HFU HF Underground
Loggings => HF Beacons => Topic started by: IRONARCHER on June 21, 2021, 0246 UTC
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Hello everyone-
I've been a lurker here on HFU for a while now and I finally have something to post about. I'm proud to announce that after a month of prototyping I have finally come up with simple little beacon design that works. Listed below are the specs of the Archer Beacon.
Run Time- 24/7
Circuit design- Simple BD-139 crystal oscillator with an IRF-510 amplifier and 7th order Chebyshev low pass filter.
Battery- Lithium 2 cell pack totaling 8400mah that's charged by 2 small 2.5W solar panels.
Charge Control- I'm using an off the shelf TC4056 charge controller and voltage step up to bring it to 12v for the transmitter.
IC controller- ATtiny85 keys the crystal oscillator.
Power output- About 2 Watts.
Enclosure- Gasket sealed waterproof project box with all connectors sealed with silicone. Added some desiccant packs just to be safe.
Antenna- 64' end fed half wave in a sloper configuration matched with a mini 49:1 impedance transformer.
Beacon Info- Sends "ABK" once every ~55 seconds in slow CW on 6998.73Khz just under the 40m band.
Beacon QTH- North western part of the US.
When the beacon is transmitting the frequency tends to be a bit drifty so it sounds kinda whoopy.
I plan on making a few improvements like a better solar panel and improving the frequency stability.
I would love some feedback on the design good or bad. Just so everyone knows, I'm very much an electronics amateur. The first time I picked up a soldering iron in any serious capacity was the toward the end of 2020 when I went down the rabbit hole homebrewing simple CW radios. I started out building small kit radios and became fascinated with the idea of building a pirate beacon after discovering HFU. The first beacon I actually heard while scanning around was the "Desert Whooper" and I was hooked. After countless hours of research, designing, prototyping, failing miserably, then finally succeeding, I'm proud to present the Archer Beacon.
Please send QSLs to
ARCHERBEACON at GMAIL dot COM
and I will send you a brand new shiny E-QSL card.
If you are interested in the design or would like a copy of the schematic just let me know.
Images attached below.
Enjoy!
(https://i.imgur.com/kV8d7l9.jpg)
(https://i.imgur.com/TDj01L4.jpg)
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i was hearing something way down in the noise but it's high noise level tonight .
give it some time , i'm sure some of these guys on here will get on it soon .
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Yeah it is pretty noisy tonight so I'm not too worried.
I checked out some web SDRs earlier and I could hear it in AZ about 1000mi away so I know it at least works.
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Nice job! Good to see some more HF beacons coming online. :)
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Doing well here this morning at 1500 utc =/-
73, Mark
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Hearing it here clearly in Lake Stevens, Washington as of 1920 UTC. I also tried it earlier today (around 1530 UTC) via an SDR on Whidbey Island and heard it there. It is a little whoopy, which makes it sound almost like a bird call at times, which is kind of fun.
Do you want me to email you a short recording?
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Mark and Treehouse SWL-
Thank you very much for your reports! I've sent you my numbered QSL cards.
Any screenshots or audio recording are very helpful and appreciated.
So far the furthest report is from Ukraine!! That blew my mind when I received that report as I never expected it to go international!
Keep the reports coming!!
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Ukraine!
good job man 8)
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Thanks for the new beacon / DX target!
Copied here at 0747 UTC on my overnight SDR recording, using a netSDR and 900 ft Sky Loop antenna.
Below is an audio recording:
http://radiohobbyist.org/blog/mypics/6998.0-USB-22-Jun-2021-07.47.38.mp3 (http://radiohobbyist.org/blog/mypics/6998.0-USB-22-Jun-2021-07.47.38.mp3)
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Awesome! Thanks for the recording as well and my eQSL card will be in your inbox shortly.
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Congratulations your beacon is 589 at this location at 0430Z.
Your beacon looks great in the pic posted and the only advice I can give is the outside wiring and critters. Two of the beacons I know of went temporarily QRT simply due to the critters. Other than that, thanks for putting the beacon on the air!!
Receiver KiwiSDR
Ant: 80m dipole at 15m
location: DM12
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Zeak-
Thanks for the report! If you PM me an email address, I will send you my eQSL card.
Good piece of advice on the external solar power wiring. I can confirm the presence of multiple types of wire eating critters in the emplacement area and now it has me worried. My next trip out I will have to reinforce it with something. The enclosure alone took several days of planning/building and even went through the trouble of a 24hr submersion test to ensure no leaks. I also made sure to consider weather, temporary lack of sun, and high winds into planning but never thought about dang critters chewing up the wire hahaha.
A quick internet search led me to a product amazon carries called "Electriduct 1/4" Rodent Resistant Braided Sleeving" that I think would solve the problem perfectly. If I decide to buy a roll, I will drop a review here for any future beacon builders that may encounter rodent problems. Seems like it would be a cheap solution to prevent unintended and premature QSTs.
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I'm hearing it right now on the VE7AV SDR, Prince George, BC.
Really chirpy, to the point of musical ^_^
*edit*
Just sent a little recording to you for QSL ID
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Heathkit-
You should be receiving my eQSL card in your email shortly. I sent the email before reading your post so I got your QTH now for my logs.
It definitely is chirpy! I'm not sure how to fix it... I think it is probably a heat problem causing frequency drift. I have a heatsink on the IRF-510 because it gets warm and I tried heatsinking the BD-139 but it made no difference. Maybe ill just leave it alone since the chirp gives it some unique character.
Any thoughts?
Also thank you for the recording. Much appreciated and ill add it to my log.
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Hi IronArcher,
Thank you much for the QSL!
Looking at the schematic, I'd say regulate the BD-139 (go from 12 to say 9V, then the 5V for the logic after that) and use a buffer. That should cure your chirp.
73's
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I will give that a try on my next beacon build. I may just be pushing it a bit too hard.
Thanks for the advice.
73
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Congratulations on the beacon build! It's a lot of fun to build solar powered gear to emplace in the wilderness. I heard Archer a little while ago on the KFS omni kiwi. Will email for the e-QSL card
Comments:
For protecting your solar panel wires try this metal braid which worked well for my little dataloggers: https://www.ebay.com/itm/302205006382?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649
It will expand quite a bit in diameter. I use a metal snake pushed through the braid and tape my wires on the end then pull it back through. A little bit of camo paint on the braid tones down the shininess. The biters and nibblers have never bothered wires protected by this stuff as I think the braid exterior gets pretty rough after expanding.
Instead of wires through drilled holes I would go to BNC bulkhead connectors with a rubber washer.
https://www.ebay.com/itm/194146492059?hash=item2d34085e9b:g:afEAAOSwN4Bgp8bx
You can use the BNCs for the DC power from the solar panels too.
Then seal the external connectors with a self fusing tape like this
https://www.harborfreight.com/10-ft-x-1-in-self-bonding-super-tape-61414.html
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I sent you an email for a QSL e-card and forgot to ask for a schematic. What voltage do your solar panels put out open circuit and what current at short circuit? Or do you know the maximum power point (MPPT) figure? What are you using to upconvert the battery voltage to 12 volts?
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Teotwaki-
Thank you for the suggestions! Now that I think about it I actually have some grounding cable on hand that should be sufficient. I wish I would have thought of that before emplacement hahaha.
Part of my initial design requirements were to keep cost as low as possible and reduce complexity (i.e. possible failure points). The prototype of the design used waterproof BNC bulkheads but I eliminated them because I only had a couple on hand and didn't want to order more. I also didn't like the idea of adding a friction connector into the mix with the inevitability of corrosion and increased resistance. I figured soldering the coax directly to the output of the lowpass filter was the simplest and most foolproof way of getting the RF where it needs to be. To be fair though, transporting a beacon with the 64' antenna and 49:1 unun "hard attached" is a pain.
The next iteration of Archer V2 will more than likely use sealed bulkheads for all connectors. Silicone caulk is great but is hard to work with (messy) and looks ugly. I like my projects to look neat even if they are intended to be abandoned and never be seen by human eyes hahaha.
For power, I used off the shelf (Amazon) parts. The solar panels are waterproof epoxy encapsulated with convenient solder points. It's advertised specs are actually pretty darn close to reality. I've used them in several projects and I'd recommend them as a cheap option.
https://www.amazon.com/ALLPOWERS-Battery-Charger-Encapsulated-130x150mm/dp/B074TYH68Z/ref=pd_bxgy_img_1/142-1809823-9436651?pd_rd_w=fKdMy&pf_rd_p=fd3ebcd0-c1a2-44cf-aba2-bbf4810b3732&pf_rd_r=2T00CBMNVVKVMEM51B4B&pd_rd_r=1c580608-9c63-48f4-96d1-6d0298f9fc7f&pd_rd_wg=fhi76&pd_rd_i=B074TYH68Z&psc=1
For solar control, battery management , and to step up the voltage to 12v I used this module based off TC4056. Simple, easy, replaceable, and comes in a pack of 6 for 13$. The output voltage is variable up to 27v but I wouldn't go much past 12v. Cant beat it for the price though.
https://www.amazon.com/AITRIP-Lithium-Battery-Charger-Adjustable/dp/B08GWTBD3T/ref=psdc_10967761_t2_B091F5PTY2
Your eQSL card will be in your email shortly. I very much appreciate the tips and I will probably use some of them in my next design.
One more thing, what do think the best option is for desiccant and moisture elimination inside your outdoor electronics projects? I had the thought of putting rice or DryZair desiccant in the free spaces of the beacon but ended up just using a small packet. Should I have done something different?
Thanks
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Those battery charger/voltage boost boards are pretty nice. i may buy some to play with.
I never worried about adding desiccant. I've used mini Pelican type cases and watertight bulkhead connectors plus California doesn't get much rain, lol. I have had some boxes get snowed on and never had a problem with moisture ingress. Depending on where in the N/W your beacon site is you could have more concerns than I do. Still, a watertight case is watertight and shouldn't need desiccant.
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I love those little boards, they allow you to use random salvaged lithium batteries for projects and allow fore USB and/or solar charging. One thing to note is that they don't provide low voltage protection. Not a big deal but I added a separate board to prevent low voltage damage to my beacons battery.
Good idea on the pelican cases. I have a couple on hand but don't want to put holes in them at the moment haha.
Dang it... now I have to go order some more cases and bulkheads!
Just curious, what model pelican case did you use?
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Hi IronArcher,
I've used rubber grommets sealed with good ol' RTV silicone (I think GE sold out to DAP for the line. It's the clear stuff). A dollop before putting it on the case to seal the case to grommet, let that cure, then feed through the wires and squeeze a bunch in and let it cure. Typical survival was 5 years on the rain coast of Cascadia for my antenna baluns.
The SOFT rubber grommets, like from Digikey, The typical harder ones from auto stores UV eats like popcorn.
73's
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Archer popped up very strong at 03:39 UTC, very chirpy and difficult to tell for sure what is being sent but I am sure this is it. Then it has faded somewhat on subsequent transmissions but is still in there. 03:45 UTC 27 JUN 2021.
Nice to have a new one to watch for! Welcome IronArcher!
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Definitely on the air and super strong into the KFS Omni http://69.27.184.58:8073/
That's definitely mangled Morse and if you look at a strong signal on the waterfall display you can make out the letters ABK
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That's definitely mangled Morse.....
You know.... I listened to it for an hour last night and found that it reminded me of a loon call. Very relaxing with that image in my head :)
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Applause for anyone who attempts to build a beacon let alone gets out in the boondocks and deploys one. There is no "How To Build Pirate Beacons" book to reference and in a lot of cases you just make a decision and see how things play out. From there the experience gained will sustain and shape future construction activities.
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Again it's super strong into the KFS Omni kiwi
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Fair signal on the KFS omni
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Archer just rocks it!
It's the only beacon I can hear pretty much 24/7, even from home QTH. It peaks S8 on the far north Canadian SDR's as far as Manitoba. It's actually fairly weak on the US KIWI SDR's.
I haven't heard any 8-megger in weeks and the noise levels have swamped any hope of hearing a 4-megger.
Keep up the great work, Archer!
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Is Archer QRT? I haven't heard it on any SDR for 24H :(
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The chirp is a FEATURE! :-)
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Hearing it well at times here this morning. The usual QSB.
73, Mark
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Yes!
Coming in here as well :)
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Is it still on the air? I just checked the KFS omni but heard nothing. Hopefully it's just poor propagation.
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Disappeared again here as well. He's not answering his emails. I pray our op didn't go SK from this plague or something :'(
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Disappeared again here as well. He's not answering his emails. I pray our op didn't go SK from this plague or something :'(
hopefully life got busy for them and they had to put the hobby aside until later
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I sent an email this morning and will report if I get an answer
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I sent an email this morning and will report if I get an answer
Yesterday I received some great information! The Archer Beacon will be coming back pending a final choice of a new location and equipment deployment. I was not given an exact time frame or location so keep on the lookout for it.
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That would be good news! Hope to hear it when I'm /6