\n<\/em><\/p>\n
TopBand?\u00c2\u00a0 Wazzat?<\/h5>\n
A saga of switching from raised radials to a version of the K2AV FCP for a 160m inverted-L<\/a>.<\/p>\n The whole idea of operating on 160m started as curiosity.\u00c2\u00a0 Before 2005 I had never operated on 160m.\u00c2\u00a0 Ever.\u00c2\u00a0 I had listened some, but never keyed the transmitter other than to experiment with arcing capacitors and high levels of SWR.\u00c2\u00a0 But it generally seemed like it would be fun, so give it a try to find out, right?<\/p>\n After looking at a couple of locations in the yard, it seemed like there just wasn’t enough room to !easily!<\/em> pull up an inverted-Vee, or other crooked dipole of such unusually large size.\u00c2\u00a0 Tall trees out-the-wazooo in the yard, but spaced closely, so it is difficult for long pulls. There is an emphasis on easy because it is an important consideration.\u00c2\u00a0 Any antenna that is a pain in the ass to maintain is more likely to be out of service at any given moment at the KazShack qth.<\/p>\n There is a great spot for a vertical rise of about 70 feet so that seemed to be the ticket.\u00c2\u00a0 But verticals have their own downside.\u00c2\u00a0 Radials – bleh!…Ick!…Ptui!\u00c2\u00a0 But any antenna is better than no antenna at all, so that’s where we get sucked into 160m madness.<\/p>\n The first preference was a top loaded “T” but the useful supports are not arranged in a good pattern for that choice. There was just no way to stretch out the top-hat of the T.<\/p>\n The supports are arranged in such a way that an inverted-L is the logical choice.\u00c2\u00a0 So a slightly long inverted L was the winner since it 1) fit into the yard where the trees line up, and 2) lends itself to capacitive matching if made slightly long.\u00c2\u00a0 The result was an inv-L\u00c2\u00a0 with the vertical section that goes up 70′, then across 40′, and across again in a different direction for another 50′.\u00c2\u00a0 Approximately 155′(47m) of wire total length.<\/p>\n That leaves the radials.\u00c2\u00a0 Buried radials just were not going to happen.\u00c2\u00a0 Far too many tree roots and stone in the back yard, and no grass at all.\u00c2\u00a0 What then is the nascent TopBander to do?<\/p>\n The first Inv-L install circa 2005 had four elevated radials of equal length, about 37′ each.\u00c2\u00a0 All were tied together and loaded via a coil at the base of the antenna.\u00c2\u00a0 No chokes, and no decent matching network. \u00c2\u00a0 In this incarnation, antenna performance was poor.\u00c2\u00a0 Even loud stations were difficult to work.\u00c2\u00a0 Heard no DX.\u00c2\u00a0 No surprises there.<\/p>\n The first “improvement”\u00c2\u00a0 circa 2007 was to add 12 random length radials, a 1.5:1 step down unun(W2FMI design), and a coaxial choke wound from about 70′ of rg-58 wound on a PVC garden pot.\u00c2\u00a0 The performance improvement, while not quantifiable was immediately noticeable.\u00c2\u00a0 Stations became easier to work on a single call, and I was now able to detect the whispers of DX stations.\u00c2\u00a0 A new K9AY for RX was also added to the mix just before these changes to the TX antenna.\u00c2\u00a0 It also appeared that the improved TX antenna was now hearing most of what could be heard on the K9AY, although the K9Ay has a much lower noise floor and is usually much easier on the ears.<\/p>\n Radials were added incrementally from 2007 through mid 2010 until there was a total of about 30.\u00c2\u00a0 The original four 37 footers were the longest, and there were another four that were approximately 27 feet long.\u00c2\u00a0 Everything else was a mish-mash of random lengths, added in pairs to the available trees in the area.\u00c2\u00a0 Somewhere along the line(2008) I also added the capacitors required to get a good match at the base of the antenna, and have a nice low SWR both at the antenna base and at the shack-end of the feed line.\u00c2\u00a0 And the nice narrow SWR bandwidth that accompanies such.<\/p>\n Performance of the final well-matched radial version of 2010 seemed to be quite good in comparison to the earliest version.\u00c2\u00a0 In 2009 and 2010 it was possible to run stations(low power) in the 160m contests, and Q’s were made more often with the western US, as well as a handful of DX stations.<\/p>\n Before any other changes were made, I took some signal strength measurements in late 2011 using the K2 as field-strength meter, with the FT-920 as transmitter.\u00c2\u00a0 The test configuration was 1) transmit full power from the FT-920 on the TX antenna at its lowest SWR point, 2)RX on the K2, using a dummy load at the end of a 7 foot jumper cable.\u00c2\u00a0 dummy load hanging off edge of desk.\u00c2\u00a0 K2 attenuator on, rf gain at max.<\/p>\n Using that configuration:<\/p>\n As poor as it is, that reading is the best actual measurement available, from what in my opinion was the best of the radial configurations.\u00c2\u00a0 Taken in early December 2011.<\/p>\n In 2009-2010, K2AV began discussing an idea he had for solving the small-lot-on-160m problem.\u00c2\u00a0 Based on his modeling and studies of ground losses, he reasoned that a single counterpoise might be a solution that would work for space limited locations.\u00c2\u00a0 He determined that a counterpoise that was 5\/16th wavelengths might show useful current cancellations if it were strategically folded, to help with the problem of ground losses.\u00c2\u00a0 So evolved the “5\/16th wave folded counterpoise”, now being generally referred to as\u00c2\u00a0 “516 FCP” or just as “an FCP” . The idea seemed to have a lot of merit, but being a serial procrastinator it took some time for me to get off my hindquarters and make the changes to try it out.<\/p>\n In early 2011, K2AV gave me one of his isolation transformers, as well as an inductor.\u00c2\u00a0 Their implementations of the FCP at K2AV’s and W0UCE’s qth required\u00c2\u00a0 additional inductance for matching(hence the inductor). They also discovered that the isolation transformer was a necessity to obtain good field strength results.\u00c2\u00a0 The transformer design is beefy enough to handle their high power operations. \u00c2\u00a0 The design of the FCP has gone through some evolutions\/refinements, and the design K2Av is recommending was originally field tested at his own qth in the 2011 CQ160m CW contest with low power, and with excellent results<\/a>.<\/p>\n My own original intent was to install his isolation transformer into my original system and transition to the FCP.\u00c2\u00a0 Curiosity compels me to wonder what sort of improvement the isolation transformer might have provided on its own in the old system.\u00c2\u00a0 That test never happened, but it is really just a matter of curiosity.\u00c2\u00a0 It would still be good to know if the transformer would have made an improvement in signal with the radial jumble.\u00c2\u00a0 I expect the choking on the radial system was less than ideal,\u00c2\u00a0 far less than what was necessary, and the system probably was subject to higher losses because of that. That transition never happened, so I missed having the new system ready for ARRL DX. Impatience won out when an opportunity to do the work came up.<\/p>\n In the week after ARRL DX, the radials\/coil were removed and K2AV’s folded counterpoise and isolation transformer were added to the antenna.\u00c2\u00a0 [NEW link: K2AV FCP home page<\/a>]\u00c2\u00a0 A new junction box was built to house the isolation transformer and matching network.\u00c2\u00a0 K2AV came by with his analyzer, and we spent a morning giving the system a look-see.\u00c2\u00a0 As it turns out, the same value of matching capacitors were suitable for use without modification, and the inductor was not required because my inv-L is long.\u00c2\u00a0 Matching the system was as simple as adding capacitance until a match was found.\u00c2\u00a0 A large value air variable could be used to find the required match in less than five minutes, then replaced with capacitors suitable for handling the currents.<\/p>\n My own matching network is a group of HV ceramic caps in parallel<\/a>[Obsolete, probably unavailable, 2016\/09\/25].\u00c2\u00a0 These are mounted on a board that allows switching some of the capacitance out to move the resonance up the band.\u00c2\u00a0 The switch board will also allow switching to a different vertical element, but that feature won’t be useful without also switching the FCP.\u00c2\u00a0 The FCP is a mono-band solution.<\/p>\n Schematic for W4KAZ 160m inverted L with K2AV FCP<\/p><\/div>\n Picture of W4KAZ 160m matching network and transformer junction box in use with 155 foot long inverted L and K2AV FCP<\/p><\/div>\n The system now up is the same\/original inverted-l vertical section with the K2AV folded counterpoise and isolation transformer in place of the prior elevated radial jumble.\u00c2\u00a0 What happened?<\/p>\n Using the K2 as field strength meter again, and using the exact same conditions as described above(sense antenna dummy load hanging from desk on 7 foot jumper):<\/p>\n The S-meter on this K2 is not calibrated in real world db, but even without knowing exact values the signal is obviously stronger than it was with the previous TX antenna system.\u00c2\u00a0 Yes, that’s in the near field, but still it is encouraging.<\/p>\n The first field test was during 2011 Stew Perry<\/a>.\u00c2\u00a0 Anecdotally, I was very happy with antenna performance.\u00c2\u00a0 It really seemed like I was louder, and it seemed I got fewer requests for fills.\u00c2\u00a0 But the time for a full effort wasn’t there, so there is just a limited amount of data.\u00c2\u00a0 Not too shabby for just three hours of operating.<\/p>\n A better sample was taken during the 2012 CQ 160m CW<\/a>.\u00c2\u00a0 (And here<\/a>.)\u00c2\u00a0 A total of 20 hours was operated. Terrible propagation conditions. \u00c2\u00a0 The first 6 or so hours were very good compared to previous 160m contests.\u00c2\u00a0 20 total hours of operation produced 593 QSO’s.\u00c2\u00a0 Even with terrible conditions, I was able to work a couple of EU stations.\u00c2\u00a0 Low Power.\u00c2\u00a0 Not as good as K2AV in 2011, but one hell of a lot better than I anticipated, especially in poor conditions.\u00c2\u00a0 K2AV is also a much better CW op, so I doubt I’ll ever be able to hit that 925 Q milestone.<\/p>\n So I’m pretty happy with the current system incorporating both the FCP and isolation transformer.\u00c2\u00a0 Many thanks to K2AV!<\/p>\n In implementing the FCP design at the KazShack, I made a few variances from the recommendations.<\/p>\n The FCP itself is constructed of stranded 14ga hardware store THHN.\u00c2\u00a0 I like the flexibility of the wire, the sturdy insulation, and most important, I have several rolls of it already bought and paid for.<\/p>\n The FCP insulators<\/a> were cut from an unused piece of PVC electrical conduit.\u00c2\u00a0 That was also what happened to be at hand in the form of spreaders from an experiment with hex-beams.\u00c2\u00a0 From the length of PVC available for the job, I cut 16 spacers of 6 inches length(~150mm).\u00c2\u00a0 Each was drilled through three times, a hole in the center, and one about .5 inches from each end.\u00c2\u00a0 On the leg with two wires, the spacing is about 5 inches(125mm), while on the leg with three conductors the spacing is only ~2.5 inches(~60mm).\u00c2\u00a0 The holes are intentionally mis-aligned<\/a> or drilled at offset angles. \u00c2\u00a0\u00c2\u00a0 That allows the wire\u00c2\u00a0 itself to place tension on the spreader to keep the spreaders in place.\u00c2\u00a0 This method makes it easy to do with an ordinary hand drill – being crooked is an advantage.\u00c2\u00a0 :)\u00c2\u00a0\u00c2\u00a0 The mis-alignment alone is not enough to keep the spreaders from sliding, so they are also wrapped with vinyl cable ties as needed.\u00c2\u00a0 The distance between each spacer works out to about 4 feet(~1.3m).\u00c2\u00a0 Vinyl cable ties are also used as spacers<\/a>\u00c2\u00a0 at the midpoint between each PVC spacer.<\/p>\n Measuring and threading the wire was the most time consuming part of the FCP construction.\u00c2\u00a0 Because all of the separators are of equal size and drilled the same the side of the FCP with three conductors<\/a> is more closely spaced than the side with two<\/a>.\u00c2\u00a0 This made mechanical construction very easy, the FCP is taut and sturdy, and does not seem to have any adverse effects on basic function.<\/p>\n The transformer and matching network is installed in a nice hamfest\/surplus telco box<\/a>, about 8x8x4.\u00c2\u00a0 This is a nice weather tight enclosure.\u00c2\u00a0 The transformer is exact to K2AV specs(by definition – it was wound by K2AV his-self!).\u00c2\u00a0 The matching network of switched parallel caps is scavenged from the old weather enclosure(a sealed PVC pipe) and re-used in the new junction box.\u00c2\u00a0 These components fit well enough, but there would not have been space to house the additional toroidal inductor had it been needed.<\/p>\n Besides the apparent\u00c2\u00a0 signal improvements over the rejected-random-raised-radial-rambling-razzledazzle, the FCP itself has other very practical mechanical merits and advantages over raised radials.<\/p>\n But Kaz, is it equivalent to a full size vertical with a dense mat of radials?<\/strong>\u00c2\u00a0 Probably not, but there is absolutely zero chance that sort of system can ever be installed at this QTH, so the point is moot. At this point, my only regret is an academic point – not having run the test of inserting the isolation transformer into the old system with the radial-jumble.\u00c2\u00a0\u00c2\u00a0 The sharp tuning of most 160m antennas suggests that common mode currents will often be a problem as one tunes away from the antenna’s resonance and the reactance increases.\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0 How much benefit is gained from either the isolation transformer or the FCP individually is unknown(to me), but still of both practical and academic interest. I’d really like to know if the old system would have been improved with the isolation transformer installed. Still of interest, but not enough for me to spend time hanging the radials back up again!<\/em>\u00c2\u00a0 ;)\u00c2\u00a0\u00c2\u00a0 Together, the FCP and transformer seem to do a damn fine job here.\u00c2\u00a0 Certainly the best system that has been active in this location.<\/p>\n What next?\u00c2\u00a0 FCP phased verticals…..FCP foursquares…..FCP parasitic arrays….. MANY possibilities -\u00c2\u00a0 if only I had the room to do it.<\/p>\n The K2AV reference page should be used for the most current work by K2AV.<\/strong><\/span> Historical references, related opinions, original subject matter posts, and a few older message threads on the TopBand mail list on pertinent topics:<\/p>\n Other links:<\/p>\n Saga of transitioning to K2AV’s FCP(folded counterpoise)<\/p>\n (Updated 03\/13\/2021 de w4kaz, add\/edit links and link to newer K2AV FCP page)\u00c2 \u00c2 NOTE: Please use this K2AV link for most current construction info <\/p>\n TopBand?\u00c2 Wazzat? <\/p>\n A saga of switching from raised radials to a version of the K2AV FCP for a 160m inverted-L.<\/p>\n The whole idea of operating on 160m started as curiosity.\u00c2 Before 2005 I had never operated on 160m.\u00c2 Ever.\u00c2 I had listened some, but never keyed the transmitter other than to experiment with arcing capacitors and high levels of SWR.\u00c2 But it generally seemed like it would be fun, so give it a try to find out, right?<\/p>\n After looking at a couple of locations in the yard, it seemed like there just wasn’t enough room to !easily! pull up an inverted-Vee, or other crooked dipole of such unusually large size.\u00c2 Tall trees out-the-wazooo in the yard, but spaced closely, so it is difficult for long pulls. There is an emphasis on easy because it is an important consideration.\u00c2 Any antenna that is a pain in the ass to maintain is more likely to be out of service at any given moment at the KazShack qth.<\/p>\n Where O where does a 160m antenna fit? <\/p>\n There is a great spot for a vertical rise of about 70 feet so that seemed to be the ticket.\u00c2 But verticals have their own downside.\u00c2 Radials – bleh!…Ick!…Ptui!\u00c2 But any antenna is better than no antenna at all, so that’s where we […]<\/p>\nWhere O where does a 160m antenna fit?<\/h5>\n
The Early years<\/h5>\n
The Intermediate<\/h5>\n
\n
Decision Time<\/h5>\n
K2AV style FCP System Installed<\/h5>\n
![\"Schematic](\"http:\/\/w4kaz.com\/qth\/wp-content\/uploads\/2012\/02\/Inv_L_match_net_corrected_2014-1024x760.png\")
<\/a>![\"Picture](\"http:\/\/w4kaz.com\/qth\/wp-content\/uploads\/2012\/02\/w4kaz_box_labels-1024x682.jpg\" "\\"W4KAZ")
<\/a>The Present….So, What of it?<\/h5>\n
\n
W4KAZ Construction Variance Notes<\/h5>\n
\n
Bottom Line…..<\/h5>\n
\nDo I care?<\/strong>\u00c2\u00a0 Nope, it “works”, and it “works” better than it’s predecessor 160m antenna systems AT THIS QTH<\/strong><\/em>.\u00c2\u00a0 Very possible\/likely that improvement is just a testimony to the poor performance of the prior system. But better is “better”.
\nIs it snake oil?\u00c2\u00a0<\/strong> Probably not, at least not according to the CW skimmer robots,\u00c2\u00a0 the results K2AV has had with his system, and more important, my own field testing during the CQ160m contest.\u00c2\u00a0 W8JI has done some comparisons of models<\/a>.\u00c2\u00a0 But since they are comparisons to antennas that will not be practical at W4KAZ location, it is academic info.\u00c2\u00a0 For use here it is about the footprint and 80 foot radials are simply not practical HERE.<\/p>\n2021-03-14 Notation….Nothing Changed<\/h5>\n
References:<\/h5>\n
\n* * *USE DATA FROM HERE:–>https:\/\/k2av.com\/<\/a> * * *<\/p>\n\n
\n
![Vinyl cable ties are also used as spacers<\/a>\u00c2\u00a0 at the midpoint between each PVC spacer.<\/p>\nMeasuring and threading the wire was the most time consuming part of the FCP construction.\u00c2\u00a0 Because all of the separators are of equal size and drilled the same the side of the FCP with three conductors<\/a> is more closely spaced than the side with two<\/a>.\u00c2\u00a0 This made mechanical construction very easy, the FCP is taut and sturdy, and does not seem to have any adverse effects on basic function.<\/p>\nThe transformer and matching network is installed in a nice hamfest\/surplus telco box<\/a>, about 8x8x4.\u00c2\u00a0 This is a nice weather tight enclosure.\u00c2\u00a0 The transformer is exact to K2AV specs(by definition – it was wound by K2AV his-self!).\u00c2\u00a0 The matching network of switched parallel caps is scavenged from the old weather enclosure(a sealed PVC pipe) and re-used in the new junction box.\u00c2\u00a0 These components fit well enough, but there would not have been space to house the additional toroidal inductor had it been needed.<\/p>\nBesides the apparent\u00c2\u00a0 signal improvements over the rejected-random-raised-radial-rambling-razzledazzle, the FCP itself has other very practical mechanical merits and advantages over raised radials.<\/p>\n\nThe folded counterpoise is simple to build.<\/li>\nThe FCP is relatively small, 32′ per side(64′ total length)<\/li>\nThe FCP is a LOT easier to deploy than 30 elevated radials, or burying a dense radial mat<\/li>\nThe FCP lends itself to following contours, and models well when the FCP is not perfectly straight<\/li>\nThe FCP will require a lot less maintenance.\u00c2\u00a0 The odds of falling branches breaking the FCP here at the home QTH are lower by a factor of 15. (2 legs of FCP vs 30+ radials in 30+ directions, all below branch shedding trees)<\/li>\nall of the above…..\u00c2\u00a0 !! yipeee!!<\/li>\n<\/ul>\nBottom Line…..<\/h5>\nBut Kaz, is it equivalent to a full size vertical with a dense mat of radials?<\/strong>\u00c2\u00a0 Probably not, but there is absolutely zero chance that sort of system can ever be installed at this QTH, so the point is moot.\nDo I care?<\/strong>\u00c2\u00a0 Nope, it “works”, and it “works” better than it’s predecessor 160m antenna systems AT THIS QTH<\/strong><\/em>.\u00c2\u00a0 Very possible\/likely that improvement is just a testimony to the poor performance of the prior system. But better is “better”.\nIs it snake oil?\u00c2\u00a0<\/strong> Probably not, at least not according to the CW skimmer robots,\u00c2\u00a0 the results K2AV has had with his system, and more important, my own field testing during the CQ160m contest.\u00c2\u00a0 W8JI has done some comparisons of models<\/a>.\u00c2\u00a0 But since they are comparisons to antennas that will not be practical at W4KAZ location, it is academic info.\u00c2\u00a0 For use here it is about the footprint and 80 foot radials are simply not practical HERE.<\/p>\n2021-03-14 Notation….Nothing Changed<\/h5>\nAt this point, my only regret is an academic point – not having run the test of inserting the isolation transformer into the old system with the radial-jumble.\u00c2\u00a0\u00c2\u00a0 The sharp tuning of most 160m antennas suggests that common mode currents will often be a problem as one tunes away from the antenna’s resonance and the reactance increases.\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0 How much benefit is gained from either the isolation transformer or the FCP individually is unknown(to me), but still of both practical and academic interest. I’d really like to know if the old system would have been improved with the isolation transformer installed. Still of interest, but not enough for me to spend time hanging the radials back up again!<\/em>\u00c2\u00a0 ;)\u00c2\u00a0\u00c2\u00a0 Together, the FCP and transformer seem to do a damn fine job here.\u00c2\u00a0 Certainly the best system that has been active in this location.<\/p>\nWhat next?\u00c2\u00a0 FCP phased verticals…..FCP foursquares…..FCP parasitic arrays….. MANY possibilities -\u00c2\u00a0 if only I had the room to do it.<\/p>\nReferences:<\/h5>\nThe K2AV reference page should be used for the most current work by K2AV.<\/strong><\/span>\n* * *USE DATA FROM HERE:–>https:\/\/k2av.com\/<\/a> * * *<\/p>\nHistorical references, related opinions, original subject matter posts, and a few older message threads on the TopBand mail list on pertinent topics:<\/p>\n\nOriginal K2AV NCJ article “The FCP<\/b>: A 160 Meter Counterpoise for a Postage-Stamp Lot “<\/a><\/li>\nW0UCE’s accumulation of information on K2AV’s 160m ideas, including the FCP<\/a><\/li>\nPhotos from W4KAZ FCP install<\/a><\/li>\nOlder K2AV discussion of the FCP<\/a><\/li>\nK9YC: “Working 160M From a Small Lot (and Larger Ones Too)”, http:\/\/audiosystemsgroup.com\/160MPacificon.pdf<\/a><\/li>\nW8JI on FCP, a comparison to antennas that I cannot have<\/a>.<\/li>\nRolling your own FCP isolation transformer, IMPORTANT<\/a><\/li>\nTopband: Where to place a preamp? Switching Beverages?<\/a><\/li>\nTopband: K2AV 160m Folded Counterpoise (FCP), parts and winding for isolation transformer<\/a><\/li>\nRe: Topband: K2AV 160m Folded Counterpoise Antenna<\/a> (wire suggestions)<\/li>\nRe: Topband: T-200 vs. T-300<\/a><\/li>\n2012-05-31, VO1HP FCP install<\/a><\/li>\nBalun Designs commercially available FCP transformer<\/a><\/li>\n<\/ol>\nOther links:<\/p>\n\nW1UJ : http:\/\/w1uj.net\/FCP\/<\/a><\/li>\nKY6R : https:\/\/ky6r.wordpress.com\/2015\/04\/27\/160m-fcp\/<\/a><\/li>\nIV3PRK(FCP @ HC1PF) : http:\/\/www.iv3prk.it\/hc1pf-tx-antenna.htm<\/a><\/li>\nDL0WH : http:\/\/dl0wh.de\/80m-vertikal-mit-gefaltetem-gegengewicht-nach-k2av\/<\/a><\/li>\nDM9EE: http:\/\/www.dm9ee.de\/FCP_info.html<\/a>, and http:\/\/dm9ee.de\/fcp-radials\/<\/a><\/li>\nW8TN : https:\/\/w8tn.blogspot.com\/2012\/07\/building-k2av-fcp-160-m-antenna.html<\/a><\/li>\nWB5NHL : http:\/\/oldcyberdude.com\/sample-page\/antennas\/160m-folded-counterpoise<\/a>?<\/li>\nLA9XGA FCP : https:\/\/la9xga.com\/?cat=54<\/a><\/li>\nM0KWR: http:\/\/m0kwr.com\/Antennas.html<\/a><\/li>\nAC2RL article in RDXA Fall 2018<\/a> (see page 16)<\/li>\nLA9XGA install: https:\/\/la9xga.com\/?p=610<\/a><\/li>\nVA3KGS & VA3AC slides on FCP in array<\/a><\/li>\nAC9EZ(pg3 in ACARTS newsletter)<\/a><\/li>\n*<\/li>\n*<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"Saga of transitioning to K2AV’s FCP(folded counterpoise)<\/p>\n(Updated 03\/13\/2021 de w4kaz, add\/edit links and link to newer K2AV FCP page)\u00c2 \u00c2 NOTE: Please use this K2AV link for most current construction info <\/p>\n TopBand?\u00c2 Wazzat? <\/p>\nA saga of switching from raised radials to a version of the K2AV FCP for a 160m inverted-L.<\/p>\nThe whole idea of operating on 160m started as curiosity.\u00c2 Before 2005 I had never operated on 160m.\u00c2 Ever.\u00c2 I had listened some, but never keyed the transmitter other than to experiment with arcing capacitors and high levels of SWR.\u00c2 But it generally seemed like it would be fun, so give it a try to find out, right?<\/p>\nAfter looking at a couple of locations in the yard, it seemed like there just wasn’t enough room to !easily! pull up an inverted-Vee, or other crooked dipole of such unusually large size.\u00c2 Tall trees out-the-wazooo in the yard, but spaced closely, so it is difficult for long pulls. There is an emphasis on easy because it is an important consideration.\u00c2 Any antenna that is a pain in the ass to maintain is more likely to be out of service at any given moment at the KazShack qth.<\/p>\n Where O where does a 160m antenna fit? <\/p>\nThere is a great spot for a vertical rise of about 70 feet so that seemed to be the ticket.\u00c2 But verticals have their own downside.\u00c2 Radials – bleh!…Ick!…Ptui!\u00c2 But any antenna is better than no antenna at all, so that’s where we […]<\/p>\nContinue reading The Evolution of a 160m Inverted-L with FCP(K2AV FCP long version)<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[7,12,10,18],"tags":[50,54,53,51,52],"_links":{"self":[{"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=\/wp\/v2\/posts\/2066"}],"collection":[{"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2066"}],"version-history":[{"count":63,"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=\/wp\/v2\/posts\/2066\/revisions"}],"predecessor-version":[{"id":3543,"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=\/wp\/v2\/posts\/2066\/revisions\/3543"}],"wp:attachment":[{"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2066"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2066"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2066"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}](\"http:\/\/w4kaz.com\/qth\/wp-content\/uploads\/2012\/02\/fuji_2011_1219006.jpg\"){kind=link}
![the side of the FCP with three conductors<\/a> is more closely spaced](\"http:\/\/w4kaz.com\/qth\/wp-content\/uploads\/2012\/02\/fuji_2011_1219010.jpg\"){kind=link}
![than the side with two<\/a>.\u00c2\u00a0 This made mechanical construction very easy, the FCP is taut and sturdy, and does not seem to have any adverse effects on basic function.<\/p>\nThe transformer and matching network is installed in a nice hamfest\/surplus telco box<\/a>, about 8x8x4.\u00c2\u00a0 This is a nice weather tight enclosure.\u00c2\u00a0 The transformer is exact to K2AV specs(by definition – it was wound by K2AV his-self!).\u00c2\u00a0 The matching network of switched parallel caps is scavenged from the old weather enclosure(a sealed PVC pipe) and re-used in the new junction box.\u00c2\u00a0 These components fit well enough, but there would not have been space to house the additional toroidal inductor had it been needed.<\/p>\nBesides the apparent\u00c2\u00a0 signal improvements over the rejected-random-raised-radial-rambling-razzledazzle, the FCP itself has other very practical mechanical merits and advantages over raised radials.<\/p>\n\nThe folded counterpoise is simple to build.<\/li>\nThe FCP is relatively small, 32′ per side(64′ total length)<\/li>\nThe FCP is a LOT easier to deploy than 30 elevated radials, or burying a dense radial mat<\/li>\nThe FCP lends itself to following contours, and models well when the FCP is not perfectly straight<\/li>\nThe FCP will require a lot less maintenance.\u00c2\u00a0 The odds of falling branches breaking the FCP here at the home QTH are lower by a factor of 15. (2 legs of FCP vs 30+ radials in 30+ directions, all below branch shedding trees)<\/li>\nall of the above…..\u00c2\u00a0 !! yipeee!!<\/li>\n<\/ul>\nBottom Line…..<\/h5>\nBut Kaz, is it equivalent to a full size vertical with a dense mat of radials?<\/strong>\u00c2\u00a0 Probably not, but there is absolutely zero chance that sort of system can ever be installed at this QTH, so the point is moot.\nDo I care?<\/strong>\u00c2\u00a0 Nope, it “works”, and it “works” better than it’s predecessor 160m antenna systems AT THIS QTH<\/strong><\/em>.\u00c2\u00a0 Very possible\/likely that improvement is just a testimony to the poor performance of the prior system. But better is “better”.\nIs it snake oil?\u00c2\u00a0<\/strong> Probably not, at least not according to the CW skimmer robots,\u00c2\u00a0 the results K2AV has had with his system, and more important, my own field testing during the CQ160m contest.\u00c2\u00a0 W8JI has done some comparisons of models<\/a>.\u00c2\u00a0 But since they are comparisons to antennas that will not be practical at W4KAZ location, it is academic info.\u00c2\u00a0 For use here it is about the footprint and 80 foot radials are simply not practical HERE.<\/p>\n2021-03-14 Notation….Nothing Changed<\/h5>\nAt this point, my only regret is an academic point – not having run the test of inserting the isolation transformer into the old system with the radial-jumble.\u00c2\u00a0\u00c2\u00a0 The sharp tuning of most 160m antennas suggests that common mode currents will often be a problem as one tunes away from the antenna’s resonance and the reactance increases.\u00c2\u00a0\u00c2\u00a0\u00c2\u00a0 How much benefit is gained from either the isolation transformer or the FCP individually is unknown(to me), but still of both practical and academic interest. I’d really like to know if the old system would have been improved with the isolation transformer installed. Still of interest, but not enough for me to spend time hanging the radials back up again!<\/em>\u00c2\u00a0 ;)\u00c2\u00a0\u00c2\u00a0 Together, the FCP and transformer seem to do a damn fine job here.\u00c2\u00a0 Certainly the best system that has been active in this location.<\/p>\nWhat next?\u00c2\u00a0 FCP phased verticals…..FCP foursquares…..FCP parasitic arrays….. MANY possibilities -\u00c2\u00a0 if only I had the room to do it.<\/p>\nReferences:<\/h5>\nThe K2AV reference page should be used for the most current work by K2AV.<\/strong><\/span>\n* * *USE DATA FROM HERE:–>https:\/\/k2av.com\/<\/a> * * *<\/p>\nHistorical references, related opinions, original subject matter posts, and a few older message threads on the TopBand mail list on pertinent topics:<\/p>\n\nOriginal K2AV NCJ article “The FCP<\/b>: A 160 Meter Counterpoise for a Postage-Stamp Lot “<\/a><\/li>\nW0UCE’s accumulation of information on K2AV’s 160m ideas, including the FCP<\/a><\/li>\nPhotos from W4KAZ FCP install<\/a><\/li>\nOlder K2AV discussion of the FCP<\/a><\/li>\nK9YC: “Working 160M From a Small Lot (and Larger Ones Too)”, http:\/\/audiosystemsgroup.com\/160MPacificon.pdf<\/a><\/li>\nW8JI on FCP, a comparison to antennas that I cannot have<\/a>.<\/li>\nRolling your own FCP isolation transformer, IMPORTANT<\/a><\/li>\nTopband: Where to place a preamp? Switching Beverages?<\/a><\/li>\nTopband: K2AV 160m Folded Counterpoise (FCP), parts and winding for isolation transformer<\/a><\/li>\nRe: Topband: K2AV 160m Folded Counterpoise Antenna<\/a> (wire suggestions)<\/li>\nRe: Topband: T-200 vs. T-300<\/a><\/li>\n2012-05-31, VO1HP FCP install<\/a><\/li>\nBalun Designs commercially available FCP transformer<\/a><\/li>\n<\/ol>\nOther links:<\/p>\n\nW1UJ : http:\/\/w1uj.net\/FCP\/<\/a><\/li>\nKY6R : https:\/\/ky6r.wordpress.com\/2015\/04\/27\/160m-fcp\/<\/a><\/li>\nIV3PRK(FCP @ HC1PF) : http:\/\/www.iv3prk.it\/hc1pf-tx-antenna.htm<\/a><\/li>\nDL0WH : http:\/\/dl0wh.de\/80m-vertikal-mit-gefaltetem-gegengewicht-nach-k2av\/<\/a><\/li>\nDM9EE: http:\/\/www.dm9ee.de\/FCP_info.html<\/a>, and http:\/\/dm9ee.de\/fcp-radials\/<\/a><\/li>\nW8TN : https:\/\/w8tn.blogspot.com\/2012\/07\/building-k2av-fcp-160-m-antenna.html<\/a><\/li>\nWB5NHL : http:\/\/oldcyberdude.com\/sample-page\/antennas\/160m-folded-counterpoise<\/a>?<\/li>\nLA9XGA FCP : https:\/\/la9xga.com\/?cat=54<\/a><\/li>\nM0KWR: http:\/\/m0kwr.com\/Antennas.html<\/a><\/li>\nAC2RL article in RDXA Fall 2018<\/a> (see page 16)<\/li>\nLA9XGA install: https:\/\/la9xga.com\/?p=610<\/a><\/li>\nVA3KGS & VA3AC slides on FCP in array<\/a><\/li>\nAC9EZ(pg3 in ACARTS newsletter)<\/a><\/li>\n*<\/li>\n*<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"Saga of transitioning to K2AV’s FCP(folded counterpoise)<\/p>\n(Updated 03\/13\/2021 de w4kaz, add\/edit links and link to newer K2AV FCP page)\u00c2 \u00c2 NOTE: Please use this K2AV link for most current construction info <\/p>\n TopBand?\u00c2 Wazzat? <\/p>\nA saga of switching from raised radials to a version of the K2AV FCP for a 160m inverted-L.<\/p>\nThe whole idea of operating on 160m started as curiosity.\u00c2 Before 2005 I had never operated on 160m.\u00c2 Ever.\u00c2 I had listened some, but never keyed the transmitter other than to experiment with arcing capacitors and high levels of SWR.\u00c2 But it generally seemed like it would be fun, so give it a try to find out, right?<\/p>\nAfter looking at a couple of locations in the yard, it seemed like there just wasn’t enough room to !easily! pull up an inverted-Vee, or other crooked dipole of such unusually large size.\u00c2 Tall trees out-the-wazooo in the yard, but spaced closely, so it is difficult for long pulls. There is an emphasis on easy because it is an important consideration.\u00c2 Any antenna that is a pain in the ass to maintain is more likely to be out of service at any given moment at the KazShack qth.<\/p>\n Where O where does a 160m antenna fit? <\/p>\nThere is a great spot for a vertical rise of about 70 feet so that seemed to be the ticket.\u00c2 But verticals have their own downside.\u00c2 Radials – bleh!…Ick!…Ptui!\u00c2 But any antenna is better than no antenna at all, so that’s where we […]<\/p>\nContinue reading The Evolution of a 160m Inverted-L with FCP(K2AV FCP long version)<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[7,12,10,18],"tags":[50,54,53,51,52],"_links":{"self":[{"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=\/wp\/v2\/posts\/2066"}],"collection":[{"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2066"}],"version-history":[{"count":63,"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=\/wp\/v2\/posts\/2066\/revisions"}],"predecessor-version":[{"id":3543,"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=\/wp\/v2\/posts\/2066\/revisions\/3543"}],"wp:attachment":[{"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2066"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2066"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/w4kaz.com\/qth\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2066"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}](\"http:\/\/w4kaz.com\/qth\/wp-content\/uploads\/2012\/02\/fuji_2011_1219008.jpg\"){kind=link}