Date: April 29, 2011

Title: The NASA Radio Jove Project

Podcaster: Steve Arnold

Link: The Nasa Radio Jove Project – http://radiojove.gsfc.nasa.gov

Description: This is my own experience of how I became interested in radio astronomy by building and using the Radio Jove Receiver to observe the Sun and the planet Jupiter. I would like to give you a brief description of the receiver as it arrives in kit form and a brief description of how to use the receiver and it’s antenna. When to listen and when not to and why. Also what you can expect to hear when using the receiver while observing the Sun and planet Jupiter. Some of the problems you may come across and possible solutions.

Bio: My name is Steve Arnold I’m an amateur astronomer from the UK I’ve been interested in all aspects of astronomy for as long as I can remember. My main interest has always been visual and imaging astronomy. I followed the Voyager space probes with avid interest in the late 70s, 80s, and 90s in my opinion the most successful space probes ever made it will be a sad day when we lose touch with them. Whether it’s history or cutting edge as long as it’s astronomy I don’t mind.

Sponsor: This episode of “365 Days of Astronomy” is sponsored by — no one. We still need sponsors for many days in 2011, so please consider sponsoring a day or two. Just click on the “Donate” button on the lower left side of this webpage, or contact us at signup@365daysofastronomy.org.

Transcript:

THE NASA RADIO JOVE PROJECT.

Hello and welcome to the 365 days of astronomy podcast for today. I’m your host my name is Steve Arnold I’m an amateur astronomer from the UK. I would like to tell you about the Nasa Radio Jove Project and how I came about getting my receiver a brief description of the receiver and it’s use. My main interest has always been visual and imaging astronomy. That is up to about three years a go we were having one of our usual British summer days cloudy, raining and generally unpleasant and all I wanted to do was observe the sun. So feeling a little fed up I thought I’m going to try and have a go at radio astronomy at least the weather can’t stop me doing that. Althought it’s not wise to do it in a thunder storm as there is a risk of a lightening strike. So I did some research I wanted something relatively cheap and easy to use. I have had some experience with electronics but none what so ever with radio astronomy except for a few visits to Jodrell Bank. I found several sites telling you how to use a short wave receiver to listen to the Sun and Jupiter but I found these difficult to get hold of in the UK also in some cases if I did find one a modification needed to be made to bypass the automatic gain control. Then I found just the thing I was looking for The Radio Jove Project.This Nasa backed project supplies a relatively cheap kit in the form of a build it yourself receiver which is capable of picking up the Galactic background radiation, radio emissions from the Sun and also the planet Jupiter. It works on a narrow frequency band centred around 20.1 Mhz and has been designed especially for the job. The kit arrives in a small box with a coil of copper wire to make the antenna with ceramic insulators and a large coil of co-axial cable, little plastic bags full of electrical components just over 100 of them, and a really good instruction manual also two CD rom’s with lots of extra information and computer programmes. Such as a version of radio Jupiter this programme is useful for predicting radio emissions from Jupiter and has a good feature which produces an imaginary antenna beam on your computer to let you know when Jupiter or the Sun is within the beam and therefore picked up by the receiver. Another useful programme is a version of radio sky-pipe this programme turns your computer into a chart recorder but without generating miles of paper. It is advantageous for you to have some experience of component identification and soldering. Althought the CD rom’s do contain tutorials on how to solder and the instruction manual gives photos of the components. It took me about a day to build and test the receiver and another couple of days to sort out the poles, guide ropes and to make the antenna. But if you don’t Know a resister from a capacitor you can purchase the receiver already built for an extra charge. The only extra things you need is a 12 volt power supply this can be a battery, a pair of headphones and the poles and guide ropes from which you hang your antenna. I use those telescopic metal washing line props you can buy from any hardware store they fold down like a car aerial for easy storage. I have eight in all I find two of these poles fixed together gives me the height I require. The height of the antenna is important too the minimum height is 3 metres with a maximum of 6 metres. This is because with this dual di-pole system the higher the antenna the lower down to the horizon it throws the beam to get the most gain from the antenna when the object is lower down. If the object is higher you can have your antenna lower. Saying that it is not practical for me to have my antenna above 4.5 metres. But this is totally depending where in the world you live and the height at which the object is in the sky. So you have bulit your receiver and hung up your antenna so what are you listening for from Jupiter you receive L-bursts and S-bursts or a mixture of the two.L-bursts these sound to me like waves crashing on a beach. S-bursts these sound like a metallic crackling similar to lots of small hail stones raining down very quickly on to a corrugated metal sheet. From the sun there is a number of different sounds the one I’ll describe here is a sharp increase in noise with a slower decrease back to background levels it looks like a classic sharks fin on the chart recorder. Radio emissions from Jupiter can be predicted with a certain amount of accuracy but emissions from the sun are unpredictable but do increase with sunspot numbers. The galactic background radiation received by the receiver is a constant hiss of white noise similar to a badly tuned TV. The galactic background noise increases and decreases slightly depending on what part of the sky is passing through the antenna beam. All the radio emissions from Jupiter and the Sun are heard with the background noise present. You can hear examples of these radio emissions by going to the Radio Jove web site. I monitor the sun and listen when I can especially when I can see sunspots. I’m sure you’ll know the sun has been relatively quiet but things should start getting more active now we are building up to the solar maximum again. You cannot listen to Jupiter during the day this is due to the ionization of the ionosphere by ultraviolet radiation from the sun which reflects the fainter radio emissions from Jupiter back into space. Radio emissions from the Sun are strong enough to punch through this ionization. But I have heard of people who have occasionally managed to pick up Jupiter during the day. The ionization breaks down a couple of hours after sunset and this allows the fainter emissions from Jupiter through.Although if sunspot numbers are high the ionosphere may remain partly ionized all night making it difficult or impossible to hear Jupiter. There are four points I would like to mention number one you need adequate room in which to place your antenna I’m lucky I have a garden large enough in which to place the antenna and more importantly an understanding wife. Number two as I mantioned earlier if there is a local thunder storm it is wise to unplug your antenna from the receiver I’m no expert but I don’t think a lightening strike will do you, your receiver and computer much good. Number three unwanted noise or interference. I think of this like light pollution for the optical astronomer. This can come from almost any electrical device. I find my local interference during the day doesn’t stop me receiving radio emissions from the Sun I may miss some of the weaker ones. But at night they can be a problem. I’ve found by running my receiver for a number of days that my local interference from TV’s e.t.c. reduce from midnight to about 5am when everyone has gone to bed this gives me a 5 hour window in which to listen to Jupiter when it’s in the right part of the sky. Radio Jove offer a ready built filter/calibrator which does help with the interference problem I would recommend it. I won’t go into to much detail here about the calibrator at this point except to say that it is for calibrating the receiver and is useful for measuring your local background levels and gives you some idea of your local levels. Number four I would like to say a big thank you to all the other Radio Jove user’s that helped and advised me when I was starting out. I still find it amazing that I can pick up the Sun and Jupiter by just hanging an antenna in my garden. I only started this project for something to do on cloudy days when I couldn’t use my optical telescope and it has opened a whole new branch of astronomy to me. I have only briefly outlined things here and I hope it gives you the incentive to have a go. If nothing else it will give the neighbours something to talk about and you to can be that “strange guy who listens to the Sun and planet Jupiter”. I wish you clear and noise free skies. Goodbye.

End of podcast:

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