Over the next few week the sensor arrays are going to be relocated to a new location.
At present the sensors are around 20m in the air and are in the top of one of Elland’s Tower blocks.
The new location is just a few metres from the roadside and is near the central roundabout.
Potentially the air quality may be impacted by the proximity to traffic and it will be interesting to see how the data compares. I believe this new location will potentially be a better measure of the air that most people in the area are breathing.
when the equipment is moved there will be a time when no data is being uploaded to the servers. Please be patient and understanding.
CHOTA 2022 will be held on Saturday 10th September 2022. Please contact John, G3XYF, if you are considering participation. NOTE: John’s email address has changed and is now email@example.com. His old email address does not work any more.
If you would like to put a station on for CHOTA, and maybe raise funds by sponsorship, then …
get permission from your local church
apply for a GB call from Ofcom
contact John on the email above
Entries so far are:
The World Association of Christian Amateurs and Listeners was founded in order to link Radio Amateurs around the world who share the Christian faith. Since 1957 when it was founded as the Huddersfield South Methodist Radio Club, G3LQK by the Revd Arthur W Shepherd it became an international organisation in 1958 called WAMRAC – the World Association of Methodist Radio Clubs. It then changed its name in 1978 to reflect the growing ecumenical nature of its membership and became WACRAL.
I was in the market for a radio to fit into the car, something that could be a fixed install as taking the other radios in and out of the car can be a little time consuming and i have fond memories of chatting to people on the drive to and from work.
Selecting a radio wasn’t easy as there at lots of choices old and new on the market, i suppose could of got the 25+ year old Kenwood TM-V7 out of the cupboard and installed that but the display pixels on that radio have gone a bit wrong and in these days of bluetooth it seems a good idea to seek out a radio that has bluetooth and can integrate with the cars audio system for hands free operation of the radio.
There’s plenty of bluetooth radios on the market and i wondered about buying a DMR, D-Star or Fusion/C4FM radio but after taking some advice and listening to local radio traffic i decided that actually a simple FM dual band vhf/uhf radio would do the job.
The Retevis RT99 was much cheaper than the DMR/D-Star/C4FM radios but was on par or perhaps a little more expensive than other FM radios that i considered.
The Radio cost £149 from Amazon and came the next day. At the same time i purchased a bluetooth speaker microphone,this was a generic device which cost a little under £50 however i could not get it to pair with the RT99 so i returned and received a full refund on the same day as i returned it. Excellent service from Amazon. But don’t bother with a generic bluetooth Mic, it probably wont work.
I found ones that do work being sold by MOONRAKER Online and other accessories for the RT99 but they were being sold as for the VERO VR-N7500 which is the same radio as the Retevis RT99 but with a different label.
Having had the radio a few days at this point i realised i didn’t need a wireless speaker mic as the supplied wired one works fine, i used the speaker mic with a 3m extension cable with male and female RJ45 connectors fitted, i had one of these in the shack already so no cost here but they can be bought for about £10.
I’d also discovered that the bluetooth works really well with my phone and cars parrot bluetooth audio integration so now the speaker mic is unplugged as it is not needed.
I purchased a bluetooth PTT from MOONRAKER for £12.95 + P&P and that arrived a few days later, it was easy to pair this with the RT99 and i have attached this device to the gear stick of the car using the supplied velcro fastener.
Basically in operation i can listen to normal broadcast radio stations as i’m driving along but as soon as an amateur radio signal lifts the squelch of the RT99 the audio from the broadcast station is muted and the amateur signal is put onto the speakers, after a few seconds of no signal the broadcast station is unmuted and returns to normal.
When i press the bluetooth PTT the audio is muted and whatever is heard by my cars microphone is transmitted, when the PTT is released the transmission stops and normal audio resumes.
The integration has been flawless so far.
The phone i use is an android Samsung Galaxy Note 10.
The RT99 is quite a generic looking box. Here is photo of it installed in the compartment where the CD changer or Satnav control box may once have been fitted. It’s a small rig and can be installed easily and it’s easy to make sure there’s enough air flow for the heat sink and small fan on the radio. This picture was taken shortly after installation and the wiring has since been routed behind the plastic covers.
Power for the radio is taken from 12v accessory socket in the boot of the vehicle.
The antenna socket is a SO239 so the antenna coax needs to be fitted with a PL259 plug in my case this then goes to an antenna mount fitted onto the boot and there is a 2m/70cm antenna attached. The antenna is a “D-Original” from LAMCO in Barnsley which i bought about 10 years ago. It works well.
Using the RT99 is fairly simple, i set it up inside the house originally to program in some stations and i’m glad i did as it needed to update firmware and the app supplied also needed an update but i’m pleased to say it works fine.
I won’t go into too much detail about the app as i suspect it will be an ever changing thing- like most apps out there but it was easy to use, perhaps a little confusing in places but worth the effort.
I’ve never used APRS before and didn’t pay any attention to this aspect when considering purchase however i’m now fascinated by this simple data transfer mode.
Station reported that i was sending tone while transmitting audio, upon investigation i found that radio as set to transmit my callsign and some other data during qso’s. I turned this off in the “ID Signalling” menu and all is now good. I’d assumed that this was needed for the APRS so had populated the fields with my callsign, however APRS is separate and under a separate menu listing.
I’ve never given much thought to 80m, living where i do, the impractical antenna situation makes it kida difficult but i thought i’d make a End Fed Long Wire at home and try it out. To external tuner here so it was trial and error to get the SWR down – right down so actually no tuner is needed. I’ve no idea what the length is.
Anyway the results were pretty good. I will give it a proper test in the coming days.