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Macavity

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Everything posted by Macavity

  1. Heheh. Well it is a bit of a weird one! But in fact, listening to almost ALL (non amateur/commercial) stuff COULD theoretically land you in trouble! Not encourage "illegal activities" here too! Enforcing it with the thousands of Aircraft Band enthusiasts (At airports too) would be an impossibility tho! As a teenage SWL / radio enthusiast, I was always careful not to "transmit" anything. My late DAD worked as a GPO "Post Office" (now BT) Draughtman... Two in-law uncles... Engineer & Linesman! Having a criminal SON might have not been a good look for our family. lol The best advice is probably not to discuss *contents* of the transmissions? I still SWEAR some of the frequencies are a bit off, but...
  2. Great Stuff, Jim! In the world of social media, I find it good to hear that (what I call) "Grass Roots" science publicity... The Universities, National Laboratories and the Schools are still doing their STEM thing! I did visit Glasgow Physics Dept., back in '79 or so. Travelled there/back (train) from Manchester on a (freezing) FOGGY Winter day! A bit grim. lol. I quickly remark *many* University Campuses are now much changed... Yes, youngsters do quickly grasp the intricacies of "complex" sciences?
  3. Great stuff, MIke. Nice "random" (they are the best!) but useful conversation. 10GHz Eh? We are not worthy... etc. etc. For VHF monitoring I have (almost?) line of sight to Liverpool, Manchester & Blackpool ATIS from this (N.Wales coast) QTH. My excuse for "checking out" frequencies around 124 MHz! I can "cut bits off" these dipoles for "satellite". Interesting to compare my "wideband" Diamond X777 with the homebrew COAX "Double Bazooka" (I sense a "Carry On" film influence?). As hoped, its center 1/4 wave coax + wire 1/4 wave ends has a much bigger bandwidth! (Note change of scale).Though huge bandwidths may NOT be your desire... D777 "Aircraft": "Double Bazooka" Coax (Note wide bandwidht plus "better" SWR!) On the SDR1A and (Excellent) SDRUno software, I had noticed a possible drop in signal strengths??? I did a "Factory reset" and things seemed to get better. Something got "a bit confused" with my button pushings? AS A WEIRDER thing, some of my Aircraft frequencies are "Bang on"... Others (as reported!) are consistent 5kHz out! As we know, you are not (strictly) supposed to listen to A/C, but [IMO] there seems something weird re. (publically!) QUOTED frequencies of some Aircraft / Stuff??? The LOCAL 2m & 70cm repeaters are pretty much on expected freqs! I have tried to do a frequency calibration? MSF(?) on 60kHz still there. I don't SEEM able to hear WWV(?) on 2.5, 5, 10, 15, 20MHz though... Anyway, just more *random* thoughts for the fellow users/enthusiasts!
  4. Thanks All / both! Grist for t'mill -- I'll have a ponder anyway... For those who like to know "What others are doing"... Not a LOT in this WIND! But still making things in anticipation of better weather (and no Covid-19)! Below shows a Coax dipole of a "Double Bazooka" type using Electrial Duct parts! At left my Sirio 3000N Discone. At right some bits from https://www.barenco.co.uk/brackets-clamps Ultimately all/some of this is destined for up here... (X30N + TV antenna) But not JUST at the moment!
  5. I noticed that the CERN Atlas collaboration now make LHC data available to the Public! The claim is that high-school, undergrad and postgrad student (and enthusiastic self-learners) can have a go at being a "Particle Physicsist"?!? https://twitter.com/CERN/status/1227969676950458370 https://home.cern/news/news/knowledge-sharing/atlas-releases-13-tev-open-data-science-education https://atlas.cern/resources/opendata With a little prior knowledge I DID actually get it to "do something"! IF you are a STEM Teacher or Student you might like to have a go? Don't ask/blame me?!? But this might inspire some future scientist? P.S. If you are not at all serious, perhaps best not to click randomly. We probably don't want to bring CERN's computers to their knees!
  6. Just came across (via Brian Cox Tweet) latest VLT images of Betelgeuse! https://www.eso.org/public/news/eso2003/ Some amazing "before and after" animations knocking around too... https://twitter.com/Astro_MiguelM/status/1228369616646365184
  7. Great stuff @wxsatuser. Since we last spoke, I have been able to resolve (various HF band) FT8 transmissions that make no "waterfall" trace at all! As a random thought regarding VNA, my "tuned" longwire (via 4:1 Unun) gives great SWRs on the (traditional) HF bands: UNfortunately, when I add the COAX feeder: "All h*ll breaks loose" ROFL! I suspect the Coax outer functions as a counterpose / part of the antenna? Who Knows? I suspect that's why most HAMS favour tuned antennas! Things seem to be much easier at VHF/UHF where the feeder is "several" wavelengths long? At the moment I am thinking of doing a survey of all signals received locally on VHF/UHF, with the SIRIO (to 3Gz!) Discone! Looks like SUCH THINGS are a thing of active / serious research! Who knows? Will I be the oldest ever candidate for the RAE... Will I try do genuine "Radio Astronomy"... Or just receive satellite weather pics. As another GENERAL question, I am thinking of adding a G8FEK BBA3 50MHz-2GHz <1dB noise LNA to my kit of parts! Is the vendor active? Has anyone tried these LNA's (or similar)? Will a 30dB LNA completely overload my RSP1A/SDRUno? I sense another ASTRO "Money Pit". lol
  8. Usually switched over to the "Horror Channel" by then? More terrifying... https://twitter.com/thismorning/status/1227549916270034944 Fairly sure I was on SOLID GROUND (Along with "Skeptic Phil" and ze French population!) re. the pronunciation of the word Bidet? "Buh-day" indeed! (OK, it's US English apparently?)
  9. Not totally relevant, but at this point, I like to recall little: https://en.wikipedia.org/wiki/3753_Cruithne (Crooinya?!?) Relative orbit non-elliptical etc. Some FUN animations!
  10. Kewl! FWIW: Thinking about VNA PLOTS has taught me a LOT about Antenna theory though? See "Smith Charts" too! Was also pleased to find that the (my) popular Diamond X30 DID actually resonate on 2m (1/2th wavelength) plus 70 cm (2x 5/8 Wavelength)! Hey the X777 "Aircraft Bander" is pretty much tuned to a "central" 124MHz and 300MHz "Military" Band? (Heheh: "Don't tell 'em, Pike re. listening to Aircraft bands!) -- But a useful test of SDRs! For general "scanning" I have found that having BOTH the Amateur band AND Aircraft band antennae is useful + judicious use of SDRPlay/SDRUno/RSP1A MW/FM and/or DAB filters! Since we seem to be allowed to discuss non-Astro (strictly) stuff: On the *HF* bands I've been playing with varying the length of a (not very!) long wire 52' "sloper" antenna (Fed via 4:1 UNUN). I'm now convinced even random wires can be tuned to "better" lengths... http://hamuniverse.com/randomwireantennalengths.html But we digress... Massively (Sorry! lol)
  11. I see the EXACT one I bought off Ebay is no longer available. But they are FUN thing to have! They are fairly "generic"... They seem to work... You don't have to "re-mortgage" for a VNA? https://youtu.be/y3kdaJ7JdOg Many more examples of the description / PC software / user guides etc. available on t'internet...
  12. Aside from (visible spectra) Spectroscopy, I had neglected to look HERE! So much interesting stuff... A long forgotten (SWL only!) amateur radio interest back in late 60s / early 70's rekindled (I thank @wxsatuser for much of that)! Recently I bought a *budget* "NanoVNA" thingie and I'm now measuring *random* "wires". SWR curves for the "white stick" X30 (blue) and X777 (orange) antennae! Basically, I'm just EXPLORING the general VHF/UHF spectrum for *anything* interesting! I have an N-type (coax) "Antenna Swith"to quickly "flip" between my various antennas... Using SDRPlay / RSP1A Combo for my "studies". Checking out various Signal strength?!? To expore HIGHER frequencies. I've just bought a SIRIO SD3000N *DISCONE* Antenna... Discone Antennae have no gain (As you know? LOL). But the original (with added whip!): The WHIP seems to add an extra low SWR resonance at 180MHz? I suspect I might just remove the "whip" (as DO most Discone users?!?) This looks to have potential > 300MHz? Thinking of trying out a "general coverage" G8FEK LNA (BBA3-SNA) to "help out" a bit? P.S. Having quite a lot of SWL fun re. FT8 Hams at *minimal* strength (Ta, wxsatuser!) Perhaps a gateway to higher and greater things: Satellites... True Radio Astronomy etc. Recently found a LADDER-SAFE (user-friendly!) PRO *antenna installer* to help me too!
  13. Thanks for answering a "specialist" question! No more expensive than some of the "fancy" GRAYHILL (BCD output etc.) offerings. The demise of "good old" manual technology? Sometime you might not want to introduce "microprocessors" (noise / complexity) into Audio / RF equipment though... Someone remarked on future "shortage of electronic components". Start collecting VINTAGE stuff?
  14. No fear of the dark... A lot of my country rambles used to end in darkness? Good to have a torch hand in such cases? Often I didn't! I am wary of URBAN environments these days? As a 70's Uni Student, I "knew no fear" -- Even on the wee-small-hours stagger home! I find standing around with "precious stuff" in a publicly accessible place doesn't work for me? Recently I was taking some "panoramic" shots with my standard Camera/Lens on local heath-land and "some weird bloke" started to follow me me around?!?!? But I sense that SOME people may not have seen an old-fashioned camera... or telescope? I admit being glad we are not comparing "man stopping power" of weapons on SGL!
  15. The thread continues. And very interesting it is too! My <appreciation> Still a way to go before making a final decision? For Electronics Nerds: Now have to find the BEST way to read out multiple(!) rotary encoders via Arduino etc. Something of a regular discussion on internet forums?! Aside: 12-way etc. (Budget) Rotary switches seem to have gone out of fashion these days? Always good to know "chassis bashing" still exists!
  16. Yes, pleased to see the ubiquitous "Eddystone Box" (for smaller projects) had not vanished... along with (the original) Maplin.
  17. Very elegant there, Steve! Thanks ALL for your various ideas. I detect something of a theme re. transparency? GMTA etc. NOT doing much today... All the hole drilling has "done my back" at bit. lol. At least this time I managed to drill ALL the various holes the correct size(s)! All praise to a nice NEW set of (sharp for a change!) drill bits... All hail the STEP drill notably.
  18. A lot of you are quite into Electronics | (Observatory) "Electrics", so I wondered: DO you have any favoured methods for *finish* stuff with a NICE Front Panel? Recently embarked on a (another hobby!) "Synth in a Suitcase" MIDI interface: There is very little *active* electronics for this one. Just a lot(!) of WIRES. A couple of Arduino Megas and 48 channel ADC shields. It works on a prototype scale, so I can complete this one "at my leisure"? The keen eyed may recognise the (typical) redundant "Maplin" Eyepiece Case. One of the benefits of Video Astro/Imaging? AT THE moment, I make a mock up of *front panels* using random hardboard. Veroboard functions as a very useful "drilling guide" for pilot holes! Even *I* can get my holes in a line using this method? I buy (find) laser-cut Acrylic as an easy to drill material for panels, but I don't think I can cut out NEAT Fader "Slots"?!?!? I CAN (inkjet) print Panel Designs on thin card. I then use transparent sticky back plastic to "protect" the result. I found an 8mm circular hole punch for controls etc. https://www.amazon.co.uk/LoongGate-Heavy-Puncher-Single-Photos/dp/B07NQFWYRJ/ I PONDER using a professional firm to *Laser Cut* my Panel design in Acrylic? There is a standard .dxm (CAD) file for laser cutters? Has anyone tried? Costs? Laser cutters seem to be limited to A3 size. Maybe I could order transparent (smaller) covers to "sandwich" smaller(!) sections of my (cardboard) printings? I saw a nifty idea recently. The guy used a professional Printed Circuit Board manufacturer to "etch" (and print) his front panels too. As ever, such services seem to be far more available in the USA than the UK. Just wondering! "Brainstorming"random ideas etc. etc.
  19. An interesting thread! I did once tease an art-loving GF with notions that e.g. photography "had rendered the whole of fine art" redundant? lol. Living dangerously? If needed, I have learned the "error of my ways"... In my favour, I had bought books on "how to draw/paint"... I Did *try*! I have rarely found MANY people showing an interest in "my" science... To me, the thing is experience... To discover and learn NEW stuff etc. To some extent, I sense, like "Athletics" some folks are better equipped physically... More sensitive eyes? Greater visual acuity? I once showed a total novice the Sun via PST. He could see (describe) stuff I couldn't! Above all I feel I am (despite my critics) an "Egalitarian"! I want to find out WHY people are attracted to different stuff... different techniques? I suppose the danger is I become a "Jack of all Trades etc." But Hey! There is a (life) time / funding thing: Staff? "Go fund me" maybe? lol (Trying to live to the next "Solar Max"... Favoured Planet positions etc.)
  20. Maybe we should have done "Arts" subjects (I often wish!) Seriously how could one engage the public re. your subject? Dour twitterings re. religion & politics + br****? Or maybe: P.S. I suspect the *video* won't work on SGL, but many of you will probably be able to access Twitter... as a *reader*?
  21. I had one... Came with good old "Vixen" 8-24mm Zoom... But perhaps that means it (or I) didn't *really* qualify? I used it to conceal a drip of superglue on a 90mm MAK! Guess I should finally come clean with the purchaser...
  22. Finished! No "rocket science", but does the (one/two) job(s) needed. I used a 2mm thick "hook & loop"(!) disk to allow a BIT of "flexure"... Marked rotation direction to avoid disk cartwheeling across room?
  23. Like it! Recently thinking about the landing site and the ABC craters... Of course the "scale" of the *actual* landing site is a different order again? I saw someone selling 3D printer files of the latter, somewhere on Twitter...
  24. Still have a couple of "standard" books I bought for myself at the time. Both good in their own way... The US perspective and UK perspective? Former more detailed... the latter has a "complete" mission transcript. Hey, I can still do an fair *impression* of Neil A's "One Small step..." etc. Complete vocal impression with "static"! lol. I doubt I'm unique in that?
  25. I did TRY to TEST a Pancake 24mm f/2.8 versus an EF 50mm STM f/1.8 https://www.amazon.co.uk/Canon-EF-1-8-STM-Lens/dp/B00XKSBMQA I used a Test Card on screen (not at infinity!) and scaled images to match... The left hand image shows Centre performance of the lens.... the right hand image shows Edge performance! Pancake 24 at f/2.8 The following suggests quantitatively the EF 50 STM has to be stopped down to f/4.0 (or more) to match the Pancake f/2.8 ???? EF 50 STM at f/1.8 EF 50 STM at f/2.8 EF 50 STM at f/4 ASIDE: The last image had some *camera shake* rather than astigmatism or whatever! lol Does the above really MEAN anything? Who knows?!? lol! I TAKE it to mean that Canon lens performance scales with price?!?!? The 40mm Pancake is said to be better than a 24mm too? BUT throwing caution to the wind, I tried a 10x stack of 2min images at f/2.8 with EF STM 50! I used dark subtraction, IRIS Gradient removal and image enhancement with GIMP levels... My conclusion is the EF50 STM was "Good enough" for me! The (more expensive) Pancake 40mm may have be better? But I decided to stick with the Pancake 24 & EF50 STM f/1.8. Canon 100D + EF50 STM f/2.8 ISO1600 + Baader UHC 10x2min (Darks, IRIS Flattened. GIMP Levels etc.): [removed word] Grana Salis as they say!
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