BOXA-LOAD 50 Ohm RF Dummy Load

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(Ex. Tax)

NOTE Customers outside the UK & EU pay the lower (Ex. Tax) prices!

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50 Ohm Dummy Load

An essential piece of equipment in any radio shack, the BOXA-LOAD is a 50 Ohm dummy load. VSWR better than 1.1:1 from 0 - 30MHz. The BOXA-LOAD includes a built-in LED RF indicator to show when you are transmitting.

Use your dummy load for transmitter testing and alignment. Also useful for testing VSWR bridges.

The kit is easy to build and would make a great club project or evening project. Attention to detail: we even supply a specially made bending/spacing jig for the power resistors so that your load looks just as good as ours! The BOXA-LOAD uses all though-hole components.

NOTE: engraved panels supplied may be black, blue or clear. 


Power rating

5 Watts continuous

10 Watts 10 minutes max.

20 Watts 1 minute max.

Allow 10 minute cooling time.

NOTE: the total power rating of the resistors used in the BOXA-LOAD is 24 Watts. To improve power handling, we mount the load resistors off the board. The BOXA-LOAD case is ventilated front and back. We rate our load conservatively.

Return loss (a measure of how well the load absorbs RF)

> 30 dB 0-30MHz (VSWR better than 1.07:1)

> 25 dB 30-70 MHz (VSWR better than 1.12:1)

> 20 dB  70-150 MHz (VSWR better than 1.22:1) 

BOXA Products:

All BOXA products are available in three configurations:

1. Board kit: a high quality PCB with all components. 

2. Board kit plus enclosure: adds a high quality rugged aluminium enclosure complete with laser-cut front and back panel. No drilling, no metalwork needed!

3. Fully built and tested: the complete product with enclosure, built and tested at our factory. Ready to use.


Instructions are available HERE!


Also available from our international agent(s):  



12 Reviews Hide Reviews Show Reviews

  • 5
    Great small dummy load and fun kit

    Posted by Tony KB8MVP on 20th Dec 2014

    I didn't really need another dummy load but this one looked very nice and had a great price. I like to teach my sons building and soldering skills and this kit was fun to build with my 10 year old. It only took about a half hour and we were in no hurry.
    I checked it with my antenna analyzer and it is nice and resistive at 49-50 ohms @ 1 - 30 MHz. It is only advertised to 30 MHz but I dialed the analyzer up to 6m and 2m and it was perfectly workable. Even at 70cm it is slightly reactive but would be plenty useful for testing a dual-band HT.
    I will be buying more kits from SB. Nice job on this kit.

  • 5
    A Quality Way to Start Again

    Posted by Pip Price G8NOP on 14th Dec 2014

    When I was first licensed, soldering came as second nature to me, but not having had the time for either home brew construction or radio operating for many years, I needed a small project to re-aquaint myself with the skill.
    Not only is the BOXA-Load a first class piece of equipment, it is a great introduction (or reintroduction) to circuit building.
    I look forward to building more of Richard's kits and hopefully there will be more to come (perhaps some QRP gear?).