Amazon 49:1 Balun Testing

I recently purchased a 49:1 balun from Amazon thinking it might be useful for POTA EFHW operations. There are several sellers listing baluns that all look like the one below. Advertised to be useful for EFHW antennas operating between 5-35 Mhz, has good reviews with prices in the $24-28 CAD range.

Amazon Balun VSWR Measurement

Before I tried tuning it with a EFHW wire I wanted to test the VSWR over the 40-10m range I planned to use it. I simulated an EFHW antenna load with a 2400 ohm resistor between the “Half Wave Wire” output and the input ground, did a 1-35 Mhz VSWR sweep with a NanoVNA-H4 via NanoVNASaver and saw the following. Looks pretty bad, maybe OK for 80m but a VSWR of almost 7 at 20m.

Comparison

But was my test setup and method valid? I had a 500W 49:1 balun kit I purchased on Ebay (still available here). I’ve never used it before, so I soldered a connector to the input and a 2400 okm resistor as an output load. Using the same NanoVNA setup I get a VSWR sweep that looks like this. Much better, VSWRs less than 1.5 over most of the 80-10m range.

Conclusion

Will be returning the Amazon balun as not fit for purpose.