IC-R71 -HF Base Receiver |
Quick Specs: |
Detailed Specifications GENERAL
IC-R71 Options
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This morning I put up a Sony AN-1 Wide Range Active Antenna on my roof for shortwave listening. Saturdays are great for antenna work since I have a 5 day work week. The antenna is a wide range active antenna with a frequency coverage of 0.15 ~ 30MHz and has a controller box in the shack side which powers a preamplifier for the antenna, there is a switch which can deactivate the amplifier on the controller (-20dB when switched off). The preamplifier in housed in the antenna module and is a FET. I decided to install it in a horizontal position facing due North to gain coverage of Eu and Stateside.
The AN-1 is no longer made by Sony, it was replaced with the AN-12 which is basically the same antenna which I believe is also no longer available also, but may be available as NOS from some places. These antennas fetch between US$138 to $170 (Postage not included).
The roof side antenna houses the amplifier and a telescopic whip which is just 1.5 M long when fully extracted. It is powered by a 9V adapter or the equivalent in pen light cells. It is very easy to install and I had the antenna installed and up and running inside of 15 minutes.
Today, daylight DX was not particularly good as DX stations were few and suspect that propagation is not too good, so I was not able to do much of an acid test and compare it with my full sized passive vertical, but from the few stations that were present ,it do quite a good and decent job at pulling the stations in although there was obviously a bit more noise and fading when compared to the vertical. This was connected up yo my Lowe HF-150.
The true acid test will come this evening when I will listen to the night time DX and compare the differences with full sized antennas. Will report more.
There is also a whip antenna coupler for use with the AN-1, this slips over the whip antenna of the portable radio and connects via a cable to the antenna controller, so this is indeed a very versatile antenna.
| SPECIFICATIONS Driver: dynamic (30mm neodymium magnet) ACCESSORY Impressions: More later after auditioning and burn in. |
Just connect up an appropriate parabolic dish antenna and LNB. This is one of my favorite pieces of equipment. There is also a selector for video output or video input and it doubles up as a minature color monitor. Very useful.
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I have not yet tried it with a large external antenna and suspect it may overload the front end, but to be fair that remains to be seen. I need to get a SMA to BNC or SMA to PL259 adapter in order to test it with external antennas. It would be worthwhile if the manufacturer included such adapters as part of the standard package. Selectivity and sensitivity from 30MHz > is very good and I was able to pick up signals very easily. More Later!
I will be using a Diamond SRH-789 shortly with this receiver to see what improvements can be further made to the overall reception.
Lowe produced a antenna preselector for the HF-150 to overcome the problems associated with overloading from strong signals, Lowe PR-150 preselector and preamp. The PR-150 covers 100 kHz to 30 MHz in seven bands segments. Each band segment comprises of a dual-tank LC filter circuit, each of which can tune over 2.5:1 within the intended frequency range.
Each filter is passive. For additional gain, there is a built in UHF bipolar transistor preamp which has low noise performance with a high dynamic range. There is also a broadband setting that can be used. The preamp may be switched in or out. The PR-150 also features an Attenuator and A/B antenna switch for 2 antennas.
It is built in a very solid metal alloy case matching the HF-150. On the back panel there is an Antenna A input (SO-239 or Hi-Z terminals) and an Antenna B input (Hi-Z terminals). Output to the receiver is 50 ohm impedance - SO-239. The unit requires 12 VDC at 50 ma. (and has a duplicate socket for power loop-through to other accessories).
The overall performance of the HF-150 is improved many fold when fitted to the PR-150 and I would deem that this is an essential component for the HF-150 if you wish to receive peak performance from your HF-150.
Even if you do not have a HF-150 and you are looking for something in the way of a preselector for your HF receiver, the PR-150 is probably a very wise choice.
Link to PR-150 Operation Manual (Pdf)
| Specifications |
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Frequency coverage ......... 100 kHz to 30 MHz |
| by Xinhua writers Yu Fei, Bai Ruixue and Wang Yushan CHANGSHA, Oct. 29 (Xinhua) -- The National University of Defense Technology (NUDT) unveiled Thursday China's fastest supercomputer, which could rival the world's most powerful computing devices.
The supercomputer, named Tianhe, meaning Milky Way, is theoretically able to do more than 1 quadrillion calculations per second (one petaflop) at peak speed. A single-day task for Tianhe might take a mainstream dual-core personal computer 160 years to complete, working non-stop -- if it can last that long. NUDT president Zhang Yulin said the 155-ton system, with 103 refrigerator-like cabinets lined up on an area of about 1,000 square meters, is expected to process seismic data for oil exploration, conduct bio-medical computing and help design aerospace vehicles. China's national high-technology research and development program and the Binhai New Area, a major economic development zonein the northern port city of Tianjin jointly financed Tianhe, which cost at least 600 million yuan (88.24 million U.S. dollars). Tianhe's peak performance reaches 1.206 petaflops, and it runs at 563.1 teraflops (1,000 teraflops equals one petaflop) on the Linpack benchmark, which was originally developed by U.S. computer scientist Jack Dongarra and has become an internationally recognized method to measure a supercomputer's real performance in practical use. Zhang said the technical data of Tianhe had been submitted to the world Top 500 list, compiled by the University of Mannheim, in Germany, the National Energy Research Scientific Computing Center, the Lawrence Berkeley National Laboratory, and the University of Tennessee in the United States. The next Top 500 supercomputer list will be released in November. The performance of Tianhe would have made it the world's fourth most powerful supercomputer in the most recent ranking in June. "I was shocked at the milestone breakthrough, which was beyond expectation," said Zhang Yunquan, a researcher with the Institute of Software of the Chinese Academy of Sciences (CAS), and an organizer of the China Top 100 list, which was released at a national conference on high-performance computers Thursday. "I previously forecast China's first petaflop computer no earlier than the end of 2010," Zhang said. The giant device, a product of 200 computer scientists and two years' work, was housed in the NUDT campus in Changsha, Hunan Province, and would be moved to the National Supercomputing Centerin Tianjin at the end of 2009, said Li Nan, chief coordinator of the program. Equipped with 6,144 Intel CPUs and 5,120 AMD GPUs, Tianhe was able to store all 27 million books in the National Library of China four times over, said Zhou Xingming, an academician of CAS and a professor with NUDT. "As far as I know, a combination of CPU and GPU is something new used to make a petaflop computer. A GPU, or graphic processing unit, plays a role as an accelerator to make the computer run faster, but reduces its power consumption and cost," Zhou explained. "After it's installed in Tianjin, we plan to add hundreds or thousands of China-made CPUs to the machine, and improve its Linpack performance to over 800 teraflops," Zhou said. Although its annual electricity bill can be as high as 18 million yuan, Tianhe could have been ranked the world's fifth greenest supercomputer, according to Green500 List in June, compiled by researchers at Virginia Tech aiming to provide a ranking of the most energy-efficient supercomputers in the world and serve as a complementary view to the TOP500. Of the world's fastest 500 supercomputers, the United States alone has invented 291, including the top 10, Europe has 145 and Asia 49, the June World Top 500 List said. In the same list, the Chinese mainland has 20 high-performance computers, with CPUs all supplied by foreign manufacturers. China's Dawning Information Industry Company is attempting to build its own supercomputer that overcomes the petaflop barrier by2010. |
| Editor: Lin Liyu |
If you are interested in a small receiver with great performance this may be a good choice for you. The unit supports sync. AM but does not have FM band, only MW through to 30MHz. It supports CW/SSB and AM mode reception.The only main problem as mentioned earlier with the HF-150 is that it was designed with the lack of proper bandpass filters in the antenna input front end circuitry of the receiver. The first mixer circuitry is prone to pick up all sorts of different signals in the receiving range of the receiver from 5 kHz to 30 MHz and can result in overloading problems when the receiver is used near strong local MW stations or with large outdoor antennas. A MW BCB rejection filter placed at the antenna input will help. This front-end overloading can show up as increased noise, local signals mixing with shortwave signals and as “ghost” signals. If the HF-150 is connected up to the matching PR-150, this will relieve the problems mentioned. 
KPAD-1 Clone Keyboard:
| Radio Netherlands Review of the Lowe HF-150 |
Introduction
Holland and Britain seem to be the main marketplace for Lowe receivers so far. This English company started making radios to its own design and specification a couple of years back, with the launch of the HF-125 and HF-225 receivers. The approach has been to try and make a simple to operate radio with the best specifications for the price. Compared to Japanese competition the radios look quite plain, but performance wise they score well. At the end of 1991 Lowe announced it was launching a small receiver for the bottom end of the market as an alternative to Japanese push button portables... sets like the Sony ICF2001D. In March 1992 we tested an off-the-shelf example of the HF-150, putting it through a series of laboratory and practical listening tests. In June 1995 we re-tested an off-the shelf sample. The results were similar to the test in 1992.
For a price of £419 in Britain (including VAT), you get a table-top communications receiver which at first glance looks surprisingly small. The case is made of metal, not plastic, and measures just 185 by 80 by 175 millimetres. It's quite light too, just 1300 grams without the 8 penlight batteries which fit into two special holders at the back of the set.
From the front there are just 5 controls... a combined on-off switch and volume control, three buttons which have several functions including the selection of the mode and memories, and a large tuning knob. A large 5 digit liquid crystal display shows the frequency you're tuned to within the nearest kilohertz, If you push a button the display gives you information about the receiver mode and memory number, but normally it shows only the frequency, and there's no light to illuminate it. That's it. Lowe sell a keypad as an optional extra that plugs into the back of the set and you place in front of the radio as you use it. That's essential if you want to move quickly about the dial... otherwise you have to move up and down in frequency by spinning the tuning knob. Getting from 30 kHz right up to 30 MHz, which represents the full coverage of the set, could take some time.
The set has no signal strength meter, you can't add extra filters at a later stage for very narrow bandwidth reception of Morse code, there's no notch filter, no noise blanker, and no tone control. But if these are extras that you can miss, then what Lowe have put inside the box turns out to be very acceptable indeed.
The dual-conversion super heterodyne design is quite straight forward. Signals come in from an external antenna. You can switch in an antenna amplifier if you're using an indoor whip, although in practice we didn't need that at all in this part of Europe where signals are always strong. Signals go through a 30 MHz low pass filter before they hit the mixing stage of the radio. Of course there's a lot of energy coming off most shortwave antennas, bearing in mind the powers used by broadcast stations.
More expensive radios use a series of filters to make sure that if you're listening to 15 MHz short-wave for instance, strong medium wave signals, or stations in the 41 and 49 metre band are attenuated before they get to the mixing stage of the radio. Too much energy at the front end of the sensitive input circuitry can lead to overloading, and the appearance of signals on the dial which are the result of mixing products inside the radio. Having said that we measured the intercept point as +3 dBm using two signals 30 kHz apart. This gives you a dynamic range of 86 dB which is a fair-to-good value for a radio of this price. We disagree with the instruction book though, that recommends a long wire of up to 30 metres. Our tests in Holland showed that if you connect a wire longer than about 12 metres, you get enormous overloading problems once the sun sets. That will be less of a problem in low signal strength areas such as the Pacific or the American mid-west.
It's often assumed that the more signal you pump into a radio, the more distant stations you'll be able to hear. Well that's not the case. We found that late at night, weak and difficult signals were more intelligible if you switch in the 20 dB of attenuation. But that control is on the back of the set which is not easy to get at. If you use the set in Europe you might want to consider a separate aerial attenuator which say steps of 6, 12, 20 dB of attenuation, and give it try on weak signals.
We measured sensitivity using a signal modulated at 60% using a 1 kHz tone. We found that our measurements corresponded well with the results given by Lowe in their instruction book. Between 50 and 500 kHz the sensitivity is around 1.8 micro volts, and around 0.8 micro volts for the medium and short- wave part of the dial. There's much difference in sensitivity between the wide and narrow filters used in the HF-150.
The radio has various modes. USB, LSB, standard AM, and you can also use what's termed synchronous AM. Unlike other Lowe sets available until now, the HF-150 allows you to listen to either the upper or lower sideband of a broadcast signal whilst in the "sync" mode. That's extremely useful when there's a strong interfering station 5 kHz away from the station you're trying to listen to. You can also use synchronous detection to reduce at least some of the effects of short-wave fading. The use of synchronous detection though in the double-sideband mode leads to some slight loss of sensitivity, but that's nothing to be concerned about. The background noise also rises slightly on the example we've tested. The radio takes up to two seconds to lock onto the desired signal, but once it's locked the radio does an excellent job of keeping in lock even when the signal fades to almost nothing.
Battery consumption of the receiver is quite high, especially when compared to similar priced competition, anything up to 275 mA at full volume. We put in a set of 8 fresh alkaline batteries and got the radio to work for just 6 hours before they were flat. You can purchase rechargeable nickel cadmium batteries. When the set is switched off they automatically charge up. It takes about 16 hours to get a full charge after which you can use the radio for portable work for about 3 hours before you need to recharge again. The cheapest solution of all is simply to use the supplied external AC adapter which plugs into the back of the radio and gives all the power you need without any hum problems.
The HF-150 has two filters that have a bandwidth of 7 and 2.9 kHz respectively. These ceramic filters have a good shape factor for the price paid. So if the signal you want to listen to is strong you can really sit back and listen to the programming. The design of the automatic gain control is excellent, so no unwanted pumping of signals. The signal distortion is very low for a radio of this time, and if you connect the radio to a hi-fi set you'd be surprised what fidelity you can get out of a strong short-wave broadcaster.
Lowe offers accessories for the HF-150: a plug-in numeric keypad; an accessory kit consisting of a whip antenna, rechargeable batteries (described above), a carrying handle and a shoulder strap. Additionally there is an excellent (though costly) preselector, a speaker with audio processing controls, and a computer interface. The computer control commands are ASCII text strings, making programming easy. There are a number of software programs available in the third party market.
Tom Sundstrom found an easy solution to those wanting to use the keypad and the computer interface, or a tape recorder and a digital signal decoder, simultaneously. The Radio Shack (Tandy elsewhere on the globe) stores sell a molded audio plug adapter that takes two mono 1/8" plugs in and outputs to a 1/8" mono plug that fits very nicely into the HF-150 rear apron jacks. It's the 274-310 (US$2.49 in the 1998 catalog, page 122).
In short, the Lowe HF-150 is an excellent choice as an entry-level communications receiver. It gives much better performance than sets like the Kenwood R-1000 which were on the market 20 years ago for the same price, showing that it is still possible to improve on performance and keep the costs reasonable.
A "Europa" version of the HF-150 started shipping in late 1997. Check Lowe's Web site for details. We have not yet tested this new model.
The Kchibo KK-96DL is the highest ranking portable DSP equipped radio in the Kchibo stables currently and represents a new trend in portable world band radios to incorporate DSP as a standard feature.
Heads up Kchibo Designers:
If any of the Kchibo designers by chance read this blog, well heads up. The design of the "radio" is nice, but! A big but, as with the S500, all the functions are printed in Chinese and you need to have English printing if you are to export this product as well as way finding around the radio which can be nightmare at first. Also You left out the "i" in "Radio" and you have printed "Rado" on the receiver, the bag and other locations! You need to get it right.
Can you extend the frequency coverage of your radios up to 30MHz?
Features:
Jog Dial to choose the step tuning pace:
Mw step 9KHz (1KHz/9KHz) / 10KHz (1KHz/10KHz),
SW Stepping 1KHz/5KHz,
FM stepper 50KHz/100KHz.
* The use of U.S. special software radio digital signal processing chips;
* Use of digital filter design, with high-performance imaging and anti-interference capability;
* Dual 16Bit DAC with low distortion audio output;
* Multi-level large-scale use of AGC circuits, radio reception strong signal handling is better;
* Wide-band tuning of the automatic circuit design, high-sensitivity receiver;
* Built-in (40 step) Electronic volume control circuit;
* DSP software, DSP on AM / FM processing, demodulation;
* Built-in high-speed MCU circuit (in the role of AGC AFC IIC PGA VOL CRT ... ...);
* Professional-grade radio, specifically :
Built-in FM frequency coverage choice, AM / FM sensitivity,
1dBu resolution of the antenna signal input intensity signals;
* Lock function to prevent misoperation;
* Can store 900 stations;
* AM / FM frequency directly or fuzzy logic input, AM frequency input accuracy up to 1KHz;
* provision of stereo earbuds, allowing you to listen to radio programs from time to time in stereo on FM bands;
* Kchibo use their own R & D and produced rechargeable lithium-ion battery-powered, 2 nos. are supplied;
* Shutdown timer for sleep, time boot function, with perpetual calendar;
* Display with battery power indication, the local dot-matrix display screen.
1. Frequency range
Frequency Modulation (FM) 87-108 MHz
64-108 Mhz (DIY)
Medium-wave (MW) 522-1710KHz (9KHz step)
520-1710KHz (10KHz step, DIY)
Short-wave (SW) 2.30-21.85 MHz
2. The number of radio frequency memories (total 900)
FM (FM) 300
MW (AM) 300
SW (short wave) 300
3. Noise limited sensitivity
Frequency Modulation (FM) better than 2 uV
AM (MW) better than 2mV / m
Short-wave (SW) better than 20 uV
4. Signal-to-Noise Ratio:
FM signal to noise ratio: > 55dB
MW signal to noise ratio: > 45dB
SW-noise ratio: > 45dB
5. Power:
Power transformer: AC220V DC 5 V
Batteries - rechargeable lithium-ion battery (3.7V/1000mAh)
Li-ion battery Model KL-1000
External power supply 5V 300mA
6. The highest current consumption level is less than 250mA
7. 100mW maximum output power
8. 25dB stereo separation
9. Speaker size Φ57mm / 16Ω/0.25W
10. Output Φ3.5mm 32Ω external headphone
11. Dimensions 145 x 90 x 23mm
12. weight of 200g (without batteries)
Lithium battery voltage: 3.7V Battery capacity: 1000mAh
The equipment on the distribution panel comprises of: 
Broadcasts to Asiaand the PacificAll times UTC (unless otherwise specified) Shortwave: Through October 25, 2009 0230-0300 11550 (50°) via Madagascar From October 25, 2009 0230-0300 11550 (50°) via Madagascar |
March 29 - October 25, 2009
| Broadcasting time(UTC)* | Frequencies (kHz) |
|---|---|
| 5:00 - 5:30 | 17810 |
| 9:00 - 9:30 | 11815 |
| 12:00 - 12:30 | 9695 |
| 14:00 - 14:30 | 11705 |
| 0:00 - 0:20 | 17810 13650 |
*UTC(Coordinated Universal Time)
DJ-G7T/E
Manufacturer's Details on the transceiver:| Get ready for action as you hear signals that you may never have heard before. The DJ-G7 tunes 0.530-1299.995MHz continuously, and you can enjoy full duplex receive in combination with the amateur 144/430/1200MHz bands. AM and WFM modes allow you to hear the aviation and broadcast bands and with the broadcast preset memories and built-in AM bar antenna radio listening is easier than ever. Enjoy a variety of scan modes and options that include Time -set scan, 50 pair of programmable scan memories, Timing adjustable priority scanning and Alinco's patented Channel-Scope?visualize the presence of radio signals on the display. There are also two modes of bug detector functions. *Restrictions may apply to frequency combinations for Full-duplex QSO.  Customize the DJ-G7 to your personal preferences. Set the parameters to suit your needs and likes. Choose the display language (English/Japanese) lamp function and display contrast and brightness. Select Auto-Power Off / Battery save function. Turn sounds (beep, bell, end beep) on or off. Set the transmitter for VOX / TOT / BCLO. Control the DTMF burst timing, link your scan banks, set priority scan-timing and memory skip functions and more. Personalize the DJ-G7 to make it, "YOUR DJ-G7".  About IPX7 Designation The IPX7 designation provides for limited waterproofing of the radio. The specifications are immersion in one meter (approx 3ft) of still sweet water for up to 30 minutes. This compatibility is factory guaranteed for a period of one year provided all the jack covers are securely in place, any accessories connected must be genuine Alinco water-proof accessories and the radio has not been disassembled by the customer. The factory has tested and made the equipment compatible to IPX7 certification during engineering. However, please understand that this equipment is NOT certified IPX7 compliant but is designed to remain operational when used in rain, severe weather or in accidental cases of dropping it in water when used in extreme conditions and is in no way stating that you should attempt use the radio under water or submerge the radio for cleaning. Warranty will not cover radios that are water / salt damage due to negligence or misuse of the product. | |
| General | |
| Frequency range: | E-version TX/RX: 144.000 - 145.995MHz / 430.000 - 439.995MHz / 1240.000 - 1299.995MHz AM/FM/TV(analog) broadcasting bands T-version TX: 144.000 - 147.995MHz / 430.000 - 449.995MHz / 1240.000 - 1299.995MHz Sub-band RX: 0.530 -1299.995MHz (Cellular frequencies 824.000 - 849.995MHz, 869.000 - 894.995MHz blocked on T-version ) |
| Modulation: | TX: F2D/F3E (RX only:WFM,AM) |
| Memory channel: | 1000 channels + 1 call channel per ham bands+50 programmed-scan pairs+100 dual-memory+100 priority+100 serch-pass |
| Antenna impedance: | 50 ohm unbalanced |
| Frequency stability: | +/- 2.5ppm |
| Supply voltage: | DC 7.4V (EBP-73 Li-Ion battery pack) / DC 4.5 - 16V (external regulated source) |
| Current consumption: (Typical value) | TX approx. 1.6A/144MHz, 1.8A/430MHz, 0.8A/1200MHz RX approx. 200mA Battery save (1:4) approx. average: Dual 56mA / Single 50mA |
| Temperature range: | -10 to +45 degrees C. (+14 to 113 F) |
| Ground: | Negative |
| Dimensions: | (WxHxD Projections exclusive): 60 x 115 x 30 mm or 2.36 x 4.53 x 1.18 in. |
| Weight: | (Antenna/EBP-73 inclusive): Approx. 296 g /9.55 oz |
| Transmitter | |
| Power output: (Approx.value) | DC13.8V: 144MHz/430MHz 5/2/1/0.3W,1200MHz 1/0.3W EBP-73: 144MHz 5/2/0.8/0.3W, 430MHz 4.5/2/0.8/0.3W, 1200MHz 1/0.3W 4 x AA cells (Max): 144MHz 2W, 430MHz 1.5W, 1200MHz 0.5W |
| Modulation: | Variable reactance |
| Spurious emission: | -60db or less |
| Max. Deviation: | +/- 5kHz |
| Mic. impedance: | 2K ohms |
| Receiver | |
| System: | Double-conversion super heterodyne (NFM,AM) Single-conversion super heterodyne (WFM) |
| Sensitivity: | 144/430MHz ham-radio bands -15dBu or better 1200MHz ham-radio band -13dBu or better Sub-band receiver (Best values): AM (10dB S/N): Lower than 50MHz -1dBu 50MHz and above -6dBu FM (12dB SINAD): 30-470MHz -15dBu 470MHz and above -7dBu WFM 76-470MHz -6dBu 470MHz and above -3dBu |
| Intermediate frequency: | Main-band FM 51.65MHz / 450KHz Sub-band AM/FM 50.75MHz / 450KHz Sub-band WFM 10.7MHz |
| Selectivity: | AM/FM -6dB 12KHz or more / -60dB 35KHz or less WFM -6dB 130KHz or more / -60dB 300KHz or less |
| AF output: | 400mW (8ohm 10%THD) |
| Specifications subject to change without notice or obligation. Specifications apply to Amateur Radio bands only. Permits required for MARS use. Product intended for use by properly licensed operators. Wide band receive related specification is for T-version only.800MHz cell-phones frequencies blocked on T version. RoHS compliant. | |
| ACCESSORIES | |
STANDARD
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Background
The Japan Radio Company is a long established company since 1915 and is considered one of the oldest and largest electronics manufacturing companies in the world. Employing over 3,000 workers, JRC is a respected expert in such areas as marine radio equipment, mobile and satellite communications, fiber optics, radar, navigation equipment, and avionics systems. Therefore, it should be no surprise that JRC's line of communications receivers are held in high regard and so highly sought after for their excellent and outstanding performance, dependability, ergonomics, and ease of use.
Over the years, JRC has manufactured a fine line of consumer grade shortwave communications receivers. Beginning with the NRD*505 and ending with the NRD*545, not to mention also a fine line of amateur radio transceivers. Japan Radio Company has incorporated state-of-the-art features into a unit designed with excellent sensitivity and to be operated with ultimate user comfort. This NRD-515 is no exception and is typically sought by collectors that are fond of it's design and capabilities and exceptional performance with no compromise. According to Fred Osterman in his book "Shortwave Receivers Past and Present" the NRD-515:
"is robustly built and straight-forward to operate. This receiver remains popular with utility DXers, tropical band enthusiasts, and general shortwave listeners. The '515' has nearly a cult-like following. Clean lines, easy operation, a solid feel and outstanding performance come together in this radio."
Interestingly, the 515 sold in the late 70's thru the mid 80's for about $1,000 to $1500....a tidy sum of money in those days. Extra features such as the memory unit and additional IF filters would push the price even higher. When new models come out, typically older shortwave receivers, like most consumer products, lose much of their original value. However, the 515 in good condition is a true exception with selling prices remarkably stable even 25 to 30 years later have remained high. There are many reasons for this.
First of all, the receiver is truly built like a battleship The receiver front panel and cover are made from heavy gauge steel and designed to last. The only plastic is found are on the various knobs and feet with the balance of the receiver is all constructed of metal - no compromise, period. Even the top of the range receivers and transceivers today cannot boast this!
Secondly, the 515 was made during an era of mostly analog dial readouts that could tune to within 5 kHz or maybe even 1 kHz. However, the red LED readout of the 515 could literally tune to a resolution of 100 Hz...an achievement unparalleled by other consumer equipment from that era and almost unheard of. Only military spec. equipment could brag about such extremely high resolution tuning. Other Japan electronic manufacturers of the era were beginning to release some models with digital readouts, but again, the resolution was only as good up to about 1 kHz.
Tuning on the 515 is accomplished using a variety of knobs. The user would determine which one of 30 MHz bands they would like to tune and move the large MHz dial into that position. JRC used a optical rotary encoder that is extremely durable. Then actual tuning to the specific frequency would occur with the large right main tuning knob, or if faster tuning was desired, using the toggle tuning switch that is located at about 2 o'clock to the main tuning knob. For most tuning, this method is sufficient. However, if tuning on SSB or for RTTY, JRC also included a fine tune control that they called the delta control. This control deviates by about + or - 3 kHz and allows for extremely precise tuning.
The 515 is a extremely stable receiver. Drift after about 30 minutes of warm-up is reported to be less than 50 Hz per hour, but avid users report that they rarely have to re tune. This stability is uncustomary for this time in the consumer market and unheard of.
A nice feature found on the 515 is the pass band tuning. This control coupled with the receiver's excellent dynamic range allowed the operator to frequently eliminate considerable, if not all, of the side band interference. When used in conjunction with the optional installed filters, the 515 becomes a fantastic unit for searching out those weak signals. The choice of filters is not mode dependent and this gives the user an extra degree of flexibility in use.
General Specifications:
