| K6JV |
Rating:  |
2018-04-23 | |
| Excellent Product |
Time Owned: 0 to 3 months. |
| I live in a very noisy neighborhood with high voltage lines running right behind the house. I have an OCF dipole that has an 58 noise level on all bands. I tried several active antennas without any success. Larry's loop antenna dropped the noise level to under S2 on all bands and with a low cost Channel Master rotator, I can now hear signals that were below the noise floor before. Great product at a reasonble cost. |
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| WA9GVK |
Rating: |
2018-03-15 | |
| Superb performance 550 kHz through 10M while nulling RFI |
Time Owned: 0 to 3 months. |
My installation is not only fixed, but is confined to an attic because of HOA restrictions. The loop isn’t too lonely, though, as I have many nearby dipole antennas spread all over the attic. With the commotion of all the antenna wires, electrical lines and metal pipes under the roof, my loop installation is quite atypical. The results provided in this review may be substantially different for loop installations on the roof or in the open field. In other words, your mileage may vary and will probably be better than mine!
Construction - The loop is made of coax approximately 36” in diameter. The coax ends are terminated with connectors into a small box at the base to house a filter and preamplifier. The construction appears to be quite durable and professionally made. Larry Plummer, W6LVP, even includes a fresh roll of black electric tape to protect all connectors from the elements for outdoor installations.
Installation – Finding a free and clear location among all the attic trusses, braces, and antenna wires was quite a challenge. The loop must allow rotation up to 180 degrees. I had to settle for a position that unfortunately is only a few feet away from the aluminum house siding. (I’d rather have the signals go through wood than metal.) The antenna is rotated by an inexpensive Channel Master 9521A Rotator that Larry recommended. To extend the antenna height to a point just under the roof I added a 12” PVC pipe to the loop’s lower PVC pipe using a Homewerks Worldwide 1 inch PVC Compression Coupling, available at Home Depot. The rotator was placed upon a metal tripod screwed down to the attic joists.
Instructions – Both Quick-Start and detailed set-up and operations guide instructions are provided. The instructions are very thorough. Most importantly instructions explain how to connect the Transmit/Receive Switch included with the antenna. Several different configurations are explained including 1) using the antenna without a separate receive antenna input, 2) using with a high power amplifier, and 3) with a transceiver with a separate receive antenna input.
Cost - The W6LVP loop antenna comes with a T/R switch required for transceivers that don’t have a separate receive antenna input (like my ICOM 746Pro.) There is no extra charge for the switch. Thus the overall loop cost is significantly less than other comparable magnetic loop antennas that don’t provide the switch gratis.
T/R Switch -The switch comes with a power supply that also provides power to the antenna pre-amp via the coax feed-line. The switch is keyed from an accessory output from the transceiver. (For the ICOM 746Pro it was the Send Control Jack RCA connector). There also is a failsafe mechanism that switches upon sensing transmitter power flow.
Customer Service – Anyone reading the eHam.net reviews for this product can readily conclude that Larry provides superb customer service. My review is no different. You can’t get better amateur radio customer service than what Larry provides and I’ve been a ham for 55 years. It is obvious that Larry takes pride in his product and wants everyone to be a happy customer. After I ordered the antenna, Larry performed a study of commercial broadcasting stations near my QTH and concluded that I would need a low-pass 45 MHz filter installed in front of the pre-amp. He provided that at no additional cost. After receiving the antenna and setting it up, I had a question on the interface with ICOM. Larry replied immediately. When I had a potential issue with the T/R switch, later identified to be a bad coax section in the attic, Larry personally called to walk me through the trouble shooting procedures. It just doesn’t get any better than that.
Antenna Performance (Well it’s about time!!!)
Operating in an attic isn’t my only challenge. My environment is electrically noisy with emissions from nearby LED lights, dimmer/switches, and who knows what else. Homes are packed in just a few feet apart. Bottom line: Not a good ham operational environment.
From the time we all were baby hams we were conditioned to think that a high S-Unit reading on our receiver was good. With the advent of digital modes, our thinking has evolved. Now it’s all about having a good signal-to-noise ratio. I mention this because in all amateur band tests, the loop antenna provided a significantly lower S-Unit level than a full-size dipole cut for the same band. But the real issue is how the loop performs in terms of signal-to-noise, and ability to null out undesirable signals.
Commercial 525 – 1700 Hz AM Radio Band – Why do I even mention this? For years I’ve used the ICOM 746Pro as an AM receiver mostly to tune in a local sports station. Up until now, my 40-meter full-size inverted V dipole was the best antenna for AM use but still had a hard time pulling in acceptable noise-less signals even when the station was running full power during the day. I also have a terrible problem with RFI from a bedroom light dimmer controlling several LED-ceiling bulbs.
Rotating the loop to null out a local RFI, the noise drop was an impressive four (4) S-Units. Rotating the loop between max and minimum desired signals, the difference was six (6) S-Units.
I can now receive sports radio any time of day with minimal background noise!
160M and 80M – I don’t have a transmit antenna for either band so a direct comparison with the loop was not possible, but FT8 and WSPRnet stations came through with S/N of -24 to +5 db.
On both 160M and 80M the front-to-side ratio of the antenna receiving a desired signal was three (3) S-Units. It also provided a very effective three (3) S-Unit null for RFI buzzing noise.
40M Amateur Band -There was a four (4) S-unit difference between max and minimum atmospheric noise as the loop was rotated and a three (3) S-Unit variation while receiving the desired signal.
My 40M full-size inverted V dipole was used to compare performance with the loop. As suggested by W6LVP, the loop is first turned for minimal noise. I used the WSPRnet for comparative antenna testing. The test was conducted over a 24 minute duration—Six (6) 2-minute test cycles on the dipole; Six (6) 2-minute test cycles for the loop. Because I was using only one receiver, the antennas were not compared simultaneously, nor are the antennas positioned in the exact same location. Furthermore the results are further affected by fading. So why do I do this test? It’s really just to get a ballpark feel for antenna goodness using some level of metrics.
In the on-air WSPR test, the resulting mean signal-to-noise level of all stations was -18 db for the dipole and -17 db for the loop.
I also like to compare antennas using FT8 to approximate the number of received signals over two 15-second cycles. This test effectively compares the number of received signals having a S/N of -24 or better. The numbers were quite comparable.
20M Amateur Band –I found an approximate one (1) S-unit difference between max and minimum atmospheric noise when the loop was rotated; same for max/min on a desired signal. (I intuitively didn’t expect this lower variation compared to the lower band findings.)
I used a full-size 20M attic antenna dipole to compare performance with the loop. I again used the WSPRnet for comparative testing. The resulting mean dipole signal-to-noise level was -20 db; for the loop: -17 db. As previously mentioned there are many reasons for the variation not actually due to antenna performance. The FT8 test also showed an approximate equivalence to the number of received signals over two 15-second cycles.
15M Amateur Band –There was a one (1) S-unit difference between max and minimum atmospheric noise as the loop was rotated; same for reception of a desired signal.
For comparison purposes I used a 15M horizontal double-bazooka dipole. (I can hear the groans.) Comparing a sampling of FT8 signals on a brief band opening:
CO8LY (Cuba): -9, 0, 5, 2 on loop; -1, 2 on dipole
PU2NBI (Brazil): -10., -9, -7, -13 on loop; -11, -10 on dipole
CX7BBR (Uruguay): -15, -17 on loop; -14, -16 , -12 on dipole
K8TL: -16, -18 on loop; -16, -14, -14 on dipole
Looking at the numbers of FT8 signals received over multiple 15 second transmit cycles show a “rough” degree of equivalence between the antennas.
10M Amateur Band - I found an approximate half (1/2) S-unit difference between max and minimum noise as the loop was rotated.
I used the DXEE antenna to compare performance with the loop. At a weak band opening I compared FT8 S/N reception of TG9ADG (Guatemala);
On loop: -7, -1, -2, 0, 1, 3, 0 db
On DXEE: -3, 0, -6, -4, 1, 0, 2 db
Without splitting hairs, the antennas were in a similar performance ballpark.
SWL Bands – A quick scan across the 41, 31 & 25-meter bands with the loop revealed good all-around listening performance. This obviated the need to switch to different amateur dipoles to optimize shortwave reception. No surprises here.
Summary & Conclusions - In both qualitative listening and quantitative on-air measurements the loop antenna for attic use performed superbly across the AM broadcast band up through 10 meters. Loop performance was on par with, and sometimes even better than, my half-wave attic antennas. A key feature is the ability of the antenna to null out pesky local RFI especially on the lower bands. Hams in physically restricted operating environments will enjoy solid reception using the loop as a general purpose HF receive antenna. Packaged with a T/R switch, this loop antenna is a great value and comes with fabulous customer support from Larry Plummer W6LVP.
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| BODGIBRO |
Rating: |
2018-03-11 | |
| Very quiet antenna |
Time Owned: 0 to 3 months. |
| Received this antenna with quick shipping from the United States into Australia and Larry Plummer could not be more helpful in giving advice and instructions on how to get the best out of it for any particular location and mounting. When I first tried it out I thought there was something wrong with it and had to recheck all my connections and ensure power was getting to the receiver end module, the antenna is so quiet I have not been used to not hearing any or minimal noise in my receiver for a long time, living in an urban environment with gradually increasing man made noise pollution was and is making reception on shortwave very challenging to say the least. This antenna can receive and hear signals that other antennas don't, my wire antennas which use baluns and good grounding systems are still picking up lots of noise, this antenna does not give you signal strength, it gives you readability which is what it's all about, it is light weight and easy to set up and is working a treat for me, thanks so much Larry for a great receiving antenna design!! |
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| KA6WKE |
Rating: |
2017-12-16 | |
| I Can Highly Recommend this Antenna |
Time Owned: 0 to 3 months. |
I've been smitten with lowband now that the propagation cycle is in the doldrums. My main station antenna for 160-30 is a 36' vertical with a 40M fullwave loop capacity hat. Lowband is usable with this antenna provided signals are S9+. My local noise level is typically S6+, but lately it's crept up S9+10.
I decided I wanted to try a magloop. After much research, I decided on Larry's RX only loop. I thought just having a RX loop would suffice. Prior to purchase, I contacted Larry to discuss my situation where I have a 50KW AM broadcast station that's about a mile away as the crow flies. There are other high powered AM stations within a 10 mile radius too. I pretty much thought a loop would be out of the question. Larry responded within a few hours and did his own research and thought the version of the loop with an 11-pole 1700 KHz BCB filter might work. Both of us weren't sure due to being so close to that station. I went ahead and purchased the antenna because Larry said if it didn't work, send it back. My version included the DC power tee too as my loop would be about 60' away from the shack.
The loop was installed 7' above the ground about 30' away from my home. It was fed with 135’ of quad shielded RG-6. My QTH is in the southern California area so I pointed the antenna at about 45 degrees and left it there. No rotator yet. I used an Icom 7600 and started with basic A/B comparison between the loop and the full size antenna. Clearly the loop was very quiet compared to the vertical. Dialing around 160 and switching between antennas while listening to a QSO, the loop took over in performance once signals got below S6. Signals unreadable on the vertical were Q5 on the loop down to the ionospheric noise level.
To test the filter, I put the 7600 on 760 Khz. It pins the S meter at S9+60 using the vertical. Switching the loop dropped the signal to about S9+10. Manually rotating the antenna, I couldn’t get a null at all – just too close. Inside the shack, I added an Array Solutions BCB filter before the 7600. That dropped the signal another couple of S units. I installed right after the bias tee a Palomar Engineers CMNF-500HF broadband RFI filter to block any BCB/RFI signals traveling along the coax. This setup has zero overload, birdies, or RFI. The loop is even quieter compared to before all the in-shack filtering.
A month later, I added a rotator to the mix. Using WWV on 2.5 MHz, I was able to peak the signal to S9, then rotate the loop broadside and experience a very deep null with the signal fading between unreadable to about S2. Very nice capability.
I entered the 2017 ARRL 160M. Any station I could hear on the loop I could complete the exchange. I kept A/B switching for the first couple of hours but ended up staying on the loop for the duration of the night. Having the rotator I was able peak signals, eliminate local noise, and work any station I could hear with the 7600 and 100 watts. Many contacts were made all over Canada , US, and well into Mexico my best DX was PJ4T first call ~3000 miles away from my QTH. Not bad for a 100 watt station!
I can highly recommend this antenna and the support you’ll get from Larry is top notch. He’ll work with your particular situation to get the best performance from his loop.
73
Mark |
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| N4AYV |
Rating: |
2017-12-03 | |
| Brings out stations I never heard before. |
Time Owned: 3 to 6 months. |
I installed this loop to receive AM and LW stations on my ICOM R-8500 receiver. This antenna replaces an active antenna of a different design I've been using for a long time.
Compared to the antenna it replaces, Larry's loop significantly reduces receive noise and received signal strength of AM broadcast stations is generally equal to, or better than, the former antenna.
This antenna was able to pull out the Medi 1 longwave broadcaster on 171 kHz enough where I could hear music and an Arabic voice! This was a "receive first" for me! I am also able to receive more NDB stations than I could with the other antenna. NDB's aren't very exciting, but receiving them is a good test for an antenna.
Larry's customer support is excellent and he is very responsive to emails. He stands behind his product.
Overall, an impressive antenna that makes an excellent companion to any SWL or ham station. |
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| WPE8EKM |
Rating: |
2017-11-03 | |
| Great Antenna Soltion |
Time Owned: 0 to 3 months. |
I contacted Larry Plummer, W6LVP, and was able to purchase the Bias-T preamplifer, the power inserter, and the wall wart power supply. In addiion he built the Bias-T preampllifier with a 1700kHz 11-pole high-pass lter and a 40 mHz low-pass filter.
I then constructed my modified loop with vsrious lengths of LMR400MAX coax: 6’, 9’, 12’, and 18’ lengths. They all work well, but the 6’ and the 18’ (triple coiled) seem to work the best.
I am interested in receiving only as a shortwave dedicated listener. I am especially interested in an amplified magnetic loop that can be compact and taken on sea-kayaking expeditions and adv-bike expeditions to rugged parts of the world. I’ve spent a lot of time teacing in the DRC Congo and hope to return there some day. Having a highly portable antenna is essential.
I’m still working out a tripod and PVC structure, but may aboid that all together. The antenna is presently hung from a windo in my central city apartment.
My other antenna is the outstanding Parr EF-SWL 45’ En-Fedz dipole, which I have strung down my apartment wall from a fifth flor window. The Parr comes with a silver-plated 9:1 Balun whch does an otstanding job reducing QRM and RFI. The sensitivity of the W6LVP amplified magnetic loop antenna is comparable to the Parr, but the reducd noise level on the bands is amazing. Almost a 50db reduction in noise level. The anility to null a signal by rotating the loop axis is a great benefit.
Whether you create your own modified version of the W6LVP amplified magnetic loop antenna or purchase the full model, it is one of the best antennas out there. The quality is impecable and Larry’s customer service is world class. |
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| K4FEG |
Rating: |
2017-11-03 | |
| A solid performing receive antenna |
Time Owned: 3 to 6 months. |
As a SWL... I wanted to acquire a simple high performance receive antenna... having already experimented with various long wire antennas, I decided I wanted a easier listening solution without having to experiment with lengths and types of wire coupled with baluns and antenna tuners... After much research, I learned that a magnetic loop antenna was one of the quietest, effective and fairly simple antennas for quiet(noise interference free) shortwave listening... The only draw back that I found was the high cost of completed receiving loop antennas... After researching and compairing available receiving loop antennas, I soon discovered that the "W6LVP Receiving Amplified Loop Antenna" provided the most bang for the buck and was the best solution for me... What Larry has done with his loop antenna, is to provide the SWL community with a superb performing product at a very reasonable/affordable price... Here are my assessments of the W6LVP Magnetic Loop Receiving Antenna:
Pros:
1. Superb performance (most important aspect)!
2. Outstanding construction and materials.
3. Simplistic design and portability.
4. Exceptional value at an affordable/competitive price.
5. Easy to assemble, clear instructions and informative information.
Cons:
"NONE"... in my opinion.
Bonus:
1. Larry's dedicated customer service and product support.
2. His valued antenna knowledge and troubleshooting/problem solving expertise.
3. Accessibility and quick response to your questions or concerns.
4. Followup on product satisfaction.
In summary... Larry (W6LVP) not only makes a great loop antenna but he also provides outstanding customer service and support. Additionally, it's all included with your purchase making it a total and complete package at a very reasonable price... A++ Thanks again Larry!
Fred (TNSWL)
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| K7NY |
Rating: |
2017-11-02 | |
| works great |
Time Owned: 0 to 3 months. |
It sure cut my noise down here. Living in the city makes it tough at times on the low bands.
Terry
K7NY |
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| AI6EH |
Rating: |
2017-10-31 | |
| Solved My Problem! |
Time Owned: 0 to 3 months. |
I was having a unique problem of not being able to hear a station 20 miles away on 80M for a weekly emergency training net, due to a high noise floor. I ordered a W6LVP receiving antenna with the optional interface box to lock out the magnetic loop's sensitive receive amplifier while transmitting on a separate antenna.
Within a few hours, I received an E-mail from Larry Plummer (W6LVP) cautioning me that he had researched high power power AM broadcast stations in my area, and that I have several closer than 5 miles, with one on 1170 running 50,000 watts. He mentioned one of the great features of an untuned receive-only magnetic loop is that it covers from below 100 kHz to above 30 MHz with no tuning or adjustment. However, that wide bandwidth makes the loop susceptible to overload distortion from very strong nearby AM broadcast transmitters.
Larry offered a solution to this problem is to place an 11-pole 1700 kHz high-pass filter between the loop and the input to the loop preamp. The filter is designed to attenuate the AM broadcast band and all other lower frequencies. (Adding the filter with the antenna shipment, added $65 to the cost while adding it later would add $65 plus $10 for shipping). Since AM broadcast and lower frequencies are not important to me, I decided to order the filter with the antenna.
While I was waiting for delivery of the loop, I ordered an interface cable for my ICOM 7200 radio keying output to control the W6LVP control box. I ordered the cable with an integral relay to isolate my radio completely from the loop electronics.
A few days later the antenna and cable arrived, just in time for the weekly net. I was delighted to finally be able to hear Net Control through the reduced band noise. And, as far as I could tell, the loop performed as well on receive as my 80M long terminated folded dipole loop up 35 feet (I know, it should be higher!). The loop amplifier worked fine, even though the magnetic loop was only a few feet from my 32-foot vertical transmitting antenna.
Bottom line: If you are considering a magnetic receive-only loop antenna, you will not likely find better support and customer satisfaction than Larry's W6LVP loop. Johnny Twist (K5ACL) posted a great YouTube video demonstration of the W6LVP mag loop antenna.
https://youtu.be/BJTTy0F04yg |
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| NN3RP |
Rating: |
2017-10-22 | |
| Great Receiving Ant! |
Time Owned: 0 to 3 months. |
A few months ago my long time, undisputable, vertical active antenna from Clifton Labs (Z1501 Active antenna) amp went south and it cannot be repaired. DX Engineering had acquired the assets of Jack Smith (rip) but there is no substitute for the damaged transistor. So I have a door stopper. They suggested their similar active antenna.
So the search began. I saw all the others but decided on the W6LVP.
I add my own observations before and after I set it up this weekend:
- Initial communication with Larry was really helpful and full of advice
- set it up for RX firstly
- added a piece of PVC 5’ to extend the length of the supplied PVC as suggested in the, easy to follow, instructions. I sprayed the PVC black
- A small tripod holds the mast / rotor / antenna system in place
- The loop is about 20’ high.
- I am happy camper with its RX performance
- the addition of a small rotor really enhances its capabilities as is expected of a loop system
- Since I leave in DC, broadcasting TV / Radio stations abound. The additional filtering suggested by Larry are necessary to avoid / eliminate those pesky signals
- the signals are super clean
After tests of only receiving, the T/R switch was connected through the transceiver / Amp by way of PTT RCA connectors. The T/R protects my several receivers. Run tests with amp on. Results as expected.
I am back in business!
Thanks, Larry for a great, cost effective, product.
73,
Rafael / NN3RP
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