NR Precision’s newest antenna market entry is the phenomenal new LOOP antenna designed by a degreed engineer. The W4OP Loop has already received extremely high reviews on eHAM and customers around the world. We feel that the W4OP LOOP antenna is the BEST Loop Antenna on the market and like all LNR’s tagline, “They Just Work!!”
It seems that more and more, amateurs are facing increasingly strict HOA’s.
This antenna is for the QRP amateur that is looking for a small antenna for home, backyard, portable or the park use, while it is also usable for hiking.
The primary design goal was to offer a loop at lower cost than what is available but with better performance, high quality construction and features not found on the currently available loops. To that end note that the loop comes standard with stabilizing feet and a no-mar table/railing clamp and an inexpensive, optional camera tripod mount is also available.
Also note that the design is water resistant with seals on the 60M switch and variable capacitor shaft. The silver SO-239 connectors are also sealed and the silver PL-259’s come with a slip on silicone boot.
To that end, this design has almost 100 parts, many of which require considerable machining to achieve excellent fit.
The coupling loop features a novel hybrid coupling scheme that guarantees a match of 1.2:1 or better from 60-6M when the antenna is mounted in the clear.
No other US loop can make this claim.
Compare this to our competition.
In addition, the coupling loop assembly easily adjusts in height to guarantee an optimal match on all bands. The height adjustment is accomplished by loosening the plastic thumb screw, adjusting the height and relocking the thumbscrew.
While height adjustment is not mandatory when changing bands, extremely low SWR can be achieved if one takes the time to adjust the coupling loop height.
The loop comes with 4 machined, powder coated stabilizing feet that attach by custom locking thumb screws. Also standard is a no-mar clamp for affixing the antenna to a table or railing. A tripod option is now available. The adapter mounts with the same 10-32 red thumbscrews that are used for the stabilizer feet.
The main tuning variable cap is dual gang and does not make use of the lossy grounding fingers. Rather, the 2 gangs are connected in series. A 6:1 reduction drive makes for easy tuning. On 10M the bandspread is very wide making for even less critical adjustment.
On 40M, the W4OP loop is 4dB better than the Alex Loop, 6dB+ better than the Alpha Loop, 5dB better than the Chameleon CHA-P loop, 10dB better than the Chameleon CHA-P loop and 10dB better than the G4TPH loop.
We have just completed the 6M option. On 6M the system behaves more like a quad loop- broadbanded and gain about equal to a dipole. Maximum radiation is now perpendicular to the plane of the loop. One full rotation of the variable cap is only 800KHz on 6M, making tuning extremely simple. Maximum radiation is at right angles to the loop as would be expected with a larger circumference loop (in terms of wavelength).
The support mast breaks down into three (3) pieces, each one under 14”. A unique tuning scale on the front of the enclosure makes for getting the loop tuned to each band extremely easy.
There is a lot of confusion regarding loop efficiency and the on-line calculators.
Calculators such as Pacific66 may have limited use in specifying an L or C for a loop, but cannot possibly predict real world efficiency because it does not ask for the information required for that calculation.
The AA5TB calculator is better but can be confusing to the uninformed, because the -3dB bandwidth (an easily measurable quantity) in the calculator is a dependent variable and loss resistance is an independent variable.
As an example, the efficiency figures quoted on the Chameleon loop site are grossly optimistic because they apparently (based on their SWR curves) put zero (0) into the Added Loss Resistance field. The most comprehensive calculator would be from Owen Duffy at:
http://owenduffy.net/calc/SmallTransmittingLoopBw2Gain.htm
This was the calculator used to arrive at the gain figures of the competitor’s loops. The Alex Loop, Alpha Loop and G4TPH along with the W4OP loop were all tested with the bottom of the loops 10’ above 2mS/m ground. In the case of the Chameleon loop, we used their SWR figures. There may be a bit of differential in the Chameleon results as they say the loop was varied in height above ground during SWR data taking.(?) It would appear that this was perhaps done to yield better SWR results on some bands.
Make sure to look in our gallery of pictures for SWR Plots!
| Small HF Loop Specs | |
| Loop Diameter: | 45″ |
| Band Coverage: | 60m – 10m (6m option planned) |
| Power Handling: | 15W SSB/CW, 10W Digital |
| Antenna Weight: | 3 Pounds |
| Connector: | Female gold/Teflon BNC |
| Shipping Size: | 18″ x 18″ x 4″ |
| Hardware | Stainless Steel & Nylon |
VHF
Successful VHF QSO between ZS3 and ZD7
Kobus van der Merwe, ZS3JPY reports that between 19:45 and 21:45 UTC on Wednesday 7 November 2018, a QSO took place on 2 metres between St Helena Isla... Read more
AnyTone AT-D878UV PLUS with Bluetooth and PTT remote
This is a demonstration of the new version of the AnyTone AT-D878UV PLUS with Bluetooth and PTT remote. Read more
Icom IC-2730
Icom proudly announces the debut of the new VHF/UHF dual band transceiver, IC-2730A/2730E. It is the successor of the long selling IC-2720H ser... Read more
2m 7 Element OWL-GT Super-Light Yagi
Sales price£139.95 Description A 7 element OWL-GT (Optimised Wideband Low Impedance) Super-Light Yagi for 144-145MHz – 2019 model FOR HORIZONTAL... Read more
New ! BIG TAJFUN 1000 144 MHz – 1KW
Description New robust Heatsinks – Fischer. Continuous 900W DIGI-modes. Quiet fans. TAJFUN 1000 is small, lightweight but robus LDMOS Power Ampl... Read more
Review
GMRS Midland Micromobile Review, MXT275, MXT400 Radios
GMRS Midland Link to Part 1 https://youtu.be/AQTQptqusfc Part 2 in the micro series on GMRS. IN this video, I will show you a couple of the rad... Read more
REVIEW: Connect Systems CS800 DMR mobile radio by VE3XPR
The Connect Systems CS800/801 (UHF/VHF) is a new value priced DMR mobile radio being offered by Connect Systems, as part of its line-up of budget DMR... Read more
Review of SDRplay SDRduo Two-Tuner SDR Radio
“SDRplay has done it again with an outstanding and technically sophisticated software-defined radio that even at $280 is still a bargain. The vi... Read more
Power Line Noise and Bat Detector – MFJ 5008
HF and VHF operation can be affected by noise on the bands which makes it hard to hear the weaker stations and adds to your fatigue. Many times the no... Read more
Equipment
AR-ALPHA 10kHz-3500MHz, Digitally processed Professional Grade, Base Type
AR-ALPHA 10kHz-3500MHz, Digitally processed Professional Grade, Base Type Read more
PicoAPRS Transceiver
“Worlds smallest APRS transceiver with TNC” offers many applications. Matchbox-sized, built-in GPS receiver. The transceiver can not only... Read more
Heathkit ® Precision RF Meter – HM-1002 – pre-order
Finally, affordable laboratory-grade accuracy. And a whole lot more. For about fifty years, SWR/power meters haven’t really changed at all. Un... Read more
Elad FDM-S3 SDR
— WIDEBAND DIRECT SAMPLING RECEIVER —- JAN 2020 SPECIFICATIONS 2 switchable HF Antenna inputs direct sampling 1 VHF Antenna input direct s... Read more
Ham Radio Go Box
Ham Radio Go Box Read more
Antenna
RQ-84 – The classic “Quad” full-size has ten elements for 10m, eight – 15 m, six – 20 m, and four full-size elements on 40m band
RQ-84 – the classic “Quad” full-size has ten elements for 10m, eight – 15 m, six – 20 m, and four full-size elements on... Read more
18el 6bander – GXP Antenas – 40/20/17/15/12/10
GXP Antenas 18el 6bander Bands 40/20/17/15/12/10 Gain (dBd) 3,9/10,6/10,3/10,5/10,2/10,5 F/B (dB) 22/26/22/23/20/21 SWR 40 le... Read more
6-160 Meter Alpha S9 Spun Fiberglass Antenna
Introduction: Acquired in 2014 by Alpha Antenna, the S9 Antennas have been completely improved and resigned. Years of perfecting the manufacturing pro... Read more
Active Antenna Amplifier (model AAA-1C)
Active Antenna Amplifier The Kit The amplifier kit consists of the following parts: Amplifier board (mounted and tested) Control board (mounted and te... Read more
Vertical Dipole Array by OH1TV
An easy to build antenna for seaside locations 17m and 15m versions were used at 9M0O DX-pedition in 2016 Some notes • Wire lengths R and D are... Read more
