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geppetto

Basic Jupiter/Solar radio astronomy

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Philip

Interesting post as usual:)

So which is the more sensitive, the modified Tentec or the Jove design? Or does modesty prevent you saying ...?

The Jove design seems a bit more sensitive or at least a bit less noisy...

Testing this afternoon and the time signals on 20MHZ were coming in well on the new dipole...

Has to be said though, the bands around this frequency are hot at the moment...

The winner all round is my SDR receiver regarding noise and sensitivity but this GepJove is a close second....

Very pleased with it:glasses1:

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Bit of a scary moment this evening....

Totaly out of nowhere we got one massive bolt of lightning and

some crashing thunder....not forcast and a hell of a suprise...

Anyhoo, sods law...the new GepJove receiver was part way through

a 48 hour soak test and yes, you've guessed it, the little rig got

some static up it and they don't like it up em! :D

Took out the front end rf amplifier FET transistor but quickly fixed and

it's back on soak test...going to fit a couple of gas discharge devices

tomorrow (sort of device you find in telephone wall sockets)

Good recording of it's death on the running Skypipe chart...

Shows normal noise floor then a hugemendous spike followed

by the expected flat line.....

Mother nature has the upper hand that's for sure

flatline.jpg

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That's an interesting test regime you've come up with. What do you use to generate your lightning? ;-)

Glad there wasn't more damage, and you've got an heirloom record now.

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hello geppetto, im very interested in this thread, im considering giving it ago

which through would you suggest being the better to try, the "jove" or the first one you did?

also, does the arial need to be as big as it is?

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Hi geppetto,

This is a brilliant thread, I have a question can you only pick solar / Jupitor on this setup ??

Rgds

John

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Gaz

The first receiver I built on this post doesn't seem to be available any more or at least I haven't seen one for a while.

I would say the Radio Jove kit is the one to go for but it is fairly expensive and it comes from the USA which adds P&P and taxes etc...

My Radio Jove look_alike is totaly built from scratch including a home made copy of the printed circuit board..... interesting project to do but you need a fair level of interest/knowledge in radio/electronics.

The aerials are fairly big at this frequency and again, the double dipole suggested in the Radio Jove project works very well but takes up a lot of space.

There are various aerial designs and I'm experimenting with smaller loops but at the end of the day, the aerial is the most important part..

I find all this stuff interesting and satisfying to experiment on but chasing elusive few and far between tiny signals is not for the faint hearted...:)

John

The receiver tunes roughly fro 20MHz to about 20.200MHz.

Within those constraints it will receive anything that's there but astro wise, Jove and Solar are the targets.

Fortunately (and this is a reason that frequency was chosen), that area is fairly quite of earth produced transmissions.

There is a time signal on 20MHz but little else to bother about.

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gepetto

The TenTec 1056 receiver is still available. I ordered a kit from Waters & Stanton - they were getting some more kits shipped from the US, and the kit arrived in the post yesterday. Was prompted to get the kit after reading about your project on the BAA Radio Astronomy site. Now looking forward to building the kit and including some of the extras you have built in. Good stuff - thank you.

Regards, Mike

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Thanks for that Mike...

Good to know some are available again.....

Just one hint, get some better quality capacitors for around the tuning circuitry...

As is, the receiver can be a bit drifty...

Not a real problem as drift in this sense of use doesn't really matter.

However, if you are picking up some earth based transmissions and you set the receiver between them then sods law says it will drift and settle onto one of those unwanted transmissions.:)

Some NPO caps or better still but harder (dearer) to get, silver mica or polystyrene 1%

Best of luck with the build:headbang:

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The receiver tunes roughly fro 20MHz to about 20.200MHz.

[...]

Fortunately (and this is a reason that frequency was chosen), that area is fairly quite of earth produced transmissions.

There is a time signal on 20MHz but little else to bother about.

This is true, has been true for some time, but we are now approaching sunspot max and propagation in the 15MHz plus region will change considerably.

Propagation stateside and elswhere will become common so a vfo to find a quietish freq. will be a nice addition I think.

Edited by Ptarmigan

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This is true, has been true for some time, but we are now approaching sunspot max and propagation in the 15MHz plus region will change considerably.

Propagation stateside and elswhere will become common so a vfo to find a quietish freq. will be a nice addition I think.

Yes indeed, 15 and 10 meters are really "hot" at the moment and I've been monitoring the chunk of bandwidth that the scratch built Radio Jove look-alike works on.

Fortunately, it remains fairly quiet even through a major lift in conditions on 15 meters a few nights back.

Within the tuning range, I get the time signal on 20Mhz which really comes in well whilst these conditions exist and there are a couple of CW beacon type transmissions nearer to 20.1 Mhz.

It seems that consistently, there are plenty of quiet spaces within the tuning range.

Reason I'm monitoring carefuly is that I want to choose the quietest sweet spot so I can have a crystal custom made for that frequency which will give a much better stability.

Having said that, it will be a VXO so I can tweak it a little..

Another thing for future experiment is a USB synthesiser kit from SDR-KITS.

Just finished building one for a QRSS project but at the price, it would make a fantastic uber stable digital VFO for the Jove receiver....

Probably cheaper than having a custom crystal made...

More on that another time...

Downside to these conditions is that Jupiter signals could end up being attenuated by the upper layers but on a brighter note, during the sunspot maximum, there are plenty

of solar flares to monitor which my kit is doing at the momement....

SDR-Kits

:)

Edited by geppetto

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Downside to these conditions is that Jupiter signals could end up being attenuated by the upper layers
Oh yes, interesting point, I had not thought of it from that side !

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Geppetto

Have completed the basic Tentec build and want to monitor the oscillator frequency. My counter is loading the oscillator tuned circuit so want to include a buffer between the oscillator output and the counter. I believe you successfully did this on your build, so wonder if you could let me have the schematic of the circuit you built.

By the way, have you been able to test your loop antenna; how did it perform?

Regards, Mike

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Hi Mike

Think I used this one...

buffer.png

Re the loops, they do work but not well enough realy..

Still got some more tests to do but my aim is to build and test

a Moxon design...

MOXON Antenna Project

These work very well. I lashed one up a couple of years back.

Still a big antenna but much smaller than the Radio Jove double

dipole...

More on that when it gets a bit warmer :)

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Hello Phil

Thanks for the schematic; a bit lazy on my part but at least I know your circuit works. I'll get building as soon as I have the parts - including some NPO capacitors for the Tentec tuned circuits. For the more specialised components I use - JAB Electronic Components for Radio Hams & Hobbyists, no connection, but can recommend them.

Ok re the loop antenna; I too had looked at the Moxon, so will be interested in how you get on, but as you say, once the warmer weather is here!

Thanks once again.

Regards, Mike

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Hello,

I thought I'd dig up this thread instead of creating a new one :-)

I'm always looking for experiments I can do together with kids & teens (and for myself, of course), and most recently stumbled across Bob Greefs website, and eventually over this thread.

Before soldering together a simple receiver I thought I'd try what is possible with a 10 band radio as suggested on the mentioned site, and ordered a cheap €4.50/$6 radio at ebay - still waiting for it to arrive at my door steps and planning on building an antenna.

I read a dipole works best and is simple to set up, but I plan on constructing something portable that can be assembled with a few winged nuts (9-13).

klappteleskop2d_grouped_reassemble_2.png

The clue about this concept is, that everything from structure to recorder will fit inside the cube that consists of the antenna structure and is secured by bolts and nuts.

This way it won't be another project catching dust in the garage or is too bulky to take along on a bike.

antenna3e_collapsed2i_min.png

I'm planning on using 5/6mm MDF or inexpensive floating laminate and M4x20 or M6 hex bolts.

boxtenna-closeup-assemble_2.png

All together the cost should be around 10€ - including receiver. Recording will be done on an android phone (PCM/WAV) until better equipment is available.

If the receiver is not sensitive enough, I will probably build a simple TRF receiver (though I heard sensitivity of the cheap radios is okay, and the bad selectivity could actually be an advantage to some degree).

I know this is not as sophisticated as the Jove receiver or the TenTec kits, but it the objective is to keep it affordable, not to be semi professional.

One thing I am putting thought into is the loop antenna. I though on using relatively thin welding wire (1.1mm diameter) as it is flexible and would fit into the box, and keeps shape nicely. I have some here, it bends nicely into small shapes and forms a rigid loop.

It might be too thin though?

Thicker coper wire might break after several uses and has to be bent into the right shape all the time.

boxtenna-closeup-assemble.png

(Two welding rods form the loop, a luster terminal joins them at the top, at the bottom a two-terminal terminal holds them together without closing the loop).

As reflector I plan on using (metallic) fly screen or a rescue blanket (the aluminum coating might be too thin, but it costs only €1.20, is light weight and versatile). Chicken wire would not fit into the box, and span wire across the structure would take rather long to set the antenna up.

boxtelescope-box.png

(Picture of the parts in the box, earlier design)

I know this is all still a bit vague, but I would like to keep it as simple as possible right now, easy to recreate for beginners, and inexpensive. If some stronger bursts will be measurable, that would be enough. I'll post pictures of the project as soon as I can; A friend might even cut it via CNC for me, which is really nice.

I hope I am not going to be bashed now. I know I'm not an radio electronic expert, that most here is just a concept and needs work, and it may be so minimalistic some will dash away a tear or two :-) I'd appreciate some constructive critique though.

Edited by Schorhr

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I realise I'm nearly 2 years laste, but this is awesome, Geppetto, nice work! So tidy!

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Wrong thread - can a mod delete this?

 

Edited by HN50
Wrong thread

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Has anyone been successful with classic dual dipole antenna? I made it and so far no results (I also waited for Io B storms and others) I'm using Airspy and spyverter.

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