3B61 Triple Binocular Ruthroff Field Measurements
This balun is built from three Binocular Ferrites, Fair-Rite Model BN61-002.
I had great expectations for this balun, but alas it failed to meet requirements.
From the graph on the right you can see it looked quite promising in the lab.
But as I always say, "THE RUBBER HITS THE ROAD IN THE FIELD, NOT IN THE LAB". And in the field it was a flop, as we shall see below.
The results were actually so bad that it makes little sense to show them on their own. Instead, I will show them compared to the same antenna using my standard 4:1 Ruthroff balun and the HPFB 1:1 Guanella choke (19 turns on an FT-240-43):
The graphs pretty much speak for themselves. The SWR is much worse than when using a Toroid in the 4:1 Ruthroff on all bands above 40m and even on 80m and 40m it is a little worse.
IMO it is a waste of time investigating the 2B61 (dual-binocular on #61).
I will try a binocular version with #43 ferrite instead.
Download 3B61 .asd files
Download 3B61 .s1p files
Download 3B61 .csv files
SUMMARY AND CONCLUSION:
Needless to say, I was very disappointed in the results achieved with this version of the Hybrid-Balun. However, Mel (K6KBE) told me that #61 ferrite does not work with this type of balun. We need to use #43 or #31.
Next: I will test a binocular balun with #43 ferrite.
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