HF Loop Antennas and Mounting Height

[mountainrider]

Marcy, I see you have yours on a rotator, how is that working for you? I'm asking because the common word is that loops are highly directional, but my MLA-30+ doesn't seem that way. It's hard to tell, you know, I try and average some SNR over 5 minutes, give it a turn and measure again, would be much easier with a rotator obviously. Thank you for your thoughts too Marcy!

I have a Wellbrook ALA1530LN and have it oriented due north/south (about 4m height). I think for HF the directionality is not that important but most signals don't arrive from due east or west anyway. I'm at about 43° N 116 W. Mediumwave is another story. I have an annoying 10kw mediumwave transmitter 3 miles due west and the N/S orientation nulls that out nicely.

 

[Phil_KD0SCJ]

Ok, I have a few things to share...

My MFJ-1886 came in, actual time from order to delivery was 5 weeks. They were preparing and then away for HAMFest in the middle of that, and I did call once for status, they said they are trying to catch up depending on how much overtime the guy wants to put in. I have it put up now, it's on a consumer-class (cheap) rotator with the base of the loop about 4 feet off the ground. I have a PVC pipe riser going up across the loop to add some structure to the top. The antenna is in a very popular deer route and it seems like cheap insurance. I am not overly impressed with how the loop is attached to the junction box, and... well, in Northern MN it's wise to overbuild anything you don't want to mess with in below-zero weather.

My entire set-up has evolved since I started this thread. My SDR is now in an outbuilding near the antennas, and I'm using it remotely via a network cable to the house. I have a 45 foot T2FD antenna in the air, horizontal at 20 foot height. The SDR has 3 switchable antenna ports, so I can do very quick A/B testing. The MFJ-1886 and the T2FD in this configuration have very similar overall performance. Not surprisingly, the T2FD brings more signal to the party, but also more noise. There is no clear winner between the two, it just depends on frequency and conditions.

The T2FD, at 45 feet, is a miniature that I put up for proof of concept. I'm replacing it with an 88 foot version which will also be a sloper. But I don't want to make this thread my personal journal or anything. So, my closing thoughts are...

1. The MFJ-1886 is a great upgrade from my original MLA-30+, which was great news given it is 8x the cost.

2. The MFJ-1886, I suspect, will outperform any wire antenna you might put up casually, that is, without a great deal of room and effort. And while an MFJ-1886 won't fit in a backpack, one could throw it in the back of a car and take it somewhere, hang it off a tree and power it with a 12V battery.

3. The MFJ-1886 actually has some serviceable reception well above the rated 30MHz. I can get my closest three NOAA stations at 164MHz, as well as my local 2-Meter repeater.

4. And, as said, lead time on the MFJ-1886 is getting better, maybe 4 weeks now. It was worth the wait, in my case.

73's and thanks for all the great information!

~Phil

 

[Omega-TI]

I'd love to see some photos!