See product design specs, as well as articles, at Balun Designs.Com. use the core mix type for the bands you'll operate on. For high power, double-up on size 240 cores. Youtube "TRX Bench" channel has a great 4-part video series on building baluns.
My experience tells me that if I want a long lasting, reliable balun (good quality components and workmanship that withstand the elements), it's more cost effective to buy off the shelf from Balun Designs or equivalent. (The amount I saved wasn't worth the trouble.) Of course, making my own is fun and educational; but I now buy my baluns from Bob. Gus K5GMB On Tue, Aug 15, 2023, 10:39 AM mike.williams shopjubilee.com via BVARC < bvarc@bvarc.org> wrote: > Time to pick your brains… > > > > I am interested in EFHW antennas for primary use on 20/40/80m – but want > to be able to run my Worthmore 600w amplifier. > > I found a MFJ model - MFJ-1982HP is rated for 800pep > > https://mfjenterprises.com/products/mfj-1982hp > > > > This antenna is available in three power ratings: > > MFJ-1982LP – 30w > > MFJ-1982MP – 300w > > *MFJ-1982HP – 800w* > > > *Anyone have experience with this antenna?* > > > > > > A couple of questions – > > 1. If you have experience with high power (>= 600w) transformers for > EFHW antennas, what design did you use > 1. Core type and number of cores > - type 53 has a higher curie temp as opposed to type 43.... > 2. Wire AWG? > 3. I see a number of YouTube videos recommending 56:1 as 49:1 > - Comments? > > > > 1. What is your recommended wire for the radiation element? > 1. Material – > > i. Copper over > steel? > > ii. Hard-drawn > copper? > > iii. Other > > b.AWG? > > i. Number of > Strands & strand count? > > c. Jacket material > > d. Other? > > > > Your guidance is appreciated! > > ’73, > > Mike KK5SC > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > BVARC@bvarc.org > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > Publicly available archives are available here: > https://www.mail-archive.com/bvarc@bvarc.org/ >
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