Yeah, the terminology here can get a bit confusing, with the overlap in concepts that model railroading often undertakes. My take on it, clumsy as it seems, is to assume that what's in the loco does considerably more than just receive the signal. The receiver aspect of it would be just one small part of the bigger whole, which is oriented toward RR operation. It's a distinction that can get lost in the shuffle, but so long as we all know what we're talking about, we should be able to understand how the concept is being used in context.
Mike Lehman
Urbana, IL
On-board radio are 'receivers' because they are receiving a radio signal. DCC is not RF, the 'decoder' is decoding a binary stream of data sent over the rails.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I'm not correcting you, only pointing out a conundrum! I'm sure someone can give us a boring definition of why this is, I will be holding bated breath!
NP 2626 "Northern Pacific, really terrific"
Northern Pacific Railway Historical Association: http://www.nprha.org/
Sheldon,
Yes, some good ideas don't go away, they get better. My Crest radio throttle worked well, but I ended up selling it because my needs changed. A very happy fellow in Canada was happy to give it a new home. I bought it originally to be an alternate cab, subbing for one of my two MRC CM20s on occassion. Then I decided it was time to changeover to DCC. Thought to use it outside at some point, but I just didn't want the hassle of sending power through the rails for that any longer. My goal is to run deadrail battery power via RC in my Bachmann Shay and take the whole thing outdoors, so the Crest really didn't fit and I needed the money for other layout priorities. The Crest held it's value very well, too
I will be keeping my eye on what Crest and others offer in terms of radio decoders, as there seem to be several brands of those hitting the market and I only need 1. That, a few bits and pieces and some LiPo batteries and I think I can be in business.
Radio control is an excellent method for several types of DC layouts, indoors and out, and still provides robust performance if you just need to run a train .
Wireless radio throttles - I still use the Aristo Craft 10 Channel Train Engineer throttles - 27MHz
And I make my own 5" "rubber ducky" antennas, and they work very well providing range of about 150' to 175'.
With the long telescoping antenna Aristo provided the range is a little more, closer to 250' or 275'.
Aristo offered a rubber ducky for a while, but it was 8" and floppy, not really good for an indoor layout any more than the long one.
It may be "old" tech, but they work great and and provide great speed control. The output is constant voltage pluse width modulated, just like the motor control out put of DCC decoders.
With conventional DC locos it provides perfect constant brightness lighting, which comes on before the loco moves, and very smooth speed control.
Simple, easy to use, reliable and rugged.
While much updated and now 2.4 GHz, Crest, which is/was the same folks as Aristo, still makes a great radio throttle for onboard in larger scales and trackside in smaller scales.
And they are developing HO size onboard receivers, which they had also offered for the older system.
http://shop.crest-electronics.net/main.sc
Sheldon
One of the things I do understand, is inflation!
NP2626 I especially like to look at the prices of things and see how much stuff used to be available.
Keep your inflation calculator handy when you are getting nostalgic about those "ridiculously low" prices.
For instance, a Model Rectifier 2-1/2 amp power pack was $32.95 in 1956. Today you would have to shell out $287.22 to bring that little baby home.
...just sayin' Ed
Yep, that's the spirit. Wisdom is as much knowing your limits as knowing what you actually know inside those limits. The nice thing about discussing old MR stuff is that we actually have a pretty good set of what is known available. That's a good starting place for having fun with the past.
gmpullman...I find it very satisfying to read about how things were done back-in- the-day. I hope others don't get discouraged and hesitate to post neat little "historic" tidbits like this.
Thanks for your comments Ed. I've been thinking of doing that, at least intermittently, maybe more extensively now that the All-Access Pass makes the MR archive widely available.
I've been doing some piecemeal reading in the archives and will spit out what I think is still worth chewing over, sorta like a mother bird...
Well, I'll try not to make it nasty. I do hope everyone treats each other gently in discussion, as we all have something of value to contribute and none of us are experts in everything, even when it's possible to largely agree on certain facts.
It also will help to at least glance over the article, if you do have some access, so that at least we're all on the same page as best possible, so to speak. Finances don't permit my doing All-Access right now and my MR collection is pretty well complete back to the early 50s, or I'd post whatever links they use as a reference in addition to the purely paper reference. I try to hit the high points, but obviously don't try to hit everything of relevance and worth discussing since it is a summary I'll try to offer as a starting point when I do turn up a nugget.
BTW, in a mostly unrelated topic, this particular MR edition also includes a thorough article on building turnouts.
carl425This all reminds me of one of my dad's favorite wise cracks "Those of you who think you know everything are particularly annoying to those of us who do".
And one of my frequently used quips... "Eat the meat, spit out the bone."
Sometimes I hear "facts" about past historical events, railroad operations and, yes, electronic developments and circuits and if I see something that I find interesting enough I'll go digging on my own and the end result is that I come away with a better understanding about how a problem was solved or a technological hurdle was overcome. If I'm skeptical and find some, or all, of the information slightly less than palatable, I "spit it out."
I have read the biographies on Edison, Tesla, Westinghouse and many of the railroad "empire builders" and admire the determination that these men had in attempting to make ours a better world.
So, like Randy, I find it very satisfying to read about how things were done back-in- the-day. I hope others don't get discouraged and hesitate to post neat little "historic" tidbits like this.
I always remind people that what's new is old. Someone mentioned Amtrak's new Head End Power (adopted around 1978 or so) and I pointed out that I have patent drawings from 1887 showing a steam powered dynamo mounted in the baggage car and a system of wiring throughout the train for lighting.
Happy modeling, Ed
rrinkerSome of us ARE interested in historically significant information
One guy's historically significant information is another's useless trivia.
This all reminds me of one of my dad's favorite wise cracks "Those of you who think you know everything are particularly annoying to those of us who do".
I have the right to remain silent. By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.
Sorry you feel that way. Some of us ARE interested in historically significant information, or how things work - and not always the latest greatest state of the art stuff.
No, I'm not going to build a vintage 1998 radio control throttle - one with a handheld control bigger than the DC power pack I use for testing, using an RC system that probably goes on eBay for 5x as much as a modern radio system (us just use the 1985 vintage Futaba I have just laying around) - and not the least because I use DCC and have no need for a radio control DC throttle. But if it's that unimportant or usless, why particpate in the first place?
It's the circuit design and the adaptation of something totally non-railroad that's interesting about this. There was a time, even after it had been surpassed by newer systems, that I was going ot build a CTC-16E system. I had most of the electronic components on hand. Then my situation changed and I had no way to have a layout for a few years - during which time DCC sprang up, so when I got back into building a layout, DCC was the obvious way to go. I also designed circuits and even wrote some of the controlling software to duplicate the original C/MRI. Those back issues of MR were among the first to go when I got the DVD, I had paged through that series so many times, every magazine was falling apart. By the time I was doing this, the original design had been repalced by the serial interface versions, instead of the large card motherboard andspecialized plug-in card for each type of computer. But I figured out a way to get what connections I needed for the layout I was building on effectively a single card. Like my CTC-16E plan, that too got put on hold, at the same time. By the time I was back, DCC was established and in comparing systems I discovered Loconet and the multiple vendor support, as well as DIY projects. That right there decided me, I could build some things myself, and others I could just use a commercial product.
When I got the 75 year DVD, I read every issue, starting with Vol 1 #1, and I found something interesting in nearly every one. Just because something is old doesn;t mean it's of no use. Sure, I'm not about to use asbestos for my scenery, and there are other materials which are no longer commonly available, not necessarily because they are dangerous but because they have been repalced by more modern materials. However - the TECHNIQUES are perfectly valid. That's where I'm coming from - this circuit and how they decoded the receiver output and made it drive variable 12V DC to run trains is INTERESTING - to me anyway, and I doubt I'm the only one, or no one would bother reading the old issues.
I knew that ACE produced some stuff using other technology. Did not pay attention to it as I am pretty much into State-O-The-Art equipment for the airplanes that I spend months building.
So Randy, you going to build one of these 1978 vintage control systems? If not, why the HECK does any of this matter?
Looked at the article, indeed it was the Digital version of the Commander. But Mark seems to disagree that you could still buy the analog one.
Looking at the circuit the LM544 is the key - before that, building a circuit like that to decoder the digital pulses would not have been simple. That same part was later used in the CTC16 receivers.
Of bigger note - the last couple of paragraphs, hinting at direct radio control of the trains, instead of radio control of the track power. Later realized by Aristo and others in larger scales, and now in HO. At the time, there was nu multiplex capability, so each loco would need its own frequency. There weren't a lot to choose from. Nowdays we can run many devices over the same frequency so having more than 5 locos isn't a big deal.
I think Mark is right here. It's the Ace Digital Commander they use.
The article does refer to "pulses" but the diagrams seems to indicate these are indeed digital, not an analog waveforms.
They cite the total cost of the components as ~$160.
What? Ace sold their PP system well past the 70's. Now that I read the instruction from it, using a PP system really DID make a much easier throttle circuit for model railroad control. It can darn near drive an SCR throttle hooked in place of the actuator!
I'm not denying you could also get DP equipment by that time. It was also a lot more expensive (since it could do a lot more, as well as being electronically much more complex).
Forget it!
No - the Ace Pulse COmmander was produced form 1972 on.
http://www.rchalloffame.org/Manufacturer/Ace/history/index.html
http://airplanesandrockets.com/electronics/Ace-Pulse-Commander/ace-pulse-commander-radio-control-system.htm
They even supplied a schematic for the system with it. I'm pretty sure this is the unit used in the article - I'll check when I get home, don't have my DVD installed here.
I recall a later article - mid to late 90's maybe, or early 2000's, sort of repeating the same thing only using a modern digital proportional radio set. Circuit for the receiver side may have even been a Keith from CVP design. Short of mechanically connecting servos to a potentiometer and a reversing switch, in 1978 trying to do an all-electronic solution with digital proportional would have been fairly difficult and/or expensive. Once lower cost components became available, it was no big deal.
rrinker I had a couple of RC magazines from just before that era, and the low end stuff was all pulse proportional instead of digital proportional - so if you moved the stick half way, the receiver system would flutter the rudder between neutral and half. I'll haveto open up the article again when I get home, I seem to recall that the Ace transmitter was a pulse proportional system. In some ways I can see this as being easier to adapt - just rectify the pule to get an average voltage and use that to drive a transistor throttle. --Randy
I had a couple of RC magazines from just before that era, and the low end stuff was all pulse proportional instead of digital proportional - so if you moved the stick half way, the receiver system would flutter the rudder between neutral and half. I'll haveto open up the article again when I get home, I seem to recall that the Ace transmitter was a pulse proportional system. In some ways I can see this as being easier to adapt - just rectify the pule to get an average voltage and use that to drive a transistor throttle.
Now, I don't understand why determining what type of system was used has much importance to the thrust of Mike’s post?
The called it digital in the article, but pulse sounds like it could just as easily apply. It was actually capable of 8 channels and the pulse/digital modulation was used to send packets at each of 8 times providing the commands. It was a little unclear to me how forward and reverse were implemented, but it was a part of the info broadcast on only one channel, instead of being a separate channels by itself.
Of course, I may have misunderstood this in some way, shape or form.
And BTW, you also had to apply for the FCC license just like R/C plane ops did.
At least it was free, the license that is.
There are pics with the article, but not posted here because they're copyrighted by our host. Obviously a good excuse to buy the All-Access Pass...
I know a bit about antennas, having been a DC to daylight radio monitor for several decades. Looks like a base-loaded antenna, which would account for its shortness despite being 27 mHz, but makes sense since you really don't need the range that R/C aircraft would require unless you have one heck of a big layout.
The article referred to a digital transmission scheme that had apparently already mostly replaced the old analog systems in 1978. I didn't read that real deep, but they did point out this was noit a beginners project. There was a complate parts list included for everything required.
rrinker A 72Mhz RC radio would actually use a shorter antenna...
A 72Mhz RC radio would actually use a shorter antenna...
My response was about what was reality, not what could; or could not, be done.
Doesn't change physics - optimal antenna lengths are directly related to the wavelength and thus the frequency. Now, if someone wanted to use a 1/4 wave antenna, and someone else wanted to use a 1/2 wave antenna....
The antenna on my 80's Futaba 4 channel radio pulled out pretty far too. Rarely needed it all the way extended at the ranges I operated my car at. My new 2.4GHz stuff all has itty bitty rubber ducky type antennas. Mostly because the wavelength for 2.4GHx is much much smaller than 72MHz, or even 900MHz.
NP2626I'm telling you how long 72 mhz R/C transmitter antena's were back then and are today and you can take that information to the bank!
The antenna on the 4-channel Kraft transmitter I owned in 1975 was somewhere in the 4 foot plus range. When testing indoors, it did work fine at MRR ranges extended only 6-12 inches.
Randy, I've been involved in the Radio Control hobby since 1969. I'm telling you how long 72 mhz R/C transmitter antena's were back then and are today and you can take that information to the bank!
No, what he's using there IS a model airpl;ane RC unit - the article is about converting an Ace transmitter to use to control trains instead of a plane. They used a 27MHz unit, so the antenna length being the same as a walkie-talkie is right. A 72Mhz RC radio would actually use a shorter antenna - unless you went longer and went for a higher multiple of the wavelength.
Remember early cordless phones, witht he long antenna to pull out? That was only one side of the system, the transmit and receive used two different frequencies, and the other antenna was internal. People jumped on the 2.4GHz and then 5.8GHz units as they became available because they needed no external antenna for that high frequency. Also like modern cell hpones, no external antenna. Not always a plus though - as you wrap your hand around the device you are blocking the RF.