After Peter Hill’s brilliant talk at the last RAG meeting, we were both motivated to pull out Andy’s radio meteor kit and give it a try. In the past Andy has had real problems getting it working at his house and we don’t know why. First step was to try it elsewhere – Damian volunteered his house for the task today.
A useful day of testing Andy’s portable meteor detecting equipment…
Picture contributions from Andy, Damian and Julie (+ annotations!)
Setting up at Damian’s house…
Dancing around the Maypole!
Done…. and ready to go!
Andy bought along a selection of aerials – in the end he chose the simplest and cheapest off the shelf one rather than the hand-made and carefully cut (length to frequency by Bill from Lichfield) versions below….
Our chairman with his radio equipment at Damian’s house (below):
Peter used his FunCube Dongle for his detections. To simplify this initial trial, Andy bought along for this test his Yaesu FT817 portable radio. We used Peter’s settings file and a cheap off the shelf aerial and cable and a car battery to power everything.
The aerial poles are an ex-military carbon fibre Clansman kit – 5.4m high! Andy initially bought these several years ago to use with his Radio Jove Jupiter radio-observing radio and aerials but they are also very useful for meteor detection!
Clansman aerial mast kit:
Immediate success with the military aerial at full height !
Screenshots from Spectrum Lab showing meteors in Damian’s garden:
Success was at the Graves’ frequency 143.049 MHz (Upper side band):
We then tried reducing the height of the aerial to roughly the same height as the aerial on the roof of my shed (2.4m) where my current aerial is located.
We found we were still able to detect aerials roughly every minute or so. Their peak magnitude did not seem to be as large as when the aerial was twice as high………so reduced height = less meteors and reduced magnitude of detection.
Next step was to take the set-up which we had just proved worked back to Andy’s house to see if it worked in his garden to test the theory that he lives in a radio black spot which explains his difficulties over so many years.
The following are screenshots from Spectrum Lab in Andy’s garden showing meteors:
Next steps for testing Andy’s meteor observing problems in his garden:
1. Test the same kit as above with different heights of aerial.
2. Erect aerial above and record meteors over 24 hours.
3. Try recording meteors with lower height aerial in Andy’s garden during meteor shower – no meteor shower major or minor today in standard lists.
4. Use aerial on top of shed with Yaesu radio to see whether meteors are detected.
5. If yes to 4 then try changing radio to FunCube Dongle to see if still works.
6. Try kit as above in Andy’s and Damian’s garden but this time using FunCube Dongle rather than Yaesu radio.
For future reference, we came up with this list of equipment we need to take with us on future radio meteor observing sessions, out of the home location (such as outreach sessions at the forestry centre):
- Yaesu FT-817 radio – make sure power cable, audio cable in the box.
- Laptop with spectrum lab and settings files.
- Computer hood or box so can see screen in sun
- Portable table and chairs or stools
- Car battery
- Multiple plug adapter so can plus both laptop and radio into the inverter (at least two plugs)
- 12V power supply for radio – alternatively 12V battery
- Mallet to hammer in pegs for aerial
- The C-Clamp on the aerial is larger than the Clansman aerial poles so need piece of wood to go in between C-Clamp and aerial.
- Clansman aerial poles kit in green bag – make sure 6 poles, 2 x round discs for attaching the guide ropes, 3 x metal strips wrapped with guide ropes x2 per strip, 5 x pegs.
- Extension cable for aerial (may not be needed depending on aerial used).
- Aerial – today we used off the shelf Yagi for UHF – cheap and cheerful but effective! If this one is used then extension cable not required as it has long cable with it.
We then returned to Andy’s house to try the same set-up at his… plus a beer!
Damian and Andy