Friday, May 6, 2011

Another attic adventure.................

After doing what seemed endless searching I have purchased an antenna for the attic. In previous posts I mounted my High Sierra Sidekick and then I tried my Pro Am AB4 antenna in the attic with not much success. It seemed the best antennas for my attic situation was the dipole. At this point in time the attic is getting filled up with dipole antennas. I have an inverted V for 20 meters and for 40 and 30 meters dipoles made from mobile whip antennas. These antennas worked fine but I was wanting to try and work most of the bands and use just one antenna. This will allow me to reinstall my Discone antenna
20 meter inverted V
40 meter whip dipole
that had to be taken down down due to space limitations. Also possibly install an active antenna for diversity mode with my Elecraft K3 as well. One of my considerations was the MFJ-1788 loop antenna. It covered 40 meters to 15 which for me was just great and it is very compact as well. One of the major draw backs was the size of the opening into my attic. The loop antenna was about 10 inches to large and it meant I would have to open up the attic entrance. It did not seem like a big deal
until I had a closer look and some of the roof supports are  connected with the framing for this entrance. I am no carpenter and don't want to start playing around with roof support framing. The other consideration was the price with taxes you are looking at over 600.00. That was just a little to steep for me for an antenna I was not sure if it was  going to work or not. Over the last month I have cleaned out the radio room of items I have not used for some time now. I was very pleased with how fast items sold and I made a grand total of 1000.00 dollars. I didn't want to drop half  of my sales to an antenna.  After looking at many multi-band dipoles I went with and ordered last night the Alpha Delta 10-40 meter DX-EE it's price
Alpha Delta DX-EE
came in at 175.00. It's a fan dipole and yes I know it can be home brewed but my schedule has me working late 3-5 days a week and sometimes on the weekends as well. So by the time I get the time to round up the material, make the traps and build the antenna it will be time for me to retire. There were many who reviewed this antenna on Eham who were using it as an attic installation and pleased with it. The total length is 40 feet not bad at all for the coverage it gives you. Mind you the band width may be narrow on 40 meters but then I do have an antenna Tuner in my Elecraft k3. At 40 feet I will still have to put a little zig zag in each leg to make sure it fits my attic. At this point I will have to do some brain storming on how to hang the antenna so I can "zig zag" it. The plan is for it to arrive next week sometime and then next weekend head up into the antenna farm and install it. Then you guessed it there will be more blogging and pictures.

2 comments:

  1. I did open up the access hatch to get the MFJ into the attic. It's probably there forever now!

    I do find the MFJ-1788 to be an excellent antenna and I recommend it to many people who are really pushed for space but on the whole my multi-band dipole does outperform it.

    One issue to think about if having more than one antenna for the same band in an attic unless you only run QRP is that the signal radiated by one antenna could be picked up by the other and might be of sufficient voltage to harm the receiver it is connected to. I've read of people blowing up their K3s when one antenna was too close to another running QRO in a field day.

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  2. Good morning Julian, I agree the MFJ-1788 is a great antenna for limited space. If it were not for the fact of having to modify the attic access way that antenna would be in the attic. My mobile whip dipoles will be in the attic for the time being while the DX-EE is there. But I never run over 5 watts and all the feed lines go through the LDG DTS-6 antenna switch. Having said that I never would trust that switch to act as isolation. So with only operating 5 watts max I hope to not run into any troubles. It would be a sad day in the shack if I toasted the K3.

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