As promised, I’ve written a short tutorial on how to get your Fine Offset cloned weather station, be it a WH1080/81 - W-8681 or whatever, optimised for DCF reception in the UK.
This should solve any problems once & for all - I hope you find it useful 
Richard
Hi Richard,
Although I don’t have one of the Wx Stns mentioned, I can see that you have done some excellent work on the topic to overcome the problems. Thankyou for passing on the detail in such an informative way. 8) To those who have these wx stns, I’m sure that it will be much appreciated. 
Good stuff, just a couple of questions:
Why do you say “the fact it is now closer to the 868 Mhz data transmitter’s PCB track antenna, is of absolutley no consequence”?
Where is the transmitter in the picture of the mast, anemometer etc.?
The data transmitter’s frequency is close to 1GHz and it’s output power is in the order of a few microwatts.
The DCF rod antenna, is tuned to 77.5 KHz, approximately 11000 times lower in frequency, than the data transmitter.
With this huge difference in operating frequencies, there is no possibilty of any cross interference - they could almost be
phyiscally coupled together and both would still operate seperatley as intended.
The transmitter unit is tucked under the mini Stevenson’s cage on the left-hand arm - You can just make out the base.
It simply slots over the transmitter unit and is held in place by friction and good old gravity.
Richard
I’m not sure I agree with that. I agree the resonance is not an issue, but I would guess that the low frequency ferrite of the DCF antenna is quite lossy/absorbent material at the data transmitter frequency and you are putting a large lump of it right next to the UHF antenna. If it works, it works, but I don’t think it’s good practice.
Point taken - however a solid brick wall in the line-of sight of the transmitter, will have a far greater impact
on the EIRP & hence received signal, than a small piece of ferrite very close to the transmission source.
The base unit/receiver is situated about 50 meters from the outdoor sensors - the signal has to pass through1 cavity
wall and 5 single brick walls. I get a good S20+ signal every 48 seconds, on the handheld UHF RX next to the station :bounncy:
Richard
Timetec, I wonder if you could give me the benefit of your experience with the WH-1081?
I’ve just bought one ‘ex-display’ on ebay. Set it up and powered it up and waited for the display to show data from the external sensors. Nothing seemed to happen although occasionally the wind-direction indicator changed indications. There was no wind-speed or external temperature display.
After a while I decided to investigate.
I couldn’t determine how to know when the “initial measurement checks” were complete or when the “…start to register the transmitter” phase was complete. Instructions warn not to touch the unit during this time but give no clue as to how to recognise this state or the following “normal display mode”.
I found your pages on the DCF issue and decided to open up the transmitter. Your tip to use a chamfered credit-card corner only resulted in a shredded C.C. edge. I eventually got the clam-shell open using screwdrivers (no chance of hiding those marks!) - I’m pretty sure it had been opened previously and stuck back together with ‘super-glue’ since at one point the front-cover edge cracked rather than the glue-bond breaking.
Anyhow, with the PCB out I got a surprise - there is no DCF antenna. Where your photographs show it tucked under the humidity sensor this board has nothing, no wires even. Unfortunately your photographs don’t show the solder-side of the PCB but I am very much hoping you’ve got such a photograph to share so I can determine which points the antenna wires should have been soldered to, and check if there is any sign they were ever there.
My second question is, is it possible the design has somehow changed and the DCF moved, or could it be the antenna really is missing?
If I can get the unit fixed and working my intention is to write a Linux driver and/or application interface for it, but first it has to work!
I’m attaching a couple of photos of the PCB so you can see for yourself and be certain we have the same unit.
Just a guess, but is it possible that you have an accessory/add-on temp sensor (if such a thing is available for that station) rather than the master temp sensor that is normally shipped with the station. Seems likely that only the master sensor would have the time receiver.
Hi - Your outdoor sensor/transmitter unit certainly does not contain any form of DCF time receiver.
There is actually a big photo of the back of the pcb on the webpage (directly above the Hedgehog photo)
You have no ferrite antenna, no DCF receiver/decoder chip or any of it’s associated components.
Incidentally, the wires from the ferrite rod antenna, are the red & black ones shown in the photo.
You say ‘My second question is, is it possible the design has somehow changed and the DCF moved, or could
it be the antenna really is missing’ - spot on… It sure is missing alright & I’d put money on it that it is tucked
away inside the base staition unit, possibly due to the problems many users have been having with reception.
Good luck - Richard
Thanks Richard, I’m opening the ‘base-station’ up as we speak. I just drove a post into the middle of the field (I’m on a farm) and mounted the weather-station on it to avoid any wind errors caused by trees and buildings.
I was so intent on looking at the individual pages on your site I totally missed the side-bar photographs!
It does seem strange the unit doesn’t seem to do anything if the DCF is in the base-station. Is the display supposed to indicate when it is receiving data from the weather-station? I thought I saw a photo with a transmitter-tower icon in the lower-left corner but I can’t see any mention of it in the instructions.
It looks as if this WH-1081 doesn’t have a DCF receiver at all. You’ll see from the attached photographs there only seems to be the 433MHz receiver in the base unit.
What is interesting is that after re-assembling the base unit I used a different set of Ni-MH AA cells (from a box of them I keep close) and almost immediately the base unit was displaying outdoor temperature and wind-speed values instead of the --.-- type values previously. The values don’t look correct (15.4C temp, 0.00 wind-speed) but this might be progress.
I then found that by touching the screen the “+ [on/off] -” buttons appeared to the right of the Tendency indicator and I was able to change the C/F indicator for the indoor temperature. Exploring further I was able to set the date and then, amazingly, set the time. Now, this is where it gets interesting.
Here’s what I see/can do for each touch of “Time”
Presses Display Actions
1 “1c d5” LCD contrast 0-9 (1c d0 - 1c d9)
2 “1” adjusts from -12 to +12 - not sure what this is
3 “24 Hr” 12/24 Hour display
4 “18” Hours adjust
5 “44” Minutes adjust
6 Exit
Does this mean the unit doesn’t have DCF at all? Do DCF units allow setting the time manually like this? I’m wondering what the 2-touch setting does since there is no indication or obvious change like there is with LCD*
It’s pleasing to report that the unit now appears to working correctly.
After fixing the weather-station into the top of a post in the middle of the field there was data reception but no wind data. Then I noticed that over an hour or so it was showing several millimetres of rain when there was no rain. I re-checked the connections on the transmitter and was laughing at myself when I found I’d accidentally connected the rain-gauge to the wind input and visa-versa :oops: :roll:
Now I’ve got over the missing DCF issue and the base station is using a different set of rechargeable Ni-MH cells it seems to be doing everything advertised, with data collection via USB to WeatherDisplay on Ubuntu Jaunty GNU/Linux 64-bit is working well too.
I’m still puzzling over the -12/+12 adjustment on the time although I’m assuming it is daylight savings.
One last question I have on this unit - there is currently a rain-shower passing over and it made me realise there isn’t a rain-sensor as such, only the rain-gauge depth indicator which is unlikely to report it. The relative humidity is reported at 74% but is there a level of R.H. below 100% that would definitely indicate a rain shower?
Even 100% humidity doesn’t mean it’s raining.
Optimised DCF for Europe ~ 1500 km ???
I have four receiver with DCF reception ( DE - Frankfurt ).
3 Oregon ( BAR-208, BAR-206, BAR-339 all with one sender 
) and one LC WS2357.
Only Oregon BAR-208 receive this signal.
What can I do to improve reception ?
Thanks in advance
Mike
PS. Receiver ( ferrite ) are in base station
Hi,
Just wonder how constant the DCF reception is for you guys?
I seem to get a signal over night but the icon disappears during the day on my (ebay) WH108?
I orientated the flat face of the mast temp/rh box towards the SE but this did not seem to make any difference.
No big problem since I guess that even a few mins of reception a day will keep the clock accurate enough.
Still think the unit is cracking value.
James
