{"id":519,"date":"2025-12-25T01:56:19","date_gmt":"2025-12-25T01:56:19","guid":{"rendered":"https:\/\/www.bob-easton.com\/n4ree\/?p=519"},"modified":"2025-12-25T01:56:22","modified_gmt":"2025-12-25T01:56:22","slug":"efocf-better-than-efhw","status":"publish","type":"post","link":"https:\/\/www.bob-easton.com\/n4ree\/2025\/12\/25\/efocf-better-than-efhw\/","title":{"rendered":"EFOCF better than EFHW?"},"content":{"rendered":"\n

Mark, the Ham Florida Man has been running a series of YouTube videos scorning the ever popular EFHW antenna. See his latest here<\/a>. The basis of his concern is that the 49:1 transformer is inefficient, robbing power before it gets to the antenna. Probably true, no matter how much research Colin, MM0OPX, has put into making them more efficient<\/a>.<\/p>\n\n\n\n

Mark’s answer is a collaboration with an RF engineer in Belgium, Joeri Van Dooren, ON6URE, who writes about all sort of antennas that he sells through his own store<\/a>. In particular, Mark suggests replacing EFHW antennas with E<\/strong>nd F<\/strong>ed O<\/strong>ff C<\/strong>enter F<\/strong>ed, EFOCF, antennas which use a 4:1 voltage balun, one with much lower losses than the 49:1. Mark is a very good spokesperson for Joeri, making all the right points. Interesting ideas that sound reasonable. Maybe I should try one?<\/p>\n\n\n\n

My deployment options here in the HOA controlled Casa Easton Antenna Test Range are few. There are no tall trees on this property, and no tall vertical structures. The best I can, unobtrusively do is a telescopic mast about 20 ft (6 meters) tall. That’s one of the reasons I use an EFHW much of the time, in an inverted vee deployment. Using a 3 ft plastic fence post at each end and the mast in the middle and about 66 ft of wire, I can easily reach anything East of the Rocky mountains from Central Florida, and sometimes well beyond, with the 5w TR-45L, QMX or QMX+ (actually 3.8w out). <\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

I like this antenna because I can effortlessly switch between 40m, 20m 15m and 10m with NO need for a tuner. <\/p>\n\n\n\n

Can I get the same convenience and improved efficiency with an EFOCF?<\/p>\n\n\n\n

Of the EFOCF antennas at Joeri’s store, the EFOC17 appears the best fit for my property. “Why the EFOC17 is the Better Choice for 40M to 10M Operation<\/a>” makes all the sales points. Length of 17 meters fits. Band coverage 40m – 10m fits. Sounds great. Let’s build one. Yes, as you know, I prefer to build when I can. The sales page for the EFOC17<\/a> has enough details for construction. I already had a good 4:1 voltage balun and plenty of wire. A group of clamp-on ferrite bead chokes<\/a> arrived after a few days. It didn’t take long to assemble and deploy. <\/p>\n\n\n\n

I deployed just as I do my EFHW, this time with the 3.7m coax counterpoise laying on the ground.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n
\n

A VNA sweep from 3Mhz to 30Mhz shows 4 resonance dips, NONE of them on the CW parts of ham bands I prefer (40m, 20m, 15m, 10m) let alone the ones mentioned in Joeri’s articles. Further, checking the individual bands I use, I found SWR measures, impedances and reactance well beyond the tolerance of my rigs and most well beyond being tunable with my Four State QRP tuner<\/a>.<\/p>\n<\/div>

\"\"<\/figure><\/div>\n\n\n\n

I captured VNA charts for individual bands, but will save the bandwidth of posting them here. A summary of the 4 bands I really want show the following SWR levels and only 2 will work with my radios without needing a tuner. Definitely not a useable antenna for my needs<\/strong>.
40m, 7.040 Mhz, 6.715:1
20m, 14.060 Mhz, 3.504:1
15m, 21.060 Mhz, 1.937:1
10m, 28.060 Mhz, 1.585:1<\/p>\n\n\n\n

\n

Noting that Joeri says “Antennas mounted higher or lower than 10 meters may exhibit different SWR values.” I tried a different deployment. An older (broken 4 times) mast was good for 4 about meters height. I hoisted the balun and coax on that mast, getting all 3.7m of choked coax off the ground, and ran the wire as a sloper to the 6m mast 17m away. While less than half way to 10m, it was much higher than the inverted vee.<\/p>\n\n\n\n

The results were not much different. Note well the lack of anything near 20m<\/strong>, my most used band.<\/p>\n<\/div>

\"\"<\/figure><\/div>\n\n\n\n

Unresolved question:<\/h2>\n\n\n\n

I can’t really expect Joeri to answer this question since I’m not using an antenna I purchased from him, only one that I think is similar to his. <\/p>\n\n\n\n

Does this antenna really need to be 10m high (impossible here), or did I make some other blunder building it?<\/p>\n","protected":false},"excerpt":{"rendered":"

Mark, the Ham Florida Man has been running a series of YouTube videos scorning the ever popular EFHW antenna. See his latest here. The basis of his concern is that the 49:1 transformer is inefficient, robbing power before it gets to the antenna. Probably true, no matter how much research Colin, MM0OPX, has put into […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[3],"tags":[],"class_list":{"0":"post-519","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-antennas","7":"entry"},"featured_image_src":null,"featured_image_src_square":null,"author_info":{"display_name":"Bob Easton","author_link":"https:\/\/www.bob-easton.com\/n4ree\/author\/n4ree\/"},"_links":{"self":[{"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/posts\/519","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/comments?post=519"}],"version-history":[{"count":2,"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/posts\/519\/revisions"}],"predecessor-version":[{"id":526,"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/posts\/519\/revisions\/526"}],"wp:attachment":[{"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/media?parent=519"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/categories?post=519"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bob-easton.com\/n4ree\/wp-json\/wp\/v2\/tags?post=519"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}