Sunday, 17 December 2017

Ode to SDRplay RSP2

Unadulterated and highly personal review follows of a product I love. Been writing this post for many months, in fact, over a year, adding and subtracting, cracking an RSP2 is not possible, like an onion, deep into the rabbit hole, then some.
Conclusion: get Visa or Mastercard out, be happy. RSP2 is the beginning, the end, the ultimate Software Defined Radio.



Got my RSP2 before 2016 Christmas as a review sample, been using since as often as I could.
Normally, I do reviews with lots of images as a rule, but rules are to be broken, and this is not a review. Do a review of your wife when cooking, who cares when the end result is a nice dinner?
SDRplay introduced their first receiver, now called RSP1, nearly two years ago. Good receive performance, combined with all-in-one form factor, and integration with one of the best front-end software made it a popular choice.
Two years is a long time for a software defined radio (SDR), therefore a facelift was in order.
Price had to remain below 200 dollars and the new product, unsurprisingly called RSP2, had to work with existing software, so the core remained the same 12-bit tuner. Pretty much everything else has changed: most of the shortcomings I mentioned in my previous review has been improved, then SDRplay added more features. Then more.
Then head of finance showed up, inquiring how SDRplay will make a profit on the RSP2, was tied to a chair and made to listen to "All I Want for Christmas" whilst engineers went back to work:
- Improved case with RF screening,
- Three antenna ports, one with bias-T, one dedicated for sub-30 MHz,
- FM and MW filters,
- software-adjustable low noise amplifier,
- clock synchronisation,
- and so on, read the official Data Sheet here.
If you don't know what any or all of the above means, be rest assured that the RSP2 is one of the latest, most technologically advanced, and most practical Software Defined Radio receiver.
SDRplay sent a production unit RSP2 for testing shortly after the official announcement - thank you. As always, what you read here is my honest opinion.
I'd like to make one thing crystal clear before we start: this is not a lab review. I don't live in a lab. rtl-sdr.com has already done one and featured the RSP2 several times, therefore I listened to the RSP1 and the RSP2, alongside the best the RTL-SDR scene and traditional solutions has to offer, in two countries at multiple locations, at sea and on land, with various antennas for over a year.
Written down what I heard at the field and at home, then interspersed notes with comparative technical details and personal observations.
Again, do not read what follows if you value your time, if thinking of buying one and need justification, stop thinking, buy one if you can afford it. 

Pricing and availability


Less than, or close to 200 dollars' equivalent local currency, depending on where you live. To Ireland, an RSP2 delivered costs a few bobs below 200 euros. That's birthday and Christmas put together money range.
200 dollars seems a large wad of cash for a small plastic box if you're unfamiliar with radio equipment prices: a handheld communications receiver, or a top portable world-band radio costs about the same.

Who is it for


- people thinking of upgrading from RTL-SDR based dongles,
- existing RSP1 users,
- newbies with a gold credit card wanting a one-time purchase,
- amateur radio ops looking into SDRs and yearning for a good solution.

Unboxing


Plastic box with printed instructions inside envelope, protective red caps on SMA ports. Slightly larger than a pack of cigarettes, small and light enough to put into a pocket, won't pull your pants down.



New case material and texture, RSP1's coffee stirrer plastic quality is gone, replaced by a textured matte black finish. Feels in the hand like an industrial handheld transceiver, better than a Baofeng, equals an Icom, still not Motorola level, but a huge improvement over the RSP1.
Minor changes on the case, antenna ports moved up, so reassembly is easier, two new MCX female ports for clock in and out - these are NOT antenna ports.
Indentation on top, slightly heavier, external changes help distinguishing it from RSP1 in the dark by feel alone.

Software


Comes with own and free native software, called SDRuno, offical link here, which also works with RTL-SDR dongles, so you can familiarize yourself if you got an ordinary dongle, or read my guide by clicking on this link.
A lot of visual real estate will be required to enjoy a maximum of 10 MHz visible span on screen. 10,000 kHz worth of instantaneous spectrum monitoring is cool, but you'll need more than a small laptop screen to actually identify a transmission. Multiple screens, as large, with as much resolution as financially possible is required to fully enjoy 10.66 MSPS.
SDRuno (officially) supports multiple 4K displays and rescaling is click-and-pull, so if you've just robbed a bank, or won the lottery, you can enjoy breathtaking resolution on three 4K LCD TVs.
I only got an old laptop which costs around $400 new, and it managed to spread 10 MSPS across two car boot sale monitors, but with a lot of fan noise. Peace and quiet returned at 5 MSPS, which is more than enough for my purposes.

No antennas nor accessories


Great as a doorstop, albeit a quite expensive one.
Please, send at least a rudimentary coax and any kind of antenna, the general public needs a solution right out from the box to hear signals.

Bias-T


A.k.a sending power down the coax cable to power an antenna-mounted preamp. As explained earlier, LNAs are good for you, not only to overcome coax loss, but to lower overall system noise figure.
RSP2 worked with LNA4ALL, novakx5 LNA, and Outernet's preamp straight away.

Built-in adjustable gain Low Noise Amplifier


Software-selectable, as in there's a button you click in SDRuno, and LNA turns on for selected antenna port.

Three antenna ports


Finally. By my estimate, 100% of enthusiasts use more than one antenna, and screwing on a frequency-specific antenna was a chore with the RSP1. Not anymore: I can keep the discone on Antenna port A for "let's browse around", power a mast-mounted LNA for airband (substitute with 2m / 70cm / whatever you fancy), and use a random wire for shortwave.
A step in the right direction, but not enough. Instead of, or in addition to clock in and out ports, I'd love to see two or three more antenna ports. 

Intermittent personal observation


RSP2 is demanding for an enthusiast. I ride motorbikes, and know my goaround moped gets me there, but by now, I realised the RSP2 is a purebred superbike. Antennas matter a lot, just like throttle control, for weak signals, the difference between a random wire and band-specific dipole was huge in an electrically quiet environment.
In a city, a T2FD is hard to beat, and the RSP shined with it. A 200-horsepower machine needs warm weather, slick tyres and a good rider for fast lap times, just like the RSP2 needs middle of nowhere, a frequency-specific antenna and familiarity with SDRuno.
Make no mistake, RSP2 does the job with a makeshift antenna, riding straight on a highway is easy. SMA connector takes center conductor from coax, so I could get really good performance during a recent plane-plotting session when I left the mag mount at home.
Turn left for the twisty bits and depths of last-degree performance is there to explore.

HF port


Green yoke supplied with RSP2, officially called I have no clue, neither my electrician trade shop when I showed them what I want, couldn't get a replacement. This plugs into the side of RSP2, meant for sub-30 MHz signals.



TCXO: Entered frequency will be tuned frequency, hasn't been an issue with RSP1, but SDRplay added the feature anyway.

Sensitivity


That means how well a receiver can receive signals. The RSP2 is very sensitive.
Very sensitive. I write this down again, because if you're used to lesser equipment, you will just stare, shaking your head in disbelief. Feel free to read eHam reviews (4.7 out of 5 stars) or Ham Radio Science's post.
Writing about comparative performance versus this or that is moot, as reception is down to 1) antenna, then 2) location, and those two variables will not be the same between readers. Whenever I need to listen to a signal I just reach for the RSP2.

An enjoyable personal journey


I soldered my first receiver with my Dad when I was 6. Three decades later, the RSP2 gives a push. A push to perfect antennas, a shove in the right direction to optimise noise reduction in my home, a mental kick to drive bumpy roads to a hilltop with less man-made noise to catch a signal. Or just for the fun of it, and that, my dear reader, is the biggest feature of this black box.
SDRplay RSP2 is the devil on your shoulder. Whispering in your ear, take me out of a city, give me a good antenna, travel with me to the end of the world, and I will golden the very moment when you and me be at the right place at the right time.

At sea


Took the RSP2 for a spin on the West coast of Ireland during a recent mobilisation, had no issues. X-band and S-band radar didn't seem to affect performance, telescopic antenna with SMA worked well, shortwave was easy with a piece of wire. Couldn't do more due to 6 on 6 off watches, RSP2 worked without a hiccup, wasn't affected by violent vessel movement, unlike I was.

FM filtering


Works nicely. Push a button, FM band wiped out, interference gone.
Easy, as it should be.

Shortwave listening


The RSP2 with SDRuno is a shortwave listener's wishlist coming true.
I had a Tecsun PL-680 along (please refrain from indulging in the portable vs SDR debate for a moment), which is highly recommended by SWLing.com and costs the same.
Audio quality was nowhere near what I could get with the RSP2, the two receivers are not even on the same page.

Living with it


Only had the RSP2 for a while, went to remote locations, without electronic noise to assess HF performance, to the top of nearby mountains to see how far I can hear, and the impression remained the same.
Practicality rules. Magnetic mount on top of the car, with airband antenna, wires leading out from back window for HF. I had a v.3 and a SMArt, plus a Ham It Up representing RTL-SDRs, a Tecsun PL-680 demonstrating what a same-price portable worldband radio can do, and me old Icom IC-R5 as backup.
SDRplay RSP2 never left me wanting.

Personal lifersaver


This is the part you won't care about.
Walked down the slope, to the top of a nearby mountain, set up shop with antennas out the car window, laptop and RSP2 on the back seat as I wanted to get spine-shaking rush to the head of hearing a signal, a small joy, something I was looking forward after 10 years of a progressively deteriorating relationship, loneliness, depression, " I feel so alone", into the sea, I had something to look forward to.

 What to do with an old RSP1?


Give it to someone who needs it, like local schools, ham club, or anyone who could use it. SDRplay sent me an RSP1 for testing aeons ago, and Jon agreed to my proposal, so I have an RSP1 for education purposes. Get in touch with SDRPlay if you live in Ireland, but please only do so if you'll use it for the common good.
This approach is one more reason to choose SDRplay. Kudos to Jon.

Nice company to deal with


Questions to support got answered quickly (support@sdrplay.com), and SDRplay is working with other front-end software such as SDRConsole. And remember, these are the people who made a previously expensive software available for free to RTL-SDR users, then added full 2.4 MSPS support.

Versus RTL-SDRs


To assemble something similar, you'd need:
- dongle with TCXO for $25, 
- one more dongles to get two more antenna ports, add $25 each,
- upconverter for $50,
- preamp for $25,
- adapters to connect all above together, $10,
- FM filter for $15,
- and so on.
More money at the end of the day, just like any consumer product in parts costs an arm and both kidneys at the till if you want to go cheapskate and save money.
Regular readers know that I love RTL-SDRs, but had to grudgingly admit that the RSP1 was a hyperspace jump, and the RSP2 with added features is, despite the seemingly high price, is a realistic alternative if you want and can use its features.
For strong local signals, an RTL-SDR dongle will get the job done for significantly less.
For weak signals, the RSP2 is better than any RTL-SDR based setup.
Mindset matters, like when I was 17, in a testosterone-induced stupor spent my savings on an air filter, bigger rims and the customary ironing board on the back. Piece by piece, and yes, cleaning and detailed polishing will make any car faster.
Fact is, I must admit with a diminishingly balder head, that extra oomph comes from displacement, and this is the point when I have mention the 12-bit nature of any SDRPlay, if you still follow.
Common RTL-SDR dongles are 8-bit, and 12-bit is more, just like a Corvette is more than a Camry.

Versus AirSpy platform


I don't know. I don't have an AirSpy, because I didn't invest in one, despite reviews praising excellent performance, for the following reasons:
1. Software.
2. Two boxes.
3. Costs more.
SDRplays are just one box, which does it all on an old laptop. With HF port on the RSP2, I need an USB cable, a telescopic antenna and a length of wire to get signals locally and from around the globe. Anywhere.
The AirSpy vs SDRplay war raging online is akin to tea or coffee, or whether you should mix chocolate into porridge or just sprinkle on top argument.
Pathetic, really, as both are great receivers, both are excellent value for money - come on guys, let the other camp flourish.
Be merry that we got choices.

Before you buy one


I'd strongly suggest to order a premium dongle (Nooelec SMArt or rtl-sdr.com v.3 or SMArTee XTR bundle) kit for the supplied antennas, and think of dongle as a bonus. Connectors and antennas are compatible and well worth the price alone, receivers are great.
An USB to USB-B cable will be also necessary, try to get one with ferrites on both ends.

What needs to be improved


More antenna ports: at least four for VHF and UHF and four for HF. I'd love to select frequency-specific antennas for a job with one click. Speaking of, I want editable names for ports in SDRuno, so I can know which port is the discone and which one is the airband.
I want to order green adapters, so I could set up band-specific antennas for mobile operation, a ferrited data cable should be compulsory, and if a company can make a receiver, why I can't order antennas to go with it?

Summary


The SDRplay RSP2 is the best affordable all-in-one software defined radio receiver.
I can't think of a better solution if you have $200.
RTL-SDR dongles are near, traditional portables have no chance. When you add factors together, the RSP2 always comes out a winner. If you had to pay a thousand dollars, the RSP2 would still win.
Nothing beats the RSP2 for value for money. Or personal growth. Or what's out there. This little small box offers so much more than words can convey, therefore I can only come to one conclusion after more than a year's use: buy as many as you can afford.

Sunday, 10 December 2017

Review: Uputronics Wideband Preamp


Review: Uputronics Wideband Preamp

Also called HABamp or Habamp, a low noise radio amplifier for radio signals between 100 MHz and 4 Ghz in a metal case with bias-T or 5V external power.
Available for $45 equivalent from the manufacturer in the UK, or for $45 from airspy.us in the USA (plus shipping).
Recevied review sample from the manufacturer without strings attached  - thank you. Customary legal bits here.
Testing has been carried out with multiple receivers, with a discone and frequency-specific ground plane antennas for innumerable months - for a reason.
Summary: ultimately, I must conclude that Uputronic's Wideband Preamp is the best external preamp available for radio enthusiasts for general use.
Pricey, but well worth it.

First impressions

Technical specifications from manufacturer, black and white version with instructions shipped in box:



Unit is massive, built like a tank (same case as all other Uputronics preamps), SMA female ports with nut and washer properly labeled.



Printed circuit board, gotta love the personal touch:


Large PCB and finned metal case contributes to excellent heat dissipation, metal case was only 2 degrees Celsius warmer than ambient room temperature of 19 degrees - to put values in perspective, rtl-sdr.com v.3 registered 37 degrees, and a Pro Stick Plus in an rtl-sdr.com metal case with thermal pads showed 42 degrees with same infrared thermometer.



Reliability was 100%. Plug in and forget. Spoke to a fellow soul who uses Uputonics gear for years, and had a blank stare whan asked about reliability: "Man, it's plugged in for I can't remember how long, never had any problems". Recent post on rtl-sdr.com showed NASA uses Uputronics preamps, case closed.

Power options


Via USB Mini-A cable: same type used on external hard drives / GoPro / Garmin satnavs etc, unit can be used with any RTL-SDR or with any receiver when amplification is desired. No hassle if you have an appropriate cable, which is not supplied, nor can be ordered from Uputronics webshop, costs a few dollars on Amazon USA or similar money in any electronics shop or on eBay.



Via bias-T: also called phantom power, receiver sending power down the cable. SDRPlay RSP2 and  RSP2, rtl-sdr.com v.3, Outernet E4000, Nooelec SMArtee XTR tested and preamp functioned flawlessly. Reportedly works with AirSpy and HackRF, or any other receiver with bias-T capability.
No indication that sufficient power is supplied to preamp - a LED would be nice.

Accessories


Available in Uputronics webshop, mounting/lug kit costs $6, factory-fit bias-T 26V option costs $9, enclosure costs $43 (not tested).



SMA Male to SMA Male coupler / barrel adapter for $4 is a must if you don't have one to connect it to SMA receivers.

Performance

Great. Does what a preamp's supposed to do, more signal, less noise, cleaner waterfall, better SNR ratios.
No offense part: Beginners, or if you don't know how an LNA works, or if you just started discovering signals, please get a discone first, or go for a ground plane for a specific frequency. You'd be wasting your cash ordering one without antennas. Serious, here.

Versus Competitors


Uncomparable. Alternatives differ in price, features, build quality, noise figures or reception range, all are a miserable far cry when handled or used on a daily basis:



Closest I'd recommend for nearly half the price is Adam's LNA4ALL with bias-T factory mod, same chipset, proven and dependable contender:



That preamp, saying LNA4ALL here, lives at the bottom of discone for more than three years, great, Uputronics spent considerable time out in the rain, good as new.
Not a competitor, as LNA is integrated into RTL-SDR dongle, is a FlightAware Pro Stick:



Orange dongle above will be the same performance, and sometimes more, than a premium dongle and external amplifier, combined.

ADS-B


Amplification will always pull in more signals, so my question was whether it's a reasonable alternative versus Uputronics' own filtered ADS-B preamp (both stations are identical ModMyPi Raspberry Pi 3s running PiAware and sharing FlightAware antenna via splitter, 24 hour's data, 2% margin of error, short coax length):



Filtering added significantly more position reports and better range:



Add a FlightAware filter after the LNA (same configuration as filtered Uputronics and Pro Stick Plus):



Results are within 2% margin of error, polar plots look almost identical:



If you already have a FA filter and want a versatile wideband preamp at the same time, it seems like you won't lose that much by not going for the filtered version.

Day-to-day use personal observations


Easy. No bother. Plug in cable, or enable bias-T with rtl-sdr.com v.3, power to LNA is on. Without any second thoughts, no mental pathfinding.
Reliability combined with good performance is the name of the game. More often than not, I reach for the Silver Finned Shark, as I call it by now, because I trust it to get the job done. Be it mast-mounted duty, or rediscovering weather satellites, or wanting an arbitrator for testing gear, I know the safe choice and one hand movement will be the chunky silver one when I can see, with fins on the side when I can't and go by touch.

Conclusion


Quality combined with excellent performance.
Alternatives might be cheaper, but none provides the mental reassurance of a well-designed product with ease of use.
Would I buy it? Yes.
If I could only have one external LNA, I'd get an Uputronics Wideband Preamp over anything else on the market. Costs a lot, but quality never goes out of fashion.

Useful accessory: Nooelec Adapter Kit

A solution for most scenarios and antenna connectors, officially called "Nooelec SMA Adapter Connectivity Kit", a plastic box with lots of shiny connectors:



Costs US$19.95  on official Nooelec website or on Amazon USA, had it in a week from the States to Europe for free as a review sample (disclaimer).

Who is this for?


Any radio lover who needs to connect different bits and pieces to radio receivers, accessories, paraphernalia and antennas, or vice versa, because the industry still haven't settled on one connector standard.

What you get


Sturdy closeable plastic box with eight compartments and fold-down latch, all 100 kg / 220 lbs of yours stood on it one-legged and didn't budge, carried box around for weeks and didn't open once. Internal dividers enable custom partitioning, no idea what purpose flimsy bit with hole serves, maybe if you're climbing a sheer wall and want to attach it to a rope?
Nooelec.com sign on top is mentally reassuring, writing what's what on each compartment might be a good idea - I had a rough idea what purpose a particular connector serves, but neighbor Jane wouldn't have a clue.
All connectors end up in SMA male termination, which is the most common on quality SDR gear, so it's possible to connect any equipment, such as Nooelec SMArt / rtl-sdr.com v.3 / SDRPlay RSP / AirSpy / whatever with SMA female sticking out.

Female N-connector: Chunky pro level equipment uses N-connectors, like transmitters and antennas in the kiloWatt range.

Female F-connector: Standard for TV in the USA, satellite and cable TV and internet modems in Europe, widespread around the world.



Great fan of this standard as easiest to assemble at home, plugs are cheap as chips at any electrical shop.

SO 239: Relic from WW2, oldtimers with tabletop HF transceivers or CB equipment might need it. Not using it at the moment, love the fact it's included, because any CB magnetic mount (or similar gear found for cheap) could be easily utilized.

BNC adapter: also known as bajonet mount, push and twist, for instance, use with scanner antennas (in image below).



For an at-home setup, CCTV T-junctions and coax notches based on BNC connectors work extremely well as a poor man's bandpass filter.

MCX: SMA Male to MCX Female, so if you got an old antenna mount, it can be used with the latest gear:




PAL: TV standard in Europe and in many parts of the world - use store-bought antennas easily.



PAL is extremely easy to work with due to size and no-brainer one-hand push-in movement.
RP SMA: RP means Reverse Polarity, easier to explain with an image:



Reverse Polarity often catches out beginners as they wish to use WiFi antennas with dongles without any success - inserting a 4mm coax center inbetween is a solution, but the proper adapter will be less hassle:



Male SMA barrel: Standard to connect any SMA to any other SMA gear, priceless when you want two otherwise useless doorstops to work in harmony.

Reliability


Tried all connectors with multiple antennas / LNAs / receivers and all functioned flawlessly. Personal sidenote: I use Nooelec connectors for over two years and not one malfunction ever, so got no doubts this kit will serve me into 2020 easily.

Barrel or pigtail?


Barrel adapters, like the contents of this kit, have less points of failure and less signal loss due to no coax cable used. Pigtails are more flexible, easier to screw on / off, but cost more.
Depends on what you wanna do: for a fixed setup when components are not moved around, like ADS-B testing, I prefer barrel connectors. For on-the-road use, pigtails are clear winners due to less stress on connectors and PCB mounting points.

Competitors and value for money


Rtl-sdr.com offers a 6-piece set for $15 without a box or quite a few alternatives, haven't tested them, so can't comment. Seriously doubt that these connectors / adapters are markedly different from other offerings on the market, try searching eBay for "SMA adapter kit", results will look identical with prices hovering around the 1.50- 3 dollar mark per piece with shipping from China, or six to eight piece kits for around 10-15 USD can be had.
8 adapters in a plastic box for $20 from a trusted brand is reasonable.
Look into what you need, examine photos above to identify you dongle / antennas / gear, think about future prospects.

Would I spend my own money on this?


Yes. Flexibility is the name of the game, especially if you've amassed an antenna connection, and it's eventually cheaper and easier to have one box that enables otherwise useless bits and pieces to function.

Wednesday, 6 December 2017

Review: RTL-SDR Blog Multipurpose Dipole Antenna Kit

What is this? Four antennas, two mounts, one antenna holder with cable and one more extension cable. Costs $10 on its own, or $25 with rtl-sdr.com v.3 dongle. Was at my doorstep in two weeks from China to Ireland, observations below are based on two months' of constant use.
Please read the official how-to guide for more information, this post is a practical look at what you get and what you can do with it.

In the envelope


Bubble wrap surrounding a cardboard box. And the box is full:



Sang the song for the dongle already, so I'll concentrate on the antenna pack:
- bendable antenna mount / tripod with camera connector screw,
- suction cup with camera connector screw,
 - mount for antennas with camera connector screw,
- two large antennas,
- two small antennas,
- 3m / 10 ft extension coax.

Bendable tripod


About hand-sized including top screw, legs are 5" / 13 cm, similar products are also called gorilla pods / bendy tripods, 'cause legs are flexible to wrap around anything a primate can grip.



Built-in ballhead with lock-down screw:



Top screw is industry-standard mount for cameras, held pocket digital camera (245g / 8 5/8 oz) without effort, hopeless with heavy Nikon body, rock solid with antenna base. Even a thrift store tripod features the same screw:



Antenna base screws onto mount or suction cup (later, read on), so if you've got a more substantial tripod for photography e.g. a Manfrotto with a ball head, an earthquake-proof setup can be done in no time.
Similar tripods can be bought on eBay for $2-4 dollars if you like the concept:



Suction cup mount


Comes in several pieces, quite confident that if you've completed any LEGO aimed for 6-9 year old kids without shrieks you'll manage, end up with this:



Hands up if you carry isopropyl alcohol or window cleaner around, which is the official procedure, preparations are the same as with any other suction cup mount used for smartphones / GPS / tablets etc: clean surface with any cloth at hand or on you, spit on / lick finger, then distribute saliva evenly on circle, push on flat surface, lock down by pressing lever down, check for firm hold.
Was holding casserole pot attached to mirror, weight unknown (digital scale said "err") but bloody heavy, the two-person dinner / straining to lift out from oven variety.
Functioned on the car, either on windowpanes or on the roof, on the trunk / boot lid, and on RV, two larger antennas fully extended at 70 mhp / 120 kmph for 800 km / 500 miles did not come off.

Antenna mount


Holds four supplied antennas, obviously two at a time, screws onto two supplied mounts detailed above. Antennas and angles can be adjusted with screw, no screwdriver supplied:


With two smaller antennas:



Not for outdoor use as per official recommendation, Hurricane Ophelia hit where I live with sustained 60-80 mph winds and copious rain to make matters worse, mount was outdoors during that period on comparative ADS-B duty without any illness.
Sidenote: manufacturers must warn against outdoor use, 'cause if your house burns down, user collects an STD whilst looking at an outside setup or what have you, insurance companies can blame any outdoor antenna as the culprit. Rtl-sdr.com previous mag mounts, Nooelec mounts with innumerable antennas, FlightAware ADS-B antenna and quite a few homemade aerials never gave me any trouble.
Not for outdoor use, again: here's what mount looked like after living outside in wet, rainy, utterly miserable conditions a.k.a. Irish winter for two months:



De-assembled mount:



For outdoor use, a barrier sealant (wax / fat / WD40 / anything acting as a barrier against water) is a must.


Four supplied antennas


Two small and two large, covering shortwave to Gigahertz range.
Fantastic feature of extendable antennas that users must understand frequency / antenna length relationship, rtl-sdr.com posted specific frequencies of common interest:



A dipole antenna, by its very nature, will be useful around the desired frequency - two shorter antennas fully collapsed (1030 MHz as above) performed well when pitted against a dedicated $45 ADS-B FlightAware antenna: 20,705 vs 11,386 positions reported over 21 hour period:



Because antennas are adjustable, fine-tuning for the desired frequency is easy-peasy and recommended for best performance.

Coax cables


Short and thin attached to base, there's an extra 10 foot / 3m extension just in case in the box. Best you get with any RTL-SDR dongle, generics' arm-length is a joke in comparison.




Antenna location is everything, take home one lesson from this post: antenna location is everything. Having cable at hand will let you place antenna in an ideal location: outdoors, away from electronics, as high as possible.


What will the neighbor say?


Nothing. People who don't know, nor care about antennas have seen or painstakingly adjusted bunny ears antennas for televisions, therefore those lovely peeking senior citizens won't move the curtain unnecessarily. Looks like a TV antenna, here's what people are accustomed to:



... but it's not a bunny ears, as I found out. For best performance, orient legs vertical / up and down, once problem sources got used to the sight of the antenna.
You'll be able to hold a painful conversation with Mary when she deliberately cuts her roses waiting for a chat without daydreaming about a cleaver, a feat you can't repeat with a discone. On the other hand, a TV License inspector will have yee (SW Ireland pronunciation of "you") over the barrel in no time if you live with stupid rules, say here or in the UK.

Competitors


None. No other manufacturer offers an equivalent antenna kit; especially not at $10. A single SMA connector telescopic costs 5-8 USD on eBay, and lest you go on any ham radio website, be prepared to pay over $20 for one antenna. A pro ADS-B antenna or discone costs around $50 at the bottom end, near $70-100 for midrange, so $10 is peanuts without monkeys.
Nooelec's SMArt family antenna kit (comes standard with regular SMArt, XTR and XTRTee) is better quality overall but without the flexibility and adjustability, generic's one puny antenna simply can not compete with what you get.

Worth the money?


Count together: bendy pod $3, suction cup $3, four telescopic antennas $1 each, 3m / 10 ft coax coax is around, say $3, toroid $1, and prices are low estimates.
Without hesitation. Antenna kit is sold out now, so I ordered the full bundle after handling the review sample, as $25 is a no-brainer for the antenna kit and dongle.

Sunday, 3 December 2017

rtl-sdr.com antenna kit: Orientation Matters

A lot. Official recommendation is to install antenna vertical (up-and-down), as a real man, didn't read the manual, then posted results in a recent ADS-B comparison.
Mea culpa, I was wrong, as an eagle-eyed reader pointed out:

"Orienting dipoles goes back to the signal polarization, horizontal vs vertical. It should match otherwise you'll get losses. But the way you've oriented it makes it vertical, but more like a whip. So there should be some improvement by using it in the correct orientation. TV signals are usually strong and so the bunny ears can withstand being in the wrong or random orientations."

Fair enough, so onto ADS-B testing, got an antenna kit from rtl-sdr.com for review and ordered one within minutes as it's well worth the money, then some ended up with two identical kits:


Back end is two ModMy Pi 3 Raspberries, so only variable is antenna used:




Then my jaw dropped, bunny ears configuration results:


Vertical dipole results:



No math required, more than 2x performance. Where's a stone I can hide under?


Polar plots


First of December, 21,033 Totals on vertical orientation, geographical coverage:



Bunny ears with 9,563 Totals on the same day, geographical coverage:



Conclusion


"RTL-SDR Blog Multipurpose Dipole Antenna Kit" works, 144 nm max range in an unamped, stock setup is simply astonishing at my location.
Would, and do recommend to grab as many as you can from the manufacturer, but others have also seen that sliced bread is better than a loaf, therefore it's sold out.





Behind the Scenes: Photography and Building a Lightbox

RTL-SDR dongles, preamps and tools of trade are small. Here's what I came up with for little money, and why it works for me.
Tips are also applicable to small product photography, and so on.

Build a lightbox


Using one, two or three lamps results in shadows, which take aeons to remove in Photoshop, and I simply have no time. Enter a lightbox, which is a cardboard box with lamps for optimal illumination, watch Youtube videos here, here, and here for inspiration just like I did, common trait is having a box and lights on the side, the more the better, first result:



Product image wasn't bad:



Problems:
1. Lights shines into camera and my eyes, and looking into thousands of lumen is not fun.
2. No reflective surfaces, less light reaching object.
3. Unacceptable shadows on the left hand side.

Improved lightbox


All light sources covered from camera, easier on me eyes:



Same with less shadows:



Being able to look at an object is worth more than more light and white speckles swimming in my vision.

Lumens and color temperature


Lumens: how much light emitted by bulb, written on packaging. Also given as W at the bottom (how much power bulb uses). The more, the better, 50 W combined from LED and fluorescents is more than enough, or 4-5000 lumens light output.



Light sources must be distributed for an even coverage and to get no shadows. I put two on top, two in the top left corner, two at bottom corners. Connections are easy-peasy, cut a hole, screw in bulb.



Sidenote: Some might say cardboard, paper and a heat source is disaster, and I totally agree. Do not use incandescent lights, floodlights or HID lights, if in doubt, test: turn off = touch with hand then hot, auch = don't use. Fluorescent and LED give more light and cooler to touch.
Color temperature: that's the number before the K on the bulb above, LED and fluorescent lights are used interchangeably, not on purpose, simply I could buy them for cheap. Most cameras are great sensing color temperature, if really skewed, can adjust in Photoshop:



Note that Auto Color (Ctrl + Shift + B) does a good job, but all image adjustments in PS should be done as adjustment layers like above. That said, for lesser images I do Ruler Tool, then Crop (C), then Ctrl - Shift - L, then B, be done.

Equipment


Sony DSC HX9V, a compact point-and-shoot. Images below are straight from camera, no Photoshop.



Automatic mode does not do the job, that's the green setting, result is dismal:




Program mode, multi-AF and multi-metering with flash:


Usable, small shadow on right for depth perception, would add +25 brightness after cropping.
Smartphones: work for on-the-go images, and great for family photos, but ultimate quality is nowhere near a dedicated camera, I use a Samsung J5 2016. Shoe from a cobbler.

Post-processing


Don't. It's better and ultimately less time to set up a lightbox, even when you play with camera for two days to find the best settings, than to spend hours in Photoshop adjusting sliders down the line, plus it's easier to get it right the first time, taking care in - great image out, 5 minutes with an image (which is more like 30 minutes once the rush for perfection overcomes you) when a post contains 20+ images is time wasted.
Do. Before a post with images goes online, I check images on a 49" screen to find any faults, invariably, there's something to improve. Deciding what needs to be completed and knowing when I gotta wake up for work leads to compromises.


Connectors and macro photography


Must crop and do post post-processing, before and after:



Ensure background is evenly illuminated, so magic wand (W) will work efficiently. Looking closely, you'll see that grooves are not cleaned on this F-connector, Eraser tool (E) is my least favorite command.
I tend to take multiple images then choose the best one, as hand shaking, distance to subject and lighting differences will make or break the final image.