Your antenna shows great craftsmanship. It's always a lot of fun to experiment with antenna mods. One of the objectives of the MLA 30+ was to give radio fans a cheaper way to hear shortwave and HF signals. Now I haven't done my own testing, but I've read up about active loop antennas. The circumference of the loop does not seem to affect receiving performance whether it's three foot in diameter or ten feet. So, keep it at 3 feet. Using copper tubing increases weight, increases wind load, doubles or even quadruples the price with no significant increase in performance. Yes, you have a more robust antenna, but its now heavier and bulkier too. And more prone to get puzzled looks from the neighbor's kid when they retrieve the basketball from your yard. One of the things that's not talked about in MLA 30+ mods is the noise generated by the power inserter. The input is USB 5v. I find that it may help lower background noise if the power inserter is run through an old Iphone/Ipad charger. The folks that make KiwiSDRs have noted that the iPhone give off less noise when powering their fine SDR box. I use an iPhone charger and I find its a full 2 s units quieter than your typical made in China charger clone. That's an appreciable difference, but with anything involving antennas, your results may vary. One of the great things about the MLA 30+ is how small and light it is. Also realize that a small antenna like this is a huge compromise compensated with a fairly noisy amp. But it brings a world of signals into the home at modest cost. The fact that this antenna does this for a tenth or a 20th of what other companies are charging for an active loop should raise everyone's eyebrows. Loop antennas are probably best for not gathering signals, but rejecting electrical noise by nulling the sides of the antenna. Less noise means less listener fatigue from my perspective. As for modding the antenna to make it more robust, the power inserter is pretty much weatherproof. Tape or seal the cable connector and you should be good to go. I notice people have no problem spending thousands for their receivers, but then are pretty lightweight when it comes to other performance enhancing mods like good grounding, proper cabling, antenna placement and noise management in their environment.
I was impressed with your ingenuity and professionalism... You went 95%, then the tape and zip ties came out! Still a cool project and I'm certain it works fine. Cheers
My guess is that he chose to use tape and zip ties to avoid using metal to mount the loop to the plastic pipe. If it does not last, it should be fairly easy to remove and try something else.
Securing loop to mask option. Tee fitting @ top, cross@ bottom, a wood dowel for insulator, pack non-hardening putty to center tubing in fittings and filling voids.
Hah, this is scary, last night I bought parts to convert my MLA 30 to BNC (for RG58 coax) and then this morning, this is the first video RU-vid recommends! I swear it's psychic at times! Thank you for making the video Arczi :)
I got a kids hula hoop (75cm), fed 12awg copper wire through the hoop and hooked it up to the MLA30+. Used some 20mm pvc pipe and connectors to mount it. The hoop was multi rainbow colour segments, so as it wasn’t Pride month, I sprayed it black. Took about an hour and cost around £7 (mostly hula hoop). Definite improvement in 40M band and even had better reception between 118-136MHz.
great work and I would be happy about a video with the connected receiver that this antenna can be outside for the next few years without being damaged by a storm
I would like to know a comparison of reception between before and after this modification, to see if we are convinced to do it. Otherwise, interesting video, friend. 73
Good question. From my point of view, the original loop is perfectly sufficient. While copper is a better electrical conductor than stainless steel, I have my doubts whether this fact really justifies the great effort. A tall mast is also not really necessary for this type of antenna. But that's just my personal opinion. However, a thicker antenna cable definitely makes sense.
I took the challenge to do the same improvemente . The quality of the signal will not be stronger, but the noise floor is better now. I tried with almost the same radius as the original antena, I dont know what the measurements of this one are. My final thoughts are, if you are really happy with the signal and you live in a quiet place there's NO point on doing this unless your antenna is very expose to storms and rain. Otherwhise leave it original.
I used a 3m length of heliax and fed it though a hole drilled in the top of the waste pipe. In the end it worked just the same as the original though. Btw you can buy black waste pipe now. Less conspicuous than the white.
Well i did not modify mine. And i'm glad i kept it original. The coax it came with i turned into coil so it acts as a poor man balun. From there i ran it into a 1:1 choke. Grounded it. And then with thick coax into the shack! Very good antenna! Love the thing.
Bonjour. Intéressant ce montage. Attention cependant au perçage du boitier de l'ampli. C'est extrêmement délicat et si le foret atterrit sur la self, c'est fichu. Pour éviter cela je préconise de mettre le boitier de l'ampli dans une boite un peu plus grands et de fixer la fiche antenne à cette même boite. On relie ensuite avec un morceau de câble le petit boitier MLA30 et le fiche fixée sur cette seconde boite. C'est sans risque.
You would most certainly destroy the device used as a preamp. I suspect an LMH6550 Op Amp/line driver or similar device. To transmit, you would have to build a keying circuit that utilizes a relay to quickly switch the preamp out of the circuit during transmit, and bypass the radio's final output directly to the antenna. This would also require an impedance match or a tuner to set SWR to the loop. The copper tubing would indeed be able to handle most wattages but the tuning would be a factor and the circular shape might be a problem. Most antennas are linear, vertically, or horizontally polarized. A circularly polarized transmission would lose half of its power if received by a linear antenna, oriented vertically or horizontally. The benefits of the magnetic loop as a receive antenna would not apply to the outgoing signal.
I have 2 MLA 30+ antennas. The Biasing Tee powers up fine on a USB plug in power adapter but when I try and power it through a portable power bank the power cuts off after a few minutes. This happens with both antenna Biasing Tees and with several different portable power banks different power cords. I would like to use the antenna for portable use but cannot power it. Is this normal or do I have two defective antennas.
The current draw for the antenna is very low. Maybe your power bank is switching off automatically because it's such a low current? Might be worth trying another power bank.
Mine did this too and figured out what was going on. I believe if the biasing tee doesn't see a signal it will auto power off. In other words hook up all your kit and power up the box with your portable. It worked for me. Lmk if it helps you
It wasn't - it's not a continuous loop, that's what he was showing with the meter....He had two pieces of copper, I assume because he didn't have one continuous piece. He only joined one side copper to copper.
Why go to all this trouble ? Why are you using hard copper tubing rather than the wire that the kit comes with? Do you get better reception with a copper pipe ? If you feel you must use copper tubing why not buy the flexible copper tubing that comes in rolls that can be stretched out by hand in about 2 minutes.
I would like to have or to hear a test of the mod and a stock side-by-side. I'm not sure that the copper pipe over the stainless loop will yield any difference at all.
@@jn1lfdI can assure you, that soldering was not professional! Due to the heatsink effect of the large amount of copper, that was just a badly done blob. Basically, a dry solder joint.
@@TonyLing It works. You can also fill PVC pipe with sand and use a heat gun to bend it into arcs. The sand supports the interior walls so they wont just collapse.
@@j.allenhood7429I had a pool installer show me a trick. He dug the trench to fit the system, then hit a length of one or two inch PVC with a brush torch to make the pipe plastic and then just dropped like a snake and it laid in just perfect!
What a waste of time and material. He really had me laughing out loud when I saw the N to BNC adaptor at the connecting cable. Why not use N at the antenny side? That would at least have made the whole thing waterproof.
