage may only be a problem in the tunnels.

So, how do R/C trains do in tunnels? Do the tunnel rails end up re-radiating some of the signal? I suppose as an experiment you could try running on plastic track through a tunnel…

Sincerely,

Joe Satnik (Generating more Q’s than A’s)

#7

Joe, I use Plastic Corrugated Drain Pipes for my Tunnels and can start, stop, reverse, bell and whistle while traveling inside them. From my usual operating location, I’ve not noticed any signal drop while inside a tunnel…I use the “Newer” TX24 as supplied by Goodson…if not mentioned before-both of my conversions utilize the track as an antenna. (that may explain my above results).

cale

#8

OK Joe.

I guess getting easily confused is a common trait among LS’ers.

ESC stands for Electronic Speed Controller. It is a very common term used worldwide by users of Digital Proportional R/C.

The RCS & EVO websites have a glossary of commonly used R/C abbreviations. Go to On Board Battery and look under Beginners.

When it comes to the theory of RFI, I will bow to your obviously superior technical capabilities.

How well R/C works in tunnels depends on the what material the tunnel is put through, the wall lining and the type of R/C and ESC used.

#9

Dear Tony,

Thanks for the kind words, explanations, and leads to the R/C abbreviations.

What ever you are doing, though, keep it up. YOU are the inventor/engineer/entrepeneur/businessman that drives a successful worldwide high quality R/C company. I’ll hide behind a huge mirror and deflect any complements back at you.

Again, Ham radio operators hunkered down in their radio shacks probably know 10 times what I know about radio wave TX and RX. Lots of them start out near 28MHz, which isn’t too far off from your 27Mhz.

Their main concern is hundreds of watts of “around the world skip”, while yours is ground wave and conserving transmitter battery life.

If I can make my thoughts understandable, I’ve succeeded. Probably the most important influence has been adjusting the rabbit ears on the TV, and twisting the tabletop radio to get better reception. “Better radio reception and range must have something to do with the angle”. Hmm…

Other influences: Electro-Magnetic Fields class, helping my Dad with his Ham shack/towers/rotors/antennae, and a friend that’s a broadcast radio engineer.

Sincerely,

Joe Satnik

#10

Hey Tony,

Nice website.

You could add to your abbreviations list:

PCB = Printed Circuit Board

Hope this helps.

Sincerely,

Joe Satnik

#11

Thanks Joe.

I will take care of it immediately on the EVO website and asap on the RCS website.

#12

Joe.
Permit me a follow up.

I checked the Glossary list and found PCB is already listed.
Granted they are not in alphabetical order but there was a reason for setting it out that way.

#13

Hi, Tony.

I didn’t navigate your entire site, but at this spot your “PCB” definition didn’t contain the words “printed circuit board”.

http://www.rcs-rc.com/?page=on_board_battery/battery_overview.html
(scroll down)

Hope this helps.

Joe Satnik

#14

Joe.

What it does say is: “The fiberglass cards upon which are mounted the components that make the R/C systems work.”

I would have thought that a pretty clear description.

#15
Joe Satnik said:
HUA
OK!!! I give up.

KUA?

BTW, at your suggestion I have added the words “Printed Circuit Board” to the EVO website version of the Glossary.
I can’t amend the RCS website version just yet as my 14 yo webmaster has been a bit slack at setting up the RCS website in a data based format so I can make changes.

#16

HUA: Heard, Understood, Acknowledged. Military slang.

Also HUAA: Heard, Understood, And Acknowledged.

Made famous in the movie “Scent of a Woman” with Al Pacino.

http://www.youtube.com/watch?v=l3ZIDT63UOA

Hope this helps.

Sincerely,

Joe Satnik

#17

Geeze, I’ve been retired too long. I thought that was just some sort of grunt!

#18
Joe Satnik said:
HUA: Heard, Understood, Acknowledged. Military slang.

Also HUAA: Heard, Understood, And Acknowledged.

Made famous in the movie “Scent of a Woman” with Al Pacino.

http://www.youtube.com/watch?v=l3ZIDT63UOA

Hope this helps.

Sincerely,

Joe Satnik


learn something evry day!

#19

Always wondered what that meant. Wasn’t used when I was in the Army.

Course back then we were still usin muskets…:wink: