Shortwave listening and everything radio including reviews, broadcasting, ham radio, field operation, DXing, maker kits, travel, emergency gear, events, and more
Many thanks to SWLing Post contributor, David Day (N1DAY), who has completed a thorough review of the MLA-30 loop antenna. In this review, he compares the MLA to the Wellbrook ALA1530-LF and a 30 foot square ground loop antenna.
In short, he finds that the MLA-30 performs fairly well on the AM broadcast/mediumwave band, but can’t compete with the Wellbrook otherwise–especially in terms of noise floor. David also noted that “the MLA-30 had a very serious issue with IMD and in some cases, stations that were clearly heard with both the Wellbrook and the ground loop were totally obliterated by IMD when switching to the MLA-30.”.
Thanks for sharing this, Balázs. The video actually makes a good point: it takes so little to make an effective FM antenna to receive local stations. I’ve been with repair technicians when working on radios They’ll often use their precision screwdriver as an antenna to test the receiver before reassembly.
I also carry a couple cheap instrumentation patch cord with alligator clips on both ends to act as a short antenna or antenna extension when needed. Honestly, It’s amazing how often I reach for them!
Many thanks to SWLing Post contributor, Ron, who shares the following review of the PK Loop Mini (A-LOOP-MTAM):
Standard PK Loose-Coupled Loops (the “A” series) are 14 inches in diameter…they are
for use with a receiver having a built-in ferrite bar antenna.
Don’t think they’re not capable of serious DX…a few years ago a friend in Texas
snagged and recorded France Inter (162 kHz) on a 14 inch standard PK LW
loop using a Sony 7600GR.
But this is about the PK Mini 10 inch loop for Medium Wave (there are none for
other ranges).
The build quality is superb as with all PK loops. The band has two ranges: 525 to
710 and 710 to about 1720 kHz. Paul Karlstrand uses a unique design consisting
of flat computer cable and a custom made circuit board to connect the turns
end-to-end.
The low end simply switches in a fixed capacitor across the variable to lower the
frequency.
The Mini has 25% less sensitivity than the standard 14 inch loop according to the website.
Currently it can be had for $66 USD delivered to your door from Melbourne…this one
was ordered on a Monday and showed up a week later,which is outstanding considering
it had to clear customs in NYC.
Performance is virtually identical with the Tecsun or Terk loops, which are 9 inch loops.
So why buy a PK?
You get what you pay for, or not…the PK is fairly robust compared to the Tecsun or Terk.
It’s made to last and it’s a PK Loop.
Thank you, Ron, for sharing your experience with the PK Loop Mini. It certainly sounds like an excellent option for travelers and, like you, I agree that the construction quality is superb!
Many thanks to SWLing Post contributor, TomL, who shares the following guest post:
Summer Daytime DXing 2019
by TomL
I took note of the mediocre band conditions this summer amongst amateur radio operators as they were making off the cuff comments about still being in a solar minimum. Some had gone out and bought upgraded transmitters to solve the problem (MOAR WATTS!). And more power thrown at a weak ionosphere does seem to help get a signal farther. I had not been out since the spring and decided to find out for myself. But instead of more watts, I wanted more height.
Greene Valley Scenic Overlook is open to the public from May through October on weekends only (and only from 11am-6pm). It was the largest land fill (aka, garbage dump) in Illinois, now covered over and producing captured methane gas. On August 3 & 4, I ventured over there to see if its 190 feet above the surroundings might help my radio reception.
After trying my luck with a 12 foot vertical antenna on a tripod (and numerous children running around it chasing butterflies or looking at the view of Chicago), I went out the next day and parked away from anyone and put up my 19 foot vertical on the roof of the car. This setup is still amazing to me and works much better than the tripod mounted antenna, probably because it has a proper ground plane as well as being 7 foot taller.
So, yes, the conditions were so-so, not too bad and not too good. Lots of weak signals and some empty frequencies that I had expected to hear some South American stations around the 5 – 10 kw range. Weak stations from Asia were more scratchy sounding than usual even with the extra 190 feet of height. Here are 5 broadcast recordings as a sample (times in UTC):
Running out of things to listen to, I wandered over to the 20 meter amateur radio band and found a different situation. Propagation was decent between the Western hemisphere and Europe. Lots of “pile ups” going on with people trying to make contact with their trans-Atlantic counterparts. Some said they were running 500 watts or more, so more power does seem to help! Here are 5 recordings to show how active it was:
This outing was quite educational and I find it curious that people running 1000 watts or less are able to be heard well between continents but the large broadcasters were difficult to hear. Antennas pointed in the right direction, at the right time of day and frequency, can certainly do amazing things, plucking those weak signals out of the air so easily. And I do think the extra height had something to do with hearing this magic, too!
Happy Listening,
TomL
NOTES:
An easy way to lookup amateur radio operator “call signs” is to go to web site QRZCQ.com which does not need a login. Some records may be out of date, but most of it is accurate.
Setup used was a cheap Dell laptop, Windows 10, SDR Console 3.03, connected to the AirSpy HF+, a Palstar amplified preselector, and an old Kiwa BCB filter, then going up to the car roof magnetic balun (a Palomar MLB2) which is then connected to the 4 magnet base and the MFJ 19 foot stainless steel antenna. You can read about it here:
Brilliant report, Tom! It’s true: the bands are fickle, but like you I always find interesting things to hear on HF. I think your setup using your vehicle as the ground plane for the antenna is a fantastic idea. Plus, set up is easy, self-supporting, and you’ll never have to worry about a park ranger, for example, complaining because you have a wire suspended from a tree. And when there are no trees? You’re still golden.
Thanks for sharing your experience and DX! Amazing that even with mediocre conditions, you still snagged some distant signals.
Many thanks to SWLing Post contributor, Eric McFadden (WD8RIF), who shares the following announcement from Ken (WA4MNT) via the QRP-L forum:
QRPGuys is open for orders after this year’s Summer shutdown. We have added a product that may be of special interest to SWL listeners and some hams. It is an active antenna splitter that will enable connection to three receivers from a single antenna.
Product Deescription:
The KN8TND Active RX Antenna Splitter will allow you to use one antenna with mulitple HF receivers simultaneously. Many hams and SWLers like to monitor several bands and/or frequencies, i.e. 14.300, international nautical emergency freq, 14.100, world HF beacons, etc, etc. Having two or three HF receiving antennas is a luxury some Hams and SWLers can’t afford. With the active receiver antenna splitter you can use one antenna and three receivers at the same time. Keep abreast of what’s going on on the bands, put some of those dust collecting receivers back in action. On a difficulty scale of 1 to 5, this kit is a 2. Build time is about 2 hours, depending on your experience, with the normal kit tools. Bear in mind, this is for receiving only. For HF transceivers you would need a T/R switch to your tuned transmitting antenna.
QRPGuys makes amazing QRP kits. Immediately after receiving Eric’s email, I purchased the active antenna splitter kit. Total cost with shipping was $25 US. A true bargain! Although I already have an ELAD Active antenna splitter, this one would be nice to take to the field as it’s much smaller and lighter weight.
