Task: Given HF or VHF equipment, get on the air making as many contacts as possible in a 24hr period.
Condition: Run a station in a less than ideal setting, be it from a field setting or other improvised environment.
Standard: Make as many contacts as possible using emergency power and wire antennas.
As the usual this station was run as a Tactical Operation Center (TOC) with equipment run off-grid. Every year is a learning experience and in some ways is more challenging than the ARRL’s summer counterpart. With a 40/80 fan dipole and a 160m Inverted L, our group performed extremely well over the 24hr period.
Critical Takeaways:
- Common knowledge doesn’t always apply as the solar minimum approaches. 40 behaved very much like 20, with trans-continental communications being made especially as the night pressed on. During the day it faded in and out.
- 80 ran very long. Contacts as far west as Colorado and Wyoming were made, but short hops across NC and VA were impossible. Due to this fact and the point above, operator experience IS CRITICAL to knowing what frequencies to choose depending on the task. NVIS is not a constant propagation effect and takes continuous experience only gained by working with people who know what they’re doing.
- Sometimes QRP levels simply won’t work even when everything with your equipment is perfect.
- Battery management and knowing the consumption on your rigs. In our case, running two IC-7200s and an IC-746, much more power was required than for a QRP-only operation. Surprisingly, the inexpensive 35aH SLA batteries from Harbor Freight held up far better than expected. I plan on investing in a few more.
- Start smoking your pork shoulder for the crew earlier, so you’re eating before 1900L.
I want to thank everyone involved for making it a fun and very worthwhile event. To everyone who participated on the air, I hope is was a fun learning experience also.
Could you post details on your fan dipole and power distribution set up? Are you using a rig runner or similar gear for radio power distribution?
How are you protecting adjacent radios from near-field overload of the front end?
Thanks
My fan dipole is simply has two 40m elements and two 80m elements running to the same feedpoint, which is a 4:1 balun. I do not use a rig runner, I make anderson power pole connections (which is standard for all of my equipment) running to the battery itself with a small LED voltimiter in series to monitor the battery.
The protection between radios operating on different bands has to do with the spacing between the antennas themselves to prevent intermodulation or overloading.
I’ll note all of the antennas used are home-built.
Thanks. That’s very helpful. Especially the voltmeter to keep batteries above the discharge threshold. I have an eBay one that I use for my Newby rig.
I also use power poles. Helps prevent negative outcomes during hook ups or “toc jump”.
I am using home brew wire antenna with 1:1 balun. Just trying to learn what works best.
I asked about intermod overload because I now have a deaf SDR that I was using as a spectrum monitor. Key lesson: antenna spacing matters and sometimes 1/4 wave isn’t quite enough.
Thanks for sharing. Helps keep me motivated to keep working and learning.
The spacing should be at least one wavelength.
I don’t have HF transmitting equipment yet but I did spend a couple of hours scanning 2m simplex and calling CQ. No signals heard so I took a friend to a local club’s WFD event and hung out a while. It was fun and I plan to be better equipped for field day 2018 and WFD 2019.
It seems like you’ve pumped up the production lately and there’s been a lot of good content, just wanted to say thanks and that I enjoy reading what you’re putting out. The stagnation of several good blogs like Danmorgan76 and Dialtone and others that have disappeared entirely is really disappointing. Long live Brushbeater.
Thanks for the kind words. On 2m, look into SSB versus FM. While there’s an increasing number of people on 2m FM (especially working SOTA activations) but SSB is the way to go. It’s one of the few reasons I can think of to still buy an 817.
I can’t speak for the others but I have no intention of going anywhere.
We had a pretty good run with WFD. Got to use some cold weather gear, cooked some mountain house and that most heavenly creation for cold weather work, SPAM!
. We were working QRP only(FT-817 and KX-2) and made phone and digital contacts on 20 and 40 meters. Antennas were homebrew dipole and an end fed with 4:1 matchbox. Seems nobody was hearing our 5watts, but it was fun just the same. Great to get out!
Unfortunately, i was home based, or 1HNC as the check in goes…
That said, for me, being a rank amateur, i still managed to make the most out it w my HF kit, a bought gv5r di pole and most importantly, a random longwire that Lode Runner here suggested for 160m…
I used spiderwire and a 4to1 ldg voltage balun, then to my ldg auto tuner, to my hf rig, a hamfest used alinco dxsr8…
the wire was strung at approx 15′ thru trees and 135′ in length, that lined the sidewalk in front of home.
i was able to make contacts on both 80 and 160, pretty impressed and validating…
i live in an hoa governed community and have to be crafty/sneaky in the manner in which i string/put up antennas.
I do believe that i will build a loop antenna around the perimeter of my small ranch and give it a go. once up it will be almost invisible…
For me, it was about applying knowledge and doing it, checking results, and adding one more layer to the skillset and knowledge base…
This spider wire stuff and 1to1 n 4to1 baluns just may be the solution i have been looking for, this stuff disappears when strung..
http://thewireman.com/antennap.html
overall, very pleased and cant wait for SFD….
thanks to NC and the rest who provide useful info and support.
Thanks for inviting me up NCS, it was a lot of fun, and the food was great. I would add to the critical takeaways –
– if you’re the RTO, then your “AO” most definitely extends to the stations and events which effect your group in the RF domain. I was caught by surprise Saturday night by a different contest that saturated the entire cw portion (and beyond) of 160M, which essentially ruined the band for us. Had I known ahead of time, it would have changed several of my choices and priorities durring setup.
– Band-Pass Filters rated for 100 watts (or better) should be part of every group’s TOC kit, otherwise you may find yourselves effectively limited to ONE HF station being on the air.
– Plan for bad weather. Small tarps or waterproof covers, and milk crates or other means of keeping antenna feedpoints/tuners/etc up out of the mud are essential to a successful field operation.
73, LodeRunner
LodeRunner
Can you suggest a source for external 100 Watt band pass filters? I have a couple for QRP from qrpkits that go with the Bitx40.
I am interested in additional BPS for attenuation of unwanted signals in both near and far fields.
Thanks
Jon,
The BPFs you purchased from QRPKits are for the receiver. What I’m referring to are single band filters that go between the rig and the antenna, so you transmit through them, as well as receive.
I’m not prepared to recommend a manufacturer/vendor for such units, until I’ve ‘done my homework’ on current designs and quality of manufacturer – the filters I have are 25+ years old and hand-made. I can tell you that good BPFs are a “specialty item” and they’re not cheap. I should probably do a post on the topic…
good BPFs are a “specialty item” and they’re not cheap. I should probably do a post on the topic…
LodeRunner
Standing by for some much needed schooling in BPF!
I set my qrp bpf as external on the Bitx since it’s my experiment learning platform. I use them for tx and rx without a fire. My Bitx is putting out about 3 W, best estimate with my DMM as only test equipment. The IRF 510 seems to be the weak link in that system. It gets real hot real quick, even running only SSB phone. That said, for $50 and a little time it has been a good rig to learn with.
Related, I am interested in proven designs for homebrew BPF and impedance transmatch. hard to sort Internet wheat from chaff on those topics. ARRL books are great theory but not helpful in “how to build”
Jon – “LodeRunner, Standing by for some much needed schooling in BPF!”
OK, will put it together and get it to NC Scout as soon as possible. It will include some additional info on the design and construction of “antenna tuners” since there is an inherent relationship between the two…
Lode runner
Thanks. Looking forward to your next installments on z-matching networks and transmission band pass filters!
Related, sort of
Does anyone have a source for surplus WD-, WF-16, and RG-213?
Sportsman’s Guide used to be a good source for WD-1. But light gauge wire like lamp cord will work just as well. WF-16 is, for all intents and purposes, much like lamp cord.
NCScout said
“Sportsman’s Guide used to be a good source for WD-1. But light gauge wire like lamp cord will work just as well. WF-16 is, for all intents and purposes, much like lamp cord.”
Scout. Thanks. My recollection is the WD-1 was steel wire with a hard insulation. My thought was that steel wire might be more durable than the THHN “house wire” I am currently using for antenna experiments.
It is steel wire. It may be more durable, but I’ve never had a durability problem with either one.
Might be that durability has more to do with the radio operator’s side of events, than it does with the wire. Maquis, etc. Wire lasts a comparatively long time.
So I can use WD-1 to build HF wire antennas? Is there enough conductor in there?
I got two (NOS) 1 mile rolls for $60.00 each from eBay. TA-1s and 312s too from different folks. Still looking for a decent SB22. Look around the net gear can be had for the right price.
My first MOS was 36K.
Cavguy
For sure! My 80m dipole elements are made of TA-1.
Was that $60 shipped? If so you got a good deal.