Portable QRP?

Discussion in 'QRP Corner' started by N5EIT, Dec 24, 2015.

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  1. N5EIT

    N5EIT Ham Member QRZ Page

    How many of us take part in portable ops?
    What is your set-up?
    How do you pack/carry it?
    Have you been successful?


    I love portable QRP. I have several kits and rigs. QRP operation has taken me on a journey. This journey started with my base station rig and continues to shrink in size, but grow in opportunity to learn and enjoy our hobby!!! It's funny how this QRP disease starts out with slight intrigue and quickly becomes an obsession...HA Portable QRP is most definitely an exercise in patience !!!

    I would love to hear about your experiences with portable QRP.

    My (current) favorite set-up is my Ten-Tec Rebel, Cross Country Wireless 40m EFHW matchbox (directly connected to Rebel / no coax), about 66' of number 18 AWG wire (no counterpoise), and I use a 5Ah SLA battery. My portable paddle is a K9LU Bulldog Paddle mounted on a 5 inch long piece of wood and wrapped with para-cord. It fits perfectly in my hand and I don't worry about it getting bashed up. I also carry a small speaker or ear buds. It all fits in a 5.11 tactical shoulder bag.
    I could lighten the load by getting one of those 30C RC Car Batteries, but then I would also have to buy a charger and I just can't bring myself to drop that kind of cash just for batteries.

    I live in the Red River bottom-lands of NW Louisiana, so I hike around a mile or so to my favorite spot on a local levee. Its higher than the surroundings by about 10 ft. I hang my EFHW as vertical as possible by using fishing weights on brick layer's twine and tossing it over high branches that hang close to the levee. I look like David fighting Goliath when I'm twirling it to throw over and over again... I also take a 10W solar panel that I purchased at Batteries Plus. It has a built in charge controller and folds / packs away quite nice. It keeps my SLA topped off on sunny days.

    I've made quite a few contacts on 40m with this set-up and find no need or increase in performance from a counterpoise "at this location". I've tried all lengths too. If I happen to use one; it's usually about 6 feet long and laying on the ground. I've found that to be a sufficient length and tested it with a field strength meter. I'm running around 4 Watts output with around 12v input and my analyzer says it's a 1.2:1 SWR. Although, like they say; every location is different. What works in one spot may not work in another.

    I have a Hendricks PFR-3B that will be finished soon and put into service. I look forward to getting on 30m CW in the field. Lots of people whine about lack of activity on that band. Having recently upgraded to General, I've found a QSO every time I get on it by persistently calling CQ and exercising patience. I can't wait for the Hendricks kit to be finished!!! It'll lighten my load by a bunch...

    So, Let's hear from you!!
     
    WA7ANT, RN3ANT and KD2RON like this.
  2. VK3YE

    VK3YE Ham Member QRZ Page

    It has its ups and downs. Most times you make contacts. 4 to 8 contacts in a 2 hour session is not unusual and some can be DX. A lot more in a contest.

    My website, which discusses portable QRP in detail, is currently down but there are many demonstrations on my YouTube channel at: https://www.youtube.com/user/vk3ye
     
  3. KI6J

    KI6J Ham Member QRZ Page

    Around 6k Qs, and 169 entities operating QRP/P. About half of those were had with a ATS rig and an EFHW.
     
  4. N5EIT

    N5EIT Ham Member QRZ Page

    That's really cool... I'm just getting started, but the "BUG" has most definitely bitten me!!!
    I subscribed to the yahoo group in hopes that I'll eventually snatch one of those up. KD1JV has designed some great stuff. My PFR-3B is one of those sweet designs. I can't wait to start using it.

    VK3YE... I have actually watched just about every one of your videos. GOOD STUFF!!!! Keep 'em coming!!!
     
  5. KK4NSF

    KK4NSF Ham Member QRZ Page

    I've only recently start doing QRP, after spending most of my time using heavier, more powerful equipment. To be honest, I discovered that anybody can buy a 100w rig and a good antenna, and have consistent results. While fun at first, and useful for rag-chewing and networks, it starts getting rather dull after a while. So.... I decided to do something a little more challenging: QRP.

    Using my Icom 703, an MFJ 971 tuner, and an end fed antenna I started doing little expeditions to odd locations.... with good results. One my recent min-DXpedition to Fort Morgan Alabama, we got an average of 12 QSO's per hour using 5w on SSB, from as far away as northern Minnesota, Wisconsin, and West Texas. On other trips I've managed North Dakota, all up and down the East Coast, and up to Alaska.... which is not too bad considering the poor band conditions we've had recently.

    Of course there have been other trips that were not so successful, due to things like not having a well-tuned antenna, poor band conditions, and so forth and so on.... but those trips were not unproductive. In each case I learned what doesn't work so well like my short vertical mounted at ground level, with radials; and my walkabout portable backpack with drag-along counterpoise wires. While they did gather some QSO's they aren't so good.... BUT they did point toward confirming what does work and so were helpful. Plus it was a lot of fun to try them out.

    I've not done any QRP CW yet. That's next on my list.

    What I've discovered is that the antenna is indeed a critical element.... but not as much as the purists will lead one to believe. I've had a number of excellent QSO's using a very small AH-703 antenna ( a well-tuned 4 ft vertical) with a counterpoise. Dipoles work well, and so do end-fed wires with a tuner. The idea that a tuner "eats up all your power, and renders QRP unworkable" is a myth. My longest QRP SSB 5w QSO to date has been to Juneau Alaska, from Mobile AL..... using an end-fed random, with a counterpoise and tuner. My conclusion is that there are a number of antennas that will work well on QRP, IF they are well though out and well tuned.

    So what else have I learned? A LOT of things about working QRP Portable:

    1. make a checklist and check it twice before you set out on a Field Trip. It would be really bad to travel all of the way out to Sand Island on a boat, only to discover that you left your antenna wire back at the dock. (not that I've actually done such a thing ;) )

    2. avoid log-jams and pile-ups. the big guns will just shoot you out of the water

    3. state your power and location on your CQ. I typically say "CQ CQ CQ this is KK4NSF QRP from Sand Island Lighthouse, calling CQ CQ" or something similar. That way, you sound more attractive to receiving stations. More than one QSO has told me that it's what attracted them to answer me.

    4. optimize your set-up in the back yard before you go. If an experiment fails in the back yard, it won't work any better out in the wild-woods.

    5. Keep an open mind, and don't get stuck in a "I've got the ultimate set-up" mentality. You don't. Such a set up doens't exist in the real world. While you may have a good or even an excellent one, there is always room for improvement and optimization. This goes especially for antennas. For some reason people find one that works for them, and then set out to badmouth all of the other options. Don't fall into this trap, since it takes much of the fun out of it for both you and those you are talking to.

    6. That being said.... make sure that you have an efficient, portable antenna. While there are a number of options out there, there are some that don't work or may not work with your set-up.

    7. research, test and experiment constantly. read all of the relevant technical materials, find those ones that seem like they'll work for you, then test them out..... and then test 'em again. That way, you learn what does and doesn't work in all sorts of circumstances and are thus better prepared for many more possible scenerios.

    8. finally- it helps to announce any field trips, special events, or QRP miniDXpeditions in advance. Since your signal may be weak in some locations, it helps if folks are listening out for it.

    well... that's what i've learned so far in my QRP experience. I'm sure it will change over time as I learn more about operating in this mode.
     
    KB9LXP, RN3ANT, KD8EDC and 1 other person like this.
  6. W7CJD

    W7CJD Ham Member QRZ Page

    I think SOTA is a good strategy to get QSO's (they have announcements on a reflector and they have SOTA listeners) and Adventure Radio Society has "Flight of the Bumblebees".

    I got my "start" with QRP, with Altoids tin kits.

    I built so many little kits: okay, that works. Build another.

    I made antennas, even aluminum foil antennas on butcher paper backing.

    Outrageous stuff.

    Not particularly good, but fun.

    I have been struggling to get the experts in
    the forum to describe simple "how to" indtructions to build a resonant dipole, for example, or a doublet, single band or multiband. Maybe two bands.

    SOTABEAMS has pull-apart wire antennas using small-size automotive bullet connectors.

    I would like to see a thread, with instructions for beginners.

    I can build such an antenna, by fooling around until I get it right, because I do have concepts.

    I managed to get antennas as right as I could. I had
    MFJ Travel Tuner, (150 Watts)
    MFJ Auto Tuner Extender, (300 Watts)
    MFJ QRP SWR, (50 Watts)
    Wattmeter, (5 Watts)

    I had to find out the difference in end-fed antennas, before I would use one.

    It is not just a length of wire.

    I would like to see straightforward "how to" instructions, for really basic wire antennas explained for beginners, even if spending some money is required.

    Like you, one we had our 100 watt push-button transceiver, I wanted to engage the hobby even more with "how it works".

    My first QRP portable was a Ten Tec Scout 555 I turned diwn the oower to under 10 watts SSB.

    I found Adventure Radio Society online.

    I greatly admired every antenna article with graphic display of propagation.

    This was my QRP antenna education.

    I recommend the Adventure Radio Society archived articles.

    Once I found Adventure Radio Society, I just had to have a "trail friendly radio" for SSB.

    I watched the development of TRF radios for CW, all good. Interesting.

    I found the Sparrow, in DE land.

    I kept hoping for 75/80 meter.

    I saw that the Small Wonder radios were always "sold out".

    Now, there is so much for QRP SSB.

    I am in QRP heaven.

    I would purchase them all, but I am nit a "collector".

    So.. I hold back a little.

    I have a YouKits TJ2B MK2 SSB on 15-17-20-40-80 meter bands, made for a limited time, because of demand to incorporate CW.

    I want the 10 watts SSB FX-9a.
     
    Last edited: Dec 25, 2015
  7. AF9J

    AF9J Ham Member QRZ Page

    I usually just do a 1/4 wave endfed with a counterpoise. My current grab & go setup (which I hope to change in the future, once the K1 is done [it arrived surprisingly quickly yesterday - only 2 days after I ordered it]), is an SW40 that I built back in the 90s, with a ZM2 tuner (also built in the 90s). I also have a Ten Tec R4030 (basically a rebranded YouKits radio), that I had a blast with on 40m during Field Day this past year, that could stand a wee bit more useage.

    My most memorable portable op? Probably the FYBO I did back in 2009. I really did FREEZE my butt off in that one. I went to a local park with an FT-897D I had at the time, that I had the accessory internal battery pack installed in, running at 5 watts. All of the park's picnic tables were covered in snow, and the wind chill was about 30 below zero, so I operated from my car (which kept me out of the wind) in the parking lot, with the windows cracked open, no heat, and the 40 & 20m enfeds tied off to nearby trees. The temp in the car was 3 degrees, and I paper logged (I had to keep the pen I used in my right hand glove, to keep the ink from freezing up!). I lasted for about 2 to 2 1/2 hours, when the combination of cold feet, and a need to go to the bathroom (the park's bathrooms were closed for the winter) drove me off the the air, and back home!

    73,
    Ellen - AF9J
     
    Last edited: Dec 25, 2015
  8. W7CJD

    W7CJD Ham Member QRZ Page

    KG5CGN,

    I admired LiPo batteries, since first seen.

    I did get the Windcamp battery pack and replacement back for my Yaesu FT-817ND.

    I thought I might purchase the battery and charger sold separately, for backup. I haven't needed an extra battery.

    Here it is.

    image.png
     
  9. VK3YE

    VK3YE Ham Member QRZ Page

    A good list from KK4NSF

    Lots of blog articles on link dipoles. Eg http://vk3zpf.com/link-dipole

    They give good predictable performance and have no hassles with counterpoises but fast band changing is a pain, especially at night.

    Unless it's a magnetic loop with narrowband tuning over a 2 or 3:1 frequency range, antenna complexity increases with the number of bands if you want a resonant antenna.

    Something like this end-fed will cover 3 bands though I've never had huge number of 10m contacts on it.

    You're right but at some stage you've got to stop the 'analysis paralysis' and just build something.

    Even if your understanding is incomplete. Take consolation that even the 'experts' disagree.

    http://www.aa5tb.com/efha.html is as good as any place to start on end-fed half waves.

    As for multiband use, the same bit of wire will be different fractions or multiples of wavelength at different frequencies. Sometimes it's nearer a quarter or three-quarter wavelength (where it's low impedence) but at others it will be nearer half (or multiple) wavelength long (where it's high impedence). Both can be matched with an L or pi network coupler.

    Lengths like 1/4 wavelength (or less) require really good grounding or effective counterpoises. Go much shorter than 1/4 wavelength (eg less than 3/16 wavelength) in an end-fed and efficiency becomes very poor. Still if that's all you can manage for 160 metres try it anyway. Others will probably also be using compromise antennas and if their noise is low they'll hear you.

    Go much longer than 5/8 wavelength and the radiation pattern splits off so that a vertical no longer concentrates most of its signal at the horizon. And if a dipole you'll get more and more lobes as you make it longer in relation to wavelength. Which may be good or may not be depending on where you wish to work.

    You can use the same end-fed wire over more than (say) a 2.5 or 3:1 frequency range but there will be compromises or unpredictability at the extremes.
     
    W7CJD likes this.
  10. W7CJD

    W7CJD Ham Member QRZ Page

    I have built so many antennas since I was 15 years old. I am 67 years old, now.

    Do the math.

    If I used a link antenna I described, I would only use it for QRP portable.

    Here is the mathematical relationship of R X and Z, explained for AC and DC so one can get the concept for how it is both scaler and so-called complex number math involved to be able to talk about what happens if you thought what happens is only happening in 2-dimensions going up and down the wire.

    re. All About Circuits

    http://www.allaboutcircuits.com/textbook/alternating-current/chpt-5/r-l-and-c-summary/#

    R X and Z

    http://www.allaboutcircuits.com/textbook/alternating-current/chpt-5/review-of-r-x-and-z/

    Now, everyone, stop talking down to QRP enthusiasts, please.

    It is not about having funds, either.

    Just get on with it.. tell it like it is, and let us decide if we want to build or buy.
     

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