REVIEW: WELLBROOK ALA1530S+ LOOP ANTENNA

PRODUCT REVIEW:

WELLBROOK ALA1530S+ LOOP ANTENNA

by Michael Stevenson (Guest Contributor)

This is a review and my opinion of the Wellbrook ALA1530S+ P–1 Active receiving Antenna. For further information, details and specifications then please visit: www.wellbrook.uk.com

Background

I have been a keen shortwave listener since 1970 and have had many receivers and antenna types during this time. Currently I have two wire antennas, a PAR Electronics EF-SWL 15 meter with impedance matching transformer, made in the US; and a home made 17 meter wire with balun. I also have a dedicated multi-stake ground or earthing system to compliment my receiver and antennas. I live in suburbia Port Macquarie, New South Wales on the east coast of Australia. Even though all our electricity wiring is under ground in our housing estate, I live in an environment where there are all types of man-made noises coming from modern electronic and electrical equipment used by my neighbours

The wire antennas I currently have are not very good at receiving weak signals in the tropical bands. However, the EF-SWL is probably the better of the two antennas for receiving less noise - the impedance matching transformer, which is earthed on one side, helps to a certain degree!

Previous Experience with Loops

Some years ago now, I read about magnetic loop antennas being very good devices for reducing man-made interference. I investigated further and actually built my own loop antenna. It was 1.4 meters in diameter using 19 mm copper tubing, and had a 25 mm gap where I placed an old fashioned dual ganged tuning capacitor similar to those used in old vintage tube radios from the 1950’s. I then coupled this large copper loop using a 1/5th size coupling loop made from 50 ohm co-ax, fed into an amplifier which in turn was fed to the receiver. I mounted this loop on top of a TV antenna rotator and used multiple cables running to the loop (apart from the 50 ohm co-ax going to the receiver) which would turn the rotator, turn the big tuning capacitor using a small geared motor and a relay which would switch in the second gang of the big tuning capacitor so I could tune down to the 120 meter band. This home made active loop antenna worked superbly for a few years and was the only way I could get to receive the tropical band stations with much reduced noise! Unfortunately, living by the coast this antenna corroded away and eventually failed! Since then, I have been searching for an alternative antenna that had less gear mounted on it and wouldn’t corrode. I tried building broadband active loop antennas but without much success!

Wellbrook

I knew about the famous Wellbrook range of loop antennas which always had excellent reviews. But with these being made in the United Kingdom, and the difference between the Australian Dollar and English Pound, the Wellbrook loops were very expensive to purchase and have shipped out from the UK to Australia.

Anyway, I finally became frustrated enough to bite the bullet and spend my money on importing a Wellbrook ALA–1530S+P–1 active broadband loop antenna. The purchase price is £250 plus £55 freight, came to a total of £305, which converted to around $561.00 Australian dollars at the time! So, certainly not a cheap antenna, that is for sure!

I ordered this antenna from Wellbrook in early December 2014 and it arrived within one week, very well packaged so it arrived completely unmarked and undamaged! A big thank you to the owner of Wellbrook, Andrew Ikin, for all his help and suggestions in setting up and mounting the ALA–1530 for best results and also for weather proofing tips!

Description

The Wellbrook ALA–1530S is a round loop one metre in diameter using 19 mm thick aluminium tubing with a 25 mm gap on the bottom. This gap is mounted in a round plastic housing, which is screwed into place and also potted in resin to keep the gap solid and also protect from the weather. The head amplifier unit is mounted inside a similar round plastic housing also potted in resin. This bolts to the top of the loop gap housing where there are two lead wires with spade terminals which go under the two screws that secure the loop to the housing. A BNC socket is mounted on the side of the amplifier housing.

Wellbrook does not supply any plugs or cables to go with the loop, the user must mount a BNC plug onto a suitable length of 50 ohm co-ax cable and plug this into the amplifier socket which also requires weather proofing and securing. The loop and amplifier housings are bolted together which also bolts onto a short 200 mm aluminium pipe. You can mount the loop on top of a fence or post, or in my case on PVC piping mast which I have mounted the loop around 10 to 12 meters above the ground. I also use an antenna rotator and guy wires to stabilise the mast against wind. I feel that best results can be obtained if the loop can be rotated to reduce noise and interference coming from an unwanted signal. It also helps to obtain maximum signal on the station you want to hear!

Inside the house, the co-ax requires another BNC plug to connect into the amplifier/receiver interface unit. This is a rectangle plastic box with an LED power light, a short length of 50 ohm co-ax cable with a BNC plug already mounted which goes to your receiver antenna input socket. A DC power socket for plugging in a 12 volt mains adaptor must be at least 500 ma current and use a conventional mains transformer (not the modern switching power supply variety which creates too much noise and interference to the reception from the loop!!!). Because I use a receiver that has a SO–259 socket and not a BNC type then I had to use a BNC to PL–259 adaptor plug, which works well!

Also, my three receivers all have different antenna sockets: My Yaesu FTDX–1200 uses a SO–259 socket, the Eton E1 uses a PAL socket and the Tecsun PL–880 uses a 3.5 mm phone socket. In each case I have had to either use a suitable BNC socket to the required plug adaptor or make up another short 50 ohm co-ax extension lead with the suitable sockets and plugs so I could connect to my receivers! There are a few radios out there that do take a BNC direct into their antenna sockets. However, many SDR (software Defined Receivers) as used on computers and laptops have BNC sockets now!

Performance Observations

So, getting down to all the nitty gritty, how does the famous Wellbrook ALA–1530 S+P–1 active loop antenna perform compared to my wire antennas? Very well indeed and quite surprising in some cases. I would say that 95% of the time, the Wellbrook receives better or at the very least equal to my wire antennas. It gives a slightly higher signal strength reading most of the time due to the amplifier gain and it is also less noisy or at least equal to my best wire antenna, the PAR Electronics EF-SWL.

To obtain maximum performance from the Wellbrook, it really should be rotated, especially when a weak signal is being received or if you are having local man-made noise. The majority of the time it can be left facing in a certain direction which seems to pick up most stations with more signal and less noise compared to the wire antennas. In some rare cases, one of my wire antennas will actually pick up a signal with less noise compared to the Wellbrook but this is mostly on frequencies above 9 mHz. From 6 mHz and down, the Wellbrook is the best antenna 99% of the time. It provides more signal and far less noise allowing reception of stations that were virtually inaudible using the wire antennas.

Conclusions

I am very pleased with the Wellbrook ALA–1530 active loop antenna. It is certainly worth the money to be able to hear difficult signals in the lower bands that would otherwise be totally buried in noise or not even heard at all! I would highly recommend it to anyone who is having similar noise problems in their suburban location! Beware though; it is not a miracle worker. You can’t just mount it and expect it to work at it’s best unless you are extremely lucky. If you can mount it in the middle of a backyard a fair distance away from any house and on top of a rotator then you will get good results!

If this Wellbrook antenna died tomorrow and was out of warranty then would I buy another one if I could afford it? You bet I would! It is lightweight, robust and would suit small backyard areas. You can also use it indoors, but household electrical noise may become a problem. You can also mount the loop in a horizontal position, allowing for omnidirectional reception and would then not require a rotator. The Wellbrook comes with a warranty and of course you have all the support from Andrew Ikin!

Audio Clip Comparisons

Here are three audio recordings that compare the Wellbrook with my wire antennas:

ABC Radio Tennant Creek on 2325 kHz with the first 22 seconds being the Wellbrook then 23 to 43 seconds is the PAR Electronics EF-SWL 15 metre wire antenna with impedance matching transformer and 44 to 60 seconds is back to the loop.



NBC East New Britain Rabaul, Papua New Guinea on 3385 kHz, 0 to 31 seconds is the Wellbrook Loop and 32 to 60 seconds is the wire antenna!



The Cross Radio, Pohnpei, Micronesia on 4755 kHz with 0 to 31 seconds being the Loop while 32 to 51 seconds is the wire and 52 to 60 seconds is back to the loop.

Michael Stevenson

Port Macquarie, NSW Australia

(Many thanks to Michael for an Australian perspective on the Wellbrook loop antenna - Rob VK3BVW)

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