Current Cost Support Forum

I don't see any instructions in the energy monitor booklet saying what is the optimum distance (or rather the maximum distance) between the display unit and the meter. I have this query because my meter is outside the block of flats I live in and on the ground floor. My flat where the display unit will be located is on the first floor. About 30 feet or so. Will that be too far for it to pick up the signal?

June Tranmer

The CC FAQ says max about 30 metres, but that is in clear sight. The actual distance will be reduced by intervening walls and their composition. If the Meter box is metal the distance will be severely reduced.

So there is no easy way to tell. Can you purchase with the right to return if it won't connect?

My experience won't help, I connect over 15 feet with 1 intervening drywall.

Come on people give the OP some guidance if you have a distant connection.

_________________
Seeker
"The Truth is out there!"

I'm having a fair bit of trouble with my own unit at the moment, loosing it's sigal quite often at about 15 feet, so my answer is not very positively encouraging unfortunately.

For the OP.
I guess, if the meter cupboard is on the outside wall and your receiver is situated somewhere close to directly above the sender unit such as close to a window on the same side, then there may be less walls and other obstructions to deteriorate the sigal.

Sometimes radio waves can reflect off things as well as be blocked by others, so sometimes what works in one location may not work in another despite any maximum distances.

I'm sure no one has tried this as of yet but if someone was really determined and had the skils, they could open up the sender unit, unsolder the existing aeriel/antenna and attach a peice of 50 ohm coax to effectively make an extension for the aeriel. The outer of the coax would need to connect to the negative battery terminal or groundplane on the PCB and the center core to the original output connection.

At the other end of the coax, the original aerial could be connected to the center core of the coax and the outer sheild left disconnected or could be splayed out to make what is termed a ground plane.

The length of the wire used for the aerial/antenna part it's self, is very important, so if someone were to attempt this one shouldn't just any old piece of wire of random length and hope for the best, as they will most likely make the situation much worse.

The correct length calculates to about 17cm for what's known as a quaterwave whip antenna. This is the length from where the groundplane ends to the tip of the antenna.

I wouldn't really reccommend doing any of this unless you/someone had a bit of experience with soldering etc.

Also bear in mind that it would viod any warranties if the units have been tampered with.

There's an idea for CC - Make a TX which can accept an external aeriel for people who need to extend the range or need to get the aeriel outside of a metal meter cupboard. CC could potentially make a higher RF power version but there are loads of legal issues and regulations associated with that, not to mention added power drain/reduced lifespan from the batteries.

Another solution would be to extend the wires on the sensor clamp which would be far easier, rather than the aeriel BUT bear in mind that the sender units are NOT water proof if used outside. Again CC could in theory produce one of these clamp extension cables quite cheaply and easily as an optional extra!

This transmitter seems to have the external aerial.http://www.smartnow.com.au/wp-content/uploads/2011/04/EnviR-transmitter.png now all we would need is the ability to attach a high-gain version.

OP. Hopefully you wont need to do anything like this. Can you borrow a transmitter and receiver from someone in your area? It would not need to be installed. Just check they are communicating.

_________________
Seeker
"The Truth is out there!"

Yes, that's the same type of unit that i have but i think maybe you have misunderstood my meaning.

I meant a removeable aerial, which attatches via a connector so that it can be replaced easily, like you say, with a higher gain aerial or a cable to extend the existing aerial to a different location. Thus avoiding all my waffle above.

The aerial that is used on that transmitter is essentially just a helical coil of wire of the same "red" type used on the Dev Boards but housed inside the plastic that you see and directly soldered to the PCB. So of course, non removable by the average user.

My points are all quite moot but i was just exploring the realms of possibility for those who may be so inclined if they really wanted to overcome a potential obsticle.

I agree with you that it would be much better to borrow a unit and try it out to know for sure.

I can tell you, that the external "aerial" is nothing else than a piece of plastic, does not contain any antenna, or anything. The transmitter has just a 16cm piece of wire inside the unit.

Sorry OP, we seem to have hijacked your thread.


Well that is very interesting. I wonder why?
I can think of two explanations.

• The styling/marketing department thought an aerial looked sexy. A clue may be in the rounded top styling.
• An external aerial was planned but was withdrawn(cost/tech reasons?) from the design before finalization

The plastic "aerial" doesn't look long enough for a 16-17 cm aerial. Is it?
Could the plastic be removed and a SMA connector inserted? Could then plug in a directional antenna.

_________________
Seeker
"The Truth is out there!"

In the transmitter unit that i have, there is a spiral wound piece of red wire inside inside the plastic aeriel. I disassembled the whole unit including the plastic aeriel, essentially out of curiosity. The two halves of the plastic aeriel are glued together and can be seperated without any significant damage to the plastic (atleast in my case) by carefully prising them apart (and using some simple tools such as a sharp scalpel etc.)

I haven't measured the exact length but it's about 16-17cm which would be the correct length for a quater wave at 433 MHz.

In my estimation the wire is probably 7 x 0.2mm stranded hookup wire or something very similar. It's exactly the same in appearance as you will find on the CC dev boards if anyone wishes to look at pictures elsewhere and not distroy their own unit.

On the EnviR LCD display unit, the same style of wire is also used and that is just pinned around the outer edge of the EnviR case with a bit of hotmelt glue to keep it in position.

Not all units may be the same, i can only comment on the particular unit that i took apart which had a spiral of this wire inside the plastic aeriel. Other units may be completely different and we may both be correct so please don't think i'm saying you are wrong.

P.S. My appologies for hijacking the thread!

So it should be possible to 'manufacture' an external antenna using the dimensions of the existing wire dimensions as a guide, coax as long as you need clear the meter box, brazing rods or even a coat hanger reshaped and trimmed to harmonic length as the active radiator and radials (4 off the ground shield of the coax/terminal connector. Alternatively a long piece of shielded wire (multiples of the original antenna) under your house or along an eave in the approximate direction of your receiver.... test by comparing signals of original and modded antennas.

I installed it and it's working. Thanks for all the help everyone.

June