Running power on Field Day

Discussion in 'General Technical Questions and Answers' started by KM4LKC, Jun 12, 2019.

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  1. KM3F

    KM3F Ham Member QRZ Page

    Field day is for the purpose of field emergency situations, not who can rack up the most points.
    When we had the Hurricane here, there was a run on gas even from out of state.
    Why would you want to waste gas powering such as amplifiers under such conditions?
    I ran on genset for 5 days and through 20gallon of gas.
    That was my field week.
    The idea of field day has gotten out of hand just like ARIES is getting out of hand.
  2. WG8Z

    WG8Z Ham Member QRZ Page


    I run a 550 watt grill starter on F.D.
    WF4W, KM4LKC and KC8VWM like this.
  3. WA7PRC

    WA7PRC Ham Member QRZ Page

    In the 70s-80s when I operated in Class A/B with others, a gasoline-fueled generator was the norm. They were noisy and required refueling often. Some were gawdawful. When all solid state rigs came along, we added 13.8V power supplies.

    Then, I thought we could eliminate the gen set and PS, and just use batteries. I gathered together four good Group 27 batteries from 3 vehicles, and placed them into a litter in parallel.
    When in the field, I've used it w/ my homebrew 40' tiltup/rotatable mast:
    A Cushcraft A3S Yagi on top gives me 20/15/10m. Inverted vees at 35' give me 80 & 40m. 80m is a cage, covering all of 80m.

    Today, I operate Class E (at home on emergency power). The preparation steps:

    • go into garage
    • turn float charger OFF
    • return
    N2EY likes this.
  4. KC8VWM

    KC8VWM Ham Member QRZ Page

    5 watts and a big 'ol piece of wire works perfectly fine for me...

    IMAG0856.jpg IMAG0813.jpg IMAG0814.jpg

    go box latest.jpg


    Attached Files:

    Last edited: Jun 14, 2019
  5. KM4LKC

    KM4LKC Premium Subscriber QRZ Page

    Great setup. All that is missing is the grill. Bet that's behind the popup! Thanks for the photos.
  6. KM4LKC

    KM4LKC Premium Subscriber QRZ Page

    I am still fascinated by your antenna setup. I wonder how many times I have read your detailed post on the construction of your go-kit. Very clever. You have me thinking about using some chalk line reels to wind up the flexweave. Remind me...where did you get the reels for your antenna system?
    KC8VWM likes this.
  7. WA7PRC

    WA7PRC Ham Member QRZ Page

    Thanks. The Yagi is VERY nice. The mast uses 1-1/4" Schedule 40 pipe (some welding required) and can be assembled & tilted by one person. More hands makes it go faster. With the mast lined-up to a zippered window, we use the "Arm Strong" rotator. "N-E-S-W" markings on the mast show the direction.

    To power the laptop PC for logging/keying/DVK, we use a homebrew DC-DC boost PS (link). Output as tested, is dead quiet from MF-HF. WinKeyer USB (
    link) generates Morse & provides T/R control. A simple passive audio interface couples the audio. We use WriteLog logger/keyer (link). With good Function key programming, I can almost not use the microphone or keyer.

    Food is whatever is there... not at all a big production. Meh. :-/
  8. KC8VWM

    KC8VWM Ham Member QRZ Page

    You can certainly use flexweave in your design however, in the real world, I found no practical reason to use flexweave when copper fishing line is strong enough for portable antennas. Copper fishing line is smooth and silky to handle and it doesn't fray apart like other stranded wire often does which makes it nice to use as portable antenna wire. It's also much lighter to carry and perhaps a little easier to roll up on fishing reels than flexweave. I find it's pretty economical too, and you can get it here:

    The fishing reels are intended for fly fishing and constructed out of aluminum, so they are stronger and far more durable than using plastic reels, and yet still lightweight for portable antenna work. They are model "Martin Caddis Creek" and are available at Walmart for around $12 each.


    fishing reel.jpg

    If you need any other information about it's construction, please don't hesitate to ask and i'll do my best to assist you.
    Last edited: Jun 14, 2019
  9. AH7I

    AH7I Ham Member QRZ Page

    Very nice! Are those binding posts for coax to wire? As in, reel out desired length of line and connect? Also, what is the center piece that holds it all together? That wire line looks like it's somewhere between #18 and #19. Thanks!

    73, -bob ah7i/w4
  10. KA2IRQ

    KA2IRQ Ham Member QRZ Page

    I agree with everyone here... all that power is unnecessary for Field Day. However, just to play Devil's advocate for a moment.. I could see a scenario where it would be beneficial to have a big power amp on HF during an emergency.

    Recent hurricanes have proven that a bit of isolation can be expected, especially on islands and rural areas. Long haul HF could be brought into operation for regional coverage (like a county or State EOC). And some EOC's have monster generators with fuel supplies that last for weeks. In those scenarios, running a power amplifier would hardly be a drop in the bucket for generator load and fuel consumption... some of these gensets have capacities in the 100 KW range. 20 extra amps during SSB transmit cycles will not be noticed and may make all the difference in getting the signal through under tough conditions during an emergency. The legal limit may not be necessary though- a few hundred watts might be the order of the day. And on the VHF/UHF level, a small amp running 100 watts or so might be beneficial as well.

    For Field Day? Leave the amps home. Unless you're activating a regional EOC with a big generator and would normally have regional HF coverage as part of your Standard Operating Procedure. Field Day is more about developing your techniques in tough conditions. Use it for that and practice with the amp another day.

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