QRP set-up for a newbie

Discussion in 'QRP Corner' started by 4G1AOC, Jul 23, 2017.

ad: L-HROutlet
ad: l-rl
ad: Left-3
ad: MessiPaoloni-1
ad: Left-2
ad: L-MFJ
ad: K5AB-Elect-1
ad: Subscribe
  1. VA3VF

    VA3VF Guest

    And in the early years of QRP-ARCI, QRP was 100W. After a long 'battle', it changed to 5W.

    73 de Vince, VA3VF
     
  2. 4G1AOC

    4G1AOC Ham Member QRZ Page

    Again Thank you for your inputs, I never realize how much I am learning right now . I will be biting the bullet for a a bnew 817 same priced as some 2nd hand ones on Ebay. Now I am figuring out what antenna to get for the 40 meter.

    Paul hit it on the nail comparing it to fishing . I am not a big time tuna fishing somewhere in the Bahamas but more of walking to the nearest stream to catch in the experience rather than the big fish.

    Do I need an Antenna tuner of some sort for my portable QRP set -up ?

    73s

    4G1 AOC
     
    KO4LZ likes this.
  3. VA3VF

    VA3VF Guest

    In the event that your antenna has a 50 ohm impedance, no. Is that the case? Only an SWR meter will confirm. Use lower power, and short transmition periods to measure.

    Impedance mismatch will not only impact the number of contacts you make, but can destroy the final stage of the transmitter.

    73 de Vince, VA3VF
     
    KO4LZ likes this.
  4. KO4LZ

    KO4LZ Ham Member QRZ Page

    Unless you're operating in open fields (no pun intended), it's unlikely that even a well-designed antenna will present a 50 ohm impedance due to interactions with nearby objects/ground/etc. In this case an antenna tuner would be recommended, if for no other reason than to protect the transceiver against excessive VSWR.

    [Note: in reality, you should notice really high VSWR and stop transmitting, so the risk to the transceiver is minimal -- high VSWR mostly affects your ability to safely transmit from a given location with a given antenna]

    This is one reason why I really like the KX2 over the 817 -- internal ATU with easy-to-read VSWR display. I've used the LDG Z-817 tuner with my 817 and it worked just fine, but it also doubled the physical size of my QRP setup (the Z-817 is almost the same size as the FT-817) and added additional complexity (RF jumper, control cable, etc.).

    Best advice is to try to have an antenna / QTH that allows you to get by without needing a tuner. When you operate portable from a variety of locations (on multiple bands), this isn't always easy to do.

    73,
    Paul, KO4LZ
     
  5. KM4DYX

    KM4DYX XML Subscriber QRZ Page

    Elecraft T-1 tuner and a bit of Velcro works well with the 817, and its a lot smaller than the LDG.
     
  6. 4G1AOC

    4G1AOC Ham Member QRZ Page

    You guys reckon I can get by with a Buddistick without a Antenna tunner ?
     
  7. G3YRO

    G3YRO Ham Member QRZ Page

    As you're a newbie, maybe I should explain the Radio Facts of Life:

    If you have a poor antenna, then you won't put out a decent signal if you're running QRP . . .

    Similarly, if you're running QRP, then you won't put out a decent signal if you have a poor antenna.

    SO . . . if you are restricted to QRP (due to needing to run from batteries) then you need to use as good an antenna as possible !

    (it's like people who buy 2 metre handhelds and wonder why they can't work many stations using the rubber helical antenna that came with the rig!)

    Personally, for what you are describing, I would make a load of simple wire dipoles, cut for any band you want to operate on, each with a centre-piece with a coax socket.

    Then when you're in your portable location just string up the dipole for the band you want to operate on (as high as possible) and you should put out a reasonable signal (plus no need for an ATU)

    If there are no trees/buildings/lamp posts etc to tie the ends of the antenna to, then you will need to get some kind of temporary pole to hold up the middle (like a telescopic fibreglass pole)

    Roger G3YRO
     
    4G1AOC likes this.
  8. KJ3X

    KJ3X XML Subscriber QRZ Page

    I got my general in December 2016 and have been operating QRP only with an 817 since(SSB).
    I love working with it, but as everyone has said, don't expect to work a pileup and wind up on top, although it has happened to me.

    Equipment:
    You will need a tuner.
    Resonant antenna for each band you want to work, or if space is an issue, and end fed and expect less out of it. I use a Yo-Yo antenna:
    https://www.hamradiofun.com/yo-yo-vee.htm
    You can make one with wire and a camping laundry reel, bnc connector and some wire.
    You may also need a computer link if you want to do digital modes

    I use an end fed at my house up around 40', and when camping I use a dipole.

    Warning-don't get an MFJ vertical and expect it to work. I tried contacting a friend with mine to no avail, then tossed a dipole in a tree and instantly had good signals go out.

    My best distance was a dipole on 20m ssb on the top of a tall ridge of 3968 miles with a 57 report, so tt can be done, you just have to be patient.

    Running 5w or less you really have to refine your skills and learn what works for you and your equipment.
     
  9. KE0EYJ

    KE0EYJ XML Subscriber QRZ Page

    Two mountain activations since making this antenna, and I've been under 1.2 to 1 on both 20m and 40m. I am about 2.1 to 1 on 15m. I can tune 17m with a manual tuner, and it works well. It's probably around 4 to 1 SWR, so losing about 1/2S, at least, on 17m. I still DX on 17m.

    It's nice not needing a tuner for my main bands, and it's very efficient. It uses coax. I also love ladder-line doublets, but this has great vertical polarization for 20m DX, and gives me 40m, too.

    If I am up high, I can DX well on 15, 17, and really well on 20m. I find 40m is mostly NVIS, but I can get lucky further out, too. During the day, I don't have propagation at 40m DX, as it is, although I have put it up on the corner of a high roof at night, and it easily works DX on all bands.

    This has been the best easy/portable wire general performance antenna for the major bands I work, so far. The biggest investment was the $110 pole, which can be used for many antennas. The wire is a pittance. The balun was about $20.

    Working 5,000 miles+ is no problem. I don't like compromises, so I don't buy portable antennas costing big $$. I like height, and I like a low angle of radiation on my main 20m DX band.

    spiderbeam 15 20 40 antenna.png
     
    Last edited: Jul 31, 2017
  10. DU7DVE

    DU7DVE Ham Member QRZ Page

    What about those people who when people are talking about SSB or CW jump in with "I've done it on milliwatts" and later on admit it was a digital mode like JT65?
     
    KO4LZ likes this.

Share This Page

ad: elecraft