Posts Tagged ‘new location’

Final repairs on MFJ loop

Time to repair the control box.
It seems that almost all the bugs have been ironed out with the MFJ 1788 loop antenna. I sure have had an adventure with the unit but things seem to be on the upswing now. Some of the indicators the MFJ loop gives you when your match is good are High noise level meaning you are in the ball park. The SWR meters on the control box that visually tell you the SWR is good. Finally there is a tone that comes from within the control box when you are auto tuning the loop. As far as I am concerned this tone is only within the range of our cat Oliver's hearing. day when I was tuning the loop in auto mode and all was going well until Julie tapped me on the headphones saying "can you not hear that ANNOYING sound!! I took my headphones off and still nothing it was not until I put my ear right up to the MFJ control box could I hear the tone. WOW my hearing must be way off  as Julie said it was very noticeable to her in the living room and to add insult to injury she also heard it over the TV. Needless to say this event happened a few more times and
Ready to remove switch
it seemed apparent that it was time to cut the wires to this speaker. While I was in there I also had to replace a switch that controls the range of the watt meter on the MFJ control head. The original switch did not work very well at all and MFJ was kind enough to send me 3 extra ones. Cutting the wires to the speaker (I could never hear) was very fast and easy but for this switch to be changed most of the unit would have to be taken apart it seemed. Once I was ready to remove the old switch and replace it with the new one it was very easy........having said "easy" it means that with the right tools it was easy. I used the Hakko 808 de-soldering gun and believe me this unit makes very easy work of removing the old solder. To the point were the defective switch just falls out of the board. In the past I have used the hand held de-soldering pumps and the wicks as well but nothing works as well as this unit. The solder station I have is the Weller WES 51 and it has served me well for many years and you can change out the tips for various jobs you want to do. So with the wires cut to the speaker and the new switch installed it's now time to just operate and no more (I hope) fooling around with the antenna.
A great tool to have

Doing the MFJ loop happy dance!!

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.

Learning more about the Alexloop

What turning the loop can do
As times goes on and I use the Alexloop more and more I am coming to realize that this antenna may not be a bad choice for my condo antenna. The loop is small and I thought may not preform that well, stacked up against my Alpha Delta DX-EE dipole antenna yes it does not far very well. BUT for limited space, fast to assemble and take down and stealth the Alexloop is a great contender. Recently I have been only using the Alexloop indoors and either on the main floor or my second floor shack. The power has been set to 5 watts and as was said in my previous posts I was able to get into Europe with some decent reports. This weekend using the loop antenna along side my K3 (Up to this point I have only been using my KX3) they seem to get along very well. The tuning of the antenna has been made easier because of the P3 and external monitor. I am able to tune to peak noise using the band scope or otherwise known as the Elecraft P3. Peaking the noise level this way has almost netted me a perfect SWR on all bands. There was only a very minor self tune I had to do in order to get the SWR flat.

Man made noise on the band
I did notice on 30m today there was lots of man made interference and by simply rotating the loop most if not all the interference was eliminated. As well after rotating the loop the signals I was listening to were still there. That to me can be a great bonus once in the city of Toronto and the interference problem may increase and by turning the loop I may be able to rid myself of some of it. I also wanted to know what the loops receive bandwidth would look like on the P3 and I am please to say that's it's great. As for transmitting I have found the loop has to be re tuned anywhere from 10 to 25 Khz depending on the band. This was a good learning weekend for me regarding the Alexloop. I have been toying with the idea of the MFJ magnetic loop as you can tune it from your desk. I have tried to add some extra length to the Alexloops coax and have had some good and bad results with tuning the loop for best SWR. I have noticed as well that when tuning the loop your body has an affect on the SWR as well. You may see a great SWR but once you have moved back to  your radio the SWR goes from your tuned 1.2 to 1 to 2.2 to 1. This is not the case all the time but has happened now and then.
A nice bandwidth with the loop
One other element I wanted to try this weekend was Skimmer, there was a contest on and I wanted to see how well it did. The results were very pleasing and I was able to see how Skimmer can help me. I have played with Skimmer in the past and just could not get it working but I stuck with it this time and am pleased with the results.
Skimmer showing the picture

The Elecraft k3 stopped working

The K3 just stopped!
This weekend I hooked up the Elecraft k3 as it was all disconnected when we had the house painted as it had to be moved for safe keeping. I wanted to make sure it still worked with all the computer software and the Alexloop. Software can be a very funny thing in that you really don't have to do anything and for some strange reason it just stops working! I am happy to report that all between the PC and Elecraft K3 is working well.

There was one heart stopping moment, it was during a tuning session of  the Alexloop and the rig. I tuned the Alexloop for max receive I then hit the tune button on the K3 with the power on 3 watts the SWR was around 3.1 to 1 so some fine tuning was needed. As I tuned the Alexloop the SWR did a sharp rise and the rig powered off!! I waited for a moment and tried to power the K3 on again and NOTHING! I then checked the incoming power and it was dead. Well I thought better the Astron 20 amp supply taking a hit than the K3. Looking at the Astron supply the lights were on and 13.8 volts was showing on the meter. As I narrowed things down it was a fuse on the power bar that the Astron feeds power to. The K3 was fused at 1 amp at the power bar and not 5 amps and the fuse on the power bar went. After the proper fuse was installed all was well again.

Blown fuse
Last week I was able to purchase for a GREAT price a used very large roll top desk and this is going to be the desk that I use for the radio setup when we move to the condo. Not sure what I am going to do with my 3 monitor setup as it's great having all three. There seems at this point to be room for one monitor and all the radio gear. Whats great about the roll top once  your done all the radio equipment hides away into a nice oak desk. At this point I am brain storming on how to incorporate the other two monitors???
As for radio time Saturday was spent getting the K3 setup and my heart restarted when it powered down. There was a contest going on so the band were very busy but it did give me a change to see how Skimmer works under a contest situation. I can see how this piece of software will give my limited size station some advantages. The picture below is what sold me on the desk, the keyboard tray and the two pull outs.

Some very big changes at VE3WDM

Goodbye crazy driving
The new temp antenna
I have been very busy these past few weeks and my lack of blog posts can testify to that. Julie and I have been bouncing around some very big ideas. We have some very exciting plans ahead of us that will both help our over all well being. It also will bring about some huge changes with my hobby but I am very happy to say that it's a challenge I can meet. Both Julie and I have over an hour drive each way to work. We get up very early, get home late and to be early each evening. Then there is the winter months with the snow and crazy driving. We have decided to put our home up for sale here in the country and move to Toronto. We will be living in a condo as our kids have moved out and are doing just fine. This means downsizing both with our home belongings and my ham radio. We want to get a place that is in Toronto and over looks Lake Ontario. Both Julie and I are very excited about this and with this move I will be 10 min's from work and Julie 15 min's. We will have a fantastic board walk just steps from out condo. It thrills us that all the advantages of the city will be not an hour away but minutes.
So how does this affect radio for me.....well my Attic DX EE has been sold and already is taken down! Not to worry I still have my Alexloop that I can set up in my radio room until we sell and move. I have some gear for sale and it is slow but sure selling. I have sold the Sub receiver in my Elecraft K3 as I will be very limited with antennas in the new place. I don't have any room for an antenna for a sub receiver.  So I have been going over antenna options in a condo. There are far and few BUT one main advantage I will have that I don't have now is height! In the condo we are looking at the 11th floor and
up. I am thinking of using at first my Alexloop and then going to the MFJ loop antenna. This will be a new adventure in my QRP ham radio challenge.
Changes are coming

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