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Tellstick Znet Lite v2 seems really bad

Posted: Wed Jan 29, 2020 6:42 am
by ArneE
Bought the Tellstick Znet Lite v2 more than a year a go to get Z-wave capability. Have used a Tellstick Duo for years with very good coverage on 433.
With the new Znet, the coverage on 433 is maybe fair (I can reach all my old sensors), but update frequency is varying. Sometimes you get new figures regularly, but sometimes the values are 10-15 minutes old or even from the day before!
I then added a Z-wave Telldus door sensor to mainly test the Z-wave functionality. The range is about 5 meters in free space! Suspected some radio disturbances and added a longer ethernet cable to have some meters distance to anything that could cause radio interference (like the router). Still about 5 meters range!? Have changed to another door sensor with exactly the same bad result.

Anyone else seeing the same behaviour (fair or bad 433 functionality and basically no functionality on Z-wave)?

Re: Tellstick Znet Lite v2 seems really bad

Posted: Wed Jan 29, 2020 7:49 am
by etompau
I have replaced a Net with a ZNet, in a system with quit a lot of sensors and 433 receivers. Distance to these vary from perhaps 2 m to 20-40 m in external garage and garden. Control of receivers and receiving of data works OK.
I use an external antenna on the ZNet, which I strongly recommend you to use (if you don't already have one).

Regarding Z-wave, don't expect to get the same distance as with 433 products. The Z-wave relies heavily on the mesh technology. It might well be correct that a single battery operated Z-wave contact only reach around 5 meters in radius distance. Ensure that the magnet contact is not mounted on a metal frame or similar, this will affect the tuning of the antenna. The same goes for the ZNet box itself, don't place it on a router/switch etc for best radio performance of the Z-wave-module.

Re: Tellstick Znet Lite v2 seems really bad

Posted: Wed Jan 29, 2020 9:41 am
by ArneE
Ok, thanks for the comments.

If the update is slow as in my case on 433 I see it hard to use for alarms (like intrusion alarm). For temperature monitoring is ok.
Adding an external antenna (other than the one provided) will probably improve performance on 433, but has nothing to do with Z-wave since that antenna is internal in the box on the circuit board.
Already that design difference will get a loss in performance compared to 433 probably around 10dBs which is a lot.

It seems Telldus guys don't know much about radio technology. I beleive they are all hackers.

So, I will try some more Z-wave devices (starting with one power supply connected close to the controller) to see if it works better (i.e. improves coverage).
I'm really looking in to buy another controller. It seems though like everything else is a lot more expensive. Maybe it is as simple as you get what you pay for as usual....

Re: Tellstick Znet Lite v2 seems really bad

Posted: Wed Jan 29, 2020 10:11 am
by etompau
As far as I know the Net and ZNet use the same 433 MHz radio chip. There is no need to re-design a working construction.
The construction probably originates from some application note.

Then, we are talking about consumer grade electronics. A spread in performance/tuning can occur.