Posts Tagged ‘AlexLoop’

Portable QRP = planning and adaptability

Last years shot of my planned location for today
It turned out to be a fantastic day  lots of sunshine and temperatures in around 23C. I was long over due and it was time to  pack up the KX3 and go on an outdoor trip with the rig. I brought along the Alexloop as well to give it a go outdoors.  Part of planning is making sure you have all that you need for the trip and not just radio stuff. There is water, one of those chairs you sling over your back, hat and sunglasses without these the trip could be not as comfortable. I arrived at my "spot" that I have gone to in the past found a nice parking spot in the shade. I then proceeded to unpack the car but could not believe the amount of mosquitoes that were buzzing around me. If planning had been better repellant would had been on the list but in all fairness at this time of year mosquitoes were the last thing on my mind. It was now time for adaptability and move to another location.
New setup in town
 There is no way I could have setup and been comfortable with the bugs at this location. I was now heading back to town and to another location. This one was along the river in town and always has a nice cool breeze off the river. I found my spot and setup did not take long at all and there was a table that was available as well. The Alexloop was very easy to setup and very fast to get it tuned up on 14.060. The KX3 was set to about 2 watts output and so began my CQ's. About 15 minutes into the portable operation the KX3 went
All packed up.
dead!! This has happen to me in the past with this radio and I knew exactly what is was! It was very poor planning on my part....the KX3 batteries were dead. Well not dead exactly but below the minimum voltage needed to operate the radio. That was the end of my out door adventure for the day and the radio is now at home getting it's batteries recharged. Monday is a holiday up this way and depending on the weather maybe I will give it a go on Monday.Going to have to look into a second set of batteries so I always have a charged set ready to go.

KX3 charging

Alexloop vs Attic dipole

Setup for test. (Laptop running Ubuntu update)
The propagation conditions have not been all that great over the last couple of days so what a better time to do some on air Alexloop vs attic dipole comparisons! Here is the setup I used my Elecraft K3 putting the Alexloop in antenna 1 on the K3 and left the dipole on antenna 2 on the K3. This way I can use the internal tuner for the dipole and remove the antenna tuner for the Alexloop with just the push of a button on the K3. The power output was 5 watts, figured I would go to the top end of QRP considering the atmospheric conditions being not so hot. The Alexloop was up in my radio room facing West out the widow and East through my house walls. The Dipole is in a "Z" configuration in the attic so it kinda is facing most all directions. The Alexloop frequency was 14.061 and the dipole was 14.059 and I was using CW along side the Reverse Beacon network. The current atmosphiric conditions at the time of the test were:
A-5
K3
SFI 157
SN 173
Below is the results of the test.....not so well it would seem the Alexloop netted zero and the dipole only one. So is seems for a more acurate comparison better conditions are needed.

Alexloop on the deck calling CQ

RBN spots (click to enlarge)
The weather once again was great and I wanted to take the Alexloop out onto my back deck to see  how it would do once again. The other day I had no spots at all but this day was a complete different story. I was operating  my KX3 at 3 watts. The antenna as was already mention is the Alexloop mounted on a tripod. I called CQ on 20m,30m and 40m it was the late afternoon and nothing could be heard at my end at all. I was spotted only in the States but conditions have not been all that great. I did hear some American stations on 30m but they were just at the noise level. By the spots on the Reverse Beacon Network my signal is getting out! I am excited to see how this antenna does once the condition improve.

A nice way to rest a sore back.

Relaxing on the deck.
Last evening myself and a bathroom mat had a little hip hop time.....translation.....I was standing on a bathroom mat lost my balance causing me to "hop" and out went the hip!!! Today it was no work, off to the Chiropractor and physio. The good news is no disk problems just muscle but I still have to be very careful as I do have lower back disk issues. So what does this have to do with ham radio....nothing....BUT this does...It was a very nice sunny day out and I wanted to relax on the deck and not become board, so I gathered up (very gently) the KX3, Alexloop, Sony MDR-V150 head phones and a pad of paper.

Some things I tried with the Alexloop
1. I emailed Alex regarding his opinion about adding some extra coax so I did not have to be that close to the loop. He (as always) emailed me back within 10 minutes explaining there should be no problem doing this. At first I did try 12 ft of RG 213 and found I could not get a decent SWR. I then tried a 6ft piece 
and all was well. This would allow me to sit at the patio table and not have the loop under the patio umbrella.

2. When tuning the loop if I was in front of the loop while adjusting it's capacitor I found I could get a 1.2.1 match on 20m..but..as soon as I moved my hand away from the loop the SWR rose to 2.1.1. I found by adjusting the loop from the back of the antenna the SWR was not affected. 
New loop to tripod adapter

3. In the past I was using plastic zip wraps to attach the antenna to the tripod. I made and wanted to try a new antenna to tripod holder made of plastic pipe and heat shrink. It turned out to work just fine and will allow me to set the antenna up much faster in the field. 
 
I called CQ on 14.060 for about a 1/2 hour and was not spotted on the Reverse beacon network. This does not concern me as conditions were not that great. It was not my plan to really make any contacts but the see how the loop fit on the deck. Also how the new adapter I made fit both tripod and Alexloop.  Regarding the Reverse beacon network not sure if it is up and running properly today. I tried to refresh the spots and it seem to get stuck trying to refresh.

My Elecraft KX3 has a ping??

This afternoon I was planning on setting up the Alexloop into the living room and try some operating with the KX3. I was wanting to see how the loop worked in the living room. I was going to bring it on the deck but there was the threat of rain. Out of the blue when I was on 15m  in CW mode whenever I keyed a letter and then released the key I would hear a very loud "ping" in the headphones. This only happened on 17m, 10m and 15m. I tried changing the headphones, using a dummy load and reducing the power to 0 but there was always a ping noise heard in my ear? I am not sure if I inadvertently changed a menu option that is causing this. This brought the living room KX3 operations to an abrupt end and off to the internet to see what was going on with the rig. I have posted the question on the Elecraft reflector as well as here on the blog.
Problem has just been solved seems if I have the rig on dual RX and VFO A and B are very close to each other I am picking up "me" on VFO B. Which makes sense and when in dual mod the head phones are split with VFO A in one ear and VFO B in the other. This would explain why the ping was only heard in one ear!

The bandwidth on the Alexloop.

The next step in my Alexloop tests is the bandwidth in which the loop has. Again the antenna is mounted in a bedroom/office on the second floor of the house so that may have some affect on the SWR. I do plan on getting the loop in the out doors were the ceiling, walls and surrounding furniture do not have an affect on the loop. Below is the bandwidth results.
28.004 (SWR at 2.2) to 28.060 (SWR at 2.1) around 60 Khz of bandwidth.
21.020 (SWR at 2.0) to 21.070 (SWR at 1.7) around 50Khz of bandwidth
14.000 (SWR at 2.1) to 14.035 (SWR at 1.9) around 35Khz of bandwidth
10.110 (SWR at 1.8) to 10.125 (SWR at 1.9) around 15Khz of bandwidth
  7.005 (SWR at 2.5) to 7.015 (SWR at 2.6) around 10Khz of bandwidth
 I did however use the ATU on the KX3 and the SWR was flat when used on all bands so if I want I can use the tuner and increase the bandwidth of the antenna. I do know that my attic dipole on 10Mhz the SWR is about 9.1 to 1 and the tuner will flatten that out and I have made lots of milli watt contacts all over the world. So the next step is to get this antenna out doors and give it a whirl out there and see how it does.


The Alexloop vs my attic dipole

The new Alexloop antenna
Just over 2 weeks ago I placed an order for the Alexloop,  For some time I have been debating what antenna to use when I was out and about with my KX3. I looked at the Miracle whip, Par end fedz antennas and the Alexloop. For my needs it boiled down to the Alexloop. I did have a miracle whip in the past and it is a great antenna but just not worth the money for the performance you get. The Alexloop was ordered and arrived within a week and a half!! I was very impressed with the reviews online and the testimonials at Eham. . The antenna comes in a very well made carry case that can be taken into the field with all parts contained for your setup......well almost all parts...a tripod is one of the recommend ways to setup the antenna for field work. There are other ways it can be deployed including holding it by hand (not as young as I used to be so this method my not work for me). You can clamp it to a pic-nick table or attach it to a chair....just for starters.  The unit cost's 299.00 and I will say this is not cheap but it's very well made and portable as well. The case that holds the unit is about 1.5 by 1 foot in total. I also want to add that the case is very well made with a shoulder strap and carry handle.

A quality case

So lets get to the nuts and bolts.....how does it work....sure anyone can say anything about their antenna but the proof is in the radio waves!!
Antenna location..cat standing guard

I wanted to do a comparison between my attic dipole which is the Alpha Delta DX-EE up about 30 feet in the attic and the Alexloop set up in my XYL's office just opposite my radio room. Let me state that this is not a comparison to see which antenna preforms better as that is not a fair comparison....but I wanted to see how well the loop did compared to my attic dipole. The Alexloop was mounted on a tripod....well ty-wrapped to it as the the Alexloop would not fit over the tripod center pole section. This is something I will have to work out later. Each of these antennas have their disadvantages....the dipole is in the attic, this means a wooden roof above, rafters all over and insulation below. The Alexloop is in a second floor room, it's a small loop antenna and very close to the ceiling. So really both antenna are far from ideal when it comes to location.
Temp tripod mount
For the rig I used my Elecraft KX3 (as this is the rig I will be using when in the parks, backyard and where ever else I decide to go!) The power output was set to 5 watts and the bands I chose were 20m and 40m. The plan was to run coax from the Alexloop to a 2 position antenna switch and switch between the two antennas. The Alexloop did not seem to take a liking to the added coax. I was not able to get the SWR down below 2. Once I used the length of coax that came with the loop (about 10 feet) all was well. This just meant I was going to have to connect and disconnect the KX3 from one antenna to the other for the comparison. I was calling  CQ on 14.060 and 7.020 on the attic dipole and call CQ on 14.050 and 7.032 on the Alexloop and check out the Reverse beacon network to see who was picking up the CQ call. Not sure if the conditions were not all that great but both on 20m and 40m the attic dipole just got hits in the U.S as did the Alexloop. There was one big surprise when the Alexloop had a hit with OL5Q (along with the attic dipole) I was very impressed that a loop antenna in a bedroom was able to get a report from OL5Q!!
My overall impressions of the Alexloop are as follows:
1. Shipping was fantastic, this antenna got here from South America faster than products I have ordered from the U.S.
2. The support is great, I had a question about the loop when it arrived and it was answered within 30 minutes!!!!
3. This unit is quality quality quality from the carry case to antenna!!
4. The tuning was a cinch, turn for peak noise and then transmit and tune for lowest SWR....takes about 20 seconds!
14.060, 7.032 Alexloop
5. Assembly is done in 4 minutes for a first timer and I imagine with practice I can cut that time in half.
6. Antenna foot print is very low profile and can be used vertical or horizontal.
7. The SWR on 20m and 40m (only bands used so far) was 1.4 at 14.060 and 1.7 at 7.032.
The bottom line is I am very very impressed with this antenna and I will be taking it to the field and updating the blog on how it does.  Up to this point would I recommend this antenna.......dam right I would it's support is excellent, quality of the product is way above par and so far the results have been very impressive.
 

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  • Matt W1MST, Managing Editor