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Tree vs antenna, I'm streeeeeetching. I tension it up, tie it off, wind blows, tree wiggles, dipole goes stretches, then goes slack. Should I not be tying it off ridgy? Some sort of rube goldberg contraption to allow the tree to sway and not stretch antenna?
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Jul 18, 2020 00:30
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If your trees are really wobbly could go with something like this: - attach pulley to tree (id say a good marine one with stainless hardware because its worth not needing to go back up there to fix it) - tie rope to end of antenna wire, possibly using one of those plastic or fiberglass isolator things - put rope through pulley in tree - tie weight to end of rope to provide tension from gravity but free movement when the tree sways something like this, or could instead bolt right into the tree: 
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Jul 18, 2020 01:07
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poeticoddity posted:I'm having a brain-fart and don't know what to google: If they're in the same room the reduced rx probably wont hurt. Cheapest way to cut the power is to have one radio vertical and the other on it's side so they're cross polarized.
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Jul 18, 2020 01:12
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I had three redwoods in a triangle with pulleys up like 60 ft, paid tree trimmers to bolt them in. I wanted to avoid paying someone to come by and fix them in the future, so I attached a loop of good rope (bought from DX engineering) to each pulley that reached all the way to the ground, then had tie downs at the base of the trunk to provide tension. Antennas were then attached to the loops and pulled up into the trees. The redwoods didnt sway much so the loops themselves (and length of rope involved) provided plenty of slack when the loops were tied down The loop setup meant that I could pull down the antenna. I could have even replaced the rope itself by tying another rope into the loop and pulling it through. Otherwise I would've needed to pay someone to come by when I wanted to change anything. Because the pulleys would be expensive to fix if they got stuck or corroded, I got some fancy stainless boat ones from a boating supply store for $$$$, and also got some big stainless screws from the same store to attach them to the tree (it sounded like even galvanized doesn't do great in redwood over years). Of course this was in the bottom of a valley with 20-40 deg horizons since that's where redwoods live, so I usually only got out to a couple states away. But it was a really sweet setup and the loops made it easy to mess with the antenna and even adjust the way it was angled between the trees
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Jul 18, 2020 01:26
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Casual Encountess posted:i am a ham now hi a ham now
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Jul 18, 2020 01:33
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Also I don't know if they make circulators that work down in ham bands, but they let you split your send and receive paths which would let you attenuate just the tx. The ones we had when I worked with rf stuff were 3-port waveguide things where the signal takes a different path depending on the signal direction. 
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Jul 18, 2020 01:41
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Progressive JPEG posted:I had three redwoods in a triangle with pulleys up like 60 ft, paid tree trimmers to bolt them in. I wanted to avoid paying someone to come by and fix them in the future, so I attached a loop of good rope (bought from DX engineering) to each pulley that reached all the way to the ground, then had tie downs at the base of the trunk to provide tension. Antennas were then attached to the loops and pulled up into the trees. The redwoods didnt sway much so the loops themselves (and length of rope involved) provided plenty of slack when the loops were tied down Progressive JPEG posted:If your trees are really wobbly could go with something like this: I followed the johny 290 approach Mavic Mini drone, "drone race clip" and carefully fly over tree. Got a fishing line up, pulled a rope with a pulley up and over.. Its a 55 foot douglas fir on one end, and a garage rafter on the other. I couldn't go "straight" down, I had to come off the canopy at quite an angle and tie off on two separate buildings. Weights on the "service end" will end up smacking the building... I suppose I could add more pulleys and put the weights up? Is a gas cylinder possible? In retrospect, I made two mistakes. 1, a lovely ebay pulley that took ~30 days to arrive from china and is going to rust, and 2) making all 4 tie off points (line for the pulley, line for the antenna) on my roofs. Try tuning 42 inches off your dipole, 3 inches at a time, each time getting on the roof, FFFF!
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Jul 18, 2020 02:10
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What if you just slackened the whole thing but hung an extra weight along the length of the span?: Use rope for the black line and antenna for the blue line? As the tree sways, the weight will just rise and fall and the line tension should remain fairly consistent.
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Jul 18, 2020 02:38
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Casual Encountess posted:i am a ham now so what radios do your police department have?
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Jul 18, 2020 11:02
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Progressive JPEG posted:If your trees are really wobbly could go with something like this: I use this technique, but slightly modify it: I get my first rope up and over a branch, tie it together in a big loop, and then also affix a pulley to it. Then, I run the rope for the antenna through that. Usually, there's enough slack that I can pull the one end of the pulley loop down, to raise the pulley to the height I need, or pull down on the other wise if I need to mess with my antenna. I'll tie down the pulley loop so it doesn't move, and then use a partially-filled water bottle or old car wiper fluid bottle for the antenna rope counter-weight. You can also use large springs from the hardware store to provide some tension as well.
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Jul 18, 2020 15:10
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ham radio? more like haraam radio
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Jul 18, 2020 15:57
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RadioPassive posted:What if you just slackened the whole thing but hung an extra weight along the length of the span?: I am blanking on the appropriate engineering term, but doing that would put a large amount of stress on the horizontal antenna wire, and likely cause it to fail.
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Jul 18, 2020 23:18
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Tension
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Jul 19, 2020 00:47
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manero posted:I use this technique, but slightly modify it: I get my first rope up and over a branch, tie it together in a big loop, and then also affix a pulley to it. Ok, so the washer jug got me thinking. I think I can fit a counterweight by the garage where everything is anchored. If I am clever, I can use additional lines to prevent the counterweight from slammin into the siding. Here is a terrible rendering of the setup right now. Instead of the "Blue line" just tied off, pulley to a 5 gallon bucket and some nonsense to limit its travel. https://i.imgur.com/SqDWEoK.png
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Jul 19, 2020 03:51
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TasogareNoKagi posted:I am blanking on the appropriate engineering term, but doing that would put a large amount of stress on the horizontal antenna wire, and likely cause it to fail. My math on a 10 pound weight in the box and a 15-degree angle on the upper black line gives 2.6 pounds of tension on the blue antenna line and 10.35 pounds of tension on the upper black line. So, a little more vertical than the black line is drawn. Is 2-3 pounds is too much tension? I've never strung an antenna up like that idk how tough they are.
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Jul 19, 2020 05:15
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regular copper isn't nearly as strong as the copper-clad steel stuff. That's fine for like 14 gauge THHN wire though. i want to say the break strength of the tiny tiny 26 gauge Wireman stuff is about 20 pounds, the 18 gauge is like 100 plus. I threw some of the 18 over a tree limb and did pullups on it once, it really is tough as hell.
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Jul 19, 2020 19:03
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Are the MSI.SDR Panadapters decent?  https://www.aliexpress.com/item/33046994958.html?spm=a2g0o.cart.0.0.78493c00dGt0mm&mp=1
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Jul 19, 2020 19:09
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taqueso posted:Are the MSI.SDR Panadapters decent? appears to be a clone of the SDRplay RSP1 https://www.rtl-sdr.com/photos-of-the-msi-sdr-dongle-a-new-sdrplay-rsp1-clone/
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Jul 19, 2020 19:21
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ok I got the 5 gallon bucket counterweight working. the wife really likes the home depot orange in the yard. horse_ebookmarklet fucked around with this message at 01:54 on Jul 20, 2020 |
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Jul 20, 2020 01:49
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taqueso posted:Are the MSI.SDR Panadapters decent? We shall find out, these got linked in the discord and at least two of us ordered 'em. I have a small collection of RTLs so I'll definitely be comparing mine when it arrives.
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Jul 20, 2020 15:27
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horse_ebookmarklet posted:Tree vs antenna, I'm streeeeeetching. I'm late to this discussion but I haven't seen anyone suggest bungee cord tensioning yet, is there a reason why not? Gives some stretch while keeping the wire tight. It's worked pretty well every time I've done it or seen it done, and it's simple and cheap.
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Jul 20, 2020 19:28
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alnilam posted:I'm late to this discussion but I haven't seen anyone suggest bungee cord tensioning yet, is there a reason why not? Gives some stretch while keeping the wire tight. It's worked pretty well every time I've done it or seen it done, and it's simple and cheap. bungees rot out fast in the elements. Hit up the hardware store and get a big extension spring, much better.  Just be careful when setting things up - springs can hold considerable energy
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Jul 20, 2020 19:46
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Good point, I guess I've only ever done it for temporary stuff like field day.
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Jul 20, 2020 20:16
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taqueso posted:Are the MSI.SDR Panadapters decent? I'm trying to get mine to work. The drivers won't install on my Windows 10 machine because I have virtualization enabled for Docker. I downloaded the latest HamPi release but it doesn't appear to boot on my Raspberry Pi 3B just yet. Not quite as plug and play as I was hoping.
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Jul 21, 2020 13:15
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Jonny Quest posted:I'm trying to get mine to work. The drivers won't install on my Windows 10 machine because I have virtualization enabled for Docker. I downloaded the latest HamPi release but it doesn't appear to boot on my Raspberry Pi 3B just yet. Not quite as plug and play as I was hoping. Hop into Discord and, or if you're already there, ping me. I had to deal with this and I might be able to provide info that helps
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Jul 22, 2020 03:01
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So we're looking at trying to put together times for the DMR net. If you don't have a DMR radio, don't worry! There are alternatives that I can go into detail if requested. If you're looking to join other ham nerds talk, please take a moment to submit https://whenisgood.net/q5bik3g to give us an idea of what times will work.
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Jul 28, 2020 00:37
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With the UK dropping the requirement to do an in-person practical, I took the opportunity and I got my my UK foundation license the other week  Yet to make any contact with anybody, the first (and only) signal I picked up was two dudes talking about their cataracts and disability badges. Bought a DMR radio too hoping to make a contact with a friend on the coast, but all the Repeaters i can pick up are analog only. Have parts to make a slimjim antenna on the way, hopefully I can get a bit better signal with that. Otherwise it’s off to find some accessible hills.
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Aug 1, 2020 10:48
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Horse Clocks posted:With the UK dropping the requirement to do an in-person practical, I took the opportunity and I got my my UK foundation license the other week Welcome! I’m a foundation too but the RSGB have now said they’ll do intermediate level exams too so I’m highly considering it. I don’t have much practical experience, basically none on HF. Maybe in the future but I’m primarily wanting to do this so I can put my own gear on the air, which foundations can’t do. I can reliably-ish pass test exams from some app but the current RSGB 2019 mock papers did kick my arse a bit. Where are you located?
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Aug 1, 2020 11:56
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Horse Clocks posted:Bought a DMR radio too hoping to make a contact with a friend on the coast, but all the Repeaters i can pick up are analog only. If you grab a cheap chinese MMDVM board and a raspberry pi you can hop on any brandmeister DMR talkgroup you want, including the one some discord goons have been playing with.
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Aug 1, 2020 13:25
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thehustler posted:Welcome! I’m a foundation too but the RSGB have now said they’ll do intermediate level exams too so I’m highly considering it. I don’t have much practical experience, basically none on HF. Maybe in the future but I’m primarily wanting to do this so I can put my own gear on the air, which foundations can’t do. I picked up the Intermediate book, on the off chance I get into it. I’m in NW London, closest to GB3HR. [Edit] went for a walk up a hill and managed to hit a DMR repeater, post a GPS position over ARPS, and found out whoever manages the DMR address book took liberties with my display name... jerk [Edit2] can get a DMR signal at home and from Caterham on the other side of London woop. Horse Clocks fucked around with this message at 19:18 on Aug 2, 2020 |
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Aug 1, 2020 14:35
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The DMR net will be happening tonight (04/08/2020) at 8:00PM PT on TG 3163563 A note about this: quote:WHEN CREATING THE CONTACT MAKE SURE TO SELECT GROUP AND NOT PRIVATE Don't get your underoos in a wad if you can't make tonight, the next net will be Friday (07/08/2020) at 6:00PM PT on the same TG. If you want to do net control, speak up; we have a script you can (or don't who cares) read to make it easier. It's been used a total of one times now, so it's getting some traction.
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Aug 4, 2020 22:15
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drunk mutt posted:The DMR net will be happening tonight (04/08/2020) at 8:00PM PT on TG 3163563 Come ready to chat. No “no traffic” bullshit.
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Aug 4, 2020 22:27
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Just a reminder post, to remind, the posters of this thread, that the DMR net will be occurring at 6:00PM PT on TG 3163563quote:WHEN CREATING THE CONTACT MAKE SURE TO SELECT GROUP AND NOT PRIVATE These posts for reminders will not continue beyond this one; if you want reminders, get on Discord. The schedule, in the event that it's updated, may be posted; but as of now it's Tuesday 8:00PM PT and Friday 6:00PM PT (Not in the middle of the loving Atlantic ocean).
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Aug 8, 2020 01:06
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drunk mutt posted:Just a reminder post, to remind, the posters of this thread, that the DMR net will be occurring at 6:00PM PT on TG 3163563 CQ DISCORD; the only link I found a few pages back is dead.
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Aug 8, 2020 21:27
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TasogareNoKagi posted:CQ DISCORD; the only link I found a few pages back is dead. https://discord.gg/R46wYGB
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Aug 8, 2020 22:26
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Lately I've been getting the itch to get on HF. As I've probably mentioned before in this thread, I'm in a basement apartment (with no patio or balcony) which means any HF setup I put together will need to be portable (there's an open field near my apartment as well as a number of parks in the area that I could operate from). Here's the setup I'm thinking of:
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Aug 9, 2020 16:08
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just upgraded to my general while (remotely) attending def con; now to get hf gear i guess!
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Aug 10, 2020 01:46
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Crusader posted:just upgraded to my general while (remotely) attending def con; now to get hf gear i guess!   
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Aug 10, 2020 02:25
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Nice! Like a dope, I foolishly believed that DEF CON was cancelled. I didn't realize they were doing it remotely.
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Aug 10, 2020 02:31
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Can someone tell me if what I've got here is actually present or is some sort of harmonic artifact that comes from using a cheap SDR radio? It is some Spanish-language shortwave radio stations that come in incredibly well here in Tampa, but scrolling around I hear the same broadcast at a lot of places across many bands, and sometimes coming in right in the middle of my 20m (which is the same broadcast as what is just above 40m). I'm contemplating buying a more expensive SDR like an RSP1A or maybe cheap out and get an MSI.SDR, but don't know if it will eliminate receiving this in a place where I don't think it actually is. Right now I am getting it on 7.33500MHz, 7.365000MHz, 14.069800MHz, 14.100000MHz, 14.13000MHz, all the exact same stream. CapnBry fucked around with this message at 14:12 on Aug 10, 2020 |
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Aug 10, 2020 14:09
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