Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

baron von vulpes

New Members
  • Content Count

    17
  • Joined

  • Last visited

Community Reputation

10 Good

About baron von vulpes

  • Rank
    Nebula
  1. Having several emails now, discussing with Tony Parks about using his small receiver for 20.1 MHz he will send me a a ready build one for evaluating. He have a moment only one x-tal for that specific frequency he can only make one at moment. But if more of you are will like to order from him later, he will sell them for $32.00 each, that is a very good offer. He will also sell kits, $22.00, but is it make uses of SMD components it is not for me. I think in combination with the active antenna Philip is experimenting with, this will make a "rock" good JOVIAN receiver. Best Regards Jogeir Lindseth
  2. Philip. The active loop is a very good idea I think, haven't read about any body that have done this before, are use using it with the diamond shape as well? Measurement of the sides? And how high up from the ground do you plan to put it up, got interested in this one Post a picture when you get it up! SDR receivers, what about modifying a Soft Rock Lite II, change the x-tal and modify the band pass filter to center frequency of 20.1 MHz? "A crystal of about 26.8 MHz would give a 1/3 sub-harmonic sampled center frequency of 3* 26.8 / 4 = 20.1 MHz. For higher frequency use, 1/3 sub-harmonic sampling needs to be used since a crystal of 4*20.1 MHz would be hard to get. The 20m BPF may be modified for 20 MHz operation by a change in capacitor C3 from 47pF to 47(14/20.1)(14/20.1)= 22pF. C4 value would change from 680pF to 680(14/20.1)(14/20.1)=330pF. The C10 and C11 values used for the 40m case would work for use with a 26.8 MHz crystal." Source Tony Parks Rocky, the software for the radio will work with that center frequency. Do you think it will make a good JOVIAN receiver? Attached is the schematic for the Lite II Combined kit. The tower is many ham radio operators dream (including me) I think, I a country like Philippines I can do thing like that, but not in any European country. So I am very pleased with my Shack and tower, yes lots of space up there for antenna and stuff. Not much progress with the CATV project, made a 386 amp for the audio output yesterday, that's all. Best Regards Jogeir Lindseth Combined Lite II 6_13_10.pdf
  3. Philip, yes you can have a lot of fun with those TV tuners, planing to have one more in the same box, an analog one. Will see what I will use it for, Antenna Analyzer? An ADC will go in the box as well, software I do not know yet, any suggestions? And the first target goal will be Cassiopeia A, the strongest radio source aside from the Sun in the sky. Will sooner or later need a LNA as well, did not find any good project so far. A nice SDR receiver is definitely on my wish list, but I have a couple of project going at the same time all ready now, so later. Guess you can call those TV tuners SDR as well :-) Your remotely power amplified loop sounds interesting, 20.1 MHz I presume. You mind tell more about that one. As for the JOVIAN receiver I think I will go for the Fox Delta kit, about £100 assembled, as their kit is not ready yet. I think that price is good, as you get a frequency counter, and the ADC is build in, the MAX187 chip is not included though, and it is boxed. I am in London now, will stay here till February 2011, and then go back to Philippines, and start to put up my antennas for 20.1 Mhz and also for the RA project. Up in my tower (see picture, of the tower with the tripod) I am planing to put up a Moxon antenna with a rotor for the 15 meter amateur band and I did read they work good for JOVIAN as well. Picture taken from my veranda in second floor. Can't do much here in London except for building the receivers and prepare things. Hopefully parts from Maplin will arrive today, so I can continue. Best Regards Jogeir Lindseth
  4. Hello Everybody. While waiting for the parts for the new 30v power-supply I continue studies of those very interesting TV tuners. You can also make a Radio Telescope (wide band receiver, spectrum analyzer) by savage an analog tuner from an old TV set or a VCR. In a simple way it can be done like the attachment picture here. But in practice you will have to use two ten turn potentiometers, 10k coarse, and a 500R for fine tuning. IF out goes to the detector and a DC amp, ADC and then to you computer. Adding a sawtooth sweep generator to VT will make it a simple spectrum analyzer. There are probably members here that know more about this than I? It would be nice to know how many of you are following this project, I know Philip and David (ex M0XUK) do, and how interesting this "branch" of astronomy are for you. Please write a line or two! I love feedback :-) Positive or negative alike. Best Regards Jogeir Lindseth
  5. Everybody! Well, I think I will scale down the Log Periodic antenna a bit, the tuner tunes from 55 MHZ to 860 MHz, but even that will be a quite big antenna. 18 element, Axial Length: 4.522049174202821, Longest element: 3.30444441. May be, as Philip suggested, an UHF TV antenna will do the trick? Even though it is not covering 408 MHz. Channel coverage:21-69 Frequency range: 470 - 862MHz Antenna gain: 14-16 dB Beam width (degrees): H30 / V33 Front - back ratio: 26 dB Impedance: 75 ohm Antenna length: 2210mm £ 49.00 from Maplin The uhfscan.bas program from MTM Scientific runs from 473 to 803 MHz, so it will be a nice antenna to scan those frequencies, I will decide later. First I have to make the tuner run properly. Did the first test today morning. My "30V" is not quite 30V, I can get only 28.2V out from a 12V transformer and a voltage tripler, if it is matter or not I do not know, but I am not quite happy with it. Anyway, when I switch it on I get about 150 - 200 mV out from the INA 122 DC amplifier, and it slightly rise when I touch the antenna with a bare wire. And white noise in the Audio Out. I hope that's indicate that the tuner is working properly. Have to figure out what to do with the 30V supply before I start to box the project, in a vinyl box from Maplin, same as Philip used for his TenTec 20.1 MHz project, they are OK for £ 9.99. Best Regards Jogeir Lindseth
  6. David, frankly, I do not know what is best, so I have to start somewhere, can you tell me why you will prefere cross-polarized before a yagi or a log-periodic antenna. All the papers I have been reading they are using yagis, quagis or log periodic antennas, "The Mauritius e-CALLISTO Helioradiospectrometer" (phu) using the antenna I am planing to copy. See the link to the pdf file on my other posting earlier today. Frequency rage from 20 - 860 MHz. Umm, maybe I can use this for JOVIAN on 20.1 MHz too... Please keep on giving input and suggestions, that what this forums are for, teach what you know, learn what you do not know. Best Regards Jogeir Lindseth
  7. Derek, Philip Yes sure is fun to play with those things, especial this one as it is so many thing you can do with it beside using it as a Radio-telescope, you can use it for a Spectrum Analyzer to scan the frequencies of your interest. I am going to do both on the same unit, switch the PICAXE. The red wires are for the AGC, puting 12v to the SIF, VIF unit as shown, will disable the AGC, you can also use a potentiometer to make it stepless. As you can read from their homepage, there is not so much to it to reprogram the PICAXE for scanning or program it for an another frequency. Can do a lot of experimenting here. As for the aerial I was in the beginning planing to use a yagi for 611 MHZ (or 408 MHz) but now I think I will build a bigger log periodic antenna so I can cover wider band-with. http://www.uom.ac.mu/events/2010/mrt/first_anniversary_of_mrt_based_CALLISTO_spectrometer.pdf I have put together the kit and did started to make a triple power supply 5v, 12v and 30v, using a LM7805, LM7812 and a LM317 for the 30v. The transformer and rectifier is from a 12 mains adapter, going to use a separate one for the 30v supply. Going to finish the power supply today, and start to test the tuner, exciting, always exciting the first time you fire up your home-build gear! That's it for now, will keep you updated, and as Philip says, this is a nice kit to a nice price, the pcb is thick and of very high quality double side. And for you who are thinking of starting with a 408, 611 MHz telescope this is the way to begin. (well, that is my opinion) Best Regards Jogeir Lindseth
  8. Everybody. The project is going slow and it have been changed from 408 MHz to 611 MHZ. The tuner board kit from MTM Scientific has arrived, time to plug the soldering iron. This is a nice and simple kit, it can be classified as a beginners kit, anyone with just a little soldering experience can put this together. Regards Jogeir Lindseth
  9. Hello every body! Looking now for a LNA to start my All Sky Survey project, anybody know of a circuit description, and what are other using? Regs Jogeir
  10. One thing is to calculate the resonant of a coil\cap, you have a clue where you maybe are, but measuring it would be better, as Philip say "They can have quite fine tuning these big loops...." Hook up yout Sinus generator, scope and frequency counter in parallel over you loop\cap and tune your generator until you see that you have resonant on you scope and read the resonant frequency on your frequency counter. Guess most of you are "optical" astronomers so you do not have those instrument, but all these is so cheep second hand now on eBay and othe places, so most hobbyist (including me) can aford to buy it. Just bought two oscilloscopes for about £10 each to use for my Radio Telescopes that I pland to build. Regs Jogeir
  11. Philip, thank you for the information. Are you using polypropylene capacitors there. I saw some were how to find the resonant frequency of a loop/cap like this, but I forgot where and how. Link up a JOVE and a SID receivers like this seems like a good idea SOLAR RADIO TELESCOPE Regs Jogeir
  12. Philip, yes it sure is, like to do lot of this stuff. We do have a nice place (and 'electric noise' quiet, house, and the shack and tower for water tank, and a big 10' x 10' platform up there for antennas) in the Philippines, not 100% finished yet, but it soon will be. At present I am in London, as it is wet season in Asia, but going back soon. I do have a VLF-3 receiver, but would like to do some SID logging as well. Can you please post some details about your SID loop antenna, and how you connect it to you PC, isolation transformer, amp, ADC? I do have a FT-857 so i can use it for 408 mhz, and also for 20.1 mhz, but as I am a ham i will not like it to be tied up to those frequencies all the time, hens i like to build separately receiver for different RA receivers. I will keep you updated as I build and opperate my stuff there in the Philippines. Regs Jogeir
  13. Hello all. I have been thinking of building a 20.1 mhz rx for JOVIAN for quite a wile now, been considering kits and the project that Philip is building now. But lately I have got more interesting in, as i study it, building a "408 MHz All Sky Survey" radio telescope, there are tons of material out there about this subject. Have any body here build a system like that? I came across this project: Link Amateur Radio Telescope Plans Can be build for a reasonable price for an hobbyist. Here is one that can do the most, more work, more expensive: Link Science Workshop Quoting: "YOU CAN ALSO USE THIS DEVICE TO DO RADIO ASTRONOMY AT C-BAND FREQUENCIES.........IF YOU ARE AIMED AT A TVRO SATELLITE, YOU WILL SEE DATA FROM ALL OF IT'S TRANSPONDERS.......IF YOU ARE LOOKING AWAY FROM THE CLARK BELT, YOU WILL BE LOOKING AT A CHUNK OF SKY WITH A WIDE BAND RECEIVER." From [removed word] Goodman's (WA3USG) article "Building a SETI Station." Link Science Workshop Great project! Regs Jogeir
  14. And here is one more 20.1 Mhz receiver, kit or ready build. Looks nice, and have a build in frequency display too. Galileo:: 20.1MHZ Direct Conversion Radio Astronomy Receiver For Radio Jove Regards Joe
  15. Sky Beast, yes you can on any rx you can tune to 20.1 Mhz But all you guys how are interested in radio astronomy and have a little know a little about electronic, take a look at this one: Science Workshop Publications Department Build a radio telescope on any frq you like from this one. Here is yet another one, simpler: CATV Tuner Amateur Radio Telescope Plans Spectrum analyzers has been out of reach for me, very expensive, but now I can have one AND a great radio telescope for a nice price. Think i will go for this one. (science-workshop) Regards Baron von Vulpes
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.