I promised an update on the 1.2 gHz mini camera w/sound system which I bought from SJT Enterprises while at April York. You may have seen him selling them in the Purple hall this year. Lots to say but will try to limit.
I set up a 4’x8’ test loop on Homasote and got out a PS2 engine and some cars.
I had a LOT of interference broadcasting from my living room to my TV in my den directly below the living room. Moved the receiver all over the house, both upstairs and downstairs and just couldn’t find an interference-free location. Around my little loop it would break up 6 to 10 times! Sometimes it would just be a quick zzzzttt and other times it would be like in olden days when you watched TV during a lightning storm and it really zapped. I recorded the sessions because Jerry, the proprietor, wanted to see the results. He said he had NEVER seen anything like my results and that it was BY FAR the worst he has ever seen.
Jerry has been very cooperative and supportive. We’ve spent many phone calls talking this over. What he thinks it’s down to is that I have too much hot-air duct-work under my living room floor, which I do. I have 3 of the 4 perimeter sides of the floor which have duct work under them. And this is in a very confined space of 15’x15’. Jerry calls my problem a problem of ‘reflection’.
But, being the nice guy that he is, he sent me a 2.4gHz mini camera w/sound, on trust, to try. I tried it. The picture is brighter and the audio is better, but the interference stayed the same. I recorded more sessions because Jerry asked for me to try certain things, so I did and sent the video to Jerry and he is stumped for a solution.
I’ve tried raising the 4’x8’ off the floor 3’ but that had marginal improvement at best.
I’ve moved the 4’x8’ layout in all places within the living room area to see if I just happened to originally set things up at the worst possible place - in the dead center of the living room. While there are
Walt, What about putting the receiver in the same room as the layout and dropping a feed to the den, utilizing an existing path thru the walls or actually an existing TV connection. Just a thought.
dougdagrump: if there’s a combination that I HAVEN’T tried I’d be surprised. I went as far as bringing my WOODEN step ladder into the same room and mounting the receiver on top of it in the middle of the loop and even that didn’t help.
TexasEd: The directions say for optimal reception to have both antennae in the same orientation - so I was careful to always do that. I even tried both being horizontal instead of the traditional vertical position.
One thing that I forgot to mention about the level of cooperation that I’m getting from Jerry: He’s planning on coming to a Monroeville (near me) train show in November and asked if he could stop by the house with some equipment to see if he could get this thing working better. Beat that for cooperation,huh? I point these things out about Jerry so it’s obvious that even he isn’t satisfied with the results and is concerned enough, and cares enough, to do the unexpected.
Is there a battery used in the camera’s power supply or does it just get power from the track?
We run a K-Line camera car on the club layout and it works pretty good, but everytime it hits a switch, crossover, some rail joints, etc., the picture pops and jerks as one might expect. Obviously the track and pickup rollers must be very clean as this causes problems also.
We have been discussing adding a rechargeable battery to the power supply as:
It would smooth track power interruptions
Batteries are great filters for noise on the internal power supply lines
Unlike the old Lionel camera car and like MTH sound systems, the battery would be charging most of the time
I will be interested to hear how it goes for you. I was also intrigued by their display at York, but I spent all my money on trains. Glad to hear you are getting great support from this gentleman.
If your using batteries for power, I’ve found they only last a few minutes before the transmission starts to become poor.
An antenna transmits sideways, so if an antenna is vertical it will radiate to the sides like a doughnut. Not vertically.
Likewise the receiving antenna will pick up the best signal from the same sort of direction. If you have one antenna on one floor and the other antenna on another floor they will not ‘see’ each other.
Ideally the receiver antenna needs to be at layout baseboard level, and as someone else has suggested, run the AV cables to your TV or PC.
The 1.2gHz and 2.4gHx wireless system uses whip antennas which are omnidirectional. Other than needing to be on, or very near, the same plane, there is no noticeable difference in lateral orientation
Governor: your comments are interesting. I don’t quite understand what you’re suggesting that though.
Jerry didn’t seem to mind that I was transmitting from upstairs to downstairs. I did try bringing the receiver into the same room. I don’t recall if I ever put it on the floor in the same room though. Jerry kept suggesting that ‘higher’ would be better. I only tried having both in a vertical position one time.
What test would you suggest that I do? I still have the test track up and am willing to try anything that might help.
As for running the signal thru a cable down to the TV, I did mention that to Jerry and he didn’t think the signal would be strong enough. I don’t have an easy way to test that and I’m not going to drill new holes in my floor/ceiling not knowing if it’ll work. I can use existing TV cable runs to get from the living room to my downstairs TV. If it works then would consider something more permanent. Remember, mine is a Christmas-only layout.
From what I gather, you have the txer in one room and the rxer (with the TV) in the room below (althoug vice versa arrives at the same conclusion).
A vertical whip antenna (or stiff wire in the case of the txer) radiates the signal in a ‘doughnut’ pattern, that is 90 degrees from the vertical i.e. sideways. There is very little signal radiating downwards from the base of the antenna, which presumably is the very direction you are wanting the signal to go.
With the rxer antenna also in a vertical position, that would be ‘expecting’ a signal from the sides, not from above.
If you haven’t done this already, it is worth laying both antennas horizontally and have the rxer as directly in line underneath the txer as possible.
One other course of action would be to have all the wireless cam equipment in the same room and use a ‘video sender’ kit to send the image to another room.
Govenor: Thanks. I have not tried anything like that. I would think there are are 3 ways to accompli***his test:
keep the camera (transmitter) upstairs but orient the antenna on it to be in the horizontal position. Keep the receiver downstairs and also orient the antenna horizontal (this is your scenario I believe).
Move the receiver upstairs to the same room and put in on the floor so that it is at the same height as the camera. have BOTH in a vertical, upright, position.
Keep the receiver upstairs in the same room. Put it on top of my wooden step ladder with the antenna oriented horizontally. set the antenna on the camera to be horizontal too. Similiar to test 1 but the receiver is in the same room.
Yes that’s right Walt, No 1 is how I meant it.
No 2 will give the best reception but obviously doesn’t get the image downstairs without more work/equipment.
No 3 won’t work if No 2 doesn’t so I wouldn’t even bother trying that one.
There is a slim possibility that there is some other equipment in the house that is causing interference on the same frequency (or a harmonic of it).
Microwaves, fridges and electric motors (both AC and DC) in various equipment can cause problems.
I tried only #1 and #2 and neither yielded results any better than I’ve been getting.
Spoke with Jerry yesterday and he said he is only a few days away from having a new prototype antenna ready for me to try.
I hope it works. Lately, each time I try something (and record it) I have a diesel either in front of of sometimes behind my steam engine with all its MTH smoke in glorious view and sounds accompanying all the motion! So cool. Then every 3 seconds there’s a zzzztt and mix in a few zaps too and, well, I just have to imagine how nice a clear constant broadcast would be.
Thanks for the suggestions. I need a new house!!! Yeah, that’s the ticket. Get a new mortgage so that I can use my $150 camera system! [:D]
Roy, excuse my rudeness for forgetting to acknowledge your comments. The camera for both camera systems are powered by battery but the receiver I have powered using a converter.
The horizontal antenna radiates downward, but needs to be aligned with the horizontal receiving antenna in the room below. The only way I know to radiate downward without requiring alignment between transmitting and receiving antennas is to use circularly-polarized antennas in both cases. Unfortunately, these are a bit more complicated than the dipoles you seem to have been using.
This is the same problem that GPS navigation signals have, radiating from above with no reliable alignment between antennas, and the same solution.
I can think of a possible workaround: Use vertical dipoles for both antennas. Put the upstairs trains on the floor and the downstairs antenna close to the ceiling, so that it is not far from the plane of the upstairs floor. A simple dipole is not highly directional; so, if the receiving antenna is no more than a few feet from the height of the train and off to one side of the track, it might get a reliable signal.
Thanks for the feedback on the battery. As I understand your more recent posts, this is occurring every 3 seconds or so. I also understand that it did not work any better when the TX and RX were in the same room.
If you are getting a clear picture (which you imply) in between the zaps, then I think signal level is not your problem. Otherwise you would have a lousy picture in between zaps.
I do not think changing to a dipole will help. Additionally a dipole requires a balanced feed line vs the ground plane and whip (1/2 of a dipole) that is the current configuration. This would require a balun to feed the center of the dipole which starts to complicate things. Without the balun the antenna pattern performance is no better than what currently exists (extending a second wire off the ground plane without a balun is simply an extension of the ground plane and not a good one either).
I think you have interference. Clean picture followed by chaos is typically interference.
As Governor suggested - look for some device that is cycling at the same periodicity in your house (i.e. an aquarium heater that is not working too well). Also try changing some of the components powering your layout, maybe there is a problem there. Make sure all your track is nice and tight at all connections. Also make sure you have a good ground to all your test system components if any of your equipment you are using requires ground.
BTW - another thought - I do not recall if you said it does this if it is not moving. If it can sit there for a long period with nothing else happening, then this would be related to the train you are running. I would also see how it performs by manually pushing the camera around if that is possible.
Good luck. I am out of town for all of this coming week at a Scout campout.
Roy, if my mention of “dipole” is what you are referring to, I wasn’t trying to suggest that a dipole would work any better than a monopole. In this case, I wouldn’t expect much difference in the radiation patterns.
I appreciate all of your suggestions and have mulled them over.
I don’t have any other electronice devices that might be sending out interferring signals so I’ll rule that one out.
As you suggested I tried:
a different transformer
Using DCS and then not using DCS
3 different PS2 engines and then one conventional engine
Tight track connections - I’m careful about that always. Plus, even though temporary, I do have it screwed down so I can move it around. But since it’s a battery powered camera I don’t get the connection there.
I hooked up 4 boxcars to an engine and taped the camera to the furthest one from the engine - versus other tests where the camera was taped to an engine.
With the camera taped to the boxcar, I unplugged the transformer. I held the car in my hand about 5’ above the track and walked it in an oval above the track.
I took everything off the track and pushed the boxcar around the track - once with power to the rails and once without power.
I record everything that I do. I didn’t notice any difference in the results no matter what test I looked at. I think my house it just not conducive to using the camera. Boo-Hoo!!!
When I watch a clear picture and think of how nice running this on my 14’x14’ Christmas layout with scenery would be I just keep holding out for some miracle solution!! It’s so cool to watch at track level.
thanks for all of the suggestions - I did try them.
Pat: No, I have not tried the K-Line car. Two reasons:
Spending $225 on a K-Line car just to see if it’s my house or the cameras seems a bit pricey - to me!
Now that I have experienced sound cameras I don’t think I’d much enjoy the soundless K-Line car.
Take it outside?! HMM, interesting. I guess I’d have to take the TV and receiver outside too to eliminate the issue of the duct work getting in the way. I think I’ll give that a go. What the hey, I’ve tried everything else!