FT-857 Manpack revisited

See part 1 here

It’s been a while since I featured my FT-857 manpack on here and I’ve been using it well for over a year now so I thought I better show some sort of update.

So here it is. The FT-857 Manpack as it stands today…

The pack all ready for use…
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The back support is nicely padded as are the straps and waist belt. It’s very comfortable to carry…
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The contents of the bottom front pocket, from left to right:

  • 70W 19v Laptop travel charger with 2 pin, 3 pin and 12v plugs. Used to provide power to the battery charger.
  • Various power connectors and 12V extension.
  • Lifepo4 Battery charger and connectors
  • H-250/U Military Handset

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The contents of the top front pocket, from left to right:

  • Spare fuses, battery monitor, velcro straps for 6M mast and small bits.
  • 40M dipole with 1:1 balun and 12M of RG-174 coax. This will get me on any HF band by using the LDG tuner on the manpack but I’m moving to a linked dipole very soon.
  • Garmin 60CSX GPS.

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The manpack fits nicely inside the main pocket…
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Compact 6M push up pole. This fits inside the main pocket and can be used as a vertical or as a support for the 40M dipole. It straps to the manpack frame with short velcro straps. It also fits inside the bag so you can walk around with it erected!
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Manpack out of the bag…
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This is a switch box that I made up to allow use of the standard fist microphone or the H-250. The 3.5mm jack plugs into the radio when using the H-250 and passed the receive audio to the handset. You can still use the fist microphone to control the radio when using the H-250 handset.
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The top of the manpack. The dual ratio UnUn is attached with velcro so it can be removed and placed remotely if needed. When used as shown, I connect the 6M push up pole (with a 6M wire inside) to the 4:1 or 9:1 terminal to achieve the best performance. When used with the 40M dipole, I disconnect the UnUN and connect the dipole to the socket on the front of the manpack.
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This is a cheap fly fishing reel that holds 20M of 1.5mm stainless steel wire. The wire is marked every meter and 5 meters with different coloured nail polish. Just pull it out to the desired length and clip the flying ground lead from the UnUn on. Instant counterpoise…
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The battery is a 8.4Ah LifePo4. It sits at 13.8v when fully charged and has a shallow discharge curve until it’s almost empty. I’ve used SLA batteries (not enough voltage to get the most from the battery and heavy) and LiPo batteries (Fully charged voltage too high so a diode based voltage dropper needed) but the LifePo4 could have been made for this application. It’s the perfect ratio of voltage and weight…
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So there you have it. The manpack updated. It’s been in heavy use and these are the additions I’ve made along the way that have made it much more versatile and complete. With the antenna, mast, battery and charger all in the bag I can just pick it up and go. No doubt it will evolve again so keep your eye on the blog for more updates.

18 Replies to “FT-857 Manpack revisited”

  1. Hello good night,very cool beautiful the FT-857D backpack,can you send me the full project and scheme for me to make the PTT H-250 Handset connect in FT-857D,conector U-183 UG1 and U-229 UG1.
    Thanks good night.
    Best regards,
    Bruno Schagas,73.
    bruno_chagas_leite@hotmail.com

  2. Great looking frame and set up every thing you need for QRP. Could you send me dimensions for frame and any information on the back pack it goes into? I am working on a three dimensional cad model to make one but do not have enough information for fabrication. Thank you.

  3. Could you email me the plans for the FT-857D Manpack? I am especially interested in the switch box that you have for the standard mic and the H-250. I really like your design, and I am very interested to try my hand at making one. Thanks in advance, and also thank you for posting all your great ideas on the internet to share with the rest of us.
    73’s Josh

  4. Hi Josh.

    Thanks for your comment. The plans for the pack are available for download from the ARPOC website. https://www.arpoc.org/portable-equipment-plans/download-7-ft-857-pack-frame.html

    Don’t forget to join the club (its free!) and read the forums whilst you are there! Maybe even look at the award scheme…

    I don’t have any details on the RJ45 to H-250 switch box as I didn’t take any photos when I built it. I’ve had a few requests for this now so I’ll take it apart in the next few days, take some pictures and make a post on my blog about it.

    Hope that helps.

  5. Good day, Matt! Great job, but i have one “why”:
    U made frame from copper tube. Its asy to buy and solder. But they are much heavey than aluminim one . If its manpack u need made it lighter as posiible, but u choose copper. S owhy? =)

  6. Thanks for your comment. Weight was not my primary concern when building the manpack. I wanted a material that was easy to work with and commonly available. Besides, the weight difference between a copper or aluminium frames makes little difference when you consider the weight of the 857, tuner, battery and other bits!

  7. Just stumbled across your site & this article whilst searching for portable antenna’s ideas.What a great bit of kit you put together.As a new amateur with an interest in vehicle & portable operations and a FT-857d it was almost like waking up on Christmas morning as a kid!
    Any further developments since this last post back in 2015 ?

    I’ve also just joined ARPOC so am looking forward to learning more about portable.

    Thank you for sharing your designs and inspiring this newbie

    Cheers

    Tim

  8. Thanks for your comment Tim.

    I’ve not changed it much since 2015 and it continues to work well.

    Hope you have lots of fun with it.

    Matt

  9. Hi Matt

    Sorry to trouble you but i tried to download the link for the frame drawing in one of the links above but even though i’m logged into arpoc it currently states i don’t have access ? Got to say again that the whole concept is mega and very clever. Just ticks all my boxes unlike a lot of other concepts I’ve seen online.

    Thanks again

    Tim

  10. Thanks Matt. New link worked ok. Just need a programme to open the cad drawing. Really appreciate you sharing this information.

    Tim

  11. Very interested in the h250 switch-box. Did you ever update your website with plans and instructions for building it?

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