How to extend the range of a 433 MHz garage door controller

Thread Starter

teliocide

Joined Sep 26, 2013
111
Greetings
A friend has installed a remote controlled gate on her property. It is RF controlled 433 MHz. The range of the transmitter is about 30 m but needs to be 60 m.
Does there exist a device such as a relay that will receive to signal from the transmitter and relay this to the receiver.
I think she is looking for a commercial (off the shelf) option but I would be interested in other solutions.
Thanks
 

MrSalts

Joined Apr 2, 2020
1,762
Greetings
A friend has installed a remote controlled gate on her property. It is RF controlled 433 MHz. The range of the transmitter is about 30 m but needs to be 60 m.
Does there exist a device such as a relay that will receive to signal from the transmitter and relay this to the receiver.
I think she is looking for a commercial (off the shelf) option but I would be interested in other solutions.
Thanks
Has she contacted the remote controlled gate's manufacturer? I can't imagine that she is the first to have this problem.

https://www.amazon.com/Extender-Transmitter-Receiver-Frequency-Repeater/dp/B07XQC1JSB
 
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SamR

Joined Mar 19, 2019
4,194
Usually, one of these is a starting point...
1651202076673.png
There are pricier/better models available but this should double your distance.
 
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Thread Starter

teliocide

Joined Sep 26, 2013
111
Thank you SamR
The seller is just an Ebay re-seller and all questions are meaninglessly answered by Chat-bot. There will be no joy there.
Thanks for your input.
 

Ya’akov

Joined Jan 27, 2019
5,660
Greetings
A friend has installed a remote controlled gate on her property. It is RF controlled 433 MHz. The range of the transmitter is about 30 m but needs to be 60 m.
Does there exist a device such as a relay that will receive to signal from the transmitter and relay this to the receiver.
I think she is looking for a commercial (off the shelf) option but I would be interested in other solutions.
Thanks
Do you have the make and model of the gate opener?

Ideally you should analyze why the performance is so poor. 30m doesn’t seem to be a particularly good range for a 433MHz control system. Some part of the system is underperforming and while it you can guess at the cause and try solutions, actually measurement and troubleshooting would be far better than guessing.

An external antenna for the receiver, as mentioned about is the obvious solution. Doing what you want and staying legal is probably only possible by increasing the sensitivity of the receive side, though it is not impossible that the transmitter is poorly designed and not taking full advantage of the legal ouput power.

@SamR‘s antenna is a ¼ wave dipole which is an omnidirectional antenna. That would have an omnidirectional radiation pattern which is probably not ideal. It is unlikely that the 60m requirement includes from behind, for example. This means that half or more of the the meager gain from a ¼λ dipole will be wasted.

The version @SamR posted relies on the aluminum mounting bracket as the gourd plane. It is far from ideal. If you do get such an antenna you can probably improve the performance by adding four radials from the base. In this case they would need to be about 184mm, and should come from the base at a 45° angle. This should make a noticeable improvement in performance.

The antenna recommended by @DickCappels is a directional antenna, specifically a Yagi-Uda array. It exhibits a high degree of directionality and rejects signals from the back. It has a large gain figure compared to the ¼ wave vertical at a cost of price, complexity, and space but it may well be worth all of that.

The important figures in choosing a Yagi-Uda or any other directional antenna will be front to back ratio which indicates the difference in reception from the front of the antenna compared to the back. This can help if interference is part of the problem, which is possible but not as likely as other things; and beam width which indicates the width of the expanding cone of reception at the front of the antenna. If the beam with is too small at the short 60m distance it might reject signals off axis in such a way to prevent operation when the transmitter is not directly aligned.

The latter, beam width, is likely the more important of the two. A little geometry will give you a reasonable estimate of the coverage area at the desired distance. Keep in mind it will get narrower the closer you get but thanks to the inverse square law, so will the received transmitter power so it might be a wash.

Bottom line is without further information, the obvious answer is an improved receiver antenna, but the device might already have the common sort of ¼λ vertical suggested. If so, one or both of two possibilities are available: shorten or improve the feedline which can be a source of substantial loss if it is low quality coax or too long, and add radials to improve the ground plane if they are not present.

I still suggest you investigate that the devices—transmitter and reciever—are actually operating properly before making modifications.
 

Janis59

Joined Aug 21, 2017
1,383
RE:""should analyze why the performance is so poor"" - about 50% of Chineese duckneck antennas are brutal crap. Test it on VNA and find WSVR like 100 or at least 10. Reccomend to start with adjusting the antenna geometry keeping in hands the VNA.Then, if antenna is OK, just apply the larger gain antenna, for example double flower pot collinear antenna with 8 dB or elongated collinear with teen dB etc.
 

SamR

Joined Mar 19, 2019
4,194
As a side note... Everything on Amazon has another source, often cheaper. But Amazon is a good place to browse the available market for goods.
 

MrSalts

Joined Apr 2, 2020
1,762
You certainly don't want your garage door opening at the same time as everyone elses on your street. Yes, now they are addressable...
But also, I'd rather see it close and open - see who is waiting in the dark to run into my garage rather than opening it when I'm a 1/4 mile away. See who is getting crushed as I wait for it to go down rather than drive away and then push the button after I get on the main road.
 

Thread Starter

teliocide

Joined Sep 26, 2013
111
Its just a cattle gate in the bush (Crocodile Dundee Country) 25 hectares of scrub. The nearest neighbour is half km away.
The objective of the installation was to open the gate from the car when raining, and to open the gate from the house when visitors arrive. House to gate is at least 60 m
There are several trees between the house and the gate.
https://www.ebay.com.au/itm/352735702767
Yes, I know it is clearly stated 30m range.
 

Thread Starter

teliocide

Joined Sep 26, 2013
111
Please could you rough sketch this for me.
Thanks
Greg


If you do get such an antenna you can probably improve the performance by adding four radials from the base. In this case they would need to be about 184mm, and should come from the base at a 45° angle. This should make a noticeable improvement in performance.
 

LowQCab

Joined Nov 6, 2012
2,050
The Hook probably won't do anything to the performance,
if you're going for the absolute maximum performance You can get, then use a small piece of Rope and a Nail..

The Loop should only be large enough to easily fit over the Hook.
most of the Loop should be Taped-down with electrical-tape to keep it physically close to the Main-Radiator.

If You are using bare Copper-Wire for the main Radiator,
the bent-over-Tip MUST BE INSULATED from the main Radiator, they MUST NOT TOUCH (Electrically).

The "folded-back" tip of the Radiator is a specifically Tuned part of the design,
and the dimensions shown in the Picture need to be followed as closely as possible.

Use high-quality, brand-name Coax-Cable, no Chinese garbage, and no "TV-related" Coax.
How the coax is connected and Soldered is critical to good performance.
.
.
.
 

Thread Starter

teliocide

Joined Sep 26, 2013
111
To put things into context where I live is the Australian equivalent of (for Americans) of Matthew Island.
The nearest fully serviced city is 2848 km away.
Getting what I want is both a challenge and a very long wait.
But the local shop has
50 Ohm RG174U Coax Cable
I have no idea of the origin so I am not sure if it is suitable?
 
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