The MFJ 1788 loop arrives!

Ready for inspection
The MFJ 1788 antenna has arrived I ended up ordering it from DX Engineering and cancelling the order at the local ham store. DX Engineering had the antenna in stock were as the local store was not able to tell me when the antenna would be in….it seemed to be a waiting game. Once ordering the antenna DX Engineering had it at my door in 3 days! I can't say enough about the great service that was provided by DX Engineering. Now having said that……..I have been doing a lot of online reading about 1788 loop and how over and
Control box test
over again they arrived damaged or just not working. Looking at the loop it seemed to be in great shape and externally survived the trip ok. As I looked at the control unit I found one of the  push buttons not working! The  range button that changes the meter from low to the high wattage scale . I opened the control box as I also heard some "rattling" noise from within the unit as well. I found the switch to be defective and in need of changing, the rattling noise was from the battery holder. It was only held in place with two-side tape and as you guess it….there was no holding left on the tape. At this point I had a choice to make:
1. Send the control box back to either MFJ or DX Engineering for repairs?
2. Ask MFJ if it's possible to make the repair myself if they were to send me the part?
I settled on option 2 as I could still use the control box until the switch arrived and not be put on hold until control box was repaired or replaced. (note: I purchased DX Engineering's last unit)
Stepper motor
The control box failed the QC check it was now time to open up the antenna (a must according to magnetic loop user group) The visual inspection looked very good now time to power up the antenna with the control box. With the cover still off the 1788 loop I wanted to make sure the internal capacitor moved freely and stopped when full rotation was reached in both directions.
All was going well until the capacitor was rotating counter clockwise and it just stopped! I then rotated the capacitor in the clockwise direction and back counter clockwise and it worked just fine. After many back and forth rotations the capacitor never acted up…..maybe this was a one off. I emailed MFJ regarding the switch and they are going to mail one to me so I can do the repair. Next is to mount the antenna and see how it performs stay tuned!
Mike Weir, VE9KK, is a regular contributor to and writes from New Brunswick, Canada. Contact him at [email protected].

12 Responses to “The MFJ 1788 loop arrives!”

  • john mann KK4ITN:

    Good luck with your new antenna Mike. Good DX to you.
    Well I have been a renewed ham for about 1 1/2 years. ReNewed because I let my Extra Class expire and had to retest.
    Yesterday two fellow hams plus myself put up my first real antenna. By real I mean its up about 65 feet. Never have I ever been so satisfied. My first contacts were all dx. XE1/CT1/IT9/OV1/IK5/G0/VE5/YN9/F5/VE2. It was great. I know I will never be in the DXCC class, but for me it was pure pleasure.
    The antenna is cut to the lower end of 40 cw. I installed a insulator in the middle and feed it with 450 ohm ladder line to a MFJ 993 intelli-tuner.
    My station is small just a Kenwood TS140s,antenna as described and a keyer.
    Now I feel like one of the BIG GUNS.
    I had been saving for a beam and tower for some time, now my dipole is going to save me big bucks!
    Thankfully I live in the country with no HOA cooties. Hate their rules and just stupid way they enforce them.
    I know I sound like I am bragging, well I am a little I guess.
    If you fellows ever hear me, I am on 21.030 to .060 or 14.030 to .060 slow down to 19 wpm or so and listen to me brag.
    Thanks and again Mike good luck.
    John – KK4ITN
    cw forever!


    Hi Mike,
    I got my MFJ loop about 5 years ago.
    First thing I tried was using the AA batteries.
    I put them in and heard a snap so something sparked.
    I then tried the auto tune as the box has a speaker but I never ever heard it beep or buzz.
    It took 2 months for MFJ to get me a copy of the schematic of the box and they sent me a fax copy so small I was not able to read a thing.
    So what I do it crank my rig down to 15 watts then tune with the push button.
    I always get zero SWR and worked some DX people dream of.
    Read my review on E ham.
    I broke every rule in the book as it’s indoors with steel all around me.
    It has RF on the coax so I put on a cheap screw on it choke and that cured it.
    But after 34 years I did what others are still wanting to do and I went back to song writing and playing guitars.
    Sick of waiting for cycle 24 and I don’t think it’s going to happen.
    The loop works well even with QRP.
    GL DXing
    Bob AF2Q

  • Mike VE3WDM:

    Good morning John and fist off welcome back to the hobby!! Sound like a great set up for sure a 65 foot tower is great and the contact seem to be just flowing into your shack. It’s great to read the excitement in your post. If you haven’t already get a blog up and going and keep us updated with posts.

  • Mike VE3WDM:

    Good morning Bob…..all I can say regarding MFJ is WOW! I am just going to use the wall wart that came with the unit. Great to hear you were able to work DX with the antenna being indoors and with steel all around. I have a 1:1 balun that I am going to add to the mix to avoid any RF on the coax. It’s just so hard to understand why prints would take so long to get to you and then on a fax you are not able to read too boot!
    This weekend I hope to give the loop a good workout and see how it does.

  • k8gu:

    Mike, sounds like typical MFJ and typical DX Engineering! Poor QC from one and great service from the other. Good luck with the new antenna and hopefully we’ll cross paths on the air someday soon, maybe even after I’ve completed “the project.”

  • ke2yk:

    Unfortunately as we say around here in NY. MFJ is where the quality goes out before the name goes on! Good luck with your MFJ products my friend and 73.

  • David WB4ONA:

    Another DOOB (dead out of box) MFJ product. Not only have I seen it in person, I keep reading about it over and over again as the years go by. What a shame.

  • Mike VE3WDM:

    Good morning K8GU, always nice to hear from you and I hope all is going well with the setup after the move. We have done that and I find it was much fast to just pack things up but when it comes to unpacking and setting up that is were the time is needed. About MFJ yes the antenna did come in not so great shape but I have had many other MFJ products that have worked right out of the box and continue to this day to give me great service. As for DX Engineering this is the first time I have dealt with them and I must say they are a class act. I got an email from them last week asking me how the service was and how I found the shipping time. They are going to get an A+ from me thats for sure.
    Have a nice weekend and again nice hearing from you.

  • Mike VE3WDM:

    Top of the morning KE2YK, not a very good reputation among the ham community to have for sure. I will say that they keep pumping out ham radio products and they do a very good job at making money at it. As for the Magnetic loop it seems to me that MFJ is the only company that sells this product (excluding the Alexloop that is not auto tune) So he as cornered the market on that antenna. As for his other products if you compare them to other companies the quality is not there but one thing ham seem to jump at is there…..the cheap price. As they say sometimes you get what you pay for. Thanks for stopping by and taking the time to comment and I will be updating the blog as I progress with the 1788 loop.

  • Mike VE3WDM:

    David thanks for taking the time to give me your feedback and it’s true it is a shame and I have myself read over again about the problems fellow ham have with MFJ. Could you imagine if the company got things together and jumped up a few QC notches how that would affect their bottom line in a positive way. Having said that when I did contact MFJ about the switch that was defective they were very fast with their response and the part was at my door in less than 2 days! They has shipped it UPS which surprised me and shipped me 2 switches……maybe they are telling me it’s just a matte of time before another switch goes south.
    David have a nice weekend and alway nice to have your comments.

  • Shane n6tnt:

    I am considering purchasing one, now that you have had it for a while what is your review of the product.

  • Eric K6HMD:

    I’ve had one of these antennas for over a year now and it’s performed extremely well. I have made contacts I though would be impossible at 100W. I have been able to out perform it by 2 S units with a (no coil) 10m 2 element buddiepole yag but this loop can’t be beat for band hopping convenience. As with most of the folks posting here I had problems with the antenna out of the box. My remote control box had issues in it did not detect the VSWR dip stop and beep. I contacted MFJ by phone and talked with a tech. In about a week I had a new control box and the antenna has been rock solid ever since. With MFJ you roll the dice as their quality control really is nil. I ordered a practice oscillator from them and it arrived broken as well. I was able to repair it but, there you go. MFJ can make some very nice products and they do stand behind what they sell but I (and many hams) wish they would take quality control far more seriously. If they focused on unflinching dedication to quality MFJ would loose their obvious and sad nick name. As far as the loop goes it’s a must buy for antenna restricted HAMs. Get it up high (18-20ft) horizontal for amazing DX performance. Low lever vertical is not bad either but you hear more noise.73 and good DX to you!

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