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QRP operating approaches

Discussion in 'QRP Corner' started by WD4ELG, Mar 22, 2021.

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  1. K3XR

    K3XR Ham Member QRZ Page

    That would be the KX3 with the SingaLink USB. The other Elecraft rigs are CW only. You can reduce power if heating is a problem or use a small 12V computer type fan to add to the cooling.
    WD4ELG likes this.
  2. N1RBD

    N1RBD XML Subscriber QRZ Page

    My biggest concern for a dedicated QRP rig is weight. Hiking in 3 miles with a 2000ft elevation gain means shedding as much weight as possible. My MTR kit weighs in a 29oz. So I'm in Cat 1. However, I use a 20/30/40 linked EFHW and an 850mAh LiPo. A 9v battery weighs 37g, while my LiPo weighs in at 74g. A little over one ounce more for a full power output plus longer operating time. I don't know why anyone would use a 9v as a primary source when ultralight LiPo batteries are available.
  3. K3XR

    K3XR Ham Member QRZ Page

    That's a huge difference when you're hiking/camping and need to carry all of your gear. Having a vehicle and/or a travel trailer helps eliminate most of the weight concerns. Obviously, you can't take the entire shack with you.

    In recent years I've had to cut down on the long hiking trips when camping and spend more time at the site. Hiking the trails, climbing the summits, or just relaxing at the's all good stuff. The winter weather is breaking here and will be uncovering the camper and have reservations for May.
    N1RBD likes this.
  4. K1CWB

    K1CWB Ham Member QRZ Page

    This is pretty cool. I like the idea of taking inventory of all your gear and laying out the different scenarios of how to put it together accordingly. Although I don't have much gear, I should probably take inventory myself and come up with at least a couple of different use cases and possible ways to kit it up. Interesting post, thanks for sharing.
    N1RBD and KG7WGX like this.
  5. KG7WGX

    KG7WGX XML Subscriber QRZ Page

    I'm going to try using a kite to support a 26 gauge antenna when we go to the beach this summer. I think this would be Category 2, operating from inside a parked vehicle. 10 Ah LiFePO4 battery behind the seat.

    While I have flown single-line kites, supporting an antenna is new, and I know there is going to be some fooling around with how to attach the antenna end to the kite line. I'm only trying to support around 33 ft of it, so the weight is minimal as long as I don't create a complex support.

    Initial experiments with a "slotted plastic guyline tensioner" look promising. A fishing snap-swivel will connect the antenna to the center hole of a 3-hole design. The outer two holes are slotted for the kite line.

    The plan is to secure the line winder to a stake, then use a glove to protect your hand when pulling the kite line in slightly to create slack to install the support. The antenna is already flaked out in a U on the sand. Then, attach the antenna and let the kite line out and raise the antenna, which has its tail end secured by another stake.

    I found some sites which cover photography from a kite, with some pretty impressive cradles to hold PZT cameras, but there wasn't much there about amateur radio use.

    Any kite deployment experts here?
  6. VK3YE

    VK3YE Ham Member QRZ Page

  7. KG7WGX

    KG7WGX XML Subscriber QRZ Page

    Thank you.

    Well, I found some more sites, in addition to your info. Shock cord, static bleed resistor, ground rod added to plans.

    The cheap kite I got appears very similar to the SOTABeams kite, which I didn't know they made.

    Weather here in PNW ideal for planning and construction now. When it gets a little nicer, it will be time to test things. ;)
  8. WD4ELG

    WD4ELG Ham Member QRZ Page


    Why use a 9V with the MTR? Because:
    • My 12V LiFePO batteries from Bioenno are at actually at 13.2 V. I don't want to fry the rig, and it says "DO NOT EVERY USE > 12V WITH MTR RIG". So I need to also bring along a Drok voltage regulator. Even more weight. Easier to just use 9V
    • 11.1V LiPo batteries like you use (on your QRZ page) scare me. Please prove me wrong. What are you using for a charger that you are not worried about fire?
  9. WD0BCT

    WD0BCT Premium Subscriber QRZ Page

    Because I invested in a 9V charger and NiMH batteries a while back and they meet my needs nicely for portability. No need to throw away working hardware. Perhaps when it's time to replace I'll upgrade to LiPo. Two things that I don't like about LiPo are cost and safety. Perhaps they will improve on them.
    A battery guru once told me that putting more and more power into smaller and smaller packages approaches bomb making. Even the NiMH batteries warn against short circuiting.

    And the above response from ELG is very true about the warning on operating the MTR3B above 12.0 volts max.
  10. N1RBD

    N1RBD XML Subscriber QRZ Page

    That's your own opinion. I don't need to "prove" anything. Thousands of people use these without incident. It's my choice to use these batteries, and I know many other ops who use them without incident. They are used every day in drones, RC cars, etc. Personally, I believe they are inherently safe and most, if not all, of the incidents that occur are due to mishandling or improper charging/usage of the batteries.

    To answer your question, I'm using a ISDT balance charger. I also take the precaution of charging the battery in a 50cal ammo can.

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