Review of MFJ-1984MP End-Fed Multi-band Antenna (# 89)

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David Casler Ask Dave

David Casler Ask Dave

Күн бұрын

Пікірлер: 257
@vcl608
@vcl608 Жыл бұрын
Dave, thank you for your commitment to helping fellow hams. Your videos are extremely informative and we appreciate you!
@ossiemoore941
@ossiemoore941 Жыл бұрын
Thank you for the "stop the press" segment on this. I have been going crazy wondering about 40m on mine. Doing what you did actually helped greatly.
@jamesfoley2720
@jamesfoley2720 3 жыл бұрын
I own one of these and it works VERY well with my FT818ND. This antenna is part of my portable station.
@09keller
@09keller 6 жыл бұрын
David, I was just looking at this antenna and found your evaluation. It was extremely helpful. Thanks for all that you do for the amateur community. Your knowledge base and professorial style are great! Thanks
@VlogdeHeer
@VlogdeHeer 5 жыл бұрын
I have the MFJ1982 and the MFJ1984, both perform very well. I made contacts (phone) with 100watts over 15000km just hanging 5m above the ground.
@johnwmacdonald994
@johnwmacdonald994 7 жыл бұрын
Great video, Dave, largely because you're able to give such sound technical interpretation as to what's going on, where I at least would be pretty lost. Thanks as always. -KC1DIW
@jamesstaley5611
@jamesstaley5611 5 жыл бұрын
At least your humming bird feeder works :)
@AdamosDad
@AdamosDad 5 жыл бұрын
I was watching them as well, there was a lot of activity at the feeder but not so much on 40. KD9OldAssMan
@n4lq
@n4lq 7 жыл бұрын
Yes this is an auto transformer but the one's from EU and Myantennas are standard transformers. That's a big difference. The coax will play a role in the antenna therefore I recommend grounding the box right at the earth, going vertical then horizontal in inverted L fashion. That eliminates all the mysterious effects....
@jay-rus4437
@jay-rus4437 4 жыл бұрын
Im currently running the emcomm III in an inverted L (kind of a lazy L though). I run 4 counterpoise at 13 feet, the main antenna vertical 22’, then horizontal from there with a slight slope to the end. At the transformer I installed an MFJ-915. Overall my 40 meter performance is pretty good
@DaninVirginia
@DaninVirginia 4 жыл бұрын
Hey Dave you've got some hummingbirds showing up for a lesson at 22:00! Great review, appreciate your thoroughness
@ltdees2362
@ltdees2362 5 жыл бұрын
...I'm a simple man, have plenty of trees and cordage to hang my reliable dipole's...your review enforces my philosophy to stay away from gadgets proclaiming to make my life easier...great review and 73's 😎
@dieselstruck
@dieselstruck 4 жыл бұрын
I agree with you in simplicity. I have to say though, this antenna is not up to par as an EFHW antenna goes. I refrained from actually buying this exact model because of the loose solder I saw on this video. I decided to pay twice for the same type of antenna from somewhere else, where it seems they have a higher quality standard, and it works without a hitch. I have worked FT8, SSB, PSK31, etc and I have gotten great QSO's. EFHW are good antennas and don't require all that Dave had to go trough on this video when built in a consistent manner. Also, no counterpoise on these, ground it. TLDR: MFJ makes a crappy EFHW, build your own or buy from a reputable antenna maker and you won't regret it.
@jay-rus4437
@jay-rus4437 4 жыл бұрын
Dani El .....running a chameleon emcomm iii, and it is a solid antenna with good performance. I did connect an mfj-915 choke at the tramsformer
@chopperboi89
@chopperboi89 7 жыл бұрын
I got the MFJ 1622, "apartment antenna" (~ $100). In my case, it was completely useless... It might be good for EmComm, but I would want something a little less unwieldy in that scenario... Since then, I've built my own end fed, running from by the 2nd floor window near my rig, and down across my property, it works great with a tuner from 80-10. Now unless you need a vertical, I'd recommend people just learn a little bit, and build their own too.
@NHSbandUnofficial
@NHSbandUnofficial 7 жыл бұрын
Dave, I built a 9:1 end fed myself. At first I had similar issues. Then with a friend's advice I lowered my transformer to about 2 feet from the ground and connected the ground to my ground rod with no counterpoise . Boom my antenna came alive and works great!
@buckmanaustin3211
@buckmanaustin3211 5 жыл бұрын
Dan, I just picked up a 1982mp and the downloadable instructions didn't specifically state 2' from the ground, but the illustration pictured it close to the ground as you did, and also said to connect the transformer to a ground rod. Sounds like Dave needs to try that.
@gfl1957
@gfl1957 5 жыл бұрын
This is a 49:1 end fed half way.
@sv4rin
@sv4rin 5 жыл бұрын
Does the fact that your mast supports are metal , interfere with the readings ?
@macgyver5108
@macgyver5108 5 жыл бұрын
You just gained MAJOR credibility points with me wearing that shirt! 😎
@surfcrs
@surfcrs 5 жыл бұрын
A classic
@scharkalvin
@scharkalvin 4 жыл бұрын
The 80 meter version of this antenna (132' long) would have a harmonic relation on 30 meters, there it's the 3rd harmonic (well close enough for government work). The problem on 40 may have been that the length of the coax was resonant. Perhaps with the box in the air and a LONGER feedline (moving the feedline resonant freq) it might have worked on all bands. Also, you might have needed a choke in the feedline at the rig.
@timothystockman7533
@timothystockman7533 5 жыл бұрын
I recently put up an 85 foot end-fed with a 45 foot counterpoise. I have an MFJ-939 tuner at the feed point and about 125 feet of coax back to the shack. It tunes up on all bands 160 - 6. One night when 80m was open I was able to work Europe wth my 100 watt IC-7100.
@TheAx504
@TheAx504 4 жыл бұрын
I have one on it’s way! Great review and valuable information. Cheers!
@johnmarron1944
@johnmarron1944 2 жыл бұрын
I got one from UK Antennas straight out of the box a 49;1 transformer 66ft ish .connected to it .boom no problems an 40 20 15 and 10 so then ordered the 110uH coil added that on the end with about another 8ft of wire and now got 80mtr too no problems at all 😉👍
@vcl608
@vcl608 Жыл бұрын
Thanks!
@davecasler
@davecasler Жыл бұрын
Many thanks for the generous Super Thanks! 73, Dave, KEØOG
@v4mp1el
@v4mp1el 4 жыл бұрын
@David, do not keep the coax/analyzer in your hands and try not to ly the coax on the ground it will screw up the readings because your are becoming part of the antenna.
@RicSpivey
@RicSpivey 3 жыл бұрын
First 2 seconds, "I wanna hear his thoughts on this topic" then "awesome shirt!" Then "always great content from Dave!"
@pd1jdw630
@pd1jdw630 6 жыл бұрын
I later found out ( before I saw this video ) the best swr is conceived by hanging the balun about a meter high of the ground [ =3 feet ]
@georged8138
@georged8138 2 жыл бұрын
the best antenna i ever bought
@terryjwood
@terryjwood Жыл бұрын
If I could only have 1 antenna, this would be it! With my MFJ antenna tuner I've been able to use this antenna on 160 m, 80m and 60, 30, 17 and 12 meters too! I've worked 123 countries using 100 watts with this antenna in a little more than a year!
@zgrafsoftware
@zgrafsoftware 2 жыл бұрын
Thanks for the video. Was considering this model, but after watching decided against it. Splendid summary statement at 23:10 -- "This is not a home antenna at all. It's just not!"
@thameswater2561
@thameswater2561 7 жыл бұрын
The World is falling a part :( we can always rely on David Casler. well done at least you will be here to keep us informed.
@1903A3shooter
@1903A3shooter 4 жыл бұрын
Well one thing you have your transformer box next to a conducting pole that is grounded. I built my first end fed single core matching right off of Steve Ellington,s videos and it was a very good performer on 40. The match was very good, the on air was 2 S-units better than my 40 inverted V at the same above ground. About 40 feet to the center of the V and to the attachment point of the end fed that was a slopping wire to the same point with the transformer 4 feet off the ground at the other end. This only shows that the wire was taking the power and sending it on its way, not every station was this good but to the station near the coast up north from Va. it was doing well. The next one I built is a two core and I have not gotten the same result on 40 with it but it just takes some HAM fiddling. Steve,s videos are very good and he get very good results and had built many. Thanks, Dave E. W4GSM
@patrickkerns2022
@patrickkerns2022 2 жыл бұрын
Would it recieve on all band?I'm looking for a all band recieve only antenna ?will work both indoor and out.any ideas? Thanks
@terryjwood
@terryjwood Жыл бұрын
It will work fine!
@richard-fy2mu
@richard-fy2mu 6 жыл бұрын
Out of fairness to MFj redo this keep box 3 to 8 feet up. slope up to 25 feet then down in l. Try with/out counterpoise or ground. Bet it redoes itself and for HOA victims not bad
@terryjwood
@terryjwood 2 жыл бұрын
I'm using 75 feet of LMR-400 and I have the box on the ground and the antenna over a tree limb (inverted V). I find get a 1.1: 1 at 7 MHz and 2:1 at 7.3. On 20, 15, and 10 (28-28.5) meters I get about 1.3:1 or better. So far I really like this antenna for my home use! I've worked Chile and Spain on 10 meters and regularly use it on 40 to check into ECARS, SCARS and the Nickle Belt Net from Pittsburgh. Just follow the online instructions and this will work just fine for you!
@thomaswright20
@thomaswright20 7 жыл бұрын
Hi Dave, I am using the myantennas 80-10 efhw antenna. I have it set up in an inverted L configuration. I have the auto transformer mounted on a wooden 4X4 post on my deck. Directly below that I have an 8 ft. ground rod connected via a 2 ft. ground wire. My swr readings are 2:1 or less on all bands and less than 1.5:1 on most bands. I believe the key to performance is keeping the ground as close as possible to the autotransformer. I also use an ugly balun in line to prevent RF from feeding back into the shack. Hope this helps. Good Luck!
@BadVorlon
@BadVorlon 7 жыл бұрын
Good choice... I use the same antenna with similar set up, with similar results. Great antenna. 73,
@JayN4GO
@JayN4GO 7 жыл бұрын
Thomas Wright hey Tom , how does the myantennas 8010 work for you? Do you mind making a video? I have 70 ft between trees but would like to come down and go at a 45 degree right angle to try to get the best I can on 75 meters. Did you have to trim the antenna ?
@dheller777
@dheller777 6 жыл бұрын
Are you having to use a lot of coax or could I keep the coax length under 10 foot as I do with my MFJ end fed?
@RangerUT
@RangerUT 3 жыл бұрын
I use 1984HP and it work good on 40-10m. 10 is a bit hard to do with no tuner. I have done 300-450watts SSB with really good results. Even barefoot 100w or less I do very good on digital modes. My setup is box is at 8' middle at about 12-13'. end at 28'
@flattire707
@flattire707 3 жыл бұрын
David, thanks for the truth about end-feds. There are any number of companies advertising end-fed multi-band antenna claiming no tuner needed. It is just not true.
@n4lq
@n4lq 7 жыл бұрын
Join the End Fed Half Wave Facebook group: facebook.com/groups/EndFedHalfWaveAntennas/
@warplanner8852
@warplanner8852 6 жыл бұрын
Dave, thank you for your effort on this review. It tells me to stay a million miles away from this antenna as manufactured by MFJ! Think I will stick with a center fed trap dipole or a trap vertical and keep life simple. 72 de k6whp dit dit
@davecasler
@davecasler 6 жыл бұрын
It's best used as a portable antenna with one end mounted very near the QRP transceiver.
@MarkDecamps
@MarkDecamps 3 жыл бұрын
I use it as a POTA antenna with great success.
@eddy2561
@eddy2561 4 жыл бұрын
HI Dave, sorry I'm late to this party......my question, won't an external autotuner such as the MFJ-939i take care of the SWR problem on 40m? It seems you're not a fan of tuners, is this correct? Tnx fer the review, 73 ~ k6sdw
@322doug
@322doug 5 жыл бұрын
Dave has the greatest antenna reviews.
@davecasler
@davecasler 5 жыл бұрын
This one was a particularly tough one!
@322doug
@322doug 5 жыл бұрын
you are very thorough, and fair. very important .@@davecasler
@BadVorlon
@BadVorlon 7 жыл бұрын
Dave, I cannot vouch for the MFJ version of this antenna, but I have used another competing version of this antenna (80-10M version) with great success. I have been so impressed with it, it has become my primary base station antenna (yes I live in a dreaded HOA and this is easy to hide). The key to these end-fed antennas using either a 1:49 or 1:64 transformer is the set up. These CAN be set up as a base station antenna. As you found out, these like their feed points close to ground, so they work best as a sloper. I have found if you mount the feed point (and transformer) between 3 and 12 feet above ground, and not use a counterpoise, but rather ground it with a short wire right to a rod (4 foot ground rod in my case) AND feed it with no more than 50 foot of coax... it works great. I have been heard as far away as Australia from the US east coast using it. On most bands 80-10 it needs no tuner (but depends on your terrain). Like you, I have realized this could also be a great field deployable antenna and have built a QRP version based on this design using FT140-43 toroid. 73.
@JosephMassimino
@JosephMassimino 7 жыл бұрын
Great info, I would like to see how you wound the toroid you used for the antenna you made. Did it work well when you tested it? If you can't pot it here, maybe you could send it to me via email from QRZ.
@davejones6006
@davejones6006 10 ай бұрын
Love the hummingbirds. Just got one of these. Hope I have better luck….
@johncliff5417
@johncliff5417 6 жыл бұрын
Nice review Dave, I was watching with great interest thinking now can Dave prove me wrong here or what. well Dave I have used all kinds of HF antennas to suit the situation of locations that I have had to operate from when in the forces. For the higher frequencies I would usualy pick to use a dipole slung up from trees or tree/mast. For the lower frequencies I would normaly use the trusty wind up drum and plug in unit of a 150 ft, wound up "Dacron" line with embedded tinned copper wire in it. The line was run out for the length required and then trapped into one side between metal washers that were connected to a 5/16 ins plug in terminal, witch was pushed into the antenna base fitted on the side of the vehicle. ie. pull out the whip sections and plug in the wire unit. the far end of the wire could be pulled up into trees or a mast. Whatever losses there were in using a ATU to get a good match was not taken into account. as long has I was able to make contact with the base HQ and pass traffic, usualy by CW was what mattered. On my own back playing with Ferrite torroids winding UNUNs , BALUNS and XFORMERS to try and do what you have just demonstrated, I gave up most of the time and just put it down to experience. Use a doublet or a fan dipole. 73 de John - G0WXU
@adlapl
@adlapl 5 жыл бұрын
Do I see humming-birds in the background? They are so wonderful! :)
@davecasler
@davecasler 5 жыл бұрын
Yes, my wife goes through literally gallons and gallons of hummingbird juice. We enjoy them every summer.
@nojiratzlaff4388
@nojiratzlaff4388 4 жыл бұрын
Might want to try using a RigExpert analyzer, Dave. Just a bit more convenient, IME.
@TI3WTI
@TI3WTI 3 жыл бұрын
Did someone noticed that the counterpoise is connected to "noting" inside the box?
@junkman2758
@junkman2758 Жыл бұрын
Curious to see the box earth grounded instead of counterpoise
@DonDegidio
@DonDegidio 7 жыл бұрын
Hi Dave, I was watching the humming birds at the feeder during the Stop Press segment of the video. 73 WB3BJU
@987kestrel
@987kestrel 7 жыл бұрын
They were going at it pretty good at 18:05. Oh and also there is a wasp nest under your deck Dave, I'm surprised you did not get stung. Looks like a pretty decent sized one.
@davecasler
@davecasler 7 жыл бұрын
There was also a wasp nest inside the folded umbrella on the picnic table. The wasps love the hummingbird feeders.
@washingtonstatepicker3460
@washingtonstatepicker3460 2 жыл бұрын
Good review! My efhw from MFJ designed for 160-10 only resonates on 40 and 20!
@garretthatfield6246
@garretthatfield6246 7 жыл бұрын
I have a similar antenna setup in my attic. I was having trouble so I added an “ugly balun” at the feed point and a 30’ counterpoise. The antenna works great on 40-10. K0RGH
@davecasler
@davecasler 7 жыл бұрын
Sound like you've had great results! Thanks for sharing your config.
@larrytruesdellsr.809
@larrytruesdellsr.809 4 жыл бұрын
What is a ugly balun?
@francismcclaughry3794
@francismcclaughry3794 4 жыл бұрын
I like these reviews of wire antenna. I have two hundred feet of wire that was used for low wire for like garden lights and I'm thinking of making a home made wire antenna I just watch a bunch of these reviews
@eduardogarciamontesdeoca5935
@eduardogarciamontesdeoca5935 4 жыл бұрын
Thanks Dave for this interesting review...
@DARTHDANSAN
@DARTHDANSAN Жыл бұрын
This is stuff get so confusing?!?!?!? Thanks for share us all the years of experience you have
@CodeMasseur
@CodeMasseur 5 жыл бұрын
Hi Dave. I just rewatched this video today -- after having owned the exact same model of MFJ-1984MP end-fed antenna, and I don't use it with a counterpoise, and not only does it work great for me in 10 meter, 15 meter, 17 meter, 20 meter, 30 meter and 40 meter, but I'm actually able to communicate on it with 80 meters as well. I guess YMMV?!? For what it's worth, this antenna goes up almost vertical in the tree, about 40-50 feet up in the air, and the transformer box sits within 2 feet of the ground. 73 de W3DJS in Atlanta, GA, USA.
@scotthawkins9185
@scotthawkins9185 5 жыл бұрын
I have had the same good results with this antenna. I have mine installed in an inverted V fashion approximately 70 feet in a tree and the box mounted to a 4x4 post about 5 ft off the ground and 20 feet of coax. Also grounded it at the 4x4 post to copper ground rod. Works excellent so far
@cubeistgames7985
@cubeistgames7985 4 жыл бұрын
Clearly having that box reasonably close to terra firma matters, and that is how the instructions show it. ( Don’t have one, but this kind of antenna arrangement has some attraction for me.
@IamNewPrepper
@IamNewPrepper 6 жыл бұрын
Hi David, A question you may be able to answer. I am not new to radio my first lic was an Advance back in the early 80's. I was with a job that offered no time for radio or other hobbies so within 2 years I sold everything until I was ready to key up again. Now being retired I started up again in March of 2018 and found radio has passed me by. :( I bought a new HF with 4BTV, and 2m/440, FT400 as a base. I decided to buy an MFJ 1984MP to give them a try thinking they have bettered themselves but no surprise they did not. have installed many antennas in my life and really did not care for it once seeing it in hand, I immediately noticed the wire was not going to be heavy enough to support its self. I ran it at about 120 degs leaving enough slack with a relief at the top end to adjust for wind, well up in March fell down in August, the wire broke as I expected (the wire is not strong enough to support its self over the length. Have been trying to contact MFJ but unable to make it past sales and put on hold for upto 27 minutes before I get disconnected. I left my number with sales but no reply. So back to my question, I have the over all footage but I need the lenght from the balun to the chock do you have any ideas on how long?
@davecasler
@davecasler 6 жыл бұрын
I don't have the antenna anymore, so can't measure it. The length might be listed in the manual or on the MFJ webpage for the antenna. Good luck!
@twohandsandaradio
@twohandsandaradio 3 жыл бұрын
I stopped it at 5:03.. is there even 14 turns? I counted 12.
@ve3bwp56
@ve3bwp56 5 жыл бұрын
Sorry I have to ask... why is Dave always holding onto the mouse?
@davecasler
@davecasler 5 жыл бұрын
It controls the speed of the teleprompter.
@KX4UL
@KX4UL 6 жыл бұрын
Excellent review! I truly enjoy your videos. Thanks for posting.
@JosephMassimino
@JosephMassimino 7 жыл бұрын
So it appears that the antenna can get all the bands that is says, but not at the same time. What I get from this is that there is no simple way to get low band and high band frequencies to work together on wire antennas. This is because the coax appears to be part of the low band frequencies, but not so much as the frequency increases. I guess that would not surprise anyone. My guess is that if you would put a choke at the balun, and stop RF from flowing back on the coax, you would stop the antenna from working on 40m altogether. Everybody knows that 66 feet is ideal for 40m, so it is the balun that is wrong at that frequency. When 7mhz is put to the wire, the wire is referenced to ground, and that starts at the balun. So i wonder if you were to raise the antenna so the coax going vertical were to match the 66 feet of the antenna before it turned away at the ground. I don't know if you have a way to get that kind of height, but it would be interesting to see what the antenna does. If it works being fully vertical, the next thing might be to test it as a slope. My thought is that the coax would radiate at 7 mhz, but not so much at the higher frequencies. There might have to be a choke as the coax hits the ground ground and makes it turn to the shack. I believe that in a fully vertical configuration the coax that is directly under the wire, will aid 40m, and not bother the higher frequencies as much. If you don't think any of what I suggest would work, I would be interested in the reasons why. I am limited to just wire antennas, so I have been trying to come up with the best I can get. Once a metal roof went on my home, the antenna situation has gotten more complicated.
@homebrewham2786
@homebrewham2786 3 жыл бұрын
love your channel dave keep it going👍📡
@mikeharnett2410
@mikeharnett2410 7 жыл бұрын
Thanks Dave. I've never had much luck with high impedance antennas, but that was in NM with very high ground mineralization. Here in IL they might work better.
@Horse335
@Horse335 4 жыл бұрын
Awesome videos. I do learn a lot form them. thank you!
@cubeistgames7985
@cubeistgames7985 4 жыл бұрын
Would the fact that, at 40M the antenna, at 20 ft in the air is a good bit less than the approx. 10M 1/4 wavelength be a factor, maybe?
@johnmarshall7212
@johnmarshall7212 4 жыл бұрын
What do you use for the antenna poles in the test range?
@tglenn3121
@tglenn3121 6 жыл бұрын
Have you ever done any video-reviews of Alpha Delta antennas?
@davecasler
@davecasler 6 жыл бұрын
No, not yet.
@markp.7931
@markp.7931 7 жыл бұрын
Hi Dave...I'd love to see a video on antenna switches. Comparing low end (Workman etc) to some higher end models. Thanks...Mark KC1GNH
@timothystockman7533
@timothystockman7533 5 жыл бұрын
An automatic tuner at the feed point might be the solution for "all band" operation using an end fed antenna.
@tomw5vlt119
@tomw5vlt119 4 жыл бұрын
A lot of folks I know are using end feds with tuners. Here tho you’re not using a tuner... so I’m not sure the applicability of your methods, or outcomes? Outcomes pertaining to effective multiband solutions ... or not ... or how well?
@notsheeple2019
@notsheeple2019 5 жыл бұрын
I have the same model but 80 to 10. 22 feet up both ends. The box 5 ft from last. Rg8x 50ft. 1.1 to 1.8 'll lbands. No extra grounds or couterpose. Only ground is clamped on coax cable near transceiver. To bad yours failed. KI5GLN
@davecasler
@davecasler 5 жыл бұрын
I did finally get it to work, but only in a portable use case.
@larryak0z672
@larryak0z672 3 жыл бұрын
My EFHW acts like it is shorted. No noise on receive and high SWR. When I unscrew the shield from the pl259 and only the center is hooked to the so239 I get receive noise. What would cause this? Thanks for this great video!
@johnaguiar5891
@johnaguiar5891 2 жыл бұрын
I have the exact same symptom on my efhw - did you find a solution ?
@dongjuang4196
@dongjuang4196 3 жыл бұрын
Hello and thanks for the review. Have you tried to put on the coax near the box a ferrite core?
@davecasler
@davecasler 3 жыл бұрын
Unfortunately no, and I gave the antenna away some time ago.
@dongjuang4196
@dongjuang4196 3 жыл бұрын
@@davecasler I have ordered myself MFJ-1982MP. It was before I saw your video. Now the antenna is on it's way to me. Shall see what it will be like...
@dongjuang4196
@dongjuang4196 3 жыл бұрын
​@@davecasler finally I've got it (Ukrainian post is the most incapable in the world). Well I must strongly disagree with you. I've hanged it temporarily: one end right outside my radio shack window at height of 6m above the ground and another end close to a tree at the 8m height. Taking into account sagging one may say that it's hanging almost horisontally at the 6m height. No counterpoise, no coaxial shield grounding. Just simply 8m of RG58 cable from the rig to the antenna. My rig is right next to the window at the second floor of my house. I must say that on all of the bands (3.5M, 7M, 10.1M, 14M, 18.1M, 21M, 24,9M, 28M) I have SWR not higher than 1.8. Only on 28M band I have good SWR just from 28.2M to 28.9M, all the rest of the bands are covered in full, most of them with SWR below 1.5, and 21M with SWR 1.8 @ 21.000kHz. SWR was measured using Diamond SX-100 and 10W rig output. I have disassembled it to look at the transformer and noticed that the ratio is not 7:1 but 6.5:1 (autotransformer with total 13 turns and 2 turns primary). Maybe that is the secret?
@davecasler
@davecasler 3 жыл бұрын
@@dongjuang4196 Glad it's working for you!
@sg39
@sg39 2 жыл бұрын
@David Casler, this is what I’m thinking, that the common mode currents are the issue. Use ferrites or a choke in the coax. I am preparing to explore the 49:1 paradigm and as a vertical or a sloper. My 9:1 unun of several years is mounted 5-feet off the ground, is connected to a close 8-foot driven ground rod, and uses a horizontal wire in NVIS fashion. I dealt with the common mode issue using ferrites to keep RF off the 50-foot run of coax to the shack and the rig. I know this is apples and oranges, but it seems that @Dong Juang has the right idea for the 49:1 product that you reviewed.
@markkerstetter4616
@markkerstetter4616 7 жыл бұрын
Doesn't the use diagram (for home use) from the manual show how you ended up? That is, the feed point is very close to the shack (short cable), near the ground (several feet relative to the window in the diagram) and grounded? The diagram shows an inverted-v; your test antenna had two different configurations (horizontal and slanted). Thanks for continuing your great series of videos. You deserve a larger audience and I believe you will get. --Mark, KE8HAA
@davecasler
@davecasler 7 жыл бұрын
Yes, the pictures do illustrate setup. However, they are labeled as examples. There is no text to say that it must be done as in the pictures. I sent MFJ some suggested text to add to their instructions.
@debohannan4315
@debohannan4315 6 жыл бұрын
Hi Dave. Since the coax is unbalanced and the antenna is balanced Shouldn't the zip have a choke on it? Seams like the shield of the coax is still radiating .
@davecasler
@davecasler 6 жыл бұрын
It probably is. But while a dipole is inherently balanced when center fed, end feeding is another story. The little balun helps, but needs a counterpoise.
@terry.stafford
@terry.stafford 3 жыл бұрын
Will the built-in antenna tuner on a Yaesu 991a bring everything in?
@davecasler
@davecasler 3 жыл бұрын
No. It’s a narrow-range tuner only going up to about 3:1 SWR.
@SteelWolf13
@SteelWolf13 4 жыл бұрын
18:50 + This my friends is how you ACTUALLY fish for Radio Signals.
@jiml40
@jiml40 7 жыл бұрын
Sure would like to see you do a review on the MFJ 2389.
@davecasler
@davecasler 7 жыл бұрын
Soooooo many antennas.......soooooooo little time!
@jiml40
@jiml40 7 жыл бұрын
David Casler 😄 I'm sure you can handle it. 😉 There is not a single review on that antenna online anywhere. MFJ will jump at the chance to have it reviewed. Consider it, at least. It's unusual in that it's kinda like a multiple band Hustler, no ground radials, base. Hf through 70 cm , it's like the Maldol hvu-8, , might even be the same manufacturer.
@graywolf1911
@graywolf1911 7 жыл бұрын
Quite interesting Dave. I have an OCF 265 foot dipole, strung up between trees, it is rated for 160 meters through 2 meters, using a 4:1 Balun at the antenna feed point. The Coax is buried, and is 165 feet of length. I don't think I will be using and endfed anytime soon, but, for some people this may be an acceptable choice.
@davecasler
@davecasler 7 жыл бұрын
The OCFD is a popular antenna, and those I've spoken who have them are quite happy with them. I've never used one myself.
@JosephAnthonyJosefius
@JosephAnthonyJosefius 3 жыл бұрын
I'm setting up the 800watt version as my permanent QTH HF antenna to replace my G5RV.
@kevinshieldsw1kps785
@kevinshieldsw1kps785 6 жыл бұрын
If it’s on the ground how do you keep water out of it? Or snow for that matter? Would you, could you put in waterproof case? New ham here, so new license not it database yet, but trying to absorb. Thanks Dave, wish you lived closer to me! -73- Kevin
@davecasler
@davecasler 6 жыл бұрын
This particular antenna seems suited best for portable use. I suspect mostly with good weather.
@rossbennett449
@rossbennett449 7 жыл бұрын
I'm new to this sort of calculation, so please help me if I'm missing something. My understanding here is that the problem on the low band was that there was reflected current washing back so it began working as a radiator and that messed up the behavior of the system. Isn't this the classic example for a common mode choke? Instead of moving to a shorter coax, why not make six or eight turns of that coax just below the matching transformer? Again, this is in addition to a good ground at the matching box. Thanks from Ross @ KI5SR
@davecasler
@davecasler 7 жыл бұрын
You're right in general, but in this case the impedance at the feedpoint is very high (thousand or more ohms) so it would have to be a huge choke to create that kind of impedance. So it looks like the match box needs to be relatively close to ground.
@markanderson8066
@markanderson8066 6 жыл бұрын
the ugly unun aka common mode choke (its NOT a balun) would be on the coax side - where the impedance is 50 ohms.. right? but the typical reason to NOT do that is that the end fed needs a counterpoise which is usually just the coax run. If you do the chock then you probably need the counterpoise. There are other videos on this tho I don't recall the presenters.
@Mr_Meowingtons
@Mr_Meowingtons 6 жыл бұрын
i would test it with a 1:1 current choke
@KO4L_Lloyd
@KO4L_Lloyd 7 жыл бұрын
Really enjoyed the video. Kinda D grade on the antenna, but it is what most antennas are - a comprimise. Thanks and I'll watch more of your posts. I subscribed so I won't miss them when you post. ps - you have interesting hummingbirds, they were flitting in and out of the feed station.
@davecasler
@davecasler 7 жыл бұрын
We're swamped with hummingbirds every year! Too many to count.
@dougtaylor7724
@dougtaylor7724 3 жыл бұрын
That is a POTA/SOTA single band antenna for sure. Can you imagine someone in a 5th floor apartment trying to tune this?
@terryjwood
@terryjwood 2 жыл бұрын
That would be a really big apartment! (66 feet!)
@buckeye5704
@buckeye5704 5 жыл бұрын
Thanks for the review and the view of your hummers buzzing around the feeder. Going by a couple comments this might work as a temp (and quick up) solution while the house in under construction, possibly longer. Use both feet... HAHAHAHA, I'm stealing that one.
@michaels8400
@michaels8400 3 жыл бұрын
I think you nailed the problem; common mode current is flowing on the outside of the co-ax. The "balun" is really an Un-Un and will not isolate the feed line from the antenna. This makes the co-ax an integral part of the antenna. MFJ should include a CM balun (AKA choke) about 2 meters from the SO239 to decouple the feed line (counterpoise may not be necessary if 2M spacing is used) . Is MFJ at fault? Well, this keeps the cost down and the antenna still works when the un-un is at or close to the ground. Is Rick Littlefield at fault for not finding this in testing? Well, I'll let his conscience be his guide. I expect this problem to be true across MFJ's end-fed antenna offerings, although I haven't checked. Too bad you've disposed of the antenna and can't test it again with the CM balun (choke).
@terryjwood
@terryjwood 2 жыл бұрын
I found this in the instruction manual: "...do not install ferrite beads or a current style choke-balun at the input of the antenna matching network -- the blocking impedance won't be high enough to be effective."
@ChaplainDaveSparks
@ChaplainDaveSparks 6 жыл бұрын
Perhaps a choke balun would counteract the longer coax ...
@larrytruesdellsr.809
@larrytruesdellsr.809 4 жыл бұрын
Aren't a choke and a balun different? You can't make a choke into a balun, right?
@DavidVine-DOCVIDPRO
@DavidVine-DOCVIDPRO 6 жыл бұрын
Thanks for the detailed and excellent instruction.
@romanhar4151
@romanhar4151 3 жыл бұрын
Thank you very much for this interessting Video. I've learned a lot.
@Stevenfclark
@Stevenfclark 6 жыл бұрын
Dave do you feel the mfj-1982mp would perform any differently, I recently purchased it and plan to mount the box to the second story 20’ of my three story home and feed the connection point through the third story window 30’ and hang the end as high as possible in the trees ideally 60’ or more. I will run a ground wire from the box to a copper ground rod below the 20’ connection, I appreciate your thoughts and consideration 73 Steve KC1HYM
@davecasler
@davecasler 6 жыл бұрын
I had a hard time testing the antenna because my test configuration was different from what MFJ had in mind. We had some back and forth about it. It seems the antenna works well in a portable situation with the cable to the radio short and both the near and far ends pretty low and the middle up higher. I would not recommend the antenna for a fixed installation.
@Stevenfclark
@Stevenfclark 6 жыл бұрын
David Casler thank you for the response Dave, I have the 300w 132’ length antenna version and will be trying it in a fixed incline installation...wish me luck, I’ll share my results with you 73 KC1HYM
@zepplinc20
@zepplinc20 4 жыл бұрын
What's with the dollar bills?
@groundzero.
@groundzero. 7 жыл бұрын
Run the box at 8' or less and a 8' ground rod to the ground side and I will bet you will be good to go.
@davecasler
@davecasler 7 жыл бұрын
Where I'm sitting in the thumbnail is about six feet away from my station ground. BTW, I sent MFJ some suggested rewording for the manual.
@markstimson2633
@markstimson2633 7 жыл бұрын
Hi dave, i am really needing your help. i woudl like a Baofeng DM-5R. Or a Plus version, i know they say about timeslot problems, but as a RX only unit, can i listen in to repeaters? Thanks in advance
@davecasler
@davecasler 7 жыл бұрын
Yes, they should listen okay. But why not get a unit that actually works at Tier 2? The GD-77 for example.
@stevenlawhon3695
@stevenlawhon3695 6 жыл бұрын
Dave i saw another video(qrp) and it was grounded to a 2meter rod. Different model antenna
@stevenlawhon3695
@stevenlawhon3695 6 жыл бұрын
HyEndFed Mark III VE3BF from Ontario made the vid.
@grasshopper9313
@grasshopper9313 7 жыл бұрын
Dave I have just got the 8 watt GT-5TP Baofeng I want to use it just for Mobile use with a mag mount antenna ,My question is will the coax take the radiation away from my head when keying down to transmit ?? n2wjs Charlie.
@davecasler
@davecasler 7 жыл бұрын
Yes
@grasshopper9313
@grasshopper9313 7 жыл бұрын
Thanks Dave n2wjs Charlie.
@GenralNuisance
@GenralNuisance 4 жыл бұрын
I bought ($69.99) the antenna seems to work fine. Question: If the 20 gauge wire breaks, can I replace it with a 10 gauge wire, or will it not work? Thanks.
@davecasler
@davecasler 4 жыл бұрын
Yes, in theory. 10 gauge wire, unless it’s copperweld or steel core, isn’t any stronger than the 20 gauge wire. (I know that seems strange, but it’s the wire material, not its thickness, that makes it hang better.
@GenralNuisance
@GenralNuisance 4 жыл бұрын
@@davecasler Thanks.
@GenralNuisance
@GenralNuisance 4 жыл бұрын
@@davecasler The chart located here: www.bing.com/search?form=MOZSBR&pc=MOZI&q=tensile+strength+of+stranded+copper+wire+gauge Seems to state otherwise. Thanks. It's the PDF download .
@HamBone01
@HamBone01 7 жыл бұрын
Would you be interested in selling some of the antennas you have been testing?
@davecasler
@davecasler 7 жыл бұрын
I'll probably use them as giveaways at events that I attend.
@eddiesparks2782
@eddiesparks2782 6 жыл бұрын
Hello Dave!, Really enjoy your channel. I just purchased this antenna and am awaiting its arrival. Would the adversity with the 40m band be workable with a tuner? Or would that not be advisable. Unfortunately I had planned on having this for fixed station due to limited space. Thanks for any advice - best regards
@davecasler
@davecasler 6 жыл бұрын
This antenna works best in a portable environment with very short coax between the transmitter and the antennas little tuning box.
@Ivor_Barry
@Ivor_Barry Жыл бұрын
@@davecasler Since the shield of the coax is forming the counterpoise for the antenna, longer would be better. I've had great success with this antenna with a long coax (more than 66 feet) and deployed in an inverted V configuration. With an antenna tuner I've used it on all amateur bands, 160 through 10 meters.
@Scraws
@Scraws 6 жыл бұрын
I have the exact same antenna. Out of the box, each end up about 12ft, and center running through a tree, maybe 20+ ft up, I gat almost all of 40, all of 20 and 15, and CW Data portion of 10. It's a little long, and if I trim it a bit, I think I can fix 10 and 40. Here are my results. MFJ-1994MP Results SWR 2:1 or less: 10M - CW/Data Only. 28.0-28.5 Tuned Low at 28.02 -- 15M Full Band. Tuned at 20.7 -- 20M Full Band. Tuned low at 13.56 -- 30M No Match 4:1 -- 40M Almost 7.0 - 7.25 But Tuned Low. I think if I shorten it a hair, I'll fix 10 & 40
@davecasler
@davecasler 6 жыл бұрын
I'm glad to hear the antenna is working well for you.
@Scraws
@Scraws 6 жыл бұрын
Weird thing. If I remove it from the tree, and have it all in open air, I almost lose 10M. It goes super narrow. 28.5-28.7 is all that's better than 2:1. Weird. I wish I understood this stuff as good as you. 73.
@paulbaker9277
@paulbaker9277 4 жыл бұрын
Thank you Dave
@kenkramer6529
@kenkramer6529 5 жыл бұрын
Just excellent. Very helpful. Well done.
@dazzacam9307
@dazzacam9307 6 жыл бұрын
Im running a 9:1 with 88 feet wire ..Box is 32 feet above the ground under my diamond x300 with the wire slopped down and tied off to my back fence ... 80-10 metres through a tuner
@varoujan78
@varoujan78 4 жыл бұрын
the antenna is not on the ground in your last test its the feedpoint on the ground( also dont use the word "box on the ground" its the feedpoint on the ground.
@tubetone74
@tubetone74 6 жыл бұрын
Very enlightening. Thanks!
@grasshopper9313
@grasshopper9313 7 жыл бұрын
You might do a Study of radio waves effects at a safe distant from head ,Hand held safe or not so safe. n2wjs Charlie.
@davecasler
@davecasler 7 жыл бұрын
I touched on that in the video on RF safety that I did for the General and Extra video series. Check out my playlists.
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