Loop v wire antenna

[radioshane]

I wonder if I could advice on if a a 40 foot HF wire antenna is the same as a HF wellbrook loop antenna or is a loop antenna better ?

 

[ka3jjz]

Loops have several advantages over wire antennas - they are more resistant to noise, and since you're talking about the Wellbrooks, they are very easy to hide. In communities that frown upon outdoor antennas - here in the States, that's the bane of a ham's existance, never mind just folks who want to listen - loops like the Wellbrook can be a real help. They tend to receive a wide range of frequencies in a small package, and are pretty efficient antennas to boot.

Depending on what kind of loop you are using, they can be directional up to, and including, the lower part of the HF spectrum. One of the most common uses of loops is in the MW DXing arena, where being able to null out one station to favor another is very common. On the lower part of HF, you might use this ability to get away from a particular source of interference. Loops are very good at hearing signals that arrive at low angles. Such signals are often the types of DX folks like to chase.

Constructing and understanding how the various kinds of loops work is a fairly complex topic, and there are TONS of references you can find on the net. Just talking about the Wellbrooks here, they are very highly regarded, and many times are used as a comparison point against other antennas. They have been reviewed in the WRTH in the past with very high marks.

Mind you, they aren't cheap, but this is one time you get what you pay for

Mike

 

[ka3jjz]

Not to confuse you further (ah heck, why not? hi), there are several loop designs that are quite large, built with lots of wire and use trees and other structures for support. Do a Google search on Delta Loops, for example. They are usually cut to a specific frequency - used by hams for transceiving, but perfectly serviceable as a receiving antenna. They do, however, require a heckuva lot of space

Mike

 

[jwt873]

I think all, (or at least most) Wellbrook loops are 'active'. This means that they have a high gain RF signal amplifier built in as part of the design. That's why a Wellbrook loop costs a lot more than 40 feet of wire.

I've never used a Welbrook loop, but I imagine one would easily outperform a simple 40 foot wire antenna hung between two trees. This is especially true on the lower frequencies (VLF/MF/HF).

 

[Turbo68]

Hi radioshane i been in the hobby for over 35 years main intrest for me is monitoring hf aircraft had up to 4 wellbrook active loops sold 2 reason being they took me ages to get the right height and distance from the house worked okay but my pk loops 20/30/40 metre band dipoles work excellent and can buy 4 of them for the price of one loop i will also be selling the other 2 loops.

Regards Lino.

 

[ridgescan]

I run a Wellbrook now and it gets the same stuff my old 100' wire with a 9:1 got. The loop does excel in MW. Very good. I can pinpoint signals because it's on a rotator and it's directional.
The 100' wire though, was very good too and I pulled in a ton of stuff with it.

 

[radioshane]

Turbo how much are you're loops I might be interested as other forum are saying it performs better then a HF wire antenna cos I need better gain cos the station I'm picking I'm loosing on a night

 

[Token]

Turbo how much are you're loops I might be interested as other forum are saying it performs better then a HF wire antenna cos I need better gain cos the station I'm picking I'm loosing on a night

What station, and what frequency?

An active loop, like the Wellbrook ALA1530S+, will, in general and in many locations, outperform a short piece of wire like a 40 foot loop. That does not mean they will outperform all wire antennas under all conditions.

You have given no details on your 40 foot loop. But assuming it is a simple 40 foot loop configured as a Full wave Sky Loop it might be resonant at about 23 MHz. It will not perform well much below that freq, and the further from that freq the less well it will perform. A larger loop would push the frequency down.

On the other hand, the Wellbrook will perform well at MW and up (100 kHz and above) and start to fall of in performance at around 20 MHz.

I have a Wellbrook ALA1530S+ as well as a few other antennas. The Wellbrook does well for little effort and simple installation, but I have better antennas. My Wellbroook is on a simple 9 foot pole and a rotor. The "better" antennas tend to be bigger and more difficult to put up. In a moderate to quiet location a resonant dipole or inverted V will outperform the Wellbrook across a few relatively narrow bands. But my 80 meter inverted V is on a 60 foot center support, so the effort to install is much greater. A large full wave Sky Loop can outperform the Wellbrook across a larger frequency range, my 160 meter Sky Loop (roughly 510 feet) generally results in a better signal (meaning better signal to noise ratio, not just stronger signal) across several sections of the HF spectrum all the way up to and including 28 MHz. However the Sky Loop requires four 40+ foot poles (and really should be higher) in a square configuration 125+ feet on a side. And my Rhombics all easily outperform the loop in the directions they are pointed and the frequency ranges they are built for, but then the smallest of the three has something like 725 feet of wire and four large supports.

So the return on a simple active loop is quite good, even if it is not absolutely the best possible antenna. They are simple to install, perform fairly well across a wide bandwidth, and can be turned with a rotor to null interfering signals or to peak desired signals.

As a general rule no one antenna covers it all on HF. A good mixture of antennas, including some resonant antennas on target bands, can result in the best combined performance. However, if I lived in a QRM heavy urban environment with limited space I would probably use an active loop, like the Wellbrook ALA1530S+, as a primary antenna.

T!

 

[ka3jjz]

Another important question to ask here is what are you using as a receiver? If you're using a portable radio, there may be times when the Wellbrook will overload the radio. Portables, generally speaking, simply aren't built to handle the large amounts of RF that an amplified loop (like the Wellbrook or Pixel) would present.

As Token and others have stated, you can use other antennas besides the Wellbrook. There are many sites (including our own wiki) with designs that you can build yourself. Learning how to properly solder a connection is key - if you don't know how, see if you can get a friendly ham to teach you.

As stated in another thread, there can be many reasons why the station you are trying to hear (what is it? What frequency? and at what time (UTC)?) is weaker at night. While a better antenna is one factor, there are several others, many of which you simply can't control. For example, is the station you are trying to hear beamed in your direction? How is propagation at that time? HF Propagation can and often does vary from day to day - what is weak one night, could be much better the next.

There are simply too many variables to consider without more information...Mike

 

[ka3jjz]

As for link for Wellbrook, see the blue text below...

Wellbrook Communications

MIke

 

[Turbo68]

Hi radioshane in australian dollars from $430-$500 that was a few years ago it would be more now cause the exchange rate is not good at all my wire antenna with a balun from pk loops $116-$150 and its true you do need a few antennas on hf but that also depends how many hf receivers you have also had a yaesu rotator with the wellbrook active loop picked up okay on ndb but i am intrested in that side of receiving but on utilities my wire antennas outperforms the loop each time.

Regards Lino

 

[radioshane]

That's strange Cos other people say loops out do wire antennas o

 

[Token]

That's strange Cos other people say loops out do wire antennas o

Anyone who says an active loop, like the Wellbrook or Pixel antennas (both very good antennas), will always outperform a wire antenna is incorrect. Period. What kind of wire antenna, how is it installed, what location, what frequency range? All “wire” antennas are not the same, nor do they all perform the same.

In some instances, for example in an urban setting with its potentially high QRM and small areas for antennas, for HF listening an active loop will often outperform a sub optimal wire antenna installation (as opposed to an optimized wire installation). This probably describes the conditions of the majority of listeners today, moderate to high QRM urban environment, limited space for antennas. Add to this the fact that making a wire antenna work well under these circumstances can require quite a bit of effort and installing an active loop is rather simple. This leads to a lot of people thinking that an active loop is “better”, and it can be, from their understanding, their specific conditions, and the level of effort they are willing to, or can, put into the antenna installation.

But if you are in a moderate to low QRM location, or take the time to find ways to mitigate the QRM, and have room for larger antennas or put real effort into making a limited space wire antennas work, you can find many wire antenna configurations that exceed the abilities of active loop antennas.

The active loop is a quick and easy answer that can perform surprisingly well for very little installation effort. It has certain specific advantages, as do most antenna types. But that does not mean it is the “best possible” antenna.

Remember that wire antennas are just antennas, they don’t have to be made of wire, that can be just a convenient form factor for many people to install. A dipole is a dipole, be it made of wire or aluminum tubing. You can make wire beams with significant gain, or you can build them of rigid metal, the rigid structure ones are easier to turn on a rotor. Multi wavelength Beverage antennas, curtain arrays, and Rhombics are all antennas with controlled radiation patterns and, again, significant gain, and antennas typically built of “wire”.

Professional listening facilities intent on optimum performance, unless space or mobility is an issue, do not typically use loop antennas, and even less often use active loops. And yet many of them use arrays of “wire” antennas.

For HF listening (and transmitting, although I typically listen much more than I transmit) I currently have 12 different wire antennas (this number changes over time, wire antennas are easy to experiment with). I also have several different “rigid” antennas, like beams, elevated ground plane antennas, rotatable dipoles, etc. And I have a couple of loops, including the Wellbrook ALA1530+.

I end up using the loops to find direction on stations at frequencies below about 6500 kHz (the bottom frequency end of my other directional and rotatable antennas) and to listen at LW/MW freqs. I also use the loops to track down noise sources when they show up. And I use other antennas for almost everything else, because for almost every signal I can find another antenna (often wire) that receives it better (higher signal to noise ratio) than one of the loops.

T!

 

[ridgescan]

I agree Token. In certain cases, my old 100' wire not only out-shined this Wellbrook, but was quieter too.
I like the loop, but it aint perfect.

 

[majoco]

I borrowed a friends Wellbrook as he rated it so highly. In comparison with my OCFD, the stronger stations were about the same but the tiddlers were actually better on the wire. I guess it had something to do with the height or it could be the Wellbrook pre-amp noise - the Wellbrook was about 5feet of the ground, the OCFD is up about 20feet.

 

[ridgescan]

I borrowed a friends Wellbrook as he rated it so highly. In comparison with my OCFD, the stronger stations were about the same but the tiddlers were actually better on the wire. I guess it had something to do with the height or it could be the Wellbrook pre-amp noise - the Wellbrook was about 5feet of the ground, the OCFD is up about 20feet.

I guess mine is too high up at 50' plus the preamp=dealing with almost as much crap as a wire. I even wound a 1:1 ugly balun at the loop feed (I read somewhere it has an effect in receive too) just for heck and it did no good. It just tends to be noisy at HF and buzzes still get into MW.

 

[invergordon]

I borrowed a friends Wellbrook as he rated it so highly.

Being the friend who loaned Martin the loop, Martin also loaned me his OCFD and I was surprised how comparable the wire was over the loop to the point where I thought I could improve the OCFD by building a dedicated dipole for listening to 8MHz aero frequencies. So I built the dipole and accompanying 1:1 balun and found signals that I hadn't heard so there's the proof that wire trumped loop!

However, I must also state that I had originally bought the loop due to real estate space limitation and for that reason the loop does perform very well. Now having bought a property with sufficient space I am convinced the wire will yield better results than the loop over time.

 

[radioshane]

Invergorden would you recommended the loop being rigged on a big 30 foot at the back of my house on my rear elevation or on a small 10 pole erected in the garden about 40 feet away ?

 

[invergordon]

My experience showed that I had much better reception results with the antenna at ground level rather at height. I initially had my loop up at 8m (24 feet) but found signals weak and difficult to copy at times so I gradually began to lower it until I found the optimum height.

With the Wellbrook comes a short alloy stub about 300mm long which I replaced with a 500mm long wooden dowel and the dowel was pushed into the ground so the bottom of the loop was only 200mm above the ground. That was the best height for me at three different properties in varying electrical environments.

I also found that the further away from electrical noise the better. Where I now live we have a decent size back yard and placing the antenna at the end of the yard as far as it would go proved the best place. I tried next to the house on the first floor gutter, 2m, 3m and 5m away from the house but eventually bought enough coax to go the full 15m and until I discovered the wonders of wire that's where it stayed for a year or so.

In summary, if you can place it as far away from noise and low to the ground you may get some good results. But as always, your environment may be different. I'm lucky here in NZ that most urban power is underground!

 

[radioshane]

I'm definatley getting a wellbrook loop does anyone know the best thing to mount it on would be
And what the power supply is for?