I understand basic electronics. I know enough about DCC to be dangerous. When it comes to radio transmission, I am completely in the dark. I have a Lenz system with CVP wireless throttles. I added two of CVPs T5000 throttles about a month ago and I am having issues with the signal strength when I am at the far corners of the layout. I've already discussed this at length in another thread.
Yesterday, while playing around, I discovered that I get a little bit stronger transmission if I hold the throttle over my head. It seemed to all but eliminate the delayed response I was getting otherwise, but it's not exactly an ideal solution. That's when I wondered whether it would be feasible to hook a stronger antenna to the CVP receiver. Currently, the receiver has about a 3 inch stick type antenna sticking up from the center of the box. The receiver sits on a shelf below the benchwork. I know they sell attachments for radio and TV antennas to strengthen the over the air signals. Would something similar work for a wireless receiver and if so, how would it attach. The antenna on my receiver looks to be nothing more than a metal rod. Would it be as simple as connecting antenna wires to that metal rod?
The other though I had would be to figure out a way to put the receiver up near the ceiling and then run the wire connections to the the main controller.
I'm just guessing at all this because I have absolutely no idea what would work and what wouldn't. Any advice would be appreciated.
The antenna you have is likely cut to the optimal ferquency that the transmitter uses. It's possible a better antenna will help, but it should be cut to the freq also, even if longer.
What will work better is to take the receiver/transmitter AND antenna together and raise the whole she-bang higher. Radio waves at the freqs wireless operates on tend to travel in straight line of sight. Any part of the layout, furniture or walls that obstructs the signal betweeb the transmitter and throttle will weaken it. If you put it up on a shelf where line of sight is easier to maintain, you'll probably notice significant improvement.
Mike Lehman
Urbana, IL
Rasing it above the layout sounds much easier.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
The radio throttles we use for our trains operate on a very narrow band of frequencies allocated by the FCC that are near those used by cell phones, and are limited in the power they can radiate. Using more than one receiving antenna is the usual way to improve reception within a large area.
The location of your receiver is not 'ideal'. Is it possible to mount it higher and not 'under' the layout? The antenna length can be a technical discussion in it's own. I am not sure what the transmission freaquency is for the CVP system is, but usually the antenna length is cut to match the freaquency or divisions of it. Many radios will have a 1/2 wave or 1/4 wave antenna. You might want to make a wire 'extention' that is double or quadruple the 3" length you have now. For a fast 'test' take a couple feet of hook-up wire and wrap it around the existing antenna and drape the remainder above the layout.
My Digitrax simplex and duplex antennas are in the baseplate mounted in the layout fascia - The simplex ones seem to be a little more critical when adjusting the antennas. I had to adjust the 'rabbit ears' to get reception all over the 25' by 20' layout area.
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
mlehman The antenna you have is likely cut to the optimal ferquency that the transmitter uses. It's possible a better antenna will help, but it should be cut to the freq also, even if longer. What will work better is to take the receiver/transmitter AND antenna together and raise the whole she-bang higher. Radio waves at the freqs wireless operates on tend to travel in straight line of sight. Any part of the layout, furniture or walls that obstructs the signal betweeb the transmitter and throttle will weaken it. If you put it up on a shelf where line of sight is easier to maintain, you'll probably notice significant improvement.
What exactly do you mean by "cut to frequency"?
Raising the receiver is certainly doable. Obstructions are unavoidable however. Currently the basement stairs drop into the middle of an around-the-walls layout and the furnace is beneath the stairs, effectively walling off one corner of the layout from the receiver. There is one spot where I have a line-of-sight window to the receiver but it is impractical to stand in that one spot and operate. The really challenge will be when I add a center peninsula with a double sided backdrop that will extend to the ceiling, effectively walling off half the layout. That is one reason I am anxious to work something out before a bad problem becomes worse.
jecorbettThe receiver sits on a shelf below the benchwork. I know they sell attachments for radio and TV antennas to strengthen the over the air signals.
i hope it's obvious that the antenna should be in the center of the space you use the handhelds.
a common place to mount the control-box/antenna is upsidedown from the ceiling
optimal length of the antenna depends on the wavelength/frequency
greg - Philadelphia & Reading / Reading
My former club had the exact same setup. (Lenz/CVP) On the permanent layout the radio reciever was hung on the cieling upside pown and worked flawlesly. The portable modules had the reciever on a shelf behind one of the modules backdrop. Just the antenna was sticking above the back drop. Unless your daisy chaining other throttle plates there is only one data cable to run.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
FOr antennas to work optimally, they must be an even multiplier of the wavelength in length. That's even whole numbers of fractions, like 1/8 wave, 1/4 wave, etc. Remember the CB era, some people had those long fiberglas whip antennas on their bumper? FOr CB radio frequencies, those are 1/4 wave. Part of the reason for the switch to higher frequency bands like for cordless phones and even cell phones, is that an optimal antenna size can fit within the device and not extend outside it. Remember when cell phones had an antenna you had to pull out?
What happens when the antenna is now at the ideal length, you get reflection back intot he circuitry, wasting most of the transmitting power. With the low power of DCC handhelds, it only causes less than ideal range. With something higher power, say a ham radio operater with a 100 watt transmitter - the feedback caused by this reflection cna damage the amplifier. A ham who works multiple bands will have multiple antennas, each tuned for the specific band. So, just extending the antenna with some wire won;t work.
Removeing obstacles - and the human body is a HUGE obstacle to radio waves, is the easiest and best thing you can do. Depending ont he design of the base unit, putting it up above yuour head can definitely help. also in some cases, upside down helps - the Digitrax radio units have the circuit board as their ground plane, so sticcing them in the ceiling but upside-down results in a wave pattern that covers teh room because it will radiate in all directions but below the plane of the circuit board.
It seems like voodoo sometimes, but the physics behind radio antennas and radiation patterns is well defined by science. It's not exactly simple, and many things that sound good can actually make things worse.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
jecorbettWhat exactly do you mean by "cut to frequency"?
Randy pretty much covered it. Antennas "resonate" something like a tuning fork. The length depends on a lot of factors and calculations, depending on the frequency and service. To get the antenna to perform better, you might switch to one that is longer, but its length will need to be determined and then the antenna cut to that length. A crude way to do it would be to either double or quadruple the length. This might help or maybe not.
You do want to get it close as possible to exactly x2 or x4. Thing is an antenna that is not resonant causes reflection of some of the signal back into the transmitter. It's possible for the "standing wave ratio" (SWR) to be so high that it causes the transmitter to fail. That's why we're being a bit cautious about just sticking something bigger on the box.
You don't need an absolutely clear view all around. That's in an ideal situation. Like life, radio usually has to deal with the less than ideal. Whatever you can do to help should result in improved signals, even if there will still be some remaining issues.
Yeah, I just said stick it up on a shelf as a quick and dirty test, but as others have noted, actually mounting it upside down on the ceiling works great.
Saw a diagram of a wireless set up. They had the reciever in a building on the layout and the antenna was hidden inside the smokestack. They had used a Walthers smokestack.
Just what I happened to see, on the layout, but out of sight.
Have fun,
Richard
mlehman Yeah, I just said stick it up on a shelf as a quick and dirty test, but as others have noted, actually mounting it upside down on the ceiling works great.
This will probably be the long term solution. I'm thinking of drilling a hole in the center of a board and turning the receiver upside down with the antenna sticking out the bottom. The board could then be mounted to the joists since I don't have a drop ceiling in my basement.
I tried Jim's suggestion to temporarily wrap some feeder wire around the antenna. It did seem to help although it is hard to say for sure because performance has been up and down since I got these new throttles. I'm guessing that is due to atmopsphere conditions. The air was clear and dry yesterday.
The nice folks at CVP Products suggested moving the receiver location short distances in various directions as sometimes just a small move can make a big difference. They also suggested experimenting with various receiver locations if small moves don't improve reception, while up high or the ceiling may end up being the best location that is not always the case.
regards, Peter
Since we are dealing with very low power radio signals here - it's not too hard to have them disrupted. The advice from CVP is right on - just moving the radio unit 6 inches further from that water pipe that's two joist bays away could easily make the difference between working and not working. Things that give off rf interference don't do so just at their actual frequency, but at all harmonics. The signal is strongest at the natural frequncy, but the harmonics are still present.
rrinker Since we are dealing with very low power radio signals here - it's not too hard to have them disrupted. The advice from CVP is right on - just moving the radio unit 6 inches further from that water pipe that's two joist bays away could easily make the difference between working and not working. Things that give off rf interference don't do so just at their actual frequency, but at all harmonics. The signal is strongest at the natural frequncy, but the harmonics are still present. --Randy
Kind of reminds me of the time I asked my friend to get out of the car and check to see if my turn signal was working. He said, "It's working. It's not working. It's working. It's not working....".
That's sometimes how this hobby makes me feel.
HO-Velo The nice folks at CVP Products suggested moving the receiver location short distances in various directions as sometimes just a small move can make a big difference. They also suggested experimenting with various receiver locations if small moves don't improve reception, while up high or the ceiling may end up being the best location that is not always the case. regards, Peter
Once the peninsula gets built, about the only option other than leaving the receiver on the shelf below the benchwork would be the ceiling. Everything else will be benchwork and aisles The only other place I could think of would be in the small gap between the staircase and the furnace and I wonder what that would do to reception with the furnace kicking on and off during the heating season.
I would check the batteries first. A friend was using rechargeable batteries and found variations in the voltage they were putting out. Once he put in new none rechargeables the problem was solved. Also if you point the arieal toward the reciever attenna with the receiver attenna at the 2 or 10 oclock position from the end of the transmitter attenna and it works better this could be an indication of a power problem, or secondarily an environment issue. The signal is strongest from a transmitter with an anttenna of that type going out towards the 10 and 2 directions from the end.
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
Definitely a possible issue. Alkaline cells are 1.5V. Most forms of rechargeable cells are only 1.2 volts. So if the throttle uses 2 in series, you're already starting at 2.4V instead of 3V.
Digitrax throttles use 9V batteries, most common rechargeable ones are 7 cell, that means only 8.4V when it's fully charged. Already over half a volt down from the recommended voltage. There are 8 cell "9V" rechargeables, they start at 9.6V, the drawback is to squeeze the extra cell in, they all have to be smaller, which means reduced capacity.
BATMAN I would check the batteries first. A friend was using rechargeable batteries and found variations in the voltage they were putting out. Once he put in new none rechargeables the problem was solved. Also if you point the arieal toward the reciever attenna with the receiver attenna at the 2 or 10 oclock position from the end of the transmitter attenna and it works better this could be an indication of a power problem, or secondarily an environment issue. The signal is strongest from a transmitter with an anttenna of that type going out towards the 10 and 2 directions from the end.
I already eliminated the batteries as a possible issue by replacing the rechargeables with the highest end Energizer AAA batteries which the owner’s manual recommended.
CVP’s old RF1300 had an external antenna, but the new T5000s have an internal antenna. If the orientation of the throttle to the receiver is an issue, that wouldn’t say much for the CVP system. An operator shouldn’t have to be concerned with which way the throttle is pointing when he is operating his trains. If I found out that was the case, the whole CVP system would go straight into the trash can.
rrinker Definitely a possible issue. Alkaline cells are 1.5V. Most forms of rechargeable cells are only 1.2 volts. So if the throttle uses 2 in series, you're already starting at 2.4V instead of 3V. Digitrax throttles use 9V batteries, most common rechargeable ones are 7 cell, that means only 8.4V when it's fully charged. Already over half a volt down from the recommended voltage. There are 8 cell "9V" rechargeables, they start at 9.6V, the drawback is to squeeze the extra cell in, they all have to be smaller, which means reduced capacity. --Randy
I used rechargeable batteries in CVP's first generation RF1300 throttle for years with no problems. If their third generation T5000 throttles don't have the strength that the first generation throttles did, they have taken a serious step backwards.
jecorbett I used rechargeable batteries in CVP's first generation RF1300 throttle for years with no problems. If their third generation T5000 throttles don't have the strength that the first generation throttles did, they have taken a serious step backwards.
In our ops group we have used the T5000's on a couple of layouts with no noticeable issues but we were running 1300's at the same time. My CVP system and all the others in my area running 1300's are bullet proof when it comes to drop outs and poor response... that is why we went with CVP in the first place!!!
If you are correct about the poor signal response in the T5000, that is bad news. I would get back on the phone with Al at CVP and work through this a little more thoroughly. Hanging antennas from the ceiling upside down is so early 2000's NCE (pre wireless redesign). Most of us went with CVP to avoid this sort of thing.
Guy
see stuff at: the Willoughby Line Site
trainnut1250 jecorbett I used rechargeable batteries in CVP's first generation RF1300 throttle for years with no problems. If their third generation T5000 throttles don't have the strength that the first generation throttles did, they have taken a serious step backwards. In our ops group we have used the T5000's on a couple of layouts with no noticeable issues but we were running 1300's at the same time. My CVP system and all the others in my area running 1300's are bullet proof when it comes to drop outs and poor response... that is why we went with CVP in the first place!!! If you are correct about the poor signal response in the T5000, that is bad news. I would get back on the phone with Al at CVP and work through this a little more thoroughly. Hanging antennas from the ceiling upside down is so early 2000's NCE (pre wireless redesign). Most of us went with CVP to avoid this sort of thing. Guy
I've spoken with CVP several times about this issue. The second time I spoke to a technical guy whose name I don't know. I mentioned that I seemed to get better response from the T5000s when the RF1300 was turned on and especially when the RF1300 was moved to the farthest corner of the layout. He told me that didn't make sense and it probably doesn't but that has been my observation. What is clear to me is that when the RF1300 is turned on, the green lights on the receiver panel remain on constantly but when the T5000s are on by themselves, the green lights are constantly blinking and sometimes go out for 5 to 6 seconds at a time. When those lights aren't on, there is no response to the throttle.
I did temporarily move the receiver from a shelf under the benchwork to the top of a 3 drawer cabinet I moved out into the aisle. There was noticieably better reception when I did that but that is a temporary solution since having an obstruction in an aisle is a pain. The only other choice seems to be to move it up to the ceiling. Not something I want to do but I need to improve the reception and that seems to be the best option at this point.
I have already admitted to not having any knowledge in the area of radio transmission but I have to wonder if going from the four AAA batteries in the RF1300 to just two in the T5000 has resulted in a lower power transmission. I like the new features on the T5000, especially having the LCD display, but I'd give them all up for the reliability I got from my RF1300.
M.StruckHave you experimented with changing the transmitter power level of the T5000? Matt
Yes. Made little difference.
Placing the receiver up high is the very first thing that should be done to help reception. Increasing transmitting power, changing tuned antennas, etc. might make a difference if you will be operating from a neighbor's house. Won't do squat to make the signal go through the large bags of water that happen to be in the way.
Martin Myers
jecorbett trainnut1250 jecorbett I used rechargeable batteries in CVP's first generation RF1300 throttle for years with no problems. If their third generation T5000 throttles don't have the strength that the first generation throttles did, they have taken a serious step backwards. In our ops group we have used the T5000's on a couple of layouts with no noticeable issues but we were running 1300's at the same time. My CVP system and all the others in my area running 1300's are bullet proof when it comes to drop outs and poor response... that is why we went with CVP in the first place!!! If you are correct about the poor signal response in the T5000, that is bad news. I would get back on the phone with Al at CVP and work through this a little more thoroughly. Hanging antennas from the ceiling upside down is so early 2000's NCE (pre wireless redesign). Most of us went with CVP to avoid this sort of thing. Guy I've spoken with CVP several times about this issue. The second time I spoke to a technical guy whose name I don't know. I mentioned that I seemed to get better response from the T5000s when the RF1300 was turned on and especially when the RF1300 was moved to the farthest corner of the layout. He told me that didn't make sense and it probably doesn't but that has been my observation. What is clear to me is that when the RF1300 is turned on, the green lights on the receiver panel remain on constantly but when the T5000s are on by themselves, the green lights are constantly blinking and sometimes go out for 5 to 6 seconds at a time. When those lights aren't on, there is no response to the throttle. I did temporarily move the receiver from a shelf under the benchwork to the top of a 3 drawer cabinet I moved out into the aisle. There was noticieably better reception when I did that but that is a temporary solution since having an obstruction in an aisle is a pain. The only other choice seems to be to move it up to the ceiling. Not something I want to do but I need to improve the reception and that seems to be the best option at this point. I have already admitted to not having any knowledge in the area of radio transmission but I have to wonder if going from the four AAA batteries in the RF1300 to just two in the T5000 has resulted in a lower power transmission. I like the new features on the T5000, especially having the LCD display, but I'd give them all up for the reliability I got from my RF1300.
Hmmm...
Another reason to stick with the 1300's...Only other idea I have is to open a discussion on the Easy DCC yahoo group if you haven't already. Last time I checked, the list has been pretty quiet, but hopefully some one there can shed some light on this.
trainnut1250 jecorbett trainnut1250 jecorbett I used rechargeable batteries in CVP's first generation RF1300 throttle for years with no problems. If their third generation T5000 throttles don't have the strength that the first generation throttles did, they have taken a serious step backwards. In our ops group we have used the T5000's on a couple of layouts with no noticeable issues but we were running 1300's at the same time. My CVP system and all the others in my area running 1300's are bullet proof when it comes to drop outs and poor response... that is why we went with CVP in the first place!!! If you are correct about the poor signal response in the T5000, that is bad news. I would get back on the phone with Al at CVP and work through this a little more thoroughly. Hanging antennas from the ceiling upside down is so early 2000's NCE (pre wireless redesign). Most of us went with CVP to avoid this sort of thing. Guy I've spoken with CVP several times about this issue. The second time I spoke to a technical guy whose name I don't know. I mentioned that I seemed to get better response from the T5000s when the RF1300 was turned on and especially when the RF1300 was moved to the farthest corner of the layout. He told me that didn't make sense and it probably doesn't but that has been my observation. What is clear to me is that when the RF1300 is turned on, the green lights on the receiver panel remain on constantly but when the T5000s are on by themselves, the green lights are constantly blinking and sometimes go out for 5 to 6 seconds at a time. When those lights aren't on, there is no response to the throttle. I did temporarily move the receiver from a shelf under the benchwork to the top of a 3 drawer cabinet I moved out into the aisle. There was noticieably better reception when I did that but that is a temporary solution since having an obstruction in an aisle is a pain. The only other choice seems to be to move it up to the ceiling. Not something I want to do but I need to improve the reception and that seems to be the best option at this point. I have already admitted to not having any knowledge in the area of radio transmission but I have to wonder if going from the four AAA batteries in the RF1300 to just two in the T5000 has resulted in a lower power transmission. I like the new features on the T5000, especially having the LCD display, but I'd give them all up for the reliability I got from my RF1300. Hmmm... Another reason to stick with the 1300's...Only other idea I have is to open a discussion on the Easy DCC yahoo group if you haven't already. Last time I checked, the list has been pretty quiet, but hopefully some one there can shed some light on this. Guy
I don't know if you followed the other thread but the reason I gave up on my RF1300 was that the #8 button quit working and I have too many locos with an 8 in the road number/address. I could have sent it back for repair but it was going to cost me a minimum of $25 plus parts and shipping. I was already planning to add a second throttle so rather than get the RF1300 repaired, I opted for a second T5000. I haven't yet put the receiver up on the ceiling and that might solve the problem. It's a pain to have to do that but it will only need to be done once and if it will give me better performance, I'm OK with that.
I use the CVP T5000 throttle to control my AirWire equipped G-scale trains outdoors and have ran into some situations where the trains get too far away or behind some bushes or boulders that cause a loss of reception, but if there are no obstructions the T5000 has a very good range outdoors.
jecorbett...I mentioned that I seemed to get better response from the T5000s when the RF1300 was turned on and especially when the RF1300 was moved to the farthest corner of the layout. He told me that didn't make sense and it probably doesn't but that has been my observation. What is clear to me is that when the RF1300 is turned on, the green lights on the receiver panel remain on constantly but when the T5000s are on by themselves, the green lights are constantly blinking and sometimes go out for 5 to 6 seconds at a time. When those lights aren't on, there is no response to the throttle...
Have you tried trying changing throttle IDs? I would try swapping the throttle IDs of the T5000 and the RF1300 and see if that makes any difference.