|
I tie my fiberglass pole to a fence post with a short luggage or ratchet strap. Spiderpole has a nice little harness you can slide over a pole that you then can attac guy wires to. I have a big parasol stand that screws into the ground that can secure the base of the pole. I'm currently on my way to a hamfest by the way - in Zwolle, the Netherlands. Hoping to find WW1 trench radios. Not too big of a chance of finding one but i've been bummed out not getting one, ever since i actually found one at the age of 15, 15 years ago. Couldn't afford it back then, neither did i have even close to enough knowledge about operating an actual spark gap transmitter in a way that doesn't get me in trouble. LimaBiker fucked around with this message at 10:12 on Oct 29, 2022 |
#
?
Oct 29, 2022 10:08
|
|
|
|
| # ? May 12, 2024 19:04 |
|
|
Back! The market was a bit odd, there were many sellers who registered but didn't show up, so many empty spots. I expected more sellers. But regardless i found quite a nice load of goodies!  - Two 1920s tubes and a big coil to make a 1920s style transmitter (RE134 3w output triode and A425 small signal triode - A reflex klystron just because it was in a 1 euro bin - Some 1970s LED pixel displays - A free LCD module - Some free rotary switches - A reel of antenna wire - 4 big egg shape porcelain isolators - Some RFC's - A pair of used but beautiful Hirschmann KLEPS measurement probes - a MFJ 1,8-30MHz antenna tuner. I almost bought all the separate parts to build a tuner myself (roller inductor, big variable capacitors etc) spending about 100 euro on the parts and then having to figure out how to make a nice enclosure. But then i found this thing. As much as i appreciate the art of diy radio'ing, i just couldn't push myself towards spending just as much money and then having to build the thing myself... - Tiny RC car, about the size of a mouse. Hope the cat likes it. - CRT tester-rejuvenator. - Some old headphones.
|
|
#
?
Oct 29, 2022 17:39
|
|
|
wonderful scores. the lil mfj tuners are, as i posted a bit ago, really good if you can snag a deal. Just don't try to run fifteen minutes of full power FT8 while you cajole it into tuning up a chunk of speaker wire on 160m and it'll be fine.
|
|
#
?
Oct 29, 2022 17:47
|
|
|
Jonny 290 posted:Just don't try to run fifteen minutes of full power FT8 while you cajole it into tuning up a chunk of speaker wire on 160m and it'll be fine. i feel seen
|
|
#
?
Oct 29, 2022 18:43
|
|
|
I will be using it with a too short antenna on 160m, but probably with no more than 50 watts or so.
|
|
#
?
Oct 29, 2022 21:56
|
|
|
1/8 wave for a monopole is totally okay. shorter than that and you'll see some scary voltages in the matching network. just keep an ear out for arcing i dont have any problems tuning up my basically-40ft-with-a-capacitance-hat vertical on 160m
|
|
#
?
Oct 29, 2022 23:03
|
|
|
Figured I'd learn how to do the math for parallel/series-parallel circuits with reactive components in them and god it sure does take forever to do all the complex number poo poo on paper. Feels like I understand the impedance matching networks better though
|
|
#
?
Oct 30, 2022 05:15
|
|
|
funny thing about taking my extra is that i didnt grok that math and just doubled down on all the other sections to hit the 70% average. by the time i was a few years into extra i'd learned that math anyways
|
|
#
?
Oct 30, 2022 05:20
|
|
|
Soo i'm gonna make a little bit of a ground/radial system next to my house. But i gotta feed in the ground wire over about 4m length, to the first floor. What do you think is best - a stretch of old vacuum cleaner power cable (2x 0,75 or 1mm^2), or some old RG58u coax with the core and shield connected together? The coax is pretty thin, but the skin effect should send most current through the braid, i think. The ground system will be some 4m long radials (our front yard simply is no bigger) and a grounding rod (directly under my shack window) connected together. E: found another length of better quality RG58 and used that. LimaBiker fucked around with this message at 16:00 on Oct 30, 2022 |
|
#
?
Oct 30, 2022 14:21
|
|
|
Yeah scrap coax is generally fine for that, it presents as a big low impedance conductor when used that way. That's another thing to keep an eye out for at swap meets though - found a 300 foot roll of 1/2" width avionics ground braid (stainless steel, super thin strands so very high density) for a fiver once. Use it all over the place.
|
|
#
?
Oct 30, 2022 17:03
|
|
|
brand engager posted:Figured I'd learn how to do the math for parallel/series-parallel circuits with reactive components in them and god it sure does take forever to do all the complex number poo poo on paper. Feels like I understand the impedance matching networks better though Got any good resources to share for learning this stuff? e: Realized I should be more specific: sources for impedance calculations and such Not general amateur radio sources… have plenty of those 
namlosh fucked around with this message at 17:51 on Oct 30, 2022 |
|
#
?
Oct 30, 2022 17:21
|
|
|
Well, the random bit of wire even works on 160m, kinda. Made a CW contact with a british guy in Tatcham, 75km east of London - from Amsterdam, the Netherlands the distance was about 400km. Hand trembling on the key, for some reason morse makes me hella nervous. Guy was patient but i didn't understand half of what he was saying, i really need to get better at it... But i feel that's pretty hard with people you don't know.
|
|
#
?
Oct 30, 2022 21:26
|
|
|
namlosh posted:Got any good resources to share for learning this stuff? I think I had these open https://www.electronicdesign.com/technologies/analog/whitepaper/21133206/back-to-basics-impedance-matching https://www.allaboutcircuits.com/textbook/alternating-current/chpt-5/series-parallel-r-l-and-c/
|
|
#
?
Oct 30, 2022 23:02
|
|
|
Discovered these signals that lasted a short while so i recorded this. What does it mean?  
|
|
#
?
Nov 2, 2022 09:48
|
|
|
those are really random and not on even khz intervals. my money's on a lovely piece of electronics doing some kind of thing that generates noise incidentally
|
|
#
?
Nov 2, 2022 16:59
|
|
|
Big Mackson posted:Discovered these signals that lasted a short while so i recorded this. never seen anything like this before! would like to listen to these, too. keep us posted?
|
|
#
?
Nov 2, 2022 20:14
|
|
|
After listening to one of the strongest signals it hears like it starts with a tone sequence and sometimes i hear faint voices. My conclusion? The conditions was just right for me to hear the carrier and tone of some sort of voice (proprietary or commercial i guess) from handheld radios. Everyday when the atmospheric conditions are at it strongest for 10 or 6 m i hear these signals for about an half hour. Maybe if i had an antenna for 6m or 10m instead of a length of wire i could get better data. Signals to the right in the picture are mostly of those voice+tones and signals on the left are of afsk/fsk? modulation. idk what the choppy wide columns are. NKOM's frequency allocation says that in the 30-37-5 mhz range are these: Active medical implants Aeronautical military systems Land military systems Maritime military systems Model control PMR Radio microphones and ALD LMR is my best guess. Big Mackson fucked around with this message at 10:04 on Nov 4, 2022 |
|
#
?
Nov 4, 2022 09:22
|
|
|
brand engager posted:I think I had these open Thx!
|
|
#
?
Nov 4, 2022 22:22
|
|
|
Big Mackson posted:LMR is my best guess. oh did you dump the whole IQ file? if so post it somewhere if you want and i'll take a gander
|
|
#
?
Nov 5, 2022 03:42
|
|
|
Jonny 290 posted:oh did you dump the whole IQ file? if so post it somewhere if you want and i'll take a gander https://drive.google.com/file/d/1c7cl3PyfaOCSS1TuT6IenlUMbUleW_yU/view?usp=sharing
|
|
#
?
Nov 7, 2022 06:54
|
|
|
swiped. i'll peruse it tomorrow or tues if i have time. thx!
|
|
#
?
Nov 7, 2022 07:05
|
|
|
i am really glad ic-7300 have an internal 5a fuse. your sacrifice will be remembered.
|
|
#
?
Nov 9, 2022 10:55
|
|
|
uh what'd you do? just curious heh
|
|
#
?
Nov 9, 2022 17:14
|
|
|
Jonny 290 posted:uh what'd you do? just curious heh bought a metal shelf and grounded it to a grounding bar thingy and put all the radio equipment on the shelf and grounded all the things to the bar. When i removed a cable going into ic-7300 (panadapter mod) it (or a loose wire on the bar that i since removed) touched something and it just went out. Power off your equipment before removing cables and stuff lol. Big Mackson fucked around with this message at 18:44 on Nov 10, 2022 |
|
#
?
Nov 10, 2022 18:41
|
|
|
When CB/10m be bussin edit: could do without people trying to shout over each other on the same channel. LOUDER EQUALS MY CHANNEL.
|
|
#
?
Nov 10, 2022 18:42
|
|
|
Big Mackson posted:bought a metal shelf and grounded it to a grounding bar thingy and put all the radio equipment on the shelf and grounded all the things to the bar. When i removed a cable going into ic-7300 (panadapter mod) it (or a loose wire on the bar that i since removed) touched something and it just went out. Power off your equipment before removing cables and stuff lol. Reading the reviews for my shack power supply (Astron RS-50M) is really fun. The only people who one-star it are the ones who don't learn/realize that the pass transistors are on the outside of the chassis, their cases are electrically hot, and they're insulated from the chassis by mica shims. So every time somebody lets a coax connector dangle or is careless with anything connected to the shack ground and it hits one of the transistor cases, they inadvertently fire up an arc welder in their shack and promptly run to the Internet to poo poo all over the Astron. lol
|
|
#
?
Nov 10, 2022 20:40
|
|
|
so how much danger am i in of frying myself with my ss-30m? i would prefer that little and poodle jones dont get zapped
|
|
#
?
Nov 10, 2022 21:47
|
|
|
I finally decided to bite the bullet and get IC-705, and now they're out of stock pretty much everywhere in Europe Shouldn't have been a sensible adult and decide "I'll buy it after the next paycheck, there's no rush"
|
|
#
?
Nov 10, 2022 22:47
|
|
|
Achmed Jones posted:so how much danger am i in of frying myself with my ss-30m? i would prefer that little and poodle jones dont get zapped should be good. the ones that have voltage on the outside of the case are the older style linear power supplies. the big heavy ones with huge transformers in them. even then its the 13.8 volts. not enough to shock you but enough to make some sparks if some metal object gets in there. yours is a modern switching style supply which means its design is from when some basic consumer protection ideas existed vs. the older style which are from a time when people thought it was ok to have 400 volts dc exposed on the outside of tube equipment. still love my old astron linear’s tho. super simple. easy to repair and modify. can be left turned on for several decades with zero faults. https://www.repeater-builder.com/astron/astron-index.html is the go to for a rabbit hole of information about the older linear style power supplies
|
|
#
?
Nov 11, 2022 04:55
|
|
|
I'm shocked. Not that it worked but it was about as easy as anything I've ever tried as a hobby. I got a $20 adafruit RTL2832, followed the nrsc5 instructions and paired a bluetooth speaker to the Pi and now I have a HD radio signal. ran into some trouble around figuring out what cmake option to use, but reading the github issues clarified it. makes me want to download that pi-ham distro and see what else I can play with.
|
|
#
?
Nov 12, 2022 22:47
|
|
|
Congrats, sounds like the best kind of project result, goal achieved and a few things learned without significant struggle.
|
|
#
?
Nov 13, 2022 00:04
|
|
|
It's a rare treat in a world where it feels like every time I find a deal or a cheap project it's just full of gremlins. Genuine crystal radio kit feeling on this one.
|
|
#
?
Nov 13, 2022 14:35
|
|
|
Boat anchors a big of a pain as I think they would be? They look so cool but I can’t imagine they’d perform nearly as well as a newer radio, and I’d image they’d heat a room/takeover a desk.
|
|
#
?
Nov 14, 2022 04:45
|
|
|
blugu64 posted:Boat anchors a big of a pain as I think they would be? They look so cool but I can’t imagine they’d perform nearly as well as a newer radio, and I’d image they’d heat a room/takeover a desk. They're cool and sound amazing, tuning up to transmit is a little bit of a pain, but if you can get say a Kenwood TS-820 for cheap, I'd say go for it.
|
|
#
?
Nov 14, 2022 05:23
|
|
|
their receivers are actually sometimes a lot better than modern ones. no phase noise in the circuit, etc. a well tuned up tube rig can hear a whisper. it's just filtering where they often fall short. old tube receiver + a modern dsp filter is pretty magic I generally don't gently caress with tube radios though just because of the plate lines. one mistake and they're wheelbarrowing you out back ive got a heathkit hf, 6m and power supply setup and the 6m rig is really fun at least (worked a contest with it and it crushed)
|
|
#
?
Nov 14, 2022 05:38
|
|
|
Consumer level tube stuff (the Hallicrafters S-38 or S-85 and such 'general coverage' receivers) are lovely to see and use for broadcast and AM stuff, but for SSB and CW sorely lacking in stability if you use them for 14MHz and higher. On 21MHz you're literally constantly adjusting the fine tuning or BFO pitch to keep up with drift. They don't usually have crystal filters - expect 10kHz bandwidth. Actual ship's receivers are absolutely fantastic. The sound quality is a lot better than from modern receivers. The sensitivity is excellent, and of course once refurbished, they will last another 50 odd years. They're often made to be serviced - my Philips BX925a has plug-in power supply capacitors - so although literally all of them need to be checked for leaky paper capacitors, actually doing it is often easier than in broadcast receivers. In my case the narrowest filter is 900hz wide, and the 2nd narrowest is 2,6kHz (at their -6dB points). So they're on the wide side for CW use. However, the sound is very 'mellow'. Even although you're hearing multiple CW signals together, it's not a grating sound. In my specific case - and that was a complaint from the users of these sets in the 1950s - the receiver isn't too stable, despite having a stabilized HV power supply. If my 2kW room heater that's running on the same circuit clicks on, i can definitely hear it drift a few hundred hz. On a stable supply, it's pretty solid once warmed up. Because of its large thermal mass, it is less sensitive to room temperature changes than my (mostly) transistorized Yaesu FT-101e. That thing jumps a few dozen Hz already if i just blow on a circuit board. If you go further back in time, to before WW2, you'll still find TRF receivers all the way up to 1940. They typically were set for one frequency, then the controls were locked and left there for as long as possible because they require some skill to tune properly. Quite often they don't have a frequency calibrated dial - only a logging dial, where the operator would write down the number on the dial and the station it corresponded with. My BX925a has a roughly calibrated MHz dial (per 100 or 50kHz) and an extremely accurate logging dial. This is actually pretty convenient - you can write down in your log book something like 'Roma Radio IAR 21552' meaning band 2, division 15, subdivision 52'. With the band switch you set it to band 2, with the motorized tuning you zoom towards division 15, and manually you scroll to subdivision 52. This can all be done in seconds. One subdivision is about 1kHz though there is no strict relationship between how many kHz something is, and the size of the subdivisions. Personally i don't worry too much about the high voltage. As long as you exclusively poke at things with your multimeter probes you're not gonna get zapped. If you are dumb and start moving the chassis on your bench while it's plugged in, you're gonna get zapped sooner or later. In 15 years time my zap counter is 1. Tried to shift the chassis of a broadcast receiver i was doing measurements on, grabbed the bottom socket contacts of the magic tuning eye. Wasn't a bad zap - i reckon i grabbed it after a bunch of current limiting resistors. Grabbing the full high voltage, however, will hurt like a bitch. LimaBiker fucked around with this message at 16:09 on Nov 14, 2022 |
|
#
?
Nov 14, 2022 15:48
|
|
|
There's also the science mode end-run of replacing the crystals etc in some of those with the little Si5351 boards set up as crystal replacements. Always wanted to see how tight I could get the old TS-520 with those. Course, now you've got a DDS or three in your rig, bringing in the aforementioned phase noise
|
|
#
?
Nov 14, 2022 20:42
|
|
|
|
|
#
?
Nov 16, 2022 09:31
|
|
|
6m runs on sporadic-e which isn't quiiiite in season yet. there's a smaller season coming up probably thanksgiving to valentine's, and a big rear end one in the summer, say memorial day to labor day. it's big when it's open. few years back i got 6m VUCC in one season with 100w and a dipole at 15 feet
|
|
#
?
Nov 16, 2022 23:25
|
|
|
|
| # ? May 12, 2024 19:04 |
|
|
hmm, i guess loss joke is too esoteric for this subforum 
|
|
#
?
Nov 17, 2022 18:54
|
|