The Mad Dog Coil, DIY Wolf River coil alternative.
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- Опубликовано: 31 июл 2024
- To purchase a fully constructed Mad Dog Coil go to maddogcoils.com.au
This is my second do it yourself coil. I activate parks regularly for the POTA, WWFF and Beaches on the air programs and this is my main goto antenna. Total number of turns of stainless wire is 104 which uses up the majority of the 15 metre length.
Main parts list:
-All threaded poly riser, 300mm x 40mm (it is a 1.5 inch inch BSPP, British standard pipe parallel). Available from Frithys Rural in South Australia. If you want Peter’s from Frithys email address I will be happy to provide it over email. Peter will ship globally. You can find my email address by searching VK4KC on QRZ.com
-1.5 inch cap, threaded (Philmac brand) item number 4814101. Available at Bunnings hardware, plumbing suppliers and Frithys rural.
-Stainless steel T-bolt hose clamp (44.5 - 50.8mm brand EnduraSeal) item number 0110772. Available at Bunnings hardware.
-Tie wire stainless steel grade 304, 1.6mm x 15 metres (brand Whites). Available at Bunnings hardware.
*Update …. A few comments from U.S. based ham’s have not found a U.S. domestic supplier for the threaded riser and end caps. If you would like to build you own then other ways of doing it are described in these videos:
• MY DIY 20-40 meter Air...
• (20) Antena vertical...
In the USA, the threaded poly pipe seem to be a rare product so I figured out that Lowes and similar stores that sell PVC and steel pipes will cut and thread any pipe you buy. They typically thread steel pipe but the same machine will easily cut threads into a PVC pipe. Simply buy a 1.5" schedule 40 pvc pipe and have it threaded as far as you need it.
Have you made one of these coils yet? How did the threading work out for you? Did you find any threaded end caps?
This video only having 13200 views (as I'm watching it) is a disgrace. This is an absolutely FANTASTIC build with everything explained PERFECTLY! This qualifies as ham radio ASMR. Brilliant, friend! Hope to see more like this!
Thank you very much for your most kind and encouraging comment. I will have a another video of the “lazy dog” antenna in about 3 weeks time.
Thats a stupid comment about it being a disgrace.
Is Ham radio and CB radio different or regeraded differently in Australia? Back in America / Canada I have been exposed to some of the same theory and electroincs. On the air i once heard that there are some more abnds and longer distances available with amateur radio. It was a short conversation in CB Radio?😀🗨🗨💥👩🎤🛀👤👩👧👦
@@user-yg4eb8bn8q Yes, at least here in Australia, it's a big difference. CB, no licence needed, only two bands both short range except under just the right conditions. Whereas amateur radio, there's three licence levels, progressing from Foundation (easy) to Advanced (advanced!) but even the basic foundation gives you 6 bands that give enough options for good comms over 0 to 1000s of km, still depending on conditions a bit😀
I totally agree!
I’ve seen a lot of ham Radio builds on RUclips and I have to say this is one of the better ones. Very nice looking piece of equipment
Nice! Clean design and great presentation.
Best build ever, I just finished one and it's looking so slick. Thanks Marty. My next one will be the jr mad dog.
Absolutely a top notch presentation, the tutorial has left no stone unturned with a clear and precise explanation of every aspect of the build... Well done, its been a outright pleasure to watch and follow.
wow! 10:03 😍 awesome garden! 💜👍 love the lack-of-lawn, and how super fancy it looks!
This video is a perfect example of why I watch RUclips. Great walkthrough and description. Thank you.
Waving at you from NW Georgia, USA
KD2MOT -Matt
Without doubt the best idea for home built variable loading coils. Thank you for this video! Rob, VK4SSE
I’ve seen a lot of ham radio builds on RUclips, and I’ve got to say this is one of the better ones. very nice looking piece of work
Hi Joseph, thank you very much. I appreciate it. Kind regards Marty VK4KC
This is absolutely fantastic. Amazing excellent build.
Hi John, thank you for your positive comment. Cheers Marty VK4KC
Bloody brilliant 👏🏼 what a great concept and execution.
Thanks Scott. Tested it today in preparation for Dorrigo park fest. Tunes up well with a 4.5 metre counterpoise wire from the antenna draped over the front of the car.
Awesome detail on this build; thoroughly enjoyed it. Now its on my list of must do.
Glad you enjoyed it.
Excellent video. I've wanted a coil for a while, and now I know I can build one!
Go for it!
Go Marty! Good stuff.. I have a WRC Silver bullet but I don't use it very often. Good easy to follow video. Great job.
Thanks Mate.
Fantastic job!! 👍 Thanks for filming and sharing 73
The integrated feed point and female connection sockets for radials…outstanding. Well done Sir. I’ve deliberated over how to improve those shortcomings for a spell without a satisfactory result.
Thank you for sharing your ingenuity with the rest of the amateur community!
Thank you for you comment. I’m glad I was able to help out.
Absoutely AWESOME Marty! 👍 This is the best loading coil I have ever seen, and that includes the commercial ones. Thanks very much for sharing your idea. 🙂 The all-thread irrigation risers are a bit hard to find up here in Canada but if I can't find one, I will try printing one on my 3D printer.
Thank you for your encouraging comment. I see that the risers are still available on the Australian eBay store at this link. www.ebay.com.au/itm/294814307544?mkcid=16&mkevt=1&mkrid=705-154756-20017-0&ssspo=dkw15RJmR2W&sssrc=2349624&ssuid=ALpUZn3RQtu&var=&widget_ver=artemis&media=COPY
Keep up the good work . Congrats !!
Very ingenious and well done. I tried to get a friend who had a pipe threader to thread some pvc pipe for me to make a form. Unfortunately he was afraid it would clog up his machine. I ended up with a Wolf River coil. I wish I had seen this all thread pipe. Never heard of it before. This kind of ingenuity is what ham radio is about. 73s
Wolf River Coils are nice. Mad Dog sells his too. I might buy one just to support his great efforts.
I was sitting in the doctors office waiting on the wife and came across your video. I really enjoyed watching it. I subscribed and hope to see more good stuff. 73’s de KY4K
Thank you for watching. I appreciate your feedback.
Excellent work!
@12:28 if you put the hose clamp on it will hold the wire from backing off on you tell you get it threaded in the hole... This is the best build video on this matter yet. Thank you.
You are correct. Another commenter suggested this to me and I have been using that method since. It works great. Thank you for your comment.
wow! I wish I would have found this one sooner on RUclips. after watching HOURS of other videos, the end result always looked like a kindergartner assembled it. yours on the other hand looks fantastic and like a commercial product! I think I will try to build yours with threaded PVC like a commenter suggested. about to start binge watching your other videos to see what else you've made!
also going to try he "magic carpet" ground plane to speed up the deploymnet and get rid of the radials.
Building this coil in Australia is probably worth while compared to buying the Wolf River Coil, considering the cost of postage nowadays. Thanks for for a great build video.
Just bought one. Looks perfect for a mobile station.
Good job!! Looks really well-made. I ended up going with the Wolf River Coils though, considering the price and the effort. Probably very satisfying to see such a project completed, but I don't even have a bench to work on. The wife would have expressed her discontent at the sight of parts being spread out on the dining table. :)
Yes I know what your saying. I’m fortunate to have a good size workshop and yard. The WRC is a great coil along with the Slidewinder from M1ECC antennas.
Well done mate, great build 👍
Thanks Hayden. I’ve been using it for most of my park activations the last few months and I’m very happy with it. I’m using the M1ECC militarily folding whip on top of it. Plus the G90 and 7 Amp/hr battery all fit in a small back pack which is quite lite.
Good job Marty.
I like it. Ive been looking at mobile solutions for my truck, and this looks really convenient. And it looks fun to build. Thanks! 73
Thank you for your comment. Yes I really enjoy playing around with this stuff.
Thank you for sharing this.
VK4KC Marty, you've done an excellent job on both of your coil versions, outstanding, just shared with my radio fellows, thanks so much 4 sharing your great job ! XE2YWI Jacob
Jacob, Thank you for your comment and encouragement. Best 73 … Marty VK4KC
Superb build
Thank you for your encouraging comment.
Good on you mate! Cheers from U.S.
A fantastic, very professional - looking build. You could also, fairly easily, do something like WRC's 'Camera Tripod Adapter Plate' and have a universal setup that could go from a mag. mount to tripod in seconds.
Thanks for the video.
Thank you for your positive comment.
Brilliant. Good job there.
Thank you for your encouraging comment. Marty VK4KC
I was wondering when someone was going to build a similar coil that didn't cost $100. Good on ya mate. I built an antenna a bit like that, but I just used a pool noodle slid over a piece of 3/4" PVC. The coil wound on the foam has very low dielectric loss, and the RF is blind, so it doesn't care how pretty the antenna is. It worked well on 40 meters.
Hi John, thanks for your comment. Great idea using the pool noodle. Ugly antennas are always special to the builder, I can attest to that!
Around 14:00, commercial products back in the day would often use a hollow bolt so that the wire could be simply slipped up inside the hollow bolt. The connection might be secured with a set-screw embedded in the hollow bolt. Saves assembly time: slip the wire in, finish the overall assembly, tighten the set screw. Also give a straight wire run from the coil up.
Yes that is certainly a good option and some of my friends have recently made the coil with.a PVC collar with a metal bolt on one side and a nylon bolt on the other to apply force.
If we could only get that pipe done up for a cheap price this would be great! I have a bud with a small lathe we might try turning some pipe and see how we get on. Great idea!
Good luck with the project. Please share how it goes for you.
Back around 1995 Don Johnson wrote a book on making the DK3 a screwdriver antenna, in the 90s I made 4 of them, making the coils out of pvc pipe threading at 10 turns per inch, on a metal lathe. we wound them on a metal lathe as well.
Thanks for sharing! You have done well!
I used 16 gauge buss wire which is solid copper wire tinned, One suggestion after you uncoil your stainless wire, I would give it a BIG tug just to straighten it out so maybe it will go on the coil better.. 73 kd8nv
Thank you for your comment and tips. That is very helpful. I will have to look into the Don Johnson book. 73, Marty VK4KC
This is great.. I’m going to give it a shot.
Good luck with the build.
Well done!
That's a beauty, sir.
Thank you for your positive comment. I’m using it for POTA and BOTA activations. 73, Marty VK4KC
Great job
Great Job. Thanks for adding my Video.
Great video and presentation! Very nice build with a clean professional looking product, my hats off to you. Nothing like making something yourself, and maybe save a few bucks in the process too.
I watched it thoroughly to build one too. After hours or searching retail/industrial sites I discovered such a poly riser does not seem to exist outside Australia. Someone with a lathe (or local machine shop) could thread a piece of PVC pipe or such - the only possible alternative I've found thus far.
An Australian supplier (CONFIT) that ships to the USA is $31.92 per riser + $50 shipping + taxes + custom/import fees not counting the caps or other parts. Which makes it cheaper to buy a finished Wolf River coil ($86.09 shipped) than to even get one poly riser to the USA... bummer.
A group or club large quantity buy may get the costs of all the parts for about the same price of the finished WR coil (for any diehard kit builders).
Thank you for your comment. Yes there are certainly many ways to get the end result. There are a few other videos showing different methods and I have added those links at the end of this video description.
I was thinking maybe the guys at home Depot would thread a piece of PVC for me ! Idk it's worth a shot.
Found my first antenna project.
That’s a great home brew HF antenna, excellent production. I fortunately own a lathe and I use thick walled PVC tube and cut a thread using the lathe, made quite a few, I like the idea of the sliding clamp. Note my callsign, VK2KC!
Thank you for your comment. With that callsign we are definitely ham radio Brothers!
@@maddogshamradio3407 can you confirm that the sliding collar is a truck intake turbo hose clamp?
@@andrewjohnmclean5488 it is a EnduraSeal Stainless steel T-Bolt hose clamp. I have also used cheaper hose clamps and they work fine.
Tried to buy a clamp from the big hardware store, but they only had the larger sizes!😟
@@andrewjohnmclean5488 some of the Bunnings stores don’t carry the smaller ones. I had to get a worker to look up what stores had stoke of them.
Great vid. Thanks!
Super job mate. I've done a lot of research on this job and I'm able to do it thanks to you. Sending you love from Turkey. TA4DR 73
Thank you for your encouraging comment. Best 73. Marty VK4KC
Cool. Thanks for sharing.
You’re most welcome
Nice mate !! Outstanding !. I'm making one. Good onya for posting
Good luck with you build. 73, Marty VK4KC
Good luck with your build. 73, Marty VK4KC
Fantastic work
Motters M7TRS 🇬🇧 73 👍🏻
Nice job mate.
Thanks Stephen. I enjoyed checking out your QRZ page. Let me know if you want any info on POTA as I’m the Admin for Australia. The main thing I’m into is portable activating from parks around Australia.
now make a rotary dipole out of it! you'l be amazed how well it works at +_10m high, well built, bit expensive, but will last a long time, thumbs up.
A thousand thank yous for using the metric measurements. The nations that do not use metric need to get their heads out of their bum. Sell your, as of yet, not patented coils for $206
Great video @maddogshamradio3407 similar poly pipe is available in the UK, however it is only threaded at the ends, not all the way through. Need to get it from Oz or China.
Thank you for your comment. Yes it looks like that is the case with regards to supply. I have linked to a couple of other videos in my initial video comments that you may find useful watching. Cheers Marty VK4KC
So i have a feeling this "trick" will help.
Straighten the stainless wire by spinning it with the drill when it's stretched out. Two things should happen one it becomes straight the other is it will work harden and become less springy.
This is a common technique for people that vape and make coils.
I believe that your bolt is 3/8" or 9.525 mm with 24 pitch thread which is the standard size for those mounts.
Awesome
My compliment excellent Bill outstanding
Thank you for you encouraging comment.
Definitely a neat build so thank you for sharing this video. I'd be curious whether you could had made your irrigation pipe about 4 inches longer and built your SO 239, ground, and collar connection into the pipe and cutting the lower half of a cap and using that as a stop for the collar, then finish the base with the mount using another cap. The Wolf River Coil is $150 US now so your build would be less plus as you say there is the satisfaction of having built it yourself.
Thanks 😁
nice building.
Thank you.
Very Cool.. Thanks for the video.. 73's
A fantastic video and explanation. A very professional job. Your video makes me feel like I can build one and have a great antenna. Thank you and 73's K5OOL
Hi Chris, thank you for your encouraging words. Glad the video was helpful.
Have you thought about connecting the shield side of the SO-239 to the mounting bolt at the bottom to also use the vehicle as a ground plane through the magnet?
Great build video!
I should do that. I actually use this more on a tripod now for portable POTA rather than the vehicle as the vehicle now has a permanent radio and antenna installed.
nice job
Great looking Coil, Sir! Southwest Germany is waving a Hand. 73 de Your Friend Uncke Guenter 💯👍🙋♂
Thank you for your nice comment. It has become my go to antenna for POTA / WWFF activations.
I have read that having one end of the coil connected to ground makes a more efficient and higher Q antenna
Great!!!
Nice. Thank you for this excellent video. 73
Thank you for your comment. I hope it helped in some way.
Great video, the hose clamp idea is spot on. I am making a coil also. My question is what readings I should have when completed and where would I read them on the coil, to see if the coil is working or have, I done something wrong. tx
Glad you liked the video. The measurement of the full coil is around the 100 micro-henries. Once you build the coil with the whip on top and counterpoise/ground wires in place you can use a antenna analyser to find the full frequency range as you slide the clamp from top to bottom. You can then mark on the coil the areas where the amateur radio bands are resonant. If you don’t have an antenna analyser many of the newer HF radios will give you a SWR reading for a particular frequency.
Both of those coils are fantastic. I would love to know how long it would need to be and what size whip attacked to get 6 to 80 on one setup. Or if it was even possible.
This is very interesting. Thank you but a note... What if you also tie the ground of the so239 to the bolt for the mag mount.. Wont that also use mag to couple to ground?
Re. SO-239 at bottom. An alternative approach would be to have an RG-8X tethered cable permanently attached. Requires only a few solder connections, and the cable simply exits the assembly. Avoids the faffing with the SO-239, but still needs the banana socket. (Surprising that nobody will be demanding that you use a 'Power Pole' terminal instead of the banana socket, LOL !!)
great !!!
Awesome fantastic terrific wow congratulations thanks 73 from kb2uew
Thank you for your comment and encouragement.
Se agradece las medidas en metros! 73
Amazing antenna! Have you calculated the inductance of the coil? Are there any losses factor associated with stainless steel wire?
Nice realization! 73
Bloody briljant
Glad it was helpful.
Marty, I tested the Poly Riser and endcaps in the microwave at full power for one minute with a glass of water. No heating!
Hi Andrew, that is a great test, and thank you for sharing the results. Looks like we can pump some decent RF power around the risers.
Very slick build. Do you have any idea how much wattage it will take? I need one that will hold at least 500 or so.
Nice project. Stainless steel wire is quite lossy at RF. That will increase bandwidth but reduce signal strength.
Yes definitely some losses there. 1 - 2 s points down compared to a copper wire dipole. Happy to accept those losses for the convenience.
@@maddogshamradio3407 silver plated copper wire is convenient and low loss.
Yes but sometimes you have to compromise,,thats the rough with the smooth,,but will do the job pretty well.
What a great job, thank you for sharing!!! I already started to make one for me hopefully it works like yours. Thank you again, 73 de VE3DAL
Thank you for your comment and good luck with your build. A few viewers have built the coil over the last few weeks and they report that it is working well for them.
@@maddogshamradio3407 Hey Marty I just finished my River Coil and I'm very happy with it. ruclips.net/video/LtI4jvf9sPE/видео.html
Great build and video Marty, very informative and detailed. Well done! de VK4ER
Thank you Owen. Just checked out your QRZ page. I too have a G90 which has been a great field radio for me.
Just what I am looking for. Thanks for a well presented video. Will VK5WB
Hi Will, thank you for your comment. Peter who owns Frithy's Rural stocks the 300mm x 40mm all threaded poly riser and end caps. His price is the lowest of all the places I’ve searched.
Hi Marty, great to see some Australian content and a great description on an excellent build. Could you please give me some measurements of the radial/counterpoise wire/wires you are using for this antenna as you did on your video for the Mag Dog Coil Jnr. thanks in advance.
The radials are 4.5 metres long. I have 5 of them.
@@maddogshamradio3407 thanks Marty, I recently did a 3week trip from Brisbane through to Lightning Ridge And parts of Northern NSW. I found the antenna worked exceptionally well wherever I set it up during my travels. Thank you for the step by step build, keep up the good work.
Does anyone inow of a source for the continuous threaded riser in the USA? I have not seen any source for it other than in Australia!
Very great construction, looks very solid and durable. Could you please tell me what the outside diameter incl. the stainless wire will be. I wonder what will be the right size of the hose clamp? I see Frithys Rural shop also selling these. I see in you video that you're using 1.6mm wire, I found many 1.5mm wire on eBay, I guess that will work, only 0.1mm difference. You just got yourself a new subscriber. Best 73's de LA3DNA Leif
Geez, that’s a lot of work.
As you suggested, I did a google search for all thread risers. All of the responses had a .au url. So, except for Australia, unobtainium. Which is a shame. This is a great idea and very well made.
In my main video comments there are a few links to some other DIY coils. Check those out for ideas also.
This coil is a thing of beauty! Thanks so much for sharing. You wouldn't consider selling these prebuilt, would you? (I had to ask.) Cheers!
Thank you for your comment. I’m only interested in experimenting rather than making them to sell. Wold River coils and the M1ECC slide winder coil are priced very well and I wouldn’t be able to compete with their prices.
👏👏👏👏👏👏
👍👍👍👍👍👍👍👍
Great job and love my Wolf River Coils, both of them❗️73 KV5P
Yes the wolf river coils are great value. And the multi collar system is an excellent way to change the band quickly. They have done very well with their design.
Nice job my friend.Ron NB3W
Thank you Ron.
Hi there! Amazing build! I’m doing one for myself but I have a question, not clear for me in the video - the bottom part of the coil also goes to ground right? Top to antenna, center pin to clip , and bottom coil to ground with the counterpoises?
The bottom part of the coil is not connected to anything. The outer shield of the coax is the only thing connected to the counterpoise. If you are doing a magnetic mount you could also connect that to the outer shield of the coax (I don’t as I rely on the counterpoise). Good luck with your build.
Great video! 73 de Diego EC1CW