Cumulus Support

Hi

I've just noticed that one of my neighbours has put up another FO station and unfortunately it is in a better line of sight than my own. My signal has to pass through several walls ! His is behind my screen (mine in front) - is there any way I can shield his signal with a grounded metal (foil) back to my screen ?

Regards

Alan

apenwith wrote:Hi

I've just noticed that one of my neighbours has put up another FO station and unfortunately it is in a better line of sight than my own. My signal has to pass through several walls ! His is behind my screen (mine in front) - is there any way I can shield his signal with a grounded metal (foil) back to my screen ?

Regards

Alan

There's no easy answer Alan,

As these systems use FM to modulate the data (I assume that this is correct) the receiver will inherit the 'capture effect' which means the strongest signal will completely block out the weaker one. Trying to screen the receiver will have little effect as the signal will be bouncing around the rooms.

The only useful way would be to re-site your remote units so that they are nearer to your receiver and a better line of sight than your neighbour's. I assume you can't re-site your receiver and computer.

There would be a technical solution. If you were to site a small aerial (even a bit of stripped off coax outer from a coax cable) both end of a low-loss piece of cable, siting the ends to the remote transmitter and the receiver respectively it may route a signal that would be stronger than your neighbour's. Can't guarantee that that would work but it's a easy option to try if you have room to cable it though walls, etc.

I am dreading this happening to me, but I know most of my near neighbours well, and they would probably ask my advice before buying a WX station; I could then advise them to get a different make on a different frequency.

Let me know how you get on.

Mike (Retired Radio and Electronics Engineer).

Hi
Thanks for that - unfortunately, as you say I can't really move the computer and the sensors are almost ideally situated on top of my barn so I'd be reluctant to move that (the sensors - not the barn). I could use a long USB cable and move the base, it's not really essential to have it in sight. I'm intrigued by the coax cable but did not really understand the make up. I don't know what aerial the receiver uses - would it be feasible to remotely locate that connected by screened cable or would that just pick up even more interference ? I think I read somewhere of someone making a yagi - possible ? I'd even thought of hard wiring as I already have a cable running in from my sunshine recorder that has spare inners.
First the coax if you wouldn't mind explaining in a bit more detail
Thanks again
Alan

Alan,
That was going to be my only suggestion as well: a directional antenna on the transmitter.

Even that's not an easy solution. Assuming you can buy/build one and properly attach it to your system...then decide whether to mount it vertically or horizontally. Then the next question might be to build a helix antenna which takes advantage of both vertical and horizontal planes.

All this assumes you have enough background (or a good friend with enough background) to buy or design and build such a system and install it. I know of no effective way to shield the neighbor's system.

Esentially, short of some sort of amplifier (which is probably illegal) moving the hardware may indeed be the easiest. I, frankly, was unaware that all FO systems were on the same frequency .... kinda silly actually since manufacturing say 10 with different freqs wouldn't cost a dime more...but that being the case its unfortunate. I have a neighbor behind me who has a system as well but thankfully its not a FO.

apenwith wrote:Hi
Thanks for that - unfortunately, as you say I can't really move the computer and the sensors are almost ideally situated on top of my barn so I'd be reluctant to move that (the sensors - not the barn). I could use a long USB cable and move the base, it's not really essential to have it in sight. I'm intrigued by the coax cable but did not really understand the make up. I don't know what aerial the receiver uses - would it be feasible to remotely locate that connected by screened cable or would that just pick up even more interference ? I think I read somewhere of someone making a yagi - possible ? I'd even thought of hard wiring as I already have a cable running in from my sunshine recorder that has spare inners.
First the coax if you wouldn't mind explaining in a bit more detail
Thanks again
Alan

Hi Alan, as Steve said you could have an antenna each end but it's a bit of a constructional nightmare custom building two long Yagis for 868MHz and there's no guarantee it would work.

If you have spare cables in the coax connect a single piece of wire about a foot long to the transmitter end of one of the spare cables and wind it around the transmitter box. Do the same to the other end and tape it to the back of the receiver. It may just transfer enough signal to the receiver for it to overcome the interference from the neighbours set up.

Do let us know if it works, it may help out some other users with poor or intermittent signals.

Good luck

Mike.

Hi Alan,

I have no background in Electronics to be honest or Radio Frequencies but,
Would it be worth comparing the '868hmz Transmitter Board' & '433mhz Transmitter Board' to see if
there are any differences, to suggest thats how the frequency is decided. If that makes sense?

Im thinking, it could be a simple join that decides the Freq, I.E 868 or 433?

If you can and you see a difference, then you may be able to mod both the Transmitter and Reciever to the new Freq?

As I say, I have no real knowledge of this, (But I'd like too), So it may be a silly idea.

All the Best

Jason

6719jason wrote:Hi Alan,

I have no background in Electronics to be honest or Radio Frequencies but,
Would it be worth comparing the '868hmz Transmitter Board' & '433mhz Transmitter Board' to see if
there are any differences, to suggest thats how the frequency is decided. If that makes sense?

Im thinking, it could be a simple join that decides the Freq, I.E 868 or 433?

If you can and you see a difference, then you may be able to mod both the Transmitter and Reciever to the new Freq?

As I say, I have no real knowledge of this, (But I'd like too), So it may be a silly idea.

All the Best

Jason

Jason, I very much doubt that there would be an option of converting the board from one frequency to another. It would require two output sections on the same board, not economical for the manufacturers.
It is a pity that they don't have a number of channels to choose from, like video senders., so that you could switch it do a different channel to avoid interference.

Mike.

Repairman77 wrote: Jason, I very much doubt that there would be an option of converting the board from one frequency to another. It would require two output sections on the same board, not economical for the manufacturers.
It is a pity that they don't have a number of channels to choose from, like video senders., so that you could switch it do a different channel to avoid interference.

Mike.

Thats fine. Mearly a suggestion. It wont do any harm to check however. As I said, I have no real knowledge of this subject.
I appreciate your comments

Jason

Off-the-wall idea (thanks Jason!):

Frequencies can be "tweaked"...that is to say that someone with an oscilloscope and a couple of small variable capacitors could actually move, slightly, both the transmitter and receiver frequencies without too much trouble but it may, too, be illegal. A small change in frequency may be enough to counter-effect the neighbor but this would be considered a "hack".

Ok since we're in the realm of surreal, here's another:

Move the transmitter closer to your house/console using phone cord extension cables and phone-cord couplers...thereby increasing the amount of signal to your console in hopes its enough to override the signal strength of the neighbor's system.

Another pint and I'll have this figured out!

How about suggesting to your neighbour that he has purchased the wrong fine offset and that he should have got the wh1081 (433MHz)....as used in NZ and other places. Probably 433 is an illegal frequency in the UK but hey....it's only for 100 metre range and very low output power.
The 868 is double the 433 +2. Must be something in the output stages or just a different crystal?

Super-T wrote:How about suggesting to your neighbour that he has purchased the wrong fine offset and that he should have got the wh1081 (433MHz)....as used in NZ and other places. Probably 433 is an illegal frequency in the UK but hey....it's only for 100 metre range and very low output power.
The 868 is double the 433 +2. Must be something in the output stages or just a different crystal?

They do use 433MHz over here for remote thermometers etc. Legal at low power.
Think the wire wound round the Transmitter and Receiver would be the first step to try, especially as you already have the cable in place with spare inners.

Mike.

My Fine Offset from Maplin uses 433 Mhz, according to the print on the battery cover.

steve wrote:My Fine Offset from Maplin uses 433 Mhz, according to the print on the battery cover.

There were no labels on my battery cover Steve, but the main box had a label on it saying '868MHz'.

I rather think they are trying to change all these remote devices over to 868Mhz as 433MHz falls right in the middle of the 70cm Amateur Radio band. Any transmissions around those frequencies would probably block out the signal to remote stations.

Guess the latest to come out from FineOffset/EasyWeather will all be 868MHz.

Mike.

Mike, one problem I have found is that if I try to run my Fine Offset (433 Mhz) and my Davis VP2 (868 Mhz) at the same time, then my VP2 is prone to losing contact with its sensors from time to time, so I assume the Fine Offset signal is interfering. Oddly (to me, anyway) the problem doesn't occur if I switch off the Fine Offset console (disconnect and remove batteries) but the sensor is still transmitting. Do you have any suggestions for resolving this?

steve wrote:Mike, one problem I have found is that if I try to run my Fine Offset (433 Mhz) and my Davis VP2 (868 Mhz) at the same time, then my VP2 is prone to losing contact with its sensors from time to time, so I assume the Fine Offset signal is interfering. Oddly (to me, anyway) the problem doesn't occur if I switch off the Fine Offset console (disconnect and remove batteries) but the sensor is still transmitting. Do you have any suggestions for resolving this?

That's very weird Steve. I can understand the 433MHz FineOffset transmitter interfering with the 868Mhz Davis receiver as it's the 2nd harmonic (or near enough). But why removing the batteries from the FineOffset console should make any difference makes not a lot of sense technically, as the console is only a receiver. However if both consoles were placed side by side the receiver local oscillator in the FineOffset console could interfere technically with the receiver in the Davis console. Have you tried experimenting by moving the two consoles as far apart and as near as possible and see if there is any interaction?
Mike.