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For some time now I have been trouble shooting my MFJ 1788 loop off and on. I have had a problem with getting 20m to tune. The best I could do was an SWR in and around 12 to 1 and really that is not good at all. Even with that SWR the K3 tuner was able to drop it too a flat match but odd things were still happening....for example
1. Tuning the loop for max noise (as low SWR was not happening) did happen but as soon as the rig was tuned in any way the noise dropped to nil.
2. Once max noise was achieved and I transmitted the max noise was gone again.
3. There was no spots on the Reverse Beacon Network while giving the tuned match a go.
4. When transmitting power levels were all over the place from 1 watt to 5 watts.

I had posted my 20m tuning problem on 2 loop user groups and had some great advice but nothing seemed to even come close to solving the problem. I then emailed MFJ  who very promptly emailed me back and advised me to change the shape of a 12 gauge copper loop that was located inside the loop. Easier said than done this involved removing half the plastic cover on the loop and changing the shape of this loop then

Adjusting the loop

checking the SWR. The hard part was trying to figure out where the sweet spot for 20m was on the loop  was. The loop would read an SWR of 12 to 1 no matter what adjustment I gave the loop. I ended up tuning the loop for the highest noise level I could hear. I figured this was as close as I could get to the sweet spot for 20m. Adjusting this small loop did not really change anything and I was getting frustrated! The best thing I find when this happens is to put the project aside and do some thinking. I did just that over the past few weeks I enjoyed the bands the loop would tune and thought about my next move. The loop consists of a rotating capacitor that tunes the loop via a motor. I had been reading on the loop reflector sites and a reoccurring conversation was how quality control at MFJ was very low. For some reason I wanted to check the spacing of the capacitor plates on the loop antenna . It turned out the plates had a warp to them and at the low end spacing was good but in and around

Some plates to close

20m's  some of the plates were very close and maybe touching each other. After some time of tweaking the plate spacing I was able to have equal spacing for the full rotation of the capacitor. The SWR on 20m is now down to 1.4 to 1 and that was the problem as I put the loop back together I kept an eye on the SWR to see if it changed at all. The piece of  equipment that really helped me out with this process was the MFJ 259B analyzer. This unit made tracking my SWR very easy, bottom line is the antenna is now working great and now it's time to get on the air and see how 20m is preforming from the condo.

Pumping out 1/2 a watt

On Saturday I was very pleased to see that my MFJ 1788 loop antenna was getting out. On Sunday it was time to push my luck to the limits, here are VE3WDM I always like to see how little power it take to make a contact. It seemed yesterday 5 watts most if not all the time was getting through. Why stop at 5 watts it was time to drop the Elecraft K3 below the 5 watt maker.............wayyyyy below! The conditions once again were very nice Flux levels were up along with the Sun spot count but the K index was also in around 4. That did not seem to matter the bands were full of contest action. Once again I stayed on 15m and it was very busy with DX from the contest. Today I made only 20 contacts as there was chores to get done around the house.

Hard at work

Yesterday's post concentrated on the country count and locations today's post is all about power levels and miles per watt. From 5 watts I dropped down to 2 watts to see what would happen and DK3GI was in my cross hairs. I was able to make the contact first call which gave me 2020 miles per watt. From there on out of my 20 contacts 19 were all over 1,000 miles per watt. Here is a run down:
1 contact made at 3 watts
4 contacts were made at 2 watts
7 contacts were made at 1 watt
6 contacts were made at .5 of a watt
1 contact made at .1 of a watt
1 contact made at 5 watts ( this being the only contact not netting me 1000 miles per watt)
Some of the miles per watt numbers
II9P at .5 of a watts netted me 18,470 miles per watt
K5RT at .1 of a watt netted me 11,808 miles per watt
CN2AA at .5 of a watt netted me 7682 miles per watt
F8CIL at .5 of a watt netted me 7662 miles per watt
F5NBX at .5 of a watt netted me 7608 miles per watt
CS2C at .5 of a watt and netted me 7216 miles per watt
This contest I was just a point giver and not in the contest to submit a score. I wanted to test out the MFJ 1788 antenna to see how my location and antenna performed. Some things that still have to be done, I have to get the contesting software and radio control software up and running. Have the SWR problem on 10m and 20m figured out with the MFJ 1788 loop, for some reason the best SWR I can get is around 9! On a positive side this contest proved to me that the antenna will get out even with QRP or QRPp power!!

The K3 doing it's work

I was able to get in a few hours in the ARRL CW contest this afternoon and  operated only on 15m. My output power was QRP 5 watts into my balcony mounted MFJ 1788 iso-loop. I was pleasantly surprised with the results I was able to make 40 DX contacts in 23 different countries. I was not able to make any 1,000 mile per watt contacts but I did come close at 4500 miles (using 5 watts). I found the noise floor to be just great and the EU stations were just booming in. There were some stations that did have trouble with my signal but over all exchanges were made first time.
My SWR was in around 1.4 to 1 and it was very simple to adjust the SWR as I went up and down the band. You just have to get the hang of tuning the loop and it is a simple push of the fine adjustment button and your all set to go. This evening I tried 40m and there was lots of EU stations but for some reason I was not able to make any contacts so after a short time I shut things down for the evening.
Tomorrow I am going to try to make some contacts with less than 5 watts and hopefully get some 1,000 miles per watt contacts.
Some of the highlights were:
Tunisia
Balearic Island
Finland
Alaska
Nicaragua

I had some spare time today to put the MFJ 1788 loop to the balcony test once again. Up to this point I have not been able to make any CW contacts with the antenna. I was able to pull in some State side WSPR spots but that was it. I was coming to the conclusion that my DX was going to be Canada to U.S contacts. Today I set the Loop antenna for 15m and the SWR was great at 1.1:1. and up and down the band I went. I heard KP2/AG2J calling CQ at 21.025 and he was booming in here. I called out to him and low and behold he came back to me with a fast report! Fast report or not my 5 watts signal from the balcony just made it to the Virgin islands!! I then heard KH6LC from Hawaii..........but I was not able to make contact BUT for the first time I was hearing some DX stations. I then was able to contact PJ4LS with some repeats on my part but I still had my 1788 loop signal down to the Antilles off the coast of Venezuela!! The other station I heard but was not able to contact was ZZ80MT in Brazil. This was a good afternoon on the radio of me I was able to hear and make some DX contacts.

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

Capacitor

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!

A shot of the loop with the "T" fitting

I have been looking for a way to place the Alexloop  in the horizontal position as from my playing with the loop it seems to work better for me on the balcony in the omnidirectional horizontal position. Yesterday I was able to pick up a 1 inch "T" fitting mainly used for piecing together plastic pipe. I was able to feed the loops center support through the "T" fitting and place it nicely on the tripod. With just a little electrical tape to hold it in place it worked great. 
I finally set things up to get  WSPR up and going, so yesterday during the day and then into the evening I was WSPRing to see how my signal was getting out from the condo. Up to this point I have only used the Reverse Beacon Network or RBN which involved CW at 5 watts. I was not thrilled with the results and was really wanting to give WSPR a go. During the day I tried 10m and 20m I started out with 1 watt and in terms of WSPR that is some pretty high power. The antenna once again was the Alexloop in the horizontal position, at first attempt on both bands the Alexloop was indoors. It was not surprise that there were no spots at all it was time to move the loop out onto the balcony. Once setup I went back to 10m and it was about 2pm local time with no results again. I then jumped over to 20m and it was just U.S stations and very few I might add that received my signal. It was time to pack it in for the afternoon and some chores had to be done and I would get back on in the evening hours.
At 7 pm local time I was up and WSPRing on 40m and with great hopes as the band sounded good and I was decoding some WSPR DX such as EA3NEI. I once again was only heard in the U.S and this time I used up to 5 watts!! Maybe it was that conditions were poor out this way as they have been over the past week. Over the weekend if I get time I am going to give WSPR a go once again and see how it works out.

The loop horizontal and nothing.

In my last post I wrote about how my Alexloop was just not getting out in the condo, I was checking the Reverse Beacon Network as I called CQ at 5 watts from my condo and there was ZERO spots! Well from that post I received lots of great suggestions on how to get VE3WDM's signal from the antenna to the world. So here is what I tried........I mounted the Alexloop in the horizontal position in the condo and it netted no spots on the Reverse Beacon Network. I then put the Alexloop on the balcony seeing that we are 60 feet in the air I felt this was a sure thing. The last option for me was to place an antenna on the balcony as it was open season to the condo cops.  I placed (in the cover of darkness) the Alexloop on the balcony and called CQ on 20m and 40m and then check the Reverse Beacon Network. To my surprise there were no spots and now I am really stumped and frustrated. The Alexloop is out in the open 60 feet in the air and no spots what the heck is going on......do those dam condo cops have ham radio jammers!!!!!! Up to this point I have only use the RBN to check for spots but there is also WSPR and I have had some bloggers suggest I use this. At this point I am not able to get WSPR up and running as there seems to be some software issues. My goal now is to sort out the issues and give WSPR a go both with the Alexloop in the condo and out on the balcony. This coming weekend I hope to get on the air with WSPR and give that a go! Im really not frustrated I see this as a challenge, for me to get ham radio on the air from a condo will but only  help others in the same situation as me get on the air.