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Specification and Facilities.
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FacilitiesDatabase System Sound recording Scan modes Modulation Modes Receiver system Specifications Performance
 

RD500






General Facilities
 

1. Video and TV sound outputs.

2. Stereo FM with phono outputs.

3. USB and LSB modes

4. Pass Band Shifting

5. Synchronous modes.

6. Choice of bandwidths in most modes.

7. Stereo CW filters with 3 bandwidths.

8. Noise Blanker.

9. Clock and timers for recording programs etc.

10. Cassette switch controlled from squelch.

11. RS232 computer interface.

12. Data Slicer for decoding.

13. FM output for pocsac etc.

14. Tuning meter (centre zero)

15. Signal strength meter.

16. Notch and peak filter (Variable).

17. Peak hold AGC, user controllable.

18. 26 VFO's for temporary frequencies.

19. 55 thousand memories, (54 thousand more than the competition).

20. 234 groups.

21. 20 Text characters per memory.

22. Clear 'plain English' menu's on-screen.

23. Text searching with review of matches - find any station by name.

24. 99 Band set-ups with start and end frequencies.

25. Skip list.

26. Easy memory store and retrieve.

27. Edit entries, move groups, tag/untag, move/delete entries, without PC.

28. Priority channel.

29. PC Keyboard socket.

30. 8.33kHz, 9kHz, 12.5kHz steps etc., or user definable.

31. 5Hz minimum steps. (Not 5 kHz!), really smooth tuning.

32. Hold, pause, Stop or continuous scanning.

33. Auto tuning (AFC)

34. Auto memory write.

35. Definable pause and hold times.

36. Sound recording and playback with start and end point editor.

37. Whip antenna i/p for HF.

38. Mains Power supply.

39. Separate antenna inputs for different band ranges.

40. Antenna changeover output.

41. Stereo headphones and loudspeaker output.

42. Great HF (Shortwave) reception.

43. PC remote control software.

44. Database software, for backing up and editing.

45. File converter software, for importing files from the Internet etc.

46. Ability to import files from paper documents.

47. Remote control handset.

48. Large example database pre-loaded.

49. 20kHz to 1750MHz tuning range, superb sensitivity.

50. 2 year guarantee.

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Introduction.
Sound recording Scan modes Modulation Modes Receiver system SpecificationsPerformance
 
 
 
 

The RD500 is a new kind of high specification receiver, it has storage capacity to hold station names and information on every signal that it encounters. Now it is possible to have a receiver which not only holds your own station selections in memory, but has a complete knowledge of its spectrum.







Imagine tuning a radio where every channel has a name, city and description instantly displayed.

Thousands of station records can be stored and sorted through, just type in a few letters or a complete description and the receiver finds the stations of interest to you.

Never before has such a powerful system been made available, until now it had been necessary to use a p.c. to provide such a large database, This is often not practical because of lack of portability and problems of interference.

The RD500 is a great receiver too, with smooth tuning, wideband coverage and great sensitivity. It can tune in apparently continuous 5Hz increments, or any step size.

It's also a scanner, an HF receiver with SSB and pass band shifting, and it?s memory can be used for digital sound recording.
 

54,700 Text Memories + Bands and VFO's!

The station memory system provides 234 groups (A1 to Z9) which can each hold between 1 and 999 records although the maximum total number of records is 54,700 with 2 Mbytes, these figures are reduced when the memory is partitioned for sound recording.

Any word or group of words or abbreviation can be searched for in the entire database. For example the user can start a search with a broad definition such as "broadcast" or "repeater" and then narrow down the search with a city name or other attribute. By first searching the group names, the total description of any station would be 20 letters in the group title plus 20 letters in the record text field. For example, one single record might be:-
 
 
Worldwide broadcast
.
 
  Voice of America #1

 

- and it can contain 54,700 records!
 

Data entry can be achieved in a number of ways, although a large database is loaded into the receiver before dispatch. Firstly the receiver can be loaded with a database from a p.c. which, for example, may comprise of a broadcast section a utility listing from the Internet, and a selection of your own net and special interest entries (merging and editing can be carried out on our p.c. software or the receiver). The receiver offers several means of editing database entries. Primarily the remote control handset is provided with the full alphabet and punctuation symbols. Also the alphabet is available on the receivers keypad in the standard format which appears on telephones, i.e. ABCabc2 on key 2 through to WXYZwxyz9 on key 9. Individual letters are accessed by repeatedly pressing the appropriate key and full punctuation symbols including the whole alphabet can be obtained by turning the tuning knob when in text mode. If a large amount of information is to be inputted and a p.c. is not available, a p.c. keyboard can be plugged into the rear din socket. We stock a miniature p.c. keyboard which is only slightly larger than the receiver and has full size keys, this is particularly useful when the receiver is used "in the field." The p.c. software can be used for both uploading and downloading data.

The PC Windows package provides an easy to use environment for manipulating memory records, group, VFO names, and band data. In the near future sound file manipulation will be included in the package and for the foreseeable future any upgrades will be freely available on our Internet page. Database upgrades can be obtained from Fairhaven on CD. We will also be making database files available on our Internet site and we can offer a programming service to callers or by mail order. We also hope to arrange our web site so that users can leave databases for others. Furthermore, users can search the Internet for information and compile their own databases, (we know of at least one 12,000 entry database on the net), and we receive databases from The International Short-wave League on broadcast station activity. We also have the  File Converter  software to enable different database formats to be altered to suit the RD500, this works much like a wordproccessor and it can move, abbreviate and truncate columns of data to suit the receivers format. Control of the receiver by means of "virtual radio" PC software allows remote access of most of the receivers controls. A picture of the receiver is displayed on the PC?s screen and the computers mouse can be used to click the buttons on the virtual radio picture, while the actual receiver follows your commands.

In band mode 99 bands can be set up which allows the receiver to scan user defined frequency ranges. Step size, scan type and mode can be set individually for each band, as well as a 20 character band name. Any band can be found by scrolling, or entering a search word.

There are 26 VFO?s selections which give spot frequencies with definable mode, name and auxiliary settings. These are used as temporary "scratch pad" memories so that the main database does not have to be altered unnecessarily.
 

VFO screen
 
A:  14.12345   AMW
VFO   Name  Field 

 

Digital sound recording.

The receivers memory can be partitioned to provide an area for digital sound recording, this means that a news flash or rare DX can be recorded, or in contest working, important details need not be lost. It can also be a great help if you are learning Morse or a new language, and it can even record from another receiver! 4 minutes of sound can be recorded with 2 Megabyte of RAM. The recorded sound is not lost when the receiver is switched off, in fact memory retention is in excess of 5 years. Other facilities on the recording menu include moveable start and end points, and repeat, so that more than one recording can be made without overwriting the whole memory, and the recorder can be left running continuously so that the start of an event is not lost.
 
 

The receiver's sound recorder menu.
 
1 Rec  2 Play  3 Rpt
4 [Stop]    5 Edit

Click here to hear a typical recording.
 
 

Scan modes.

Channel searching: The most basic form of scanning. The current frequency is taken as the starting point and the receiver scans upwards incrementing the frequency by an amount related to the current mode. The direction of the search can be reversed by use of the Up/Down keys. The frequency range is not limited as in band scanning.

Stop: Stops the scan when a signal is encountered and continues when the signal disappears.

Continuous: Allows the receiver to auto tune up or down with the squelch lifted.

Hold: Waits for a period (defined by the user), after the signal has gone, before moving on, to avoid missing part of a two way conversation.

Pause: Waits on an occupied channel for a time (defined by the user) before continuing to scan.

Skip: When SKIP is in operation a bank of user definable frequencies are checked by the scanner each time a signal is encountered, if the frequency corresponds with a frequency within the skip bank the scan will continue. This means that a band can be searched for new frequencies whilst ignoring signals that are already known about.

Auto memory: In this mode a memory will be allocated each time the squelch is activated. A record of frequency and mode is recorded in a new group, and the record can then be named or deleted by the user.

Auto tuning: In this mode the receiver takes over tuning if the receiver has not been properly tuned into a station.

Priority: When PRIO. is active the receiver alternates between its normal scanning routine and the priority channel.

Group scan: Scans sequentially through all the memory records associated with a the selected group.
 
 

Scanning setup displays
 
1.Mode=[Stop] 2.Skip
3. Prio   4.More

Option 4.  (More)
 
1. Autotune 
2. AutoMem  3. More

       
Modulation Modes

This menu allows selection of the demodulation mode. Pressing a number key selects the mode that is currently displayed next to the number, pressing the key again changes the mode to its counterpart e.g. 1. LSB-USB, 2. CWL-CWU. Option 4. gives ASD (double sideband synchronous) or selection of the upper or lower sidebands whilst in sync mode. This is useful when an interfering signal only effects one sideband of the required signal. EXT allows an external input to the receiver and its audio filtering and sound recorder.
 
1 [LSB]  2 CWL 3 NFM
4 ASD   5 AMW  6 EXT

Synchronous A.M. Synchronous A.M. is a system that phase locks the receiver tuning to the frequency of the incoming station. This allows the carrier insertion oscillator (or BFO) to replace a fading carrier, preventing the enormous distortion associated with this type of fading. Synchronous double sideband or synchronous USB and LSB can be selected to eliminate adjacent channel interference.

FM Modes: The HF receiver is equipped with NBFM as standard and the 1750MHz version is also fitted with stereo WBFM and video.
 

Stereo CW: CW Mode uses a filter which can spread the audio spectrum across the stereo panorama, causing spatial separation of C.W. signals. This makes it easier to focus upon individual signals, those that are lower than the filter frequency appear to the left and frequencies that are higher than the filter roll off appear to the right. The filter can be peaked at 800Hz in 3 selectable bandwidths. A low pass filter option is also provided this gives mono audio which is rolled off at 800Hz, peaking the filter by selecting different bandwidths gives a conventional band pass filter.
 

CW filter display
 
CW Filt 1[LP]   2 BP
4 [Flat]   5 Mid   6 Pk

 
 
 
 

Other features

Notch and peak filter: This filter is provided to eliminate tones caused by adjacent signals (in notch mode), or it can be used to select C.W. signals in peak mode. The filter frequency is controlled by the knob marked 'filter'.

AVC (automatic volume control): This system improves the quality of audio in SYNC AM modes by augmenting the AGC system (which is carrier derived), by feeding back the audio signal level to the AGC system. This gives less level variation of audio level when listening to signals that are subject to fading.

Cassette control: Cassette recorder control can be selected and triggered by the squelch. Stereo audio and switching is provided on the auxiliary din socket which can also provide 12Vdc and squelch switched 12Vdc.

Aerial change over output: This 5 volt output changes level at 10 MHz and 300MHz and can be buffered to drive aerial change over relays to allow connection of up to 5 aerials.

Pass band tuning: Pass band tuning allows reduction in the receiver I.F. bandwidth for reducing adjacent channel interference such as overlapping ssb signals. Control is provided by selecting PBT in SSB SYNC AM or CW modes and pressing the up and down keys. This simultaneously varies the CIO frequency whilst correcting the receiver tuning.
 
14 . 12345 ASD
PBS + 1.7 kHz Use DN/UP

 

Noise Blanker: The RD500 noise blanker has a separate 455KHz I.F. which amplifies wideband impulse noise and provides blanking pulses. This system is very effective at reducing car ignition noise and electrical switching noise.

AGC: The receivers A.G.C. response is tailored to give a fast attack and a short hold period followed by a fast decay. The timing of the response is user presettable for each mode.
 
SLOW  [1]  2   3   FAST
4. [AM]  5. SSB  6.SYNC

S meter: The RD500 also has a 60 level S meter, and tuning meter which can be displayed in the text field, and a treble cut low pass filter is provided to improve noisy signals.

Time clock: The receivers time clock can be set to any time zone by city name and it has 4 programmable timers for program recording and a sleep timer.
 
UTC 10:59:30 AM 12/6/02
1.Mode  2.Set  3.Timer

 

Receiver system
 

The RD500 is designed as a high performance dual conversion AM/SSB/FM/Synchronous receiver, with I.F?s at  IF 45.000MHz and 455KHz. It has a versatile processor system with 60K of program ROM and 2M bytes of RAM, which gives the receiver the ability to store entire scanning directories.
 

Tuning

It has a low noise PLL tuning system which gives smooth continuous tuning without periodic plops. It has both digital and analogue phase comparators,  pretuning and 3 individual  FET VCO?s at HF and 3 VCO?s at VHF and UHF.
 

Filters

In ssb mode it uses a narrow 2.4 kHz Murata CFJ455K5 filter with a CFW455IT tail filter. The ssb filter is also used in AM narrow, and in AM wide, a 6kHz CFW455IT is used. In sync AM wide, both CFW455IT?s are used.
 

Signal path

A sensitive FET  HF pre amp (selectable), is followed by a bipolar mixer which provides good sensitivity and a high 3rd order intercept, This is followed by a 45MHz roofing filter and a low noise second mixer and IF, which provide a wide dynamic range. The full wave, balanced detector has very low distortion over a wide dynamic range, and the AGC is delayed to maximise the signal to noise ratio of small signals while the two stage AGC decay shape is tailored to suit SSB speech. At VHF, three tuned RF filters are provided for preselection in the ranges of 48 to 175MHz, 175 to 460MHz and 460 to 860MHz, a high pass section and an additional Shotkey diode mixer is used above 860MHz. These preselection stages are followed by low noise mosfet amplifiers and a high IP3 bipolar mixer.
All mode reception is catered for by the HF receiver section except WBFM and video. The Video section uses a SAW filter, followed by a true-synchronous vision IF demodulator (PLL) IC, to provide high vision quality. The demodulation of the TV sound and FM radio is provided by a PLL/NTSC demodulation circuit, followed by a stereo decoder IC which is switchable to mono to improve audio under low signal conditions.

 

 
Specifications.
Performance
 
 

Frequency coverage: 0 to 1750MHz (gap at 36 to 46 MHz)
 

Reception modes: LSB, USB, AM, CW, Synchronous AM (USB, LSB and DSB), NBFM, Wideband FM, STEREO FM, Video o/p,
TV sound (6 MHz sub carrier 6.5MHz option).
 

Tuning steps: 5Hz in SSB,CW and AMS modes, 100Hz in AM/FM modes, or user definable. Step size increases with spin-wheel rotation.
 

Memories: 54,700 memories (on board), each with 20 characters of text, frequency and mode per entry.
 

Display: Alphanumeric character display showing frequency to 10 Hz, tuning or S - meter, record text and menus.
 

AGC: Peak hold period and selectable decay speeds.
 

Aerial inputs: 50 ohm input via SO-239 (HF) and N-type (VHF/UHF) sockets. High-impedance HF input for whip aerial.
 

R F attenuator: 20dB HF and VHF/UHF.
 

Audio outputs: Stereo line output 0 dB via phono sockets.

 
Record input/output at approx. 200mV on din socket

External loudspeaker o/p

Headphone output (stereo)


Video o/p:  Colour PAL and NTSC composite.
 

Data Slicer:  Suitable for Hamcom and JVfax type PC computer programs. +- 10v approx for connection to  DSR or RXD.
 

Scan speed:  50 memories/steps per second maximum.
 

Power Supply: 12V DC supply @ 800mA minimum.
Mains power unit supplied as standard. 1A 230v AC
 

Dimensions: Size 205mm wide x 65mm high x 193 deep
 

Weight: approx. 1600g.
 

Options:

Mini PC keyboard for data entry.
 
 

PC Software:

Virtual radio -for remote control (Part of database software).

Database - for backing up and editing,

File Converter - for processing files from document scanners and the Internet.
 


 
Performance

 
Sensitivity

(Typical in 50 ohm aerial input, for 12dB signal to noise ratio).
 

SSB:approx 0.12uV 500kHz to 999MHz

AM(HF): 0.5uV 500kHz to 32MHz

FM(HF): 0.25uV 500kHz to 32MHz

AM(VHF/UHF): 0.5uV 48MHz to 999MHz

FM (VHF/UHF):<0.3uV (Typically O.22uV at VHF)

Squelch Threshold: Opens at 0.06uV (Typical, VHF)


 

I.F Filter Bandwidths
 

SSB Filter - 2.4kHz
(Also available in Sync SSB and AM Narrow).

Wide Filter - AM Wide and AM Sync - 6 kHz

NBFM Filter - 12kHz or 6kHz.
(Also available in AM mode for music reception).


HF Third order intermodulation distortion

Intercept point. Approx. +10dB (w/o preamp)

Spurious responses >65dB rejection of images, IFs, etc.

Audio output 2.0W into 4R .

Headphone amplifier into 32R = 80mW
 
 
 
 



 
 
 
 
 
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