|
monopole for 10 meters
|
#
?
Jul 27, 2015 02:57
|
|
|
|
| # ? May 23, 2024 21:33 |
|
|
i am now having a hunch that the spy radio's non-working-ness is due to the failure of the 30-cell nicad pack that's supposed to supply -12, +12, and +24 volts how the hell am i supposed to replace that with anything that's not just another nicad pack???
|
|
#
?
Jul 27, 2015 03:48
|
|
|
buy/build a bench supply
|
|
#
?
Jul 27, 2015 03:50
|
|
|
disassemble, note all battery locations and wirings to deliver the power to the right leads and how to wire it out of packs, and build your own packs you must you must you must increase your busted nicd capacity with brand new ones cell for cell
|
|
#
?
Jul 27, 2015 04:31
|
|
|
Bloody posted:buy/build a bench supply yeah but then the "off/opr/chg" switch will no longer charge it  is there some way to get those voltages out of a lipo pack/packs without Fuckiness? can I just wire up a bunch of packs for all the different voltages?
|
|
#
?
Jul 27, 2015 04:32
|
|
|
atomicthumbs posted:yeah but then the "off/opr/chg" switch will no longer charge it it is possible but probably a big pile of mess and i wouldn't trust its charging circuit with a lipo pack
|
|
#
?
Jul 27, 2015 04:48
|
|
|
basically you'd want a pack with gnd, +12, +24, and +48
|
|
#
?
Jul 27, 2015 04:50
|
|
|
ideally i'd be wiring a BMS in there. maybe 3 very well insulated BMSs with +12v output in series?
|
|
#
?
Jul 27, 2015 05:39
|
|
|
I would get one of those ready made switching power supply modules for each voltage.
|
|
#
?
Jul 27, 2015 08:08
|
|
|
is there any reason I shouldn't slice this glass mount analog onstar antenna with a razor blade? it's got an f connector on the inside. glass mount is poo poo anyway right? e: there's a GPS antenna on my windshield too. I'll probably leave that
|
|
#
?
Jul 27, 2015 16:03
|
|
|
my mate's had a glass mount antenna on his car for years since it lacks roof rails, it's some nagoya type, works pretty well apparently but that's a 2 ft. whip fed through the glass, not some piece of copper taped on the inside of the windshield, i say slice it and put in something better instead
|
|
#
?
Jul 27, 2015 16:25
|
|
|
yeah this is also a whip that I could presumably replace. but I guess my 3/4 whip up front kills any stealth factor anyway. I'm just gonna slice it. I don't quite understand how they feed thru the glass, induction or smth I suppose. took the 2m and broadcast whips off and ran the suburban thru a car wash. and cleaned all the glass too. looks so so so much better with clean glass. PuTTY riot fucked around with this message at 17:05 on Jul 27, 2015 |
|
#
?
Jul 27, 2015 17:03
|
|
|
if i were designing it i'd start by trying some plates to get capacitive coupling, if enough capacitance is there then it'd be transparent and dual band design would be simpler but a more clever designer might try a tuned loop to get inductive coupling, the loop could potentially also be part of the matching network
|
|
#
?
Jul 27, 2015 17:43
|
|
|
hmm. that's some good adhesive. I think I'm gonna wait and borrow the heat gun at work and then have a go again with a razor blade.
|
|
#
?
Jul 27, 2015 18:09
|
|
|
citric acid is my go to for almost all kind of adhesive, dissolves most kind of tape in a few minutes
|
|
#
?
Jul 27, 2015 18:23
|
|
|
goo gone it is. brb.
|
|
#
?
Jul 27, 2015 18:36
|
|
|
it's done. looks much better imo
|
|
#
?
Jul 27, 2015 19:25
|
|
|
noticed that the 1 kHz IF filter on the mackay receiver isn't working right, no signal really looks to be a short on the information filter plug in board, i can trace the short from the switch right up to the crystal filter sub-board unfortunately i put the receiver schematics in a box i put in the mail earlier today, so gonna have to unsolder the crystal board to see if it's just a solder bridge or a dead crystal/cap
|
|
#
?
Jul 27, 2015 19:40
|
|
|
So do I need to drive a stake into the ground for a monopole?
|
|
#
?
Jul 27, 2015 19:41
|
|
|
technically no as you got those radials, but it's not going to hurt anything.
|
|
#
?
Jul 27, 2015 19:42
|
|
|
I dunno whats up with it then. I have it cut to 8"2', but the internal SWR meter is showing a 3:1 when I transmit on 10 meters.
|
|
#
?
Jul 27, 2015 19:59
|
|
|
surely for a monopole you'd need the pole isolated from the ground, and a solid connection into the ground to the coax shield? for poor ground conductivity you might need radials, a wire mesh fence should work well if the spacing isn't too large second hand old ham tip: running the coax along the ground instead of in the air works somewhat like a balun, reducing noise etc.
|
|
#
?
Jul 27, 2015 20:06
|
|
|
he's got radials. also keep in mind that the resonance point of a monopole is like 37 ohms. expect a 1.5 swr at the dip. you're basically gonna have to tune around and see where its resonant. or cut/add a couple cm at a time
|
|
#
?
Jul 27, 2015 20:10
|
|
|
OK I found it. The female to female adapter I'm using to connect the coax to the antenna is a piece of poo poo that doesn't always connect the outer conductors. It was reading over a megohm of resistance from the outer conductor at the radio end to the ground at the antenna. It's fine now that I've fiddled with it until it made a good connection. Now the SWR is 1.25 at the bottom end of 10 meters and about 1.75 at the top of the band. It's this piece of poo poo right here http://www.amazon.com/gp/product/B00R2LY2VS
|
|
#
?
Jul 27, 2015 20:30
|
|
|
Hell yeah very cool. Good work! you'll want to bookmark this http://www.qsl.net/wj5o/bcn.htm
|
|
#
?
Jul 27, 2015 20:32
|
|
|
there's something very satisfying about fixing a crusty knob, the VFO wheel on the mackay receiver is a fancy optical chopper wheel, before it would spin about half a turn if i set it going, after a good PTFE spray squirt it spins for about 100 rotations i can see why they included a dial lock switch, it's extremely sensitive (but also very responsive since all the counting is done with TTL instead of some 1970s microprocessor like in most modern chinese radios) the dodgy speaker on/off button also started latching perfectly after i did some tefloning also, this radio has the best feature ever made, inside on the top there's a little clip that holds the allen key used to remove the knobs  e: and just won a H-350 military radio handset to use with the marine radio, it's an H-250 (standard prick 77 radio handset) but upgraded with a better mic and rewired for duplex not quite a marine handset but i have a 250 for my VHF and it's actually a lot better for weak signals than speakers and the microphone has some degree of noise cancelling and the right impedance for the exciter longview fucked around with this message at 22:06 on Jul 27, 2015 |
|
#
?
Jul 27, 2015 21:57
|
|
|
movers brought my poo poo today, time to see how lovely the 2m scene is and whether or not I can hang a dipole in my back yard without breaking my neck. there's a couple big conifers back there with no branches for like 30' so that could work as for insulators, is it ok to use the plastic electric fence insulators you'd get at a farm supply store? like this  hell, i should just buy some of those and a bunch of fencing wire, make a "shepherd's dipole" and submit it to whatever the new zealand equivalent of the arrl is.
|
|
#
?
Jul 27, 2015 22:31
|
|
|
those will suffice 100%. go nutslongview posted:also, this radio has the best feature ever made, inside on the top there's a little clip that holds the allen key used to remove the knobs ONLY redeeming feature of that piece of poo poo bencher paddle - allen key for adjustment in a fahnestock clip underneath
|
|
#
?
Jul 27, 2015 22:32
|
|
|
yeah there's nothing special about insulators really as far as i know only issue with using random wire for antennas is that apparently steel has poor conductivity compared to copper so you might lose some efficiency. my loop was built with special antenna wire made with both copper and steel strands to combine strength and conductivity
|
|
#
?
Jul 27, 2015 22:35
|
|
|
i have a 10m dipole that i built back in CA, with a lovely "ugly balun", and i guess I'll try to rig that up, but what other antennas should i look at building for my back yard? it's pretty big, probably about 40'x40', with some trees at the SE, NE, and NW corners. House is along the south side, split-level so the east half of the house is 2 stories. edit: i have an all-band hf rig
|
|
#
?
Jul 27, 2015 22:37
|
|
|
Those should be fine. I used a piece of PVC. Hey 290-- Can I do this  but use that cm108 fob i've got, and somehow rig up PTT on that as well? or should i say gently caress all that and just straight wire it and use vox?
|
|
#
?
Jul 27, 2015 22:40
|
|
|
Pham Nuwen posted:i have a 10m dipole that i built back in CA, with a lovely "ugly balun", and i guess I'll try to rig that up, but what other antennas should i look at building for my back yard? it's pretty big, probably about 40'x40', with some trees at the SE, NE, and NW corners. House is along the south side, split-level so the east half of the house is 2 stories. are you looking for DXing or just general purpose? if you have a decent tuner you can make almost anything work, i got very good performance out of my 80m horizontal delta loop running NVIS, and with the right feed that type of antenna will tune up on any band a lot of people like trap dipoles, stay away from windomes and other unbalanced antennas like longwires if you can, RFI into the shack tends to be a problem, always use a balun
|
|
#
?
Jul 27, 2015 22:50
|
|
|
i dont even know on HF any more. i have barely heard a thing in days and though slow cw is fun, i have no more interest in yelling into a mic over and over to "really light copy OM cant quite make you out"
|
|
#
?
Jul 27, 2015 22:56
|
|
|
longview posted:are you looking for DXing or just general purpose? i don't really have a decent tuner, just the auto tuner in the rig. i could try to find something on ebay or see if any of the local old farts have some stuff to sell. oh drat the ABQ hamfest is in 10 days: https://dukecityhamfest.org/ delta loop seems doable, i'll look at it some more
|
|
#
?
Jul 27, 2015 22:59
|
|
|
internal ATUs can be pretty good the issue with tuning coax fed antennas is that the loss in the coax gets multiplied due to the standing waves (or put another way, the signal travelling back and forth through the coax until it comes out at the antenna with the right phase/amplitude). that's why i used 300 ohm ladder line with a 1:6 balun for my loop despite it nominally being around 100 ohms at the resonant frequency that tuned up with the TS-850S/AT tuner which is specified for 22-120 ohm or so another fix is putting the tuner near the antenna, like the icom AH-4 or the new LDG remote tuners delta or square loops can be excellent performers for DX on low bands too if they're vertical, depending on the feed point the radiation angle is pretty low we put up the horizontal loop in about 3 hours total including drilling holes in the walls so it's a dead simple antenna design
|
|
#
?
Jul 27, 2015 23:06
|
|
|
ive been solidly impressed with the "won't really do past 3:1" atu in the 746. it seamlessly locks down the 18ft vertical to 1:1 on anything between 30 and 10. obv 20/17/10 are best performance, but all the others work too. and the vert is fed through, no exaggeration, 8 feet of RG-8, so I know coax loss isn't eating up a bad match it gets kinda pissy down around 40 and 80 meters but had no problem stretching the windom out to full band on 40/20 (when the windom was up) meanwhile i have that monster Ultimate Transmatch design tuner that i built for jello that will tune anything on any frequency. its hilarious
|
|
#
?
Jul 27, 2015 23:18
|
|
|
i think that after i buy the spool of RFC400 though i'm going to buy a hustler 4btv and mount it elevated on the back of the bus with a few radials sticking out. add wires for 30 and 17m and you're done (lol nobody goes on 12m) one of the best antennas i ever had was a tree hung 40m vertical with three 1/4 wave radials stretched out 10 feet off the ground
|
|
#
?
Jul 27, 2015 23:22
|
|
|
i have two possible rooms for setting up ham poo poo, is it better to have the station on the second floor so you can be close to the antenna, or at ground level so you can get a good ground easily?
|
|
#
?
Jul 27, 2015 23:22
|
|
|
second floor by far imo.
|
|
#
?
Jul 27, 2015 23:23
|
|
|
|
| # ? May 23, 2024 21:33 |
|
|
i've got a second floor radio room, my main concern is with grounding -- there's no actual way to get an RF ground (though in practice this is impossible unless your house is made from brass or copper due to the requirement of lamba/~20 maximum ground lead length) in that room i haven't had any issues, but this was part of the reason i decided on a nominally balanced antenna to keep the gear and me from becoming part of the antenna, but there's almost certainlt a fair about of common mode RF in that room compared to ground level
|
|
#
?
Jul 27, 2015 23:29
|
|