Many thanks to SWLing Post contributor, Chris Rogers, who writes:
Hi Thomas,
An interesting new product has just been released for pre order, a US made Chameleon model CHA-RXL receive loop covering from 137 kHz -30 MHz.
Looking at the options it comes on the web page it mentions a Loop type ”US single section” or “two sections European”. I am not sure of the difference however. In the specifications it claims a 36” loop.
However a very interesting new antenna to compete with the likes of Wellbrook, W6LVP etc
Hopefully you may, or one of your readers get one for review.
Thank you, Chris! I do plan to check out and review this loop from Chameleon. I’ve been evaluating a number of their ham radio field antennas and can say that the quality is simply military grade.
I’m guessing (and it is truly a guess) that the EU version of the antenna is simply in two sections to save the customer excess shipping charges based on the package dimensions.
Thanks again for the tip.
Would like to see a side by side like for like comparison/shootout between this, the Wellbrook and W6LVP. The MLA30 isn’t in the same league at all.
Another active loop option is from LZ1AQ (https://active-antenna.eu/amplifier-kit/). It’s not really a kit, per se, in that the amp and controller are assembled, but you provide the mast, loop, cabling, etc. It gets very good reviews, and has a lot of versatility in how you choose to make the loop (or multiple loops), and he has a lot of technical and practical information on his site.
I have one on order – about 130USD shipped. It just hit NYC a day ago after leaving Bulgaria on the 9th, so I’m guessing about 3 weeks delivered (also based on an transceiver/SDR/antenna switch I ordered from him recently).
The gain figures are interesting but really misleads a newcomer into thinking that more gain is better.
With loops, that’s not necessarily true
As you mentioned, what you want to see (among other things) is a better signal to noise ratio. Put another way you want to be able to hear the signal with less, not more, noise. A poor amplifier is likely to be noisy and could even defeat the whole purpose of using a loop in the first place.
The price on this is similar to other high end loops such as Wellbrook, NTI Bonito etc. What separates high end loops from cheaper loops is the antenna preamp design and the ability to handle strong signals without overloading, and have very low signal to noise ratio. Hopefully a review of this loop compared to other similar loops will prove whether the cost of this is justified.
Incidentally from the user manual there is a gain graph and the antenna gain is given as 25db gain around 1mhz and around 12.5db at 30mhz.
Best bang for your buck loop antenna
http://www.crosscountrywireless.net/loop_antenna_amplifier.htm
According to the manual the non USA version is supplied without the plug pack power supply. A 115 V input plug pack is useless outside of 60 Hz mains areas. The 230 V plug pack is not that expensive.
It is interesting that they say that the frequency range is from 137 kHz. Europe and Africa is the only areas where low frequency broadcasting is allowed by the International Telecommunications Union. It mentions twin loop for Europe. Is this to improve sensitivity at the low frequency end?
The 137 khz range was mentioned because in the US hams have an experimental band between 135.7 and 137.8 khz – the 2200 meter band. Even tho it cuts off at 137 khz, likely you would still get some response at 135.7, altho at reduced performance
Looking at the manual, the loop does cover the entire 2200 meter band. Useful for folks that go low…
> “The 230 V plug pack is not that expensive.”
*Clean* linear (i.e. non-switchmode) low voltage plugpacks & power supplies are almost impossible to get in the UK & Europe, thanks to efficiency regulations, and I understand increasingly difficult to find in the USA. They’re also getting very difficult to find here in Aus, as you may know, as well as relatively expensive due to limited demand and small quantities imported.
If you’re considering this unit because of the sturdiness of the loop element, consider this as a counter argument – you could buy the W6LVP experimenter’s kit (at USD180 with the recently announced increased prices), and if you’re handy, make your own loop element and save even more.
You can’t blame him for raising prices – this is happening everywhere, even in the electronics market.
$420 for an amplifier in a box and a DC injector is quite some number!
The loop is extra, as are the cable and the power supply. This also solves the riddle about the two-part loop for Europe: They wanted to reduce the packing size.
So they must amortize their R&D on 100 sold products or so. How many could they sell for $200? I cannot see how the production costs of 1.000 units could be higher than $100 per unit. Compare it to the QCX QRP transceiver kit: That costs, including the case, $80.
In the US at least this price point is nearly the same as the Pixel / DX Engineering, if not a bit more. For the same frequency coverage, the W6LVP has it beat at half the cost. The MFJs don’t cover quite as far down but they are, at least at first glance, as good as this. Sorry Chameleon but your marketing research is very poor
Mike
Good point regarding the W6LVP. At first glance, it would appear the Chameleon is of stronger build quality than the W6LVP. I suppose time will tell if it outperforms the W6LVP. At this price point, it had better… and admittedly I’ve seen comparisons where the performance difference between the W6LVP vs MLA-30 is negligible. Still interested, but the Chameleon price point that may prove difficult to justify.
I’ve heard about such comparisons too and unfortunately they were pretty pointless: They were made in a more or less noisy environment which limits the SNR of both loops, hence making any loop of this type (active, simple loop conductor) appear to perform more or less the same, which then (IIRC) got the tester pretty riled up about the W6LP. But SNR is only on metric, another one is the other end of the dynamic range, how they respond to strong signals inside and outside of their coverage range, and that’s where differences between very cheap and a pretty pricy SMLs are to be expected. So it might even be true that the difference is neglible but as of yet I haven’t seen a proper (practical or lab testing) comparison that proves that.
You can read the FULL User Guide at the following link:
https://www.dropbox.com/s/39bxg6uv50fwzcj/RX%20Loop%20Prod%20Final.pdf?dl=0
Carl
looking at the shippef items there’s a “tuning unit”; now I wonder if it’s a (varactor ?) tuned loop, any info about that ?
Skipping thru the manual I didn’t see any ‘tuning unit’. This does have an amplifier, not a tuning unit.
$420! How come?
That’s what they think people are willing to pay, based on the fact that people happily paid $400 for other active loops, including yours truly. 🙂
I’m with you Gustavo. The price is very high for a receive only loop.
This antenna certainly has my interest. I’m currently using an MLA-30 loop in my attic and getting great results considering how little I paid for it. The Chameleon CHA RXL definitely looks far more substantial and sturdy and would likely last a lifetime in an attic installation. If reviews demonstrate a marked advantage in reception and S/N ratio over the MLA-30, I might have to consider it.
Thomas. Think your guess is correct. On page 5 of the user guide, when the parts of the antenna are described, under item d ‘Loop Flange’, mention is made of the Export version of the loop being in two pieces. Shipping dimensions & cost therefore makes sense.