QRP Antenna's

[JohnyMac]

Just curious (Why reinvent the wheel) what kind antenna are you using for your QRP (Low power) radio when out in the bush?

I am using the EARCH I have described in the past. I am not really happy with it. So I am expanding my search. Suggestions?

When I use my semi-permanent G5RV+ antenna with the little Yaesu 817ND, reception is great and if I am patient I can connect with folks. I connected with a guy earlier in the week with a station in France on 5 watts. 

Suggestions?

[Jackalope]

The important thing to remember is the EARCH (End fed Zepp) and the G5RV are both compromises.  I guess, if you want an ideal, inexpensive antenna, then go with a single band dipole, or even a multi-band dipole for the bands that you regularly use.  An improvement in antenna is the least expensive method of improving your signal, both receiving and transmitting.  Do you have a copy of the ARRL antenna book?  Get lots of wire in the air, put up a Rhombic antenna and really put out a signal!

[voyaginator]

Yep! totally agree with the wire dipole  make the length for the frequency and you get the best and cheapest QRP antenna. If you want to make it easier get a https://goo.gl/mb9i7z   1:1 balun, easier to hang your wire and that's it 

[JohnyMac]

Thanks gents!

In my heart of heats I know my best option is a dipole. I was just thinking of weight and compactness for a bush antenna.

Just thinking out loud here (My downfall for sure) I am wondering if at the end of each side of the dipole antenna wires I fasten a Anderson power pole or a banana plug. And as I change the frequency I add/delete lengths to the dipole antenna to better match the SWR. 

Here is an interesting QRP Balun - Thoughts? http://www.balundesigns.com/qrp-model-1110-1-1-isolation-choke-balun-1-54-mhz/

[pkveazey]

Now that you've got it all worked out, let me throw a monkey wrench into the whole thing. I use a center fed 160 meter dipole and LDG Autotuner for everything, but I use an 80 meter Hamstick mounted at 40 feet up for 80 meters because it works better than anything else that I've tried. If you need something that is good for all situations and is portable, you should consider a bundle of Hamsticks, and a magmount or mirror mount(3/8" X 24 thread). They are $20 each and you can bundle them together and and then select the one you need for the band you are going to work. I went HF Mobile once and used an 80, 40,and 10 meter Hamstick all mounted to one mount with one piece of RG8 coax and let the autotuner find the resonant antenna. It worked great and the guys I talked to down in Florida, 600 miles away, couldn't tell the difference from my mobile or base. The basic idea is its a fan dipole, only its vertical. If you don't have a large enough groundplane, just hook up a long piece of wire to the ground side and make sure its at least a 1/4 wave long at the lowest frequency you plan to use. 64 feet should work for anything you want to do unless you plan on working 160 meters. I could go all technical on you about why its OK to use a ground plane that's too long, but I won't. Just remember that on a Mobile with the antenna mounted on the roof, the Ground Plane is like a big metal ball that may or may not be the exact size you would expect the be resonant, but it works doesn't it.
As to using a 1:1 balun, just consider that the losses in a 1:1 balun usually are about equal to the mismatch without using a balun. A dipole is only 75 Ohms if its a flattop. Any angle you put between the hot leg and the ground leg lowers the impedence. Anything from 45 degrees to 90 degrees will drop the impedence closer to 52 Ohms. Think about an inverted Vee shape and you'll see why they don't need a Balun. My center fed 160 dipole is horizontal and in an L shape with no balun.

[JohnyMac]

Interesting pkveazey. Thank you for your thoughts.

My goal is to put together a CGB (Communication Go Bag) that as taking into account "...weight and compactness for a bush antenna" as I wrote earlier.

Currently my goal is to be able to stack everything (radio, tuner, antenna, etc.) into a 100 round-.50 Caliber ammo can. I will not be using the aforementioned ammo can due to weight. Anyhow, this is the size I am allowing myself. Ultimately I will be looking for a lunch box similar to this one but in mylar for its EMP proof function.

This bag will then go into a GOD (Get Out of Dodge) bag. I am striving for the GOD bag to be under 25 pounds. In my backpacking days working with my partner we were able to keep the weight of our bags under 20 pounds so I know it is doable. LOL, when I started out backpacking my bag was ~35 pounds. I/we learned pretty quick that was way to heavy to travel the greatest distance in a day and not be exhausted when we arrived at our destination. To be quite frank, I do not know how foot soldiers can carry the weight that they do.

Anyway, I have diverted slightly from the subject line of this post - I need a small and compact antenna that can receive RX and TX with minimum background noise (End-feds are notorious for noise) and reach out there.

Yesterday afternoon I easily made a great conversation on 40m with a station in Saginaw, MI. I was using the 817 on 5 watts, fed through a G5RV+ antenna and my LDG, Z-817 tuner. 

73

[Jackalope]

  PK's idea of using hamsticks has some merit, but it's not very efficient and it has a limited low SWR bandwidth.  Yup, a tuner can make it work but it does limit the amount of RF that radiates from the hamstick.  Think of a hamstick as a rubber duck for HF.  They do have their uses, especially for folks with limited real estate for antennas.  MFJ and others sell a bracket which allows the operator to mount two same band hamsticks in a dipole configuration.  This sort of set-up costs less than a Buddipole or Buddistick, and it has about the same level of performance.  A hamstick is one notch above a miracle whip antenna, and I have all the above antennas, so I speak from experience.

     Johny, the mylar bag will have limited durability.  I usually put my equipment in mylar bags inside ammo cans for redundancy.  Regarding the weight in a backpack, I believe in endurance training.  You can train your body to carry heavier weights, it just takes time.  My BOB is in the 45 pound range, and that's carrying two radios.  Due to my work, unfortunately I get to carry that kind of weight fairly often.  I'm definitely slower as I get older, but I can still comfortably carry the weight.  I've got to get my dog accustomed to carrying more weight too.

   Getting back to antennas, are you going to operate many bands, or just a couple of bands?  You also have to consider antenna supports, etc.  Lots of variables and lots of ways to emit RF, that's the fun of radio. 

[JohnyMac]

As Jackalope wrote, "that's the fun of radio.". Yeah LOL, but a muted LOL. I am no way as patient as you 

1) I am a "A" type personality; Consequently, at 61, I try to not expect Rome to be built in a day. However, I understand my personality
    short comings so I try not to reinvent the wheel either. I tend to gather info from what others have done and modify to my needs.
2) I would like to RX and TX on all channels from 2m on out to 160m - I want it all! But in reality I would be happy with 20m to 75/80m. To
    do that and if I use a dipole configuration, I would just use different wire lengths and a tuner. Which was one of the reasons I was
    thinking aloud of adding/deleting the length of a dipole end via banana plugs or Anderson Power Poles. Back to #1 above, just
    needing someone to have done it before and for me to modify it to meet my needs.

So gentlemen, be patient with my "get it done and then move on" personality as I stroll reluctantly down this QRP path. Hopefully some other type "A" guy or gal will learn through my journey. 

[Jackalope]

The powerpole length adjustment will work fine.  Try it and let us all know how it works :-)

[JohnyMac]

After finding the time needed to do this little project I have completed it. Here is the AAR...

1) I used Anderson Power Pole connectors and 14 gauge stranded insulated wire. Green wire as this color seemed to
    blend into the branches of trees nicely.
2) I started out with a pre-figured-out length of wire thanks to this calculator for 10 meter. Once cut and attached to a basic 1:1 Balun/coax/center insulator I
    tested the SWR. I ended up cutting the wire back ~ 1" to get a perfect swr match.
3) Then using the same above calculator I figured out the length of wire for 15 meter and subtracted the length of wire I
     used for the 10 meter and using Anderson Power pole connectors attached the new piece. Checked the SWR and
     made adjustments to the length as needed.
4) Well I did step 3 for 17 meter, 20 meter, 40 meter and 80 meter bands.
5) Once I was done I hoisted center insulator with the 10 meter wire set-up about 40 feet into a tree and used an
    inverted V configuration. Well no contacts. Not surprising but - The old blood pressure started to rise. Hooked on the
    next hank of wire for 15 meter and viola! I got a contact from a guy in Puerto Rico who answered my CQ call. Now
    that was without a tuner mind you. Attached the 17 meter hank next and no contact. Tried 20 meter and nobody
    answered my CQ call but I was able to get through to a Kansas State QSO party. Four separate stations.

    Late in the day my 13 year old neighbor heard my radio and came over and was able to get a few 20 meter contacts
    too and when we attached the 40 meter hank of wire he got one 40 meter contact. Again with not using a tuner.

    After dinner and into dusk, I made a 40 meter Kansas State QSO connection and one connection to a CQ call-out.
    Similarly when I added the last hank to make my dipole the proper length I jumped in on several planned nets.
6) Please keep in mind that I did not use a tuner for each segment but stayed within the band for the specific length of
    the wire. When I use the full length of the connected wire hanks and used a tuner, there was no issues tuning up the
    antenna in seconds.

Do's and don'ts...
A) After you figure out the proper length for the band you are going to cut wire for make sure you use a SWR meter to
    check the calculations. Using the Anderson Power Pole connectors I found that with each hank attached, i had to cut
    back on the calculated length slightly.
B) You need something to hold the Anderson Power Poll connectors together or to much tension or a gust of wind would
    disconnect them. At first I used a piece of electrical tape but later switched to a rubber band which seemed to work
    the best. 
C) I put a piece of electrical tape on each hank showing the meter band it represented. I then coiled each hank of wire
    and put it in a quart zip lock bag which was labeled too.
D) I used positive (red) Anderson Power Poll connectors for one side of the dipole and black (negative) for the other. No
    other reason then to make sure the hanks did not get mixed up.

Conclusion...
I now have a light QRP dipole antenna, that if I choose, can work for each band independent of a manual or auto tuner.   

[Jackalope]

   Very cool!  Well done!

[Kbop]

yep, nicely done, thanks for the write up!

[Jackalope]

   The Emtech tuners are available again. https://steadynet.com/emtech/zm2-prebuilt-bnc-connectors      They're great little QRP tuners, I use one with my FT-817.  I like them because they're so simple to operate, and no meters are necessary.  You just tune until a LED goes out and the radio is matched with the antenna.  Plus they'll tune both balance and unbalanced loads. 

    Johny, I look forward to your further antenna construction adventures!

[JohnyMac]

  gentlemen.

[lewisp]

Cool work using the power poles to adjust length.
I like the homebrew stuff!
I have been using a Packtenna for about 9 months now, and it's been great in the field.
15 meters down to 80,phone and digital, easy to tune on my 817 , super small and light and  very versatle. Lots of contacts on all the bands, and good performance in my WSPR net testing too.
Likely it wil now be my go-to antenna for a grab and go radio bag. I love my yo-yo antennas too, very useful and reliable,  but the Packtenna is way smaller and easier to run. 

[JohnyMac]

Interesting lewisp on your Pasktenna antenna. 

When you get a chance it would be great if you would describe it. Wire and coax length/ground and or counterpoise.

By the way welcome! When you get a chance take two minutes to intro yourself on the Introduction Board.

Welcome 

[lewisp]

The "Packtenna mini" is a great rig.
Basically it's a 9:1 UN mounted on a piece of computer board that doubles as the wire winder for transport, then into a random wire. Mine is about 29 feet.
It has slots for running a counterpoise if desired, though I have never done it.
I usually use a piece of RG-174 coax with BNCs, and it tunes up great every time. It can handle 100 watts if needed,  but I only use 5-10 max for my portable stuff.
Packtenna.com
Find them on youtube too!

[JohnyMac]

Cool beans lewisp! 

Do you use it as a slooper or inverted 'V' or....

Thx 

[lewisp]

Made quite a few contacts with it on phone and digital. So far with my WSPR testing, I have used it as a vertical and a sloper with great results, and even done a little NVIS with it on 40 meters. I strung it tight at about 3 feet above the ground. Results were mixed. I need to do more testing.  It is an end-fed, so a V would be tricky I think.
I like the yo-yo antennas for a good inverted V.