Dramatic Difference with Lightning Detection Signal

After finding the radio interference problem caused by a plug in power supply unit, (link to Thread), this also caused power quality issues to the Blitzortung lightning detector to which it was powering, here we have a before and after traces of background noise:

blitz badPulses caused the automatic gain to be reduced, effecting the detection range.

blitz goodConsiderable improvement of signal quality.

detectionLightning detection trace, this trace was captured during the storm activity in the image below.


The green squares indicate stations online, the grey squares are stations that are currently offline.

Electrical Interference – The hunt with my mate Billy.

I have had a problem of a really strong pulsating radio interference signal lifting my noise floor, the strongest signal were at 350Mhz, 521.5Mhz, 924.7 Mhz, 990.3Mhz, 1.802Mhz, 145.537Mhz and 145.000Mhz detected by my trusty AM radio, Billy.

SAM_5244 (Large)Billy the Fish with a broken gill.

Preliminary investigations walking around the house and outside pointed to it being the neighbours solar panels as when I got near to his garage where the inverter is located, Billy went nuts, it was as though it was radiating out everywhere, putting Billy over my buried radials in lawn amplified this signal up, even putting the radio near the earthed outside tap picked the interference up.

As I was convinced the interference was from outside of my house, the only way to prove this was to turn the power OFF to the house, so with Billy in hand, I turned the power OFF expecting the radio to go quiet, but it didn’t!

Looking around in the garage, where I turned the power off, for a source of the noise, I saw the UPS for the PC was ON, turning this OFF the noise reduced, but still did not stop, walking around with Billy the interference was still very evident.

Went inside the house and heard two other UPS bleeping, the first one is in a room directly above the garage and as soon as I turned this OFF the majority of the noise stopped.

SAM_5251 (Large)

The next visit was to a room off my home office where my network kit is installed, the main UPS is fitted there, turning this off and the radio went dead quiet, so much for my theory of blaming the neighbours solar panels!!

SAM_5246 (Large)

So now to start turning things back on, with all the breakers off, I turned the main power switch ON, and the radio stayed quite, turning the breakers ON one by one, I didn’t get very far until the radio kicked off again.

First breaker causing a problem was the garage sockets, turning the switches on the sockets OFF in turn, I came to one which stopped the noise when turned off, it was a 12v switched mode power supply for a camera causing the interference.

The next breaker to cause me a problem was the one to the house sockets, switching this ON, yet again caused the radio to detect interference, back into the house with Billy, the hunt was on!

It turned out to be right under my nose in the office, it was the Blitzortung lightning detection controllers power supply unit.

SAM_5243 (Large)

I will investigate sourcing a low noise 5v DC linear PSU as well as making improvements to the controllers earthing as I don’t want to disable the unit.

I do have background hum from the power supplies feeding the Netgear switches and other small load items, but it’s nowhere near as bad as it was and I know what’s causing it, which is good, total elimination is the optimal solution, but proberbly unrealistic, so bit by bit I’ll chip away and get the noise floor as low as I can.

Web Site – Alerting of Inaccurate Data

Data has to be accurate and reliable, this is especially true of weather data, Chatteris Weather uploads in ‘Rapid Fire’ mode its data status for a whole range of variables every 2.5 seconds, this allows the gauges and wind speed and direction to seem so responsive, so how do you when the site its not updating or putting it another way, how do you know if the data is stale?

Here at Chatteris Weather, we use three ways (excluding the status update page).


If the site is going to be down for maintenance, we will post up description and predicted down-time, this message will be displayed in a yellow warning box at the top of each page.


The Weather PC uploads a changed file each and every time, this file is called clientraw, a script within the weather template compares the time of last clientraw arrival with the current time, if no change has taken place, a yellow alert box will open on the home page and it will say that an error has occurred and the clientraw file has not updated for x minutes.

This works really well, however, as I have an older PC running numerous weather related programs, when one which is particularly heavy on processing starts, the clientraw error might appear until this program finishes and PC resource are again available, an example of a short duration, but high processor usage is the creation of the movie files used in the time-lapse playback pages.

It may well be that clicking on refresh, will clear the error message.

The clientraw error message is fine to let site visitors know of a problem, but I need to know if something’s not right without constantly being sat on the site, I have done this in a number of ways, one is using a free service provided by Pingdom, this checks the accessibility of Chatteris Weather and sends me an e-mail if it gets no response, I have set the check time to every 15 minutes, the downside to this method is that Pingdom has to visit the site in order to determine if its available and consequently my ‘Whos-Online’ script counts it as a visitor, hence installing the RevolverMap as this discounts these ‘bot’ visits.

ping logo

ping1Example of Pingdom status report.

Pingdom alert e-mail examples (The check-time was originally set to 1 minute before I relaised the impact on visitor numbers) –

PingdomAlert DOWN:
Http://www.chatteris.biz (www.chatteris.biz) is down since 12/08/2014 08:49:37AM.

PingdomAlert UP:
Http://www.chatteris.biz (www.chatteris.biz) is UP again at 12/08/2014 08:58:37AM, after 9m of downtime.


An additional way of alerting site visitors is with script ‘Flatline-check.php’, this offers an alert message to site visitors that a problem exists and that it has been escalated, this script not only reads the clientraw file, but crosschecks that certain key sensors are working, it does this by creating a file called flatline-status.txt, this file display a range of readings:-

1) Average Wind Speed
3) Wind Direction
4) Outside Temperature
6) Barometer
72) Dew Point Temperature

The parameter numbers relate to clientraw table as above. Every 30 minutes a schedule (cron job) runs on the Go Daddy server which compares the latest ‘flatline-status.txt’ file to the earlier version, if they have changed indicating a healthy upload, no action is taken, if a problem is detected i.e. no changes made, I get an alerting e-mail, the next time data is refreshed, I get a further e-mail informing me that service has been restored.

‘Flatline-status.php’ actual alert e-mails –

Weather Data Appears Flatlined.
01-03-15 2:16 pm now. Last data change recorded at 01-03-15 1:35 pm (0.0 26 3.9 1017.1 3.2)

Weather Data Back Online.
Back active at 01-03-15 3:14 pm (4.1 329 4.2 1018.9 3.4)

error2Alert messages – this was after a planned power outage.

The top message was generated by ‘clientraw.php’ script, the lower messages based on ‘Flatlines-status.php’ would have appeared some 27 minutes later followed by an alerting e-mail, these are the ones pasted above.

Well, that’s how I do it so hopefully the data displayed is current, if not, at least two of us will know 😉

UK Extremes Script

I’ve noticed over the last few weeks, that every now and again the menubar, which is on the left side of the web page, has generated a string of errors which clear after a short while. The script responsible was ‘worldextremesGadet.php’ which uses the web site ogimet.com to gather UK weather highs and lows, after about the third time of this happening I started looking around for an alternative in case it fails completely.

I noticed a number of other private weather station sites displaying the same data derived from the UK Met Office, so after searching WXForum, I found the scripts and installed them, after re-reading the forum thread and making the required changes, everything is now working as before, but with the addition of the sunniest place in the UK information (not that it matters at this time of the year!).

extUK Extremes located in the Menubar – (Image only in case you were wondering why it hasn’t updated!).

Martin from Hebwx wrote a small script which I have also incorporated, this automatically changes the year used for the copyright notification and also brings in the Met Office Logo which is a nice addition.

Weather Site 1st Year in Operation

Chatteris Weather has been online for a year on the 28th December 2014, or should I say, been online using a template of Saratoga Weather, combined with the URL of Chatteris.biz and a new web host in e-rice.

My original site was hosted by Talktalk, one a new host was sorted, all the original files regarding build details etc, were transferred. A link to these pages can be found in the menubar under External Links, clicking on WEB will take you their.

Over the past year lots of modifications and tweaks have been done (and continue to be done) to keep the site as bug free as possible and to keep on top of dead links, sometimes pages or complete scripts have to be disabled to maintain the site in working order, I decide to revisit the effected scripts and see what could be done, tackling the script “Who-Online” first.

The script ‘Whos-Online’ required a GeoLiteCity upgrade file to be installed every month, during last months update the SQL database became corrupt causing the weather site to fail, I was reluctant to upgrade to a higher script version as the original one took a lot of effort to get working, however, no other option existed and I upgraded from V2.25 to V 3.00.

With the help of wxforum members, the new script is now working, I also took the opportunity to attach a table showing the nation flags of visitors. (Update – The flag table would only register visitors who visited the page with the table on it, I have changed to Revelovermaps as this allowed me to link the small globe in the menu bar to the main display on the Whos-Online page so no matter which page is viewed, it is included within the counter)

During the process of installing ‘Whos-Online’ I noticed that the cloud height graphic was not being displayed on the pages where it is used – Cloud Type Page – for example, this was found to be linked to an error generated in the weather templates Setting.php script, the cloud graphic script -cloud-base.php – can work without the link to Settings.php as data can be called from other sources, as soon as Settings.php was commented out, the graphic came back online.

So two results in one, happy birthday Chatteris Weather 🙂

Weather Site Tweaks

Due to having a stinking cold I’ve been banished to my man cave so I took the opportunity to update weather pages which haven’t worked properly or just plain needed a coat of looking at.

The most noticeable adjustments have been:

Menu Bar & Contact Form –

I have added a shortcut graphical link on the Menu Bar to  a newly configured Skype account call button, the call button can also be directly accessed via the Contact Form page.

Ham Radio Page
Added Stormy.gif to lift the page out of being slightly bland.
Added Solar X-Ray and Geomagnetic Field status.

The source for both of these can be found in my Links page.

Space Weather Page
Due to a major upgrade to the site where the links for this page derive from, the wxspace.php script which is behind space weather called on images and information which simply wasn’t there, Martin from Hebrides Weather (www.hebwx.co.uk
has done a great job in re-establishing the bulk of the relevant links and making the script available via the WXforum, this enabled me to get the page up and running again quite quickly, also, for the very first time I have the 3 day Solar-Geophysical Forecast running which is automatically updated every 30 minutes.

Festive greetings from Chatteris Weather.

CCTV Pan/Tilt Controller – Part 1

A good friend of mine asked is I could get him a CCTV Pan/tilt head so he could remotely control the position of his aerials which would be especially useful in the tracking of satellites, some time later I noticed that a guy was upgrading a CCTV system, I went over to him and asked I could have the scrap head, came home with it and straight onto the internet for the make and model, but more specifically the wiring details.

The one I obtained was made by Shawley Antony Ltd who are no longer trading, but the head works just fine on 24vDC with the added bonus of having electromechanical brakes for both Pan and Tilt and having potentiometers so that I can have a go at getting positional feedback displayed.

In order to make a decent project I used Ebay to get a joystick, Pulse Width Modulator motor speed control and a voltage reducer all from China at silly prices.

I created the personalised overlay using Visio, this allows me the layer the drawing and the dimensional drilling detail can then be used to template the drilling pattern before being turned off, and the finished overlay printed.

SAM_5220 (Medium)Control Unit under construction

The way the controller will work is via a 24vDC supply, the 5vDC regulator will provide power to the LM3914 which will be configured for spot display of voltage derived from a potential divider circuit using the head pots, the LM3914 will drive the LEDs indicating the compass positions, I’m not sure if this will work accurately reflecting the head position, but that will be for the next part of the blog when the parts arrive. A similar arrangement will be used to drive the three LEDs showing if the head platform is at the horizontal, transitioning or vertical plane.

The switch marked Pan/Tilt Power, when operated will release the head brakes and light the associated LED, also, power will be applied to the speed controller enabling the joystick to operate the head at a variable speed set by turning the Speed Control knob, the advantage of using a pulse width modulated speed controller is that the motor does not lose torque at low speeds and will therefore not ‘stall’ under load.

SAM_5221 (Medium)Awaiting parts to complete the controller

The picture shows the internal setup for the motor left/right/up/down movement which is operational, the flying leads have been attached to the LEDs ready for the next stage…Watch this space for the next installment.

Link to Part 2.

Changing Call sign

I didn’t realize how many programs or places I needed to change my details from the old Intermediate call sign to my new M0HTA one, so I thought I’d list them:

Echolink (both desktop and Mobile App)
APRS (Mobile App)
DL-FLdigi (High Altitude Balloon tracking)
Ham Radio Deluxe (including update status html file)
European Phase Shift Club
Chatteris.biz Ham Radio links

I’m sure I’ve missed a few as well!!

WSPR – Propagation Report on 10 Watts

Now revision is over, I’ve been playing with WSPR (Weak Signal Propagation Reporter)pronounced ‘whisper’, I’ve had the program for quite a while but never really dedicated any time to setting it up, other rather checking that I can connect to the Kenwood and it allows the program to receive and transmit.

I set WSPR to report on the 30m band with a spot receiving frequency of 10.138.70MHz USB with a 2 minute RX/TX cycle using 10 Watts, unbelievably my very first report back was from the USA, this is a screen grab after a couple of hours:

WSPR on 10w
Map showing stations who received my 10 Watt transmission

Maybe my inverted ‘L’ isn’t as bad as thought! I’ll keep it running for a while and see who else can hear me. I will add to this post with more screen grabs when it has been running for longer and I get some even further contacts hopefully.

The screen shot below was taken on the 20th May 2017, I was running a Kenwood TS-200- at 5watts :



Advanced Exam – Update

I sat the Advanced Amateur Radio exam on the 8 December, the venue was Cauis (pronounced Key’s) College in Cambridge city center with the exam starting at 19:00, Martin from Cambridge University Wireless Club (CUW) arranged the venue and invigilated, Colin from Cambridge and District Amateur Radio Club acted as the second invigilator.

The exam had an allocated time of two hours and three in total taking the exam, the results are due 6 working days after receipt of the completed papers at RSGB Headquarters in Bedford, so I’m hoping to hear one way or the other by Tuesday 16 December using the OFCOM licensing web portal as I’m told this is where you find out earlier than wait for the results letter, the downside is that if your registration code used on the OFCOM site does not allow you past the application stage, then it may not be good news :-(.

Watch this space and I’ll post up as soon as I know.

17 December 14 – Well it’s good news, checked the OFCOM web site and bingo, passed the advanced, my new call sign is M0HTA, when I got home the envelope containing the certificate was waiting for me, posted on the 16th.

In my blog I’ve mentioned Hamtests and QADV being used as part of my pre exam revision, here are a couple of screen shots of what I did:


hamtestSet of 10 test questions with a 10 minute time limit.

hamtest1Set of 62 test questions with a 2 hour time limit.

The results dropped on the 7th December as my exam was on the 8th and I was panicking!


QADV resultsCombined results of QADV.

Sorry for the compressed image – the last version used was downloaded on the 6th December, 2 days before the exam.

QADV I found to be very well supported in regard to upgrades and it was very easy to use,  the screen grabs were from my Laptop, the program was also installed on my desktop so the number of tests actually undertaken is a lot higher than shown (each version change wipes your previous results)!

Many thanks to the providers of Hamtests, QADV, advice from members of CDARC and CUW for facilitating the exam.

General information and status updates.

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