HAM Radio: Callums 64:1 a EFHW for the DX Commander..
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- Опубликовано: 10 окт 2020
- Callum (The DX Commander) asked for a 49:1 or 64:1 End feed half Wave (EFHW) so he could test one against his DXC All Band Vertical antenna, So I built him one... :)
Fair-rite 240-43 core
1.8mm enamel coated copper wire
Weather proof plastic box
Stainless steel M6 nuts and bolts
SO239
100pF 3KV Capacitor
16 Turns, 2 are coupled
Please subscribe :)
Many thanks
Mike M0MSN 
Развлечения
Another great video. It does demonstrate the advantages of having the correct tools. Like that little device for removing the enamel...
RUclips is repeating all your episodes, it always looks so easy watching you. You get more done by accident than I can with a month's worth of planning.
MASTER & masterpiece!! Bravo Mike!👍👌
Thank you 👍
Great little build. I enjoy watching your soldering skills..... I need to sort that out!!
Thanks 👍
I use one of these (49:1) and they work great. I have about 250 feet of wire attached to mine so i can sort of work top-band. It must have worked because i spoke to Callum with it at only about 20 foot high on 80m. Highly recommend people giving this system a try.
Don't really need 64:1 but always enjoy your content Mike, so watched it regardless! I am thinking of making a doublet and therefore may need a 4:1 (I think??!!), and also an EFHW so possibly a 49:1 at some point. Keep up the great work Mike, especially re the hands-on content as it is some of the best I've seen. No messing, no time wasting pre-amble, no bs.... just straight into it. #kudos. John - 2W0JVB 👍
merci pour ce beaux .propre .et joli travaille comme d habitude 73 a plus
Beautiful.
Sweet Mike! I built a 49-1 with two Amidon FT240-43 cores. I wound mine counterclockwise like you did but being paranoid I unwound it, wasting that wire and wound it clockwise, as if rf knows the difference, and housed it in an outdoor utility box. So far I've only used it on receive and measured the Rx on receive into a 138 ft piece of wire. At resonance, in the low end of the 40 meter CW band it was at 200 ohms but close to 50 ohms on 20 meters. de WD5L
left, right, counterclockwise, clockwise it's all bananas. LOL
Nice job as usual Mike 👍
Thanks 👍
Nice work Mike 👌👍👏
Thanks 👍
Apparently reading on toroids if you doubled or tripled the efficiency goes up a bit. Going to test this one thanks for sharing Mike!
You are welcome
Excellent video. The only issue with the DX Commander being deployed portable, is the counterpoise wires. Poles themselves are awesome, but we always end up tripping over the counterpoise wires when it's setup near the camp.
I hope Callum takes the endfed seriously.
Thanks for sharing this video.
👍
@DX Commander Awesome 👍
EFHW does not need counterpoise wire.
@John Cliff a 50 ohm dummy load has great VSWR...
Nice Job 7351, I was made one 9/1 with a toroide of an old TV. Works fine without ATU 160 meters 80 meters 40 meters not so good on 20 meters not so good on 11 meters but works well from 28 Mhz to 30Mhz. TKS fer sharing. 7351.
Very cool!
Neat job.
Thanks!
These are very good to Use in a HOA because, A wire from the a House to a Tree is not Visible to them to from the Street!
Nice........................
ottimo lavoro !!!!.
Grazie
I love your videos. You probably will do this before it is finally installed but, on my home made transformers, I use two FT-240-31 for a broader frequency and power range and also vent the sides and create a couple of 1/8" weep holes in the bottom covered on the inside with small pieces of plastic screen glued with hot glue.
Thanks for the tips!
Do you have good luck with the type 31's? I use type 52's and am very impressed
👍
I've made one just like this but I get a short when putting a meter over the SO239, is that expected considering its the same bit of copper wire soldered between the center pin and the ground having had the enamel sanded off? Cheers.
keep reading the comments have answered this somewhere Thanks 👍
Smart job Mike! What do you recon it's power handling capabilities would be with 1.8mm wire and the single 240-43 toroid?
100 to 200 watts
Don't forget the choke. Because you added the 10m band with the capacitor here is a suggestion. Using 2ea FT240-61 toroid use RG-58 wrapped 17 pass throughs AND leave a tail on the output side of about 4m-5m with a PL-259 to connect to your new 64:1 auto-trans.
Have a bulkhead SO-238 on your container for your main feed coax to connect to. FYI- using this choke you DO NOT need a ground counter poise.
Thanks for the great tip.. 👍
Can anyone point me in the right direction on how to model baluns and ununs using either eznec or similar software?
I've seen both 64:1 and 49:1 ratios specified for EFHW antennas. Not sure which one works best.
Much of a muchness one feels.
Hi Mike. Do you have a part number/suggested retailer for the weatherproof box?
Ebay
Nice build. First thing he'll do is peel off your stickers, put his own on and flog it on his website 😂
LOL
Sweet little build Mike. The 1.8 mm wire works out to about 13 AWG so call it 14 AVG. Curious what type and value capacitor you are using?
disc ceramic 100pf 3kv
Nice build, I'm about to make something very similar. Nice n easy to test as well if you have a NanoVNA. One question though, where do you get the boxes from? Everywhere I've tried either doesn't have that type or is out of stock?
eBay. 👍
Who else 'blew' on the solder when he put the capacitor in place !
yep
64:1 will work well on 80/40, but poorly on 10/12/15. The impedance transformation is too high for the upper bands. I use 14/2 turns or preferably 13/2 turns ratio
Thank you 👍 will give it a try
Your a brave man, if I dared to do this, on the kitchen worktop my wife aka Atilla the Hen would kill me. 73 Paul M0BSW
She is a good catch... :)
@@mike-M0MSN Ahhh a switch from a hen to a fish. Right smart change. 😉😊😏🙄😇
I was wondering as a seasoned radio ham how many radio station kitchen worktops have small drill holes in the top? Oops sorry love
Bravo, from yc0log, juliet kilo tango, Jakarta, Indonesia
Nicely done as usual Mike. Please can you say what material your eyelet tags are made from. I have aluminium ones, which of course don't solder.
All the tags are Tined Copper from RScom
Very nice. I made a 49:1 14 gauge enamel wire using 3 type 240-52 toriods. I also have the DX Commander. My end fed is in inverted L. Up 35 out 90 ish feet. I have found very little difference on receive between antennas most of the time. 40-10. I don’t have the 80 on DXC yet.
Why did you go with 64:1?
found it to be more stable and better for 20m - 10m Bands
hy mike, How long is the wire behid the 1:49 and no coil in the line ?
20M of wire before the coil and 1.5M after the coil.
Tnx Mike.... fine Projekts.....
I thoght you would test it showing the return loss etc. Nice former
May be in the next video
Nice work, neat tidy, well detailed...does it work well?
Yes, absolutely
How is performance and QRM level ? and how much meter wire use 80 to 10 M antenna ? 73 TA4AU
Take a look.. g0kya.blogspot.com/2017/01/a-shortened-multi-band-end-fed-half.html
Mike, you operate that hot glue like you been to way too many women’s club functions... just sayin’ I’ll be gluing my cores into the 49:1, I just built as well.
I’m a bit confused with this dx commander Is it the pole or any wire antenna it’s supports ? , if I fixed a slimline made from 300 ribbon to the top of one would that be a 2m dx commander as well😳
Well, I guess that would be a slim Jim for 2M supported by a DXCommander. In the same way the 64:1 is. I do hope that you are no longer confused 🤔
The Dremel ..YES....I'll never use a sandpaper scap again. Well not quite never.
HaHa
How powerful is this UNUN?
Up to 400 Watts PEP
43 mix is better than the 31 for HF. Upper hf (12-10-6 meters) and above use the 31 with 1 or 2 less turns per side on the balun.
Hmmm did you say whether you are winding a 49 or 64 to 1 coil. How many wraps did you make on the toroid? No weep hole...
I have used both and, in my opinion, the 31 mix is preferable to the 43 mix. This is especially true if your intend to run more than 100 watts or have long digital or cw qsos. The Ferrite toroids will not return to their original state if the temperature gets close or exceeds the Curie temperature. The 31 mix has a much higher Curie temperature than the 43 mix. Additionally,, the 31 mix is more linear over rated frequencies than the 43 mix. Check the Fair-Rite or Amidon data sheets.
@@hankhamner3671 I thought the 31 was for chokes. Hmm,
Gonna have to get you Callum both a power screwdriver...
Cheers I’ll watch the post 😂😂
Mike, always enjoy your content and enthusiasm. I am wondering if i could use this design at my home. I have had to take down my vertical from the bungalow due to complaints. Maximum height at bungalow is 7-8mtrs with a 16mtr run to end of garden max height at that end would be 3mtrs?
Cheers
Yes, absolutely
Why a 64:1 and bands to be used? Thanks.
I prefer the Higher Impedance of the 64:1, 80M to 20M bands
@@mike-M0MSN I got a 9:1 with results so the internal tuner can handle. Now, ordered and received the 49:1 and planning to install it and test. Wondering about the 64:1, but if I decide to test, will do my own this time instead of ordering. Thanks.
would a 240-31 core work ?
this doc should help reeve.com/Documents/Articles%20Papers/Ferrite%20Beads/Reeve-Hagen_FerriteBeads_P1.pdf. but Yes
@@mike-M0MSN cheers Mike 👍
I have no idea what this vid shows. Have no ham equipment. Not a ham guy. I would like to know if there's a way to get internet in the middle of nowhere via ham somehow. Closest cell tower is 18 km away. Thanks.
Yep and you do not need to be a Ham, see link www.wimo.com/en/antennas/gsm-lte-mobile-phone-antennas/antennas-for-4g-lte/60072
why not use a vice and a drill motor ?
great idea
Put on another sticker that says warranty void if seal broken!
LOL.
For a Ham that's a challenge not a deterrent ; )
That cap will say byebye on first digital mode. You need a bigger gun :) Guess hos I know :) - 73 LB6CI
lol, cap upgrade needed
@@mike-M0MSN Yes sir 😂👍
And what size cap do you recommend?
Well I have had a 150pf 4KV cap in my EFhW for over 3 years now without any issues, (350 max watts) but the higher voltages the better.
Why 64 to 1 vs. 49 to 1?
I prefer a 64:1 (3200 ohms) as this transformer gives you more head room.
@@mike-M0MSN sorry to sound stupid.... What do you mean by Head room? Do you mean useable bandwidth.... Does 64 to 1 allow for a shorter wire?
No, the end of a halfwave wire is around 2000 to 3500 ohms so a 49:1 works as 50x49 =2450 ohms at the antenna connector and 50 ohms at the coax connector. Now if the EFHW wire is at 3000 ohms the 49:1would still work but with a higher SWR. I use a 64:1 as I feel it works better as it allows for a higher impedance.
Have you tried a 31 mix toroid? K9WWW
No I haven't, I will take a look..Thank you 👍
I think you missed 1 winding. You only count the wires passing through the middle of the toroid. So I only count 15, should be 16 correct? Half of 16 is 8 and 8 squared is 64. 56.25:1 is what I think you have, no?
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