HAM RADIO: Whats better a 64:1 or 49:1 Build and Test
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- Опубліковано 2 лип 2022
- Have you ever wondered which Transformer to buy or build should you get a 49:1 or perhaps the 64:1 dose it even make any difference ? Tune in and sit back because I have done all the work for you.
So which one is KING....
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Cheers
Mike - M0MSN
P.S. do not take my word for it, give it a go for yourself. - Розваги
Really interesting and very useful, especially the chart comparison. Thanks, Mike! 👍
As always great video, thanks for taking the time to teach us!
I just LOVE the clear cover on the 2-core 49:1 at the end...it lets you see it working! ;-) ;-)
Thanks for the solid experiment, Mike. As you said, it's a real close call, and it is dependent on your particular setup, though your results certainly favor the 2-core 49:1 box. Well done!
Thanks,
Great video Mike as usual, very informative ✋
Very interesting, comparing the 64:1 and 49:1 transformers. The SWR results would tend to slightly favor the 49:1, but SWR is one thing and how well they perform at transmitting and receiving RF is another! Like you say, jury has to be out on this one, more results needed.
I do like those boxes you've used with the clear lid, certainly lets you see that all is well in there, without the need to keep removing the cover.
Regards, David (M0XQZ)
why is everyone hung up on just the 49 or 64 to 1 debate?. yes if you have a 2 turn primary you can have a 14 or 16 turn secondary... but you can also have a 15 turn secondary which can give you a 56:1 Z transform too. (ditto intermediate steps for a 3 turn primary). Rather than just looking at the rig's swr try checking things out with a vna or mfj antenna analyser & read the resistance directly.... if it is showing less than 50 ohms out the divide down ratio is too high hence you need fewer secondary turns. If the R is too high you need to divide the efhw down more hence need more secondary turns. Note the impedance of YOUR efhw is also impacted by the earth side "tail" length too. The best set-up for one person may not be the same as that for another (ditto if you rebuild your own set-up on another base somewhere else). Given an odd open circuit turn or two isn't going to impact things much means you could just try having a switch on the o/p selecting the 14th, 15th or 16th tap. (or 18/19/20/22 for a 3 turn primary)
Impressive SWR numbers from all of these!
Enjoyed this one mike ,thankyou 👍
I’ve never seen a ham radio before. Wow they are cool looking. I especially like that spectrum waterfall graph. It looks so cool and reminds me of submarine warfare films like Hunt for Red October.
Thanks Mike!
Thank you Mike
Thank you that was great!!!
I love the video. Relative newbie to HF. Already have a CaHRTenna Artemis with a 2:14 toroid on 40m-20m. Antenna tuned to do FT8 portable and works well with my QDX. Printing an EFHW winder now on the 3D at the library. I am watching videos and saw an interesting idea you may want to test. The guy had an extra winding on a 49:1 making it a 2:15 ratio. I know my ratio is non standard and don’t care, because this is the way it is wound. Sounded like something you would try.
I have an idea from watching a lot of videos about this. My thoughts on this is the 2 turn works better across all the bands and the 3 turns works better in the lower frequency. But the 3 turns don't work well up in the higher frequencies. The 2 cores will give better all around and really do better with higher power, even around 100 watts. I am going to make my with 2 240-43 with 2 turns. There is a video where they took 2 transformers 1 to 43, then 43 to 1. Tested the power in and out of this. Did this with 2 turns, 3 turns with 1 core, 2 cores, 3 cores. 43 to 1, 64 to 1. Did a chart of all of it. Not just the SWR but the power out the other end after it was changed back to 50 ohms. This gave the loss in the transformers.
thank you for your post very interesting. :)
Mike, the impedance of an end fed half wave wire antenna at resonance varies between 2000 and 4000 ohms depending upon configuration (ie. inverted L, inverted V, sloper, etc,), height above ground, your local ground conductivity, and nearness to trees and other structures. If in your situation the impedance is closer to 2500 ohms, then a 49-1 autotransformer will provide the lowest SWR minimum. On the other hand, if your impedance is closer to 3200 ohms then the 64-1 autotransformer will provide the lowest SWR minimum. The optimum, (ie. minimum SWR) clearly depends on the specific antenna installation. However, as you point out, either will work quite nicely, particularly on the low bands.
yep, and well said thanks Steven
I love playing with the 49:1 on various ad hoc antennas I build from scrap pieces. Most end up in the bin :-) .
I still use the 64:1 you sent me. Thanks working great
Good to hear Paul, yes still use mind.
Mike you FINALLY put-to-bed my wondering which ratio AND number of primary windings would work best EFHW antenna!!...in just one video!! MY DEEPEST THANKS for your work and taking the time to show the differences!! GREAT VIDEO!! Best 73's, Ron, K6PAM. (How come whenever I pause to read a GREAT ARTICLE, your name is ALWAYS attached to it!! LOL!! THANK YOU, MATE!!
Perfect!
Unfortunately I am unable to operate HF from my home QTH so most of my HF is QRP/P. If I can I will always gravitate to my portable fan dipole (10, 20 & 40 resonant) but if I am going really lightweight my homebrew 49:1 is my goto choice. No tuner required on 10, 15, 20 & 40 and on QRP I have managed many QSO's. I make these so cheaply and would highly recommend them. Thank you so much for posting.
Similar results achieved here too, fairly inconclusive. I have a 20metre efhw attached at the moment, planning on a 40metre wire specifically for 80metres as the harmonics don't quite line up within 80 and 10metres. There are mods you can do to the wire, but for me a separate wire isn't a problem. From your video it looks like i'll be adding a ground, as noise is fairly significant here. Great video, Cheers Mike 73 de GØUSL
Hi Mark, yep 👍
Unless you have a common mode choke between the transformer and feedline, the feedline is part of the antenna, so YMMV widely. If the feedpoint is elevated, a counterpoise will be needed when using a common mode choke. FWIW, I began experimenting with roof-mounted EFHW antennas in the mid-90s and found that the transformer/counterpoise/choke combo worked best. Also, I built a 10m plus 6m EFHW (for my Motorola Syntor-X9000) and used, if I recall correctly, mixture 61 cores.
correct a choke is a must simple test squeeze up and down the coax near the transformer look at swr on analyser and if any change then you coax is radiating
Thanks for doing this test and sorry I missed this video only a year late you know what they say better to be late than never de W9US🤣🤣🤣
Great video as usual. I have been playing with 3 cores with the 240-52 mix and 12 ga wire. Sorry I don't know the sillymeter size, only bananas. 🤣 I have been having better luck with permeability and heat when my operator friend is at legal limit. Antenna building is an amazing hobby and endless.
So true, have fun.
Mike....it is great to see you posting again
Many thanks, work have been taking all my time recently. 🙂
@@mike-M0MSN work is one way God provides for all your needs.
You have really nice fitting and tight wraps around your core. I would very much like to see you do a video on how to get tight wraps like that. I have a dickens of a time getting mine tight. As to the battle of the transformer ratios: Many outside factors can affect the impedance of the radiating element of an EFHW, so I am not sure that saying 64:1 is better or worse than 49:1 is valid. The 49:1 matches impedances in the 2500 ohm ranges, and the 64:1 matches impedances more in the 3500 ohm range. If a person uses tiny diameter wire, say for a backpacking EFHW, then the 64:1 may be a better choice, as the smaller the diameter of wire for the element, the higher the impedance. Doing my own A/B testing with both versions and using the same wire for both, I could not tell any difference during normal radio usage. However, based on a UA-cam presentation by MM0OPX, I discovered that the popular ft-240-43 core is not the most efficient core. The Fair-Rite 2643251002 core has about the same mass and is about 25% more efficient. Again doing A/B antenna testing, I found the gain in efficiency to be very noticeable in picking up more stations. Just this moring is a good example. I tuned to 7.039.3 to see if I could hear the Russian "K" beacon, and it was weak, but readable. On the 240 core, the signal was missing altogether. Thank you for your great videos! 73.
The best solution will always be no UNUN, but an L/C coupler. Thanks for video! 73, Jakub OK1TCM.
Interesting is there any practical details on this anywhere.
Very interesting comparison. To stick with a 64:1, what benefit do you get from adding additional turns - say to a 24/3 from a 16/2. Has anyone tried a 32/4 ? It would seem to me that the additional windings would improve the efficiency, but I haven’t been able to find any information on it. Answers are probably over my head anyway.
Thanks for the video.
I was under the impression that a half wave end fed length of wire cut for some frequency had the end impedance range between 1800 to 5000 ohms, And so, we pick the average of this range as our target point or 2450 ohms for making an impedance conversion device or trans-match with, Using a 49:1 ratio. We'd test it with a 2450 ohm load. and expect to get a 49:1 impedance conversion from 2450 ohm to match our 50 ohm radios.
Yet we could also use an end fed half wave length of wire with a 64 :1 trans-match, and use a 3000 ohm resistor as a load to test it with. Here we target a bit above the average in that same 1800 to 5000 ohm impedance range. And expect to get an impedance conversion from the 3000 ohm portion of that same range down to the 50 ohms our radio seeks.
And we could use a 36:1 trans-match to pick a little below that same average range. and test this with a 1800 ohm load. And we'd expect to convert the 1800 ohm impedance down to our the 50 ohms our radio seeks.
But most of us target the average with what we consider the center or average of that range, at 2450 ohms between the range of 1800 to 5000 ohms. We can experiment towards either side of this center point if we want to. Height and set up can change things out in the field. You make it's length match for your location when you tuned it.
A half wave length of wire cut for our desired lowest frequency of use remains the same length in any case, once it is electrically adjusted to allow the trans-match to tune the lowest desired frequency to the 50 ohms we desire.
its the impedance conversion we do with the trans-match box and our windings of it As a fixed and unchanged working device, that converts this place (2450 ohms impedance for instance) on that over all range of 1800 to 5,000 ohms to the 50 ohms our radio seeks with a 49:1 made trans-match.
Any half wave length of wire we cut for any frequency we desire, will work the same on any similar box if it is properly made.wither 133 feet for 3.5 MHz, 66 feet for 7.0 Mhz, or 33 feet for 14 MHz.
The wire itself can vary in it's property's, so we do adjust it. just As you cut yours to gain the lowest SWR reading for the 3000 ohm range with your 64:1 trans-match. It is electrically adjusted as a electrical half wave long antenna, its also adjusted as a half wave length of wire for use with a 49:1 now, or a 36:1 trans-match in those impedanceconversions as well. The issue is that you targeted the center of that range between 1800 to 5000 ohms impedance when you installed the 49:1
just as any wire length is the half wave length of "some" frequency, I have cut a length of wire and used the same 49:1 trans-match for a 8 MHz marine band antenna. The wire actually determines the lowest frequency of use, and the trans-match box is a fixed device or tool, that then makes it's designed impedance match our 50 ohm radios. My wire was 58.5 for that 8 MHz marine band antenna. A half wave piece of wire cut for that frequency.
With ferrite material cores, those harmonics we can also make use of on other ham bands, I see as a free bonus.The older iron powder cores did not have this bonus.They were single banded half wave end fed antennas. Yet still a half wave length long piece of wire. And the same 49:1 impedance conversion. I have made those too.
I see it like this, on an antenna analyzer, that low SWR Dip will be somewhere, I find it and then move it to my desired frequency, this is tuning the wire as an electrical half wave length for that frequency, By adjusting its physical length so it matches the electrical length of a half wave length antenna for that frequency where the low SWR dip aligns with the analyzer on that frequency.. I already know the trans-match box works. I already used the correct load resister to test it with.
Brilliant and very insightful. Many thanks for your post Possumn
Interesting
Posted a short video with a few of my saved NanoVNA SWR curves. The difference is not huge... 1:64 slightly better SWR on 80 and 40m... 1:49 slightly better on 15 and 10m with 100pF compensation capacitor and FT114-43 on my shortened EFHW with 110uH coil - Mind you the way you hang up your antenna: Sloping (+angle) or straight, height above ground, how many 90° turns to squeeze it into a tiny garden, has a much bigger impact imho.
73 Tobias and LabCat Amy 🐈⬛
For low power and QRP use 64 & 49:1 are great.. But if you ever are going to AMP up 500watts to legal limit go with the 9:1 UNUN for multiband use, less chance of compromising the cores..
...the common mode choke comes in when you are unable to bring the coax away at right angles or back, behind or away from the radiating element and not parallel in any way, so then you would need a separate wire for a counterpoise. Then the coax needs a common mode choke to make it no longer part of the actual antenna.. The coax then becomes just a feedline. If the coax shield is also the counterpoise, which is acceptable (mine is 65' of LMR 400) which is the case in my situation you need to do nothing.
The take away from this is... 2 43 mix cores are a bit better than 1, higher power levels need 3, likely because voice peaks even at 100 watts or more do not come close to saturating the cores which start to raise the curie temperatures. 43:1 is a bit better than 64:1, seems to give a bit better overall match (50 ohms to 2400) (Mikes coax length, type and antenna length is unknown... 130', straight line or L shaped in some way?) the use of what looks to be #16 wire , is smart, reduces simple I/R current losses at the low Z point so 100 watts into 50 ohms gives a max 1.4142 amps in the balun windings. If you put 100 watts into the balun and you can detect little or no change in temperature (a calorimeter might work here) you have a very efficient 49:1 transformer/balun... Virtually all losses in a balun are in the form of heat caused by Z mismatches, thin wire for windings and/or core saturation at various power levels. Mike has this black art mostly figured...
The earth ground can be at the balun if convenient or at the rig, it's there to bleed off any DC static build up on the antenna, particularly on dry days and which can cause noise.
Richard... VA7AA
With the 49:1 balun my 40mtr wire resonated on 3850khz , its fed with 5 mtrs RG58 at 3mtrs agl going over 15 or 16 mtr tower , replaced it with 64:1 balun , resonated on 3666khz , JUST REPLACED BALUN. ZS6AF
Thanks for excellent in formation. I plan to use my 40m QRP cw ( 7 W ) transceiver with EFHV antenna. Does it matter which one I choose 49:1 64:1 given QRP?
Hi @Mike-M0MSN thank you for your hard work. I'm wondering what is the antenna length? shape ? and is it modded once in a while? thanks..
I've been studying this myself too and trying to decide what yo do. I think the three turn primary is what screwed the pooch for you on 10m. That's 50percent higher inductance.
I think from your experiments that I'll use 2 cores and 49:1 for my portable POTA EFHW I'm going to build. I may try 64:1 first and if necessary back off a couple turns if necesary.
Yep agreed :)
I've made both am likeing 49.1 better on the SWR it below 1.5 on all bands 80 to 10m at 133 feet wire I would like to extend it to top band in the future. Great video mike
Hello Mike, another great video mate, I've not missed one so far but a question for you.
What length wire are you using?
Ive recently purchased a 49:1 unun, on test i used a 19.6m length of wire with no counterpoise. Results from 40 up were 1.4 to 1.8 but 10m was above 2.5. I've now ordered 50m of Dipoflex wire by M&P. Im hoping to run a 133ft length with the 49:1 unun, this should give me 80m with a bit of luck but I'm wondering about a counterpoise at that length.
Would you recommend the counterpoise and if so, in your estimations, what length?
73, keep those videos coming, I'm running out of things to watch.
Mike, some folks on this side of the pond put a capacitor in the exact middle of the antenna to lower the resonance on 10, 12, and 15. Have you used an analyzer to see where or how far up 10 meters is? Steve Ellington has done a lot of testing of the EFHW on YTUBE. I bought some parts to build one, but my health and needing to get my home rebuild done got into the way?
Greetings Mike, Curious question - What length antenna are you using? There is as much chatter about antenna length as about turns ratios and the 100 pf capacitor! Oh, and let's not forget the core mixes and colours ...
73 de kg5rk
The first 2 turns does work as primary AND Secondary turns?
And which is the best, depends on the environment and antennawire etc.. It will never be everywhere the same.
Hey.. Do you happen to remember where you got the box and magnet wire from? Can't really find anything similar
Are there any videos of you making the 49:1 2T 2C unit? ........ I know you used a 43 mix if not mistaken, but what size were the cores?
Now you tell me! :)
Ha Ha
Interesting, picked up a 64 to 1 from Cal a while ago, not tried it out yet though. What is the approximate length of your antenna Mike please. Must get a 49 to 1 sometime.
im after an unun for 160m EFHW and was wondering if you'd any info on which cores/windings are best? thanks
Mix 31 if my memory is good..
I restore old tube am radios and sometimes the capacitors in the if cans have silver mica disease so we take the cans out cut the original mica's out then add a pair to the legs after reinstalling some radio schematics give you the internal capacitance some don't ,most people say just throw a couple of 100pf in there but sometimes the sensitivity hurts what I do is install two adjustable caps do an alignment on the radio then take them out measure them and then put the right mica's in then realign. My question is has anyone tried this on the unun's to see if there is a better match than 100pf on their given antenna configuration?
9:1 is more efficient I tested for a single band, but 49:1 is good for multi-band choice.
nice test. if you fancy making me a 49/1 twin core let me know
Lol
Any reason why u cant connect 3 or more halfwaves on same feedpoint ? A 40 mtr wire as halfwave for 80 mtr then a + - 27mtr for 60mtr 5400khz plus minus , then a 14 mtr wire as a halfwave for 30 mtr ? We do that on 50 ohm dipoles . ZS6AF Johan Visagie
Great job mate. What length wire used? FOO WAS HERE sTePhEn - Queenlsand OZ
Hello Mike , thanks for you nice video's
I have one question , i wil try to make the 49:1 with 2 cores but is the winding the same as with one core?
73
Lauw
Yes, correct
Just about to make one of these to a good friend of mine and is very grateful for your wonderful video! I Was wondering 64:1 or 49:1, dual or single core... Seems like a single 240-43 will be good enough when using 100w, the loss compared to a
dual setup seems to be negligible.
By the way, will there be any follow up on the frame antennas on their performance?
Thanks for your great videos! 🙂
73's sa5vox
Yep, and thanks 73
Did you have any form of compensation coil on the wire to change the tune for the higher bands?
Nope, I will do an update soon showing the complete installation
Mike, SWR under 2 is... puff!
WHAT of this coils listen best ! send best, work best !
I am back to 9:1on 31t 40,5 meter line , that work very well.
I am going to try a random 9:1 next.. 👍
@@mike-M0MSN Nice
What was the vertical wire length in these tests. 1/2 wave at 20m ?? i thought i heard it but missed it in re watching. Jay
Half wave for 40 so 20M long. lol
For someone who experiments with antennas so much, I am amazed you don't have a nano VNA. They eat the MFJ analyzers for breakfast. BTW if you want meaningful results you should measure at the feed point or via an n * electrical half wave of coax or better still if you have a VNA just calibrate at the antenna end of the feedline. I can highly recommend Alan W2AEW 's video series on the nano VNA
I have a HP VNA and all my coax lengths are Andrew FD4 at 42 or 20 metres long depending on the antenna. But you have a good point. Thanks
Why not put a switch to add or exclude the last two turns on the secondary, so you have both 49 and 64 on one core? It would help tune different wire lengths I think.
You do not need a switch, a tap on the coil will do it.
Mike, what length did you cut the 64:1? The length worked well on both transformers including the 49:1.
Half wave for 40 plus a 110uH coil with 1.3m tail
@@mike-M0MSN Mike, was it the coil you built in the recent video and it was less than 100uH or did the coil actually measure 110 uH? Garry / WD0DUD
I don't see the twisted pair on the first two turns... Are they not needed?
Maybe that is why mine fail my testing..
No you do not need to twist if you tap. :)
With the 64:1 and to a lesser extent 49:1 transformer, there is evidence that what your seeing is transformer losses rather than actual transformation of the impedance. Estimating the impedance of a long wire at 500R, then 500/64=8R and 500/49=10R, but these values alone would result in a poor VSWR in both cases of about 6:1 the use of an antenna analyser showing real and imaginary impedance values would give the true result including losses.
It's like the question, "What's better? A 10A fuse or a 30A fuse? Which one should I use in my application here?"
True
I have a question... since I also want to remove the noise a little. If I would ground the antenna... my issue is that mine is in the attic. Wold it influence the antenna in a way maybe if I run a wire down to the ground where I have the possibility to ground it ? Is nice that yours is actually close to the ground point 😁. 73 DE YO6DXE.
I wouldn't run a ground wire ( it more like a counterpose) try a common mode choke to reduce the noise. it may help?
@@mike-M0MSN That is what I thought about. Thanks Mike. I must buy some toroids and I will order one to make the choke as well. 73 DE YO6DXE.
What was your antenna wire length please?
Im guessing its a halfwave on 40 meters or perhaps 80...
Half wave for 40 plus a 110uH coil with a 1.3m tail.
And these are all running your 20.35m wire with the 110uH coil + some leg of wire?
Yep
You say the SWR with the 49:1 is ZERO. No, it is 1:1. Not "1", but rather "1:1". OK, I am picking fly s*** our of the pepper. Shame on me.
As for your results, I believe they are correct. It appears that as you add turns to the transformer, the higher frequency performance suffers, probably due to the increasing series winding inductance and inter-winding capacitance. These two properties form small LC circuits in series with each other, making this is an extremely complex problem which may not always intuitive. You have done a reasonably good job of testing these configurations and the results are what they are. Good video.
I like to go to websdr's all over US and elsewhere and xmit cw. Can see immediatly how well an antenna or xfrmr is doing. These 64-1 9-1 49-1 etc are so confusing when they dont tell you if its impedance or number of turns they are talking about.
Just remember that it is all about the square root 14 turns to 2 prim, = 14/2 = 7. 7x7=49. 49x50 (50 ohms) = 2450ohms (EFHW)
ratio 56:1 is the best optimum if I.m correct in turns it will be 15:2 which gives 56.25:1 (close enough) of course everything depends on the core (31 vs 43) as the same ratio can be done with 30:4 but then an inductance becomes a low pass filter if the core is too efficient. (What you could observe on your 64:1)
I always wondered about the median option of the 15/2-56:1. It seems to transform a wider range of a likely high Z presented by the EFHW. So, I did my version of the Chameleon Lightweight EFHW as 15/2. It worked great and tuned everywhere quite well. (Besides, It looked to me like that’s what Chameleon was doing) btw..a 240-43 was used.
Do you need to earth an end fed transformer ? This still confuses me.
No you do not need to earth an EFHW, but it does help with noise and VSWR..🙂
How long was the antenna?
Thanks
i'm wondering about that too
but how effective is an endfed antenna against a dipole antenna on transmit and reception
I can answer this question.... I just put up my first end fed with a 49:1 and 130ft of wire, the noise floor is gone compared to my inverted Vee fan dipoles. Bands are in pretty bad shape today to give results on TX, but I'll be back to update this post when I get results... but I think most people are going to tell you the same thing.... the end fed is so quiet !
Yep all about what’s best for you.
hi mate, what toroid toroid type vs mix value. thanks
Depends in this one it is a 240/43 but you could use a 240/31
it would be interesting to see the 2 put up against pskreporter to see if there is any impact on getting out.
Thank you for this. I don't think it makes a difference personally, with my setup. Is there any chance you can just simply point a camera at your TS890 and make a nice long video letting us hear it receive different stations, weak and strong? Let us listen to band noise, and filters being used. All of this helps, especially considering there is a genuine lack of videos that do that with this radio. You have a brilliant radio and I'd like to properly hear the receiver as I'm sure many would. Can you do that? It would be much appreciated.
Well that sound like a great idea, yep coming soon.
@@mike-M0MSN Very kind. Such a lovely radio and everyone is used to their Icom 7300 and they think all radios sound the same. But alas, they don't! Thank you so much. The 890 has always intrigued me. I've ssid it before, you are the Jermey Clarkson of radio edits!
I have questions: Did you build the 49 to 1 transformer with a 140-43 toroid? And: How long is your wire you used for the test? And how did you build the counterpoise wires? How long are they?
I’d be interested to hear.
240 43 types
@@mike-M0MSN 25% rate of answer ;) Tnx.
@@DO7OO that's because the other answers are in the posts, but if it helps halfwave length for 40 plus a 110uH coil and 1.3m tail..no counter just earthed.
What was the radiator length here?
20M
Mike you mentioned your antenna was "cut" for a 64:1 -- what do you mean? 📌📌📌
I've been looking at many videos of EFHW and never heard them mention changing the antenna length depending on whether using a 49:1 or a 64:1.
I have seen them mention about the height changing the antenna impedance, which determines whether to use 49:1 or 64:1 -- If memory serves the high antenna was best with the 64:1.
Thanks for the comment, that maybe the case, however, as the length of the EFHW, was cut using a 64:1 at the end, to set the VSWR. I had no idea if the length of the wire would be correct for a 49:1 transformer. It turns out that it make little if no difference. 👍🍌🍌
@@mike-M0MSN Thankyou Mike. Yeah - that makes perfect sense.
Just made my UNUN a 59:1 - taking the middle ground - as from what I've seen the impedance goes up with height - but I'm still not quite at 0.6 WLengths so did the 59:1 to compromise. We'll soon see how that works out. I'll be trying out a different form of mid-span capacitor on it to bring the low F side into the 75M phone band as well.
Appreciate channels like yours that share your experiences.
The thickness of the antenna wire plays a role in the difference between 1:49 or 1:64 transformer! A thicker 14 awg antenna wire will be about ±2500 ohms while a 16 awg antenna wire will be ±3200 ohms.
Lots of TX with no ID!
Where did you get these parts for the transformer
eBay
I guess I should have worded my question differently what is the name or brand of these parts on eBay
240 43mix for the toroid and any case that will fit. All the bits and bobs are none branded.
What I don't understand (as someone who is just starting out) is why, after over 100 years, are we still jacking around trying to figure out what works?
I would presume that what works well for one, doesn't necessarily work well for another.
It is all about experimentation and finding out what is best for your station.
It is also good if the bands work right to allow for testing of it all when you can!!
Yep, would agree with Gary, I have both the 64 and 49:1 and a DX Commander ABV, a couple of mono band dipoles and each antenna works better than the other at different times…. Go figure..
If we just want what works, we would just buy the products for sale. The homemade solutions and experiments are for learning and understanding. With this kind of hands on education new leaps are made and sometimes new creations are the result. Callum’s DX Commander was built upon pre-existing concepts but he was inspired to try to build something new from our community’s collective theory and understanding. Not to mention, the pride of self built tools can’t be understated.
Because everything in an antenna affects everything else. Placement above the ground, nearby metallic surfaces, distance from the ground of the Unun, toroid type, number of windings, coax feed length, grounded or not, shielding on the antenna wire, type of coax, etc etc. It’s a system and you can’t change one thing without causing something else to behave differently. Dave Casler says the rule of antennas is that “everything affects everything”
I have nothing against you, Mike, but it takes a lot of time and money and patience to work on elecronics for amateur radio and sometimes it makes people ill both physically and mentally. A lot of work and effort for a ver meager sense of accomplishment and actual scientific results. On another note however RF electronics and the HF band have always been interesting to me. I have spent a lot of time around it, where a close family memebr of mine has been arounf audio so VHF and frequency modulation. Where I am use to the sounds of AM and SSB and static in the Hf spectrum. Regarless of how much information I have availbale to me, modes like SSB are challenging to really understand.
What about 60m and 160m?
Not tested ☹️
You could have done the same thing with your 259b without transmitting a signal, assuming you have any kind of antenna analyzer.
Yep, but where the fun in that? (did use my VNA off camera)
Thank you for showing us all how NOT to do things. Everyone of those transmissions were done illegally with not a single ID. during the entire video. The jury may be out as to which balun is better, but the jury is not out on all the illegal transmissions. GUILTY is the verdict. Have a great day.
I don’t know what country you or the author is in, but in ours, we are allowed what are termed “short test transmissions” without ident. Why don’t you go down to your local supermarket and get yourself a shiny plastic police badge, and pull your socks and shorts up very high! 😊
Richard sounds like a grum/py 0ld man wanna be p0lice but end up as a keyboard warri0r 😂
Thank you for your input Richard, Just because it is not in the video does not mean it was not done, we are allowed to make a call to say that testing is going to take place and then continue to test without giving a call sign, just as you are not longer require to give a call sign on every over in day to day rags Identity is only require at the start. however if you wish for the video to be 20 minutes longer than needed, so that you can hear a call sign I will comply.
Tosser.
Sir, your screws (and your nuts...), should be stainless steel!
Yes..... lol
With the exception of 7.10Mhz being 1.15:1 as opposed to 1.1:1 (practically imperceptible ... 99.52 watts vs 99.77 watts out of 100 watts) the 2 core 49:1 tied or beat either of the 64:1 transformers.
So, for those of us unwilling to invest 15 minutes in this escapade, what's the verdict? Also, you guarantee that this will be identical to my station layout?
..exactly! That's my point!
Well if you watched it you would have the answer. Horses for courses
@@mike-M0MSN Mike, I was a little harsh and I apologize. After all, I certainly did not even produce a video. I stumbled on a pair of videos by DL2MAN where he summarizes his testing much like I mentioned.
m.ua-cam.com/video/nNzTf1F12BE/v-deo.html
What a pointless test. Click bait. Basing "better" on SWR? Do hams never learn?
Well you did not listen to my comments then…
@@mike-M0MSN Mike, There always seems to be one person out there posting negative comments with nothing intelligent to add... we appreciate your efforts to test both the 49:1 and 64:1 transformers, the data you provided and your findings - Thanks for the work you put into this video!
@LW The primary purpose of the high ratio Un-Un is to provide a better match from the high impedance end-fed half-wave antenna to the 50-ohm coax, so the very first parameter of essential interest is how well it matches, precisely as indicated by the measure SWR across the bands of interest. Just because there are other parameters to consider, doesn't knock match from its position as arguably the initial parameter to achieve adequate results. If you choose to ignore it, then just skip the Un-Un and connect directly. Good luck with that on a half-wave. Yes, yes, yes..., after matching, then you go into other considerations such as loss.
Thank you Mike for the work you have done ! Vy73 DL1AQU Michael
Fine business ordered some parts today for a 49:1 , everything but the wire ? Can you get by with insulated 14 KE4TDG. 73
This video & comments section was super helpful! I would give it 2x likes, if I could. Thanks, again! - 73, Chris V. de AC3Q
Glad it helped!