ICR-75A QST revisi..
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1. www mfjenterprises com Manufacturer s suggested retail price 150 Typical cur rent street price 140 Samlex SEC 1223 The Samlex 1223 ties the Yaesu FP 1023 for smallest enclosure honors A lighted rocker style power switch is mounted on the front panel The power cord is removable The dc connection points are large color coded 5 way binding posts The supply can be eas Table 6 Samlex SEC 1223 Manufacturer s specifications Power requirements 100 130 V ac or 200 260 V ac at 50 60 Hz jumper selectable Output voltage 13 8 V dc Output current continuous 23 A Size hwd 2 2x7x8 25 inches weight 3 5 pounds Lab Measurements Output voltage no load 13 94 V dc Output voltage 21 A load 13 79 V dc Low line drop out voltage 95 V ac Dc variation during dynamic testing 200 mV Figure 9 An oscilloscope trace of the dc output of the Samlex 1223 under load The vertical scale is 200 mV div and the horizontal scale is 10 ms div The level of the dc ripple is low lt 30 mV p p but there are spikes due to switching that extend out to about 600 mV p p Reference Level 0 dB 40 50 60 70 Frequency MHz Figure 10 A spectral plot of the output of the Samlex 1223 under load There are several ranges including several within the US amateur bands where the broadband noise is moderate ily converted for 2202. Memory names can be up to eight alpha numeric characters each The IC R75 lets you choose to display either the memory name or the frequency that it represents Listeners often find they want to record some of the signals they hear The IC R75 accommodates recording by making line level audio available at a rear panel jack There s also a REC REMOTE jack to turn your machine on and off There s a 24 hour clock built in For unattended listening you can take advan tage of the IC R75 s timer and remote tape recorder hookups to automatically start your recorder either when the receiver hits a signal while scanning or at the appointed hour you ve set on the timer Computer Control Icing on the cake 1s the ability to control the IC R75 via a genuine RS 232C connec tor on the rear panel to permit a serial con nection to a PC In addition as already men tioned the REMOTE jack on the rear panel allows connection with another similarly equipped ICOM receiver or transceiver or of up to four ICOM receivers to a PC for command control via an optional CT 17 CI V level converter The Instruction Manual provides details on commands Computer control software RS R75 has just become available Menus The IC R75 menu accessible by sim ply pressing the front panel SET button makes available a host of user settable items ranging from the level of the con firmation beep that sounds when a button has been pressed to C
3. Product Review amp Short Takes Columns from QST Magazine January 2000 Product Reviews ICOM IC R75 Communications Receiver QST Compares Switching Power Supplies Short Takes Palomar Engineers VLF Converter RadioCom 4 0 Copyright 2000 by the American Radio Relay League Inc All rights reserved PRODUCT REVIEW ICOM IC R75 Communications Receiver By Rick Lindquist NIRL Senior News Editor If you ve ever thought it might be great to have an extra set of ears in the shack you d be wise to consider this latest com munications receiver from ICOM Let s face it Hams as a rule do not find much use these days for standalone receivers Most of the boxes we buy also contain the requisite transmitting circuitry being able to fit that capability into the IC R75 box an IC 7TR 75 would make an especially attractive package But even as a mere receiver the IC R75 is a terrific complement for the typical ham shack A Receiver in the Shack A dwindling number of us still remem ber the days when a discrete receiver was standard equipment in every ham shack Today that s the exception of course Most hams will claim they have no use for a sepa rate receiver they ve got a general cov erage receiver in their transceiver box Maybe so but few transceiver receiv ers are designed for the primary function of listening something a few of us enjoy do ing when the blush is off the lat
4. The dc output of the supplies was ac coupled to a spectrum analyzer and the analyzer was swept from 1 5 to 100 MHz These spectral plots are also included as figures Each of the supplies of course was also subjected to on the air testing in dif ferent locations and station configurations More on those results later Astron SS 30M The Astron SS 30M sports the largest cabinet in this group Generously sized dual voltage and current meters take up nearly the entire front panel A lighted rocker style power switch is located in the lower left hand corner The de connection points are located on the back panel and consist of two 4 20 threaded studs about 4 inch long with hex nuts and washers The polarity labeling for these can be difficult to see the and symbols are Table 2 Astron SS 30M serial number 98080024 Manufacturer s specifications Power requirement 90 132 V ac or 180 264 V ac at 50 60 Hz switch selectable Output voltage 13 8 V dc Output current continuous 25 A Size hwd 3 75x7x8 63 inches weight 5 pounds Lab Measurements Output voltage no load 13 83 V dc Output voltage 21 A load 13 66 V dc Low line drop out voltage 94 V ac Dc variation during dynamic testing 150 mV embossed into the metal and the terminals are not color coded You ll want to pay close at tention when hooking up your radios and ac cessories The power cord is removable and as is t
5. MHz IF and 1 8 2 8 and 3 3 kHz at the lower IF A Versatile Receiver You can do a lot with the IC R75 and within the performance limitations we ve already outlined and which are spelled out in detail in Table 1 the R75 provides lots of listening fun Aside from its all mode capabilities the R75 gives you lots of scan ning possibilities and it s easy to set up scanning Programmed memory selective memory scans all are possible There are two band edge memories A nifty inclusion is the auto memory write scan that auto matically puts signals it encounters during a scan into a sequestered set of channels 19 in all for later review There s also a priority watch that will automatically keep an ear on a selected memory channel and go to it the instant it becomes active I especially liked the ability to name memories but I found the memory naming method a bit out of the ordinary To name a memory you input the character you want by pushing different keys on the keypad one or more times For example the 2 key in puts the numeral two and letters A B and C the 3 key the numeral 3 and the letters D E and F and so forth The appropriate letters are marked on the keys just like a telephone keypad except the Q and Z are on the 0 key The upside of this scheme is that it takes less time to input a name than systems that force you to scroll or step through all numbers and letters till you find the one you want
6. V operation by remov ing an internal jumper The cooling fan is temperature con trolled It s mounted internally and forces air out through a grill on the bottom of the cabinet Once activated the sound level of the fan noise is moderate The enclosure particularly the front panel warms up con siderably after 2 hour of continuous op eration powering a 21 A load A small 6 page User Manual with in stallation and operating instructions a specifications table a troubleshooting guide and details on removing the jumper for 220 V ac operation is included Manufacturer Samlex America 110 17 Fawcett Rd Port Coquitlam BC Canada V3K 6V2 800 561 5885 fax 604 525 5221 http www samlexamerica com Manufacturer s suggested retail price 100 Typical current street price 100 The Yaesu FP 1023 The Yaesu FP 1023 and the Samlex are very similar The enclosure is small and seems well suited for portable operation where luggage space is at a premium A lighted rocker style power switch is mounted on the front panel The power cord is removable The dc connection points are large color coded 5 way binding posts Conversion for 220 V ac operation is easy simply remove an internal jumper The cooling fan is temperature con trolled It s mounted internally and forces air out through a grill on the bottom of the cabinet Once activated the sound level of the fan noise is moderate The supply en DC Power Supply M
7. as the frequency display tell you which memory you ve got dialed up Other im portant icons are clear and prominent Like the original IC 706 there s no band switch You can directly enter a new frequency or set the tuning step to the cor rect display digit and dial away Up and down buttons let you page swiftly through memories all 99 of them The front panel layout is sensible and accessible This is a piece of gear you liter ally can get your hands on without your fin gers getting in the way of what you re trying to do There s a nice large knob with a de cently sized dimple on it The knob incorpo rates a rubber grip ring It has a nice feel to it The drag is adjustable You can lock the settings with a push of the LOCK button on the front panel A metal bail is easily deployed from the bottom of the set to angle up the front panel for better viewing The right hand frequency keypad which also functions to enter memory channel names is terrific All buttons and knobs are substantial and clearly labeled There s a 4 inch phone jack on the front panel Much of being able to operate this little receiver I learned from my experi ences with other ICOM gear You can connect two separate antennas to the IC R75 and select either from a front panel button I d have preferred to see two 50 Q SO 239 connectors but the IC R75 offers an SO 239 for ANT 1 and snap on con nectors for ANT 2 to wire a 500 Q
8. or other high impedance antenna such as a longwire The receiver powers from 13 8 V dc via Joe Bottiglieri AA1GW Assistant Technical Editor From January 2000 QST ARRL Table 1 ICOM IC R75 serial number 01206 Manufacturer s Claimed Specifications Frequency coverage 0 03 60 MHz Power requirement 1 1 A 11 7 15 9 V dc An ac power supply is provided Modes of operation SSB CW AM S AM FM AFSK Receiver SSB CW sensitivity bandwidth not specified 10 dB S N 0 1 1 8 MHz lt 2 0 uV 1 8 28 MHz lt 0 16 mV 28 30 MHz lt 0 18 mV 50 54 MHz lt 0 13 uV AM sensitivity 10 dB S N 0 1 1 8 MHz lt 5 6 uV 1 8 30 MHz lt 1 6 mV 50 54 MHz lt 1 uV FM sensitivity 12 dB SINAD 28 30 MHz lt 0 22 uV 50 54 MHz lt 1 uV Blocking dynamic range Not specified Two tone third order IMD dynamic range Not specified Third order intercept Not specified Second order intercept Not specified FM adjacent channel rejection Not specified Measured in the ARRL Lab As specified 2 A Tested at 13 8 V As specified Receiver Dynamic Testing Noise floor mds 500 Hz filter Preamp off Preamp one Preamp two 1 0 MHz 130 dBm 137 dBm 140 dBm 3 5 MHz 133 dBm 141 dBm 143 dBm 14 MHz 132 dBm 138 dBm 142 dBm 50 MHz 127 dBm 136 dBm 140 dBm 10 dB S N N 1 kHz tone 30 modulation Preamp off Preamp one Preamp two 1 0 MHz 1 7 uV 0 8 uV 0 6 uV 3 8 MHz 1 2 uV 0 6 u
9. output of the MFJ 4225MV under load The vertical scale is 50 mV div and the horizontal scale is 5 ms div The level of the dc ripple is low lt 20 mV p p Spikes due to switching only measure about 70 mV p p Reference Level 0 dB 40 50 60 70 80 Frequency MHz Figure 8 A spectral plot of the output of the MFJ 4225MV under load Overall the noise generated by this supply is very low with the exception of the range of frequencies between about 7 5 and 10 MHz about 9 to 15 V dc very handy for test bench applications The ac power cord is permanently at tached to the cabinet The back panel in cludes a recessed slide switch for easy se lection of 110 or 220 V ac operation The cooling fan is mounted internally just inside the left panel of the cabinet The fan is on continuously when power is sup plied to the unit but the fan speed and the meter backlighting level varies with the output voltage setting The level of sound generated by the fan at the 13 8 V dc out put setting is moderate The power supply is cool to the touch even after 2 hour of continuous operation connected to a 21 A load A 4 page Instruction Manual is provided and includes a table of specifications in stallation and operating instructions and a detailed schematic Manufacturer MFJ Enterprises 300 Industrial Park Rd Starksville MS 39759 800 647 1800 fax 662 323 6551 http
10. supply exhibited very low levels of broadband noise and the peaks that do appear fall outside of the US amateur bands above 160 meters ICOM PS 85 The ICOM PS 85 is designed to be the matching supply for a number of the HF and multiband transceivers in their line The front panel is small about 4 inches square and the enclosure is rather deep A rocker type power switch and a red LED power in dicator are mounted on the front panel The ac power cord is removable The dc power cord is about 18 inches long and is permanently attached It terminates in a six pin Molex connector that mates with most of the current 100 W transceivers Separate terminals for powering additional station accessories are not provided The PS 85 is the only supply in this group that does not include the ability to convert it for 220 V ac operation An internal cooling fan is mounted just inside the back panel The fan is not tem perature controlled it runs continuously when the supply is on The sound level of the fan is moderate The case temperature remained low even after 2 hour of continu ous operation into a 21 A load ICOM includes a single Instructions sheet with operating instructions and speci fications Manufacturer ICOM America 2380 116 Ave NE Bellevue WA 98004 425 454 8155 fax 425 454 1509 http www icomamerica com Manufacturer s suggested retail price 406 Typical cur rent street price 295 Th
11. the two tone third order dynamic range on FM It was in the 60 dB range worst case on HF and VHF again see Table 1 This number typically is comparable to FM adjacent channel rejection Some VHF mobiles have better DR and ad jacent channel numbers This could impact the receiver s ability to avoid interference from nearby signals At wider spacings the DR was much improved 106 dB at 50 MHz Filters and DSP Digital signal processing is an option in this receiver and it s something I d highly recommend the IC R75 accepts the same UT 106 DSP board as the later models of the IC 706 ICOM is now including this as standard equipment Ed The DSP board adds audio frequency level noise re duction and auto notch It works in all modes and it sure helps to make things easier on the ears when noise starts to get the best of the signals The noise reduction level is adjustable via the menu There s also a noise blanker to minimize pulse type noise As with most upper tier receivers the IC R75 lets you add a filter at the second and third IFs The IC R75 offers quite a few choices here We added a 500 Hz CW fil ter at the higher IF which is a real plus if you re into CW Real serious CW listeners will want a narrow CW filter at the lower IF too ICOM offers CW filters at 250 350 CW RTTY and 500 Hz for the 9 MHz IF and 250 and 500 Hz at the 455 kHz IF SSB filters are available at 1 9 and 2 8 kHz for the 9
12. 2700 fax 562 404 1210 http www yaesu com Manufacturer s suggested retail price 169 Typical current street price 149 Operational Impressions and Considerations A quick glance through this collection of oscilloscope traces and spectral plots indicates at least as far as the overall pu rity of the supplied dc power is concerned that the clear choices here are the Astron SS 30M or the MFJ 4225 These exhibit admirable performance and deserve praise for their superior design Before you pull out your credit card and dial up your fa vorite Amateur Radio products dealer how ever let s consider the actual implications of selecting one of the runners up On the air tests helped to shed some light on a very important consideration the level of the broadband RF noise that s gen erated by these supplies is proportional to the load The oscilloscope traces and the spectral plots represent the characteristics of the supplied dc power at loads that simu late transmit conditions Since under the majority of operating conditions transmis sion and reception will not be occurring simultaneously the levels of RF noise ex perienced during receive when the load is typically only about 5 that of trans mit are considerably smaller This was verified in the field testing Each of the six power supplies was substi tuted for the existing conventional dc sup plies in three typical HF station configura tions Five of t
13. 706 several times while monitoring distant beacons Despite the lack of conversion gain performance the difference was astonishing In many cases I couldn t hear the navaids at all with the IC 706 but they were clearly audible when received through the Palomar converter Bottom Line There are strange and fascinating things going on below 500 kHz The Palomar VLF converter offers a cost effective way for you to eavesdrop using your present ham transceiver Manufacturer Palomar Engineers PO Box 462222 Escondido CA 92046 tel 760 747 3343 http www Palomar Engineers com Suggested list price 89 95 ISF Next Short Take Steve Ford WB8IMY QST Managing Editor O5 January 2000 59 RadioCom 4 0 RadioCom version 4 0 might best be described as a software based multimode communication processor Like many other HF digital programs available today RadioCom uses your PC sound card as an analog to digital converter With sophisticated digital signal processing algorithms RadioCom filters and decodes a vari ety of signals including RTTY CW AMTOR SITOR PSK31 FAX SSTV and more In the latest version the same techniques are used to encode RTTY PSK31 FAX and SSTV signals for transmission RadioCom can also send CW by keying your rig through an avail able COM port RadioCom will work with almost any SSB receiver or trans ceiver All you really need are shielded cables to carry the audio between your radio
14. S 40 the MFJ 4225MV the Samlex SEC 1223 and the Yaesu FP 1023 Each of these dc switching power supplies carries continuous output current ratings that make them suitable for use with any of the currently available 100 W transceivers About the time that we were finalizing this review Alinco announced the release of a switching supply of their own the DM 330MV ICOM has also redesigned and re released an updated version of the PS 85 We ll keep these two in mind as pos sible subjects for a future column The Battery of Tests The lab tests run on each of the units began with measurements of the actual dc output voltage at loads of 1 1 A and 21 A Next a Variac was inserted in the ac line and the minimum ac voltage input required to retain proper regulation of the dc output was determined This value is recorded in the tables as the low line drop out voltage The amount of ripple on the dc output and the presence or absence of any high frequency ringing spikes while under load was also investigated The resulting oscil loscope traces appear in the figures A dynamic test was set up using an HF transceiver In this test each supply was subjected to a pulsed load that rapidly al ternated between approximately 1 1 and 21 A The resulting variation in the supplied dc voltage appears in the tables In the final lab test the supplies were set to 13 8 V if adjustable and a load that drew about 20 A was connected
15. V 0 4 uV 53 MHz 2 4 uV 1 0 uV 0 5 uV For 12 dB SINAD Preamp off Preamp one Preamp two 29 MHz 0 5 uV 0 2 uV 0 2 uV 52 MHz 1 0 uV 0 4 uV 0 2 uV Blocking dynamic range 500 Hz filter Preamp off Preamp one Preamp two 3 5 MHz 122 dB 120 dB 115 dB 14 MHz 122 dB 120 dB 113 dB 50 MHz 119 dB 119 dB 111 dB Two tone third order IMD dynamic range 500 Hz filter Preamp off Preamp one Preamp two 3 5 MHz 91 dB 89 dB 87 dB 14 MHz 88 dB 86 dB 87 dB 50 MHz 88 dB 86 dB 84 dB Preamp off Preamp one Preamp two 3 5 MHz 3 6 dBm 7 7 dBm 13 dBm 14 MHz 0 3 dBm 9 1 dBm 17 dBm 50 MHz 4 9 dBm 7 1 dBm 14 dBm Preamp off 60 dBm preamp one 65 dBm preamp two 51 20 kHz channel spacing both preamps on FM two tone third order IMD dynamic range Not specified S meter sensitivity Not specified Squelch sensitivity SSB CW RTTY lt 5 6 uV FM lt 0 32 uV Receiver audio output 2 W at 10 THD into 8 Q IF audio response Not specified Spurious and image rejection except IF rejection on 50 MHz 70 dB 29 MHz 67 dB 52 MHz 60 dB 20 kHz channel spacing both preamps on 29 MHz 67 dB 52 MHz 70 dB 10 MHz channel spacing both preamps on 52 MHz 106 dB S9 signal at 14 2 MHz preamp off 82 uV preamp one 31 uV preamp two 9 5 uV 50 MHz preamp off 178 uV preamp one 60 uV preamp two 20 uV At threshold both preamps on SSB 16 uV FM 29 MHz 0 08 uV 52 MHz 0 2 uV 2 3 W at 10 THD in
16. W pitch backlight ing level auto tuning speed and front panel display backlighting The Last Word The IC R75 stands ready to extend the listening capabilities of the average ham shack If you enjoy listening to LF and HF you ll appreciate the IC R75 Manufacturer ICOM America 2380 116 Ave NE Bellevue WA 98004 425 454 8155 fax 425 454 1509 http www icomamerica com Manufacturer s sug gested retail price IC R75 949 Typical current street price 800 FL 100 500 Hz CW RTTY filter 133 RS R75 software 80 From January 2000 QST ARRL QST Compares Switching Power Supplies Reviewed by Joe Bottiglieri AAIGW Do you occasionally enjoy taking your dc powered transceiver along on your va cation or out into the field for generator powered operations such as Field Day Are you tired of hauling around that bulky transformer based power supply If this sounds familiar you ve probably noticed the wide selection of switching dc power supplies that have hit the Amateur Radio market over the last few years Their compact size and light weight fractions of that of the more conventional alternatives would seem to make them the perfect trav eling companion particularly for use in conjunction with those subcompact multi band wonders that have become the radios of choice for squeezing into suitcases and backpacks This time around we ll have a look at the Astron SS 30M the ICOM PS 85 the Kenwood P
17. and your sound card The RadioCom package includes a hardware modem level converter that will allow you to control almost any computer ready radio through the software RadioCom supports ICOM Yaesu AOR Kenwood Lowe NRD and Drake equipment with drivers for other brands available on line RadioCom s level converter is an important feature to keep in mind when you consider the 250 price tag Most commercial level converters cost in the neighborhood of 100 or more So when you subtract this cost from the total you are really paying about 150 or less for the RadioCom software Deciphering the Manual RadioCom is a complex piece of software so it seemed like a good idea to read the manual and that was where I immediately ran into trouble RadioCom 1s the brainchild of Bonito Inc a firm based in Hermannsburg Germany If I could read German fluently I would have been better off studying the German version of the manual also on the CD because the English translation is very poor I had to read slowly and carefully pausing often to decipher strangely worded sentences In a few cases I was left with only a vague idea of what the writer was attempting to say To their credit Bonito recognizes the problem and has indicated that they are work ing on a much improved translation As it stands now the English manual is a serious impediment to understanding and using RadioCom RadioCom 4 0 ICOM IC 706 MKII m 4 gt KEM on Ler L
18. cillator mixer combo converts 10 to 500 kHz to 3510 to 4000 kHz In the VLF S the model tested for this review the conversion output is 4010 to 4500 kHz So with the VLF S in line 4010 kHz becomes 10 kHz 4020 kHz is 20 kHz and so on As is often the case with receive converters of this type the frequency conversion can be inaccurate This is usually caused by an oscillator running at the wrong frequency It turned out that my VLF B was receiving about 7 kHz above what my IC 706 display was indicating When my transceiver displayed 4053 for example I was really listening at 60 kHz rather than 53 kHz There is no frequency adjustment inside the Palomar converter so I simply added 7 kHz to whatever I saw on the 706 s display A small trimmer capacitor across the crystal might be a worthwhile addition to allow users to adjust for display inaccuracies It s worth mentioning that the converter s ON OFF switch func tions as a bypass connecting your radio directly to the antenna when the switch is in the OFF position The switching arrange ment isn t designed to handle any sort of RF power so I wouldn t recommend transmitting through it On Air Performance I installed the Palomar converter ahead of my ICOM IC 706 transceiver using my 125 foot long wire antenna and subjected it to many evenings of listening One of my first stops was at 60 kHz where I heard the time code transmissions from WW VB the National Institute of Standar
19. ck Own an IC 706 or one of the other later model ICOM transceivers with a computer REMOTE jack With a simple connecting cable you can make up yourself the IC R75 becomes a main or auxiliary receiver each unit controlling the other and letting you share the best features of each Hook it up to your 706 and you can share the IC R75 s ability to punch in fre quencies on the keypad or even the receiver s stored memories For ham radio use you Il need to add a T R switching sys tem It s a great opportunity to resurrect that old Dow Key relay you ve got in the junk box from your separate receiver Novice days An Accessible Receiver The IC R75 suggests a cross between the IC 706 and IC 746 transceivers a bit closer to the latter in terms of size styling and front panel layout but more compact and without the large LCD screen The R75 s sizeable display offers big numbers or channel names it s your call and yel low orange backlighting There s a multi segment LED S meter that reads out up to Bottom Line A versatile HF 6 meter receiver that offers a good measure of performance ina compact package All mode capability for the ham and utility listeners and synchro nous AM for the SWLs should make the IC R75 a popular choice for a wide variety of radio enthusiasts 4 ec mir he a m5 STIE 0 ANT1 FAGC saa D7 f L SCAN UPA 60 dB over S9 Numerals almost as large
20. ds and Technology station in Fort Collins Colorado With 50 kW of power WWVB blankets the country with its signal ARRL Lab Measurements Palomar VLF B Converter Current consumption lt 20 mA L O Accuracy 6 9 kHz error Conversion gain 0 dB to 14 dB loss frequency dependent Conversion gain over frequency Frequency Gain kHz dB 200 2 250 5 300 9 400 12 500 14 Frequency Gain Palomar Engineers VLF Converter F8 Setup Save oai REUEECH Flisubeck Smooth Integ Zoom Color al amp He p Pic ile sics O 15 Out evel CES ClrScr it File Name WWUB____ ESC to abort S N 13 ee 20 Oct 99 Figure 1 WWVB s 60 kHz signal under the DSP microscope using AF9Y s FFTDSP software http www webcom com af9y radio10 htm The bright line represents WWVB The white area along the right margin of the image represents the varying signal strength Notice the drop in strength with local sunrise Using AF9Y s FFTDSP software I ran my computer through out an entire night to profile WWVB s signal You can see a portion of the results in Figure 1 In the Amateur Radio section of my Web site at http home att net wb8imy home htm I ve also posted a short WAV audio file of the WWVB signal received with the Palomar VLF converter Above 200 kHz there were quite a few navigation beacons sending their two and three letter Morse identifications I switched between the Palomar converter and my IC
21. e Kenwood PS 40 The Kenwood PS 40 is approximately the same size as the TS 50 HF transceiver A rocker type power switch is mounted on the front panel A small red LED indicates when the supply is on The power cord is removable Large color coded dc power terminals are mounted on the rear panel The PS 40 is OOD Maes Da SWITCHING POWER SU Table 3 ICOM PS 85 serial number 01913 Manufacturer s specifications Power requirement 100 120 V ac fixed Output voltage 13 8 V dc t5 Output current continuous 20 A Size hwd 3 7x4 4x11 3 inches weight 5 5 pounds Lab Measurements Output voltage no load 13 9 V dc Output voltage 21 A load 13 6 V dc Low line drop out voltage 80 V ac Dc variation during dynamic testing 200 mV Figure 3 An oscilloscope trace of the dc output of the ICOM IC 85 under load The vertical scale is 100 mV div and the horizontal scale is 5 ms div The level of the dc ripple is about 100 mV p p and there are spikes due to switching that extend out to about 600 mV p p Reference Level 0 30 40 50 60 70 80 Frequency MHz 90 100 Figure 4 A spectral plot of the output of the ICOM PS 85 under load This supply exhibited the highest levels of broadband noise of the group Table 4 Kenwood PS 40 serial number 80500885 Manufacturer s specifications Power requirement 115 230 V ac 10 at 50 60 Hz switch selectable Outp
22. eather maps and the occasional news re port or satellite image It did an adequate job copying SSTY although it can only decode Martin 1 Scottie 1 SC2 180 and Ro bot 72 formats Using the slant adjustment was a pain because it is very sluggish even with my 330 MHz Pentium II but the pro gram saves the alignment settings for the various SSTV formats once you finally manage to straighten out the images CW decod ing was on par with most CW decoders I ve tried and RadioCom performed quite well with RTTY signals Its ability to decode PSK31 however was marginal Tuning was extremely touchy making it difficult to obtain clean text even with strong signals RadioCom s horizontally scrolling waterfall display and tuning in dicators were not easy to interpret and the manual was of little help When it comes to transmitting RadioCom is still a work in progress Instead of combining the transmit and receive functions for each mode into single windows for example RadioCom places them in separate windows that you must open and close when you switch from transmit to receive This cumbersome arrangement means that you cannot type ahead in RTTY or PSK31 you can t see what the other fellow is sending when you have the transmit window open Worse yet the RTTY and PSK31 transmit buffers do not automatically clear themselves after you transmit If you don t delete the text you ve just sent it remains in the buffer and in the window and wi
23. eration are some examples For the majority of the casual fixed sta tion and portable operators nearly any of the currently available switching power supplies should provide acceptable perfor mance Carefully consider your operating requirements and weigh your options We would like to thank Rudy Severns N6LE for his help in preparing this review Rudy provided the majority of the labora tory measurement data that appears in the tables and figures sF From January 2000 QST ARRL SHORT TAKES There isn t much to the Palomar VLF converter and that is one of its strong points This little 2 x 4 25 x 4 25 inch unit is designed for the easiest installation possible You connect your antenna to the SO 239 input then attach a coaxial jumper be tween the converter output connector another SO 239 and your radio There is one switch on the front panel labeled ON and OFF along with a red LED to indicate the ON state The converter doesn t have a power supply Instead there is a clip on the rear panel for a 9 V battery The Palomar converter is simple on the inside as well Incom ing signals are first subjected to a 3 stage low pass filter which is essential to block overload from nearby AM broadcasters After the low pass filter the VLF signals reach a mixer stage com posed of a 1496 mixer IC and a crystal controlled oscillator de signed around an MPF102 transistor If you purchase the model VLF A the os
24. est contest or DXpedition feeding frenzy For the SWL or BCL of course listening is the only game The IC R75 is definitely designed for lis tening which is of course as it should be An all mode receiver it also offers things like synchronous AM detection to enhance AM broadcast enjoyment by ameliorating the effects of multipathing and fading It also incorporates superb dual passband tuning to combat interfering signals plus the possi bility to add optional crystal filters for enhanced selectivity Simply push the FIL button to set the narrow filter for the mode you ve selected if installed You ll find CW CW R reverse and RTTY mode settings Another nice touch it offers adjustable CW pitch via the menu This triple conversion design has IFs at 69 MHz 9 MHz and 455 kHz While it only draws about A at full volume the AF stage delivers a healthy 2 W or so to the front firing speaker The LF capabilities of this receiver are something to keep in mind in terms of the pending request by the ARRL to allocate bands at 136 kHz and at 160 190 kHz Ex perimenters and QRP enthusiasts who en joy building transmitters might find an able companion for their endeavors in the R75 f CoM IC R75 e a h Ee O AF Pantha TWIN PBT J puos Power N P r o P But from my point of view the coolest feature of the IC R75 is its ability to truly integrate itself into a ham sha
25. he case with most of these supplies is the same type that s typically used on com puter equipment A recessed switch allows selection of 110 or 220 V ac operation A large temperature controlled external cooling fan protrudes from the center of the rear panel It only activates after extended operation under load Once running the sound level generated by the fan is low to moderate and the case temperature remains low even after 2 hour of continuous op eration under a 21 A load The documentation that s packed with the SS 30M includes a sheet with a listing of the specifications of their entire line of switch ing supplies and a second sheet with infor mation on their other power supply products Manufacturer Astron Corp 9 Autry Irvine CA 92618 949 458 7277 fax 949 458 0826 http www astroncorp com Manufacturer s suggested price 172 Typical current street price 150 From January 2000 QST ARRL Figure 1 An oscilloscope trace of the dc output of the Astron SS 30M under load The vertical scale is 50 mV div the horizontal scale is 5 ms div Note these scaling factors vary in some of the other figures The level of the dc ripple is very low lt 20 mV p p and there are no discernable high frequency spikes Reference Level 0 40 50 60 70 80 Frequency MHz Figure 2 A spectral plot of the output of the Astron SS 30M under load This
26. he six supplies tested did not generate any perceivable interference in the station receivers even when these were tuned to the frequencies outside of the ham bands where the spectral plots indicated elevated levels of RF noise This is certainly good news for 160 meter operators and those who enjoy exploring the shortwave bands occasionally How does this one sound type trans mit quality testing using SSB FM and CW also revealed no noticeable difference in the quality of the transmitted signals when powering the transceivers using either the conventional or the switching supplies The only supply that resulted in any in terference in typical transceive operation was the ICOM PS 85 This supply gener ated a series of spurious signals about 85 kHz apart that slowly drifted across the en tire 10 meter band in one receiver and even affected reception on some of the lower bands on the others Ferrite material in stalled on the ac and dc power cords did not seem to reduce the interference Hope fully ICOM has been able to address these problems in their recently released updated version There are a few instances where the level of broadband RF noise generated by a supply under load could create interfer ence problems Multi radio operations where several transceivers are set up in close proximity contest stations where a second receiver is sharing the same supply with a transceiver or mode A full duplex satellite op
27. ise Jor a es 123456789 20 I tone al ag EE ls Ln e E E A EE E DCF77 PTB TS RTTY Line Invers 1 Meteo Warszawa Fax 00 0 0 Meteo Praha RTTY Le CF Halifax cw K Meteo Tokyo FAX Meteo Praha x Audio Zy Fax ae Fax R Rj Sstv z Sstv Ss Cw ES ZP cw i C DCF77 i Info Decoder Baudrate shirt EER O Po i EB Mark BAe ij ka Stop TE e E mode fasinating to say thetleast and ee think it will catch on big tim shor tt ey sxatiedon ouo tQn nekl ede kk5 sw Tp Ha tm ree _ 6 leeEH KK5SW de W7BWI Your RST 579 579 good cofy We only hawe three miles to alMort here My wife most of the shopping and aually makes t a list so she doesPt ha to go back Hi There are new PSKers comingpn ellteae to it seems My old friend in Port Orford OR will probabl be on Sefore RadioCom in the PSK31 receive mode Pros and Cons The middle portion of the RadioCom main screen contains a lengthy scrolling list of RTTY CW and FAX stations with their frequencies call signs locations and signal specifications RTTY shift and baud rate for example With radio control activated you need only double click your mouse on any line and your rig will instantly switch to the proper frequency and mode You can modify the list adding or subtracting stations as you wish This is a very convenient feature RadioCom did an outstanding job decoding HF fax transmis sions which are mostly w
28. ll be sent again the next time you click on the transmit button I discovered this glitch the hard way RadioCom is Eurocentric software and this is most apparent with the DCF77 decoder DCF77 is a 76 kHz station located near Frankfurt Germany that transmits precision time code signals simi lar to our 60 kKHz WWVB RadioCom will decode the DCF77 sig nals and automatically update its large numerical time display along with your PC clock if you desire Unfortunately most of us can t receive DCF77 in the US and RadioCom s DCF77 decoder will not work with WWVB I tried I hope that newer versions of RadioCom for the American market will provide WWVB decoding instead Bottom Line If you enjoy eavesdropping on HF digital signals RadioCom 4 0 offers impressive flexibility and performance It s fascinating just to play with the variable DSP filters to see what you can really hear beneath the noise and interference But for Amateur Radio applications RadioCom needs to return to the drawing board With a better English manual and other improvements the next version of RadioCom could make hams sit up and take notice Manufacturer Bonito Inc distributed in the US by Computer International 207 South Old US 27 Saint Johns MI 48879 1903 tel 517 224 1791 computer email mintcity com Suggested retail price 250 QSF Steve Ford WB8IMY QST Managing Editor 66 January 2000 Q5F
29. nals overall While not outstanding in this regard the receiver is in the plus numbers on 3 5 and 50 MHz and it breaks even on 14 MHz This is good In very practical terms this means that you can take this receiver out on a busy HF band during a contest weekend and un der optimal selectivity conditions the front end won t fold up when the neighbor hood bully is bellowing down the band with his killerwatt For problem situations though the R75 s twin passband tuning can be a huge plus The radio also has an at tenuator that comes in handy when too much gain becomes an issue There s plenty of sensitivity to go around in most cases Up until now we ve been talking about CW and SSB performance by and large Of course with a receiver like this you ll want to know how it does on AM and FM Again the sensitivity numbers are respectable or better especially with the preamp engaged I happen to enjoy listening to AM broad casts so this is a big plus In fact while checking out the R75 the local Public Ra dio station was begging so the incentive was even greater to listen elsewhere An even bigger plus is the inclusion of synchronous AM detection on the R75 On certain signals it can make all the difference between enjoyable and annoying listening Simply push and hold the AM button once you ve tuned in your station it will switch to AM S and you re in business Less impressive was
30. nection Operation specifications and troubleshoot ing aincluding tips on reducing interference Manufacturer Kenwood Communica tions Corp 2201 E Dominguez St Long Beach CA 90801 310 639 5300 fax 310 537 8235 http www kenwood net Manufacturer s suggested retail price 230 Typical current street price 225 MFJ 4225MV The MFJ 4225MYV is shaped a bit like a cube it s taller narrower and shallower than most of the other supplies in this roundup The front panel is busy there are large backlit meters for current and volt age a rocker type power switch LED in dicators for the power and fan and a ciga rette lighter type dc power jack Five way binding posts for the dc output are provided on the front panel This supply is the only one in the group that offers an external control for the out put voltage The voltage is variable from 5 10 15 20 25 0 obrir Assi Table 5 MFJ 4225MV Manufacturer s specifications Power requirements 85 135 V ac at 47 62 Hz or 170 260 V ac at 47 63 Hz switch selectable Output voltage variable 9 15 V dc Output current continuous 22 A Size hwd 4 5x5 75x6 inches weight 3 7 pounds Lab Measurements Output voltage no load 14 4 V dc Output voltage 21 A load 14 14 V dc Low line drop out voltage lt 85 V ac Dc variation during dynamic testing 200 mV From January 2000 QST ARRL Figure 7 An oscilloscope trace of the dc
31. odel FP 1023 Table 7 Yaesu FP 1023 Manufacturer s specifications Power requirements 100 130 V ac or 200 260 V ac at 50 60 Hz jumper selectable Output voltage 13 8 V dc Output Current continuous 23 A Size hwd 2 2x7x8 25 inches weight 3 5 pounds Lab Measurements Output voltage no load 13 9 V dc Output voltage 21 A load 13 75 V dc Low line drop out voltage 90 V ac Dc variation during dynamic testing 200 mV Figure 11 An oscilloscope trace of the dc output of the Yaesu FP 1023 under load The vertical scale is 200 mV div and the horizontal scale is 10 ms div The level of the dc ripple is low lt 30 mV p p but there are spikes due to switching that extend out to about 600 mV p p Reference Level 0 40 50 60 70 80 Frequency MHz 90 100 Figure 12 A spectral plot of the output of the Yaesu FP 1023 under load There are several ranges including several within the US amateur bands where the broadband noise is moderate closure especially the front panel gets considerably warm after about hour of continuous operation connected toa 21 A load A small 6 page User Manual with in stallation and operating instructions a specification table a troubleshooting guide and details on removing the jumper for 220 V ac operation is included Manufacturer Yaesu USA 17210 Edwards Rd Cerritos CA 90703 562 404
32. to 8 Q Range at 6dB points bandwidth CW N 500 Hz filter 221 972 Hz 751 Hz CW W 67 2625 Hz 2558 Hz USB W 87 2591 Hz 2504 Hz LSB W 64 2597 Hz 2533 Hz AM 66 2510 Hz 2444 Hz First IF rejection 14 MHz 81 dB image rejection 14 MHz 72 dB Size hwd 3 7x9 5x9 inches weight 6 6 pounds Note Unless otherwise noted all dynamic range measurements are taken at the ARRL Lab standard spacing of 20 kHz Measurement was noise limited at the value indicated Sensitivity reduced below 0 06 MHz the supplied and sizeable ac adapter Fortunately it s wired with a plug on the end of a cord so you don t have to figure out where to plug in the hefty cube A Capable Receiver The R75 packs a lot of performance into its compact frame Keep in mind that ICOM was able to concentrate on simply produc ing a decent performing receiver here they From January 2000 QST ARRL didn t have to worry about what was hap pening on the transmitter side With the R75 you ve got a receiver that not only covers a huge chunk of the known HF spectrum plus the low end of the VHF the only thing that would have made it better would be to have included coverage comparable to the IC 706 but that s for the next version but also has ample sensitiv ity over its coverage range ARRL Lab test ing showed the preamp off sensitivity hov ered around 130 dBm right up there with the big boys but it includes
33. two preamp stages to boost sensitivity by as much as 10 dB These really can come in handy A few words on dynamic range This is an aspect of receivers that while important often gets less than a full discussion in the typical transceiver review It s also some thing that many amateurs are still unfamil iar with at least as it pertains to receiver performance In fact outstanding receiver performance largely hinges on outstanding dynamic range which defines a receiver s ability to distinguish weaker signals in the presence of nearby stronger ones In the ARRL Lab we measure dynamic range for SSB and CW in the CW mode with the narrowest filter employed and in jecting interfering signals 20 kHz away from the signal we re trying to listen to The R75 is no slacker in this regard The two tone third order IMD dynamic range of the R75 is more than merely respectable in the vicinity of 90 dB on HF through 50 MHz This is in a league with the receivers in many mid priced transceivers As it does even on more expensive re ceivers the two tone third order IMD de grades slightly with the application of the preamplifier In this case it s no big deal only a couple of dB or so see Table 1 The presence of the preamps is a big boost pun intended A lot of people look at the third order intercept number as a measure of quality for a receiver This is an indication of how the receiver handles strong sig
34. ut voltage 13 8 V dc 5 Output current continuous 20 A Size hwd 2 5x7x8 9 inches weight 4 4 pounds Lab Measurements Output voltage no load 14 4 V dc Output voltage 21 A load 14 14 V dc Low line drop out voltage 97 V ac Dc variation during dynamic testing 200 mV Figure 5 An oscilloscope trace of the dc output of the Kenwood PS 40 under load The vertical scale is 50 mV div and the horizontal scale is 5 ms div The level of the dc ripple is low lt 20 mV p p but there are spikes due to switching that extend out to about 200 mV p p Reference Level 0 dB 30 40 50 60 70 80 Frequency MHz 90 100 Figure 6 A spectral plot of the output of the Kenwood PS 40 under load While there are some ranges where broadband noise is evident the majority of these are outside of the US amateur bands From January 2000 QST ARRL the only supply in this group to include a separate connection point for chassis ground A small recessed slide switch al lows you to easily select between 110 and 220 V ac operation The cooling fan is mounted externally on the rear panel It runs continuously when the power is on The sound level of the fan is moderate to high the loudest of the bunch The supply remains cool even after 2 hour of continuous operation with a 21 A load Kenwood provides a 4 page Instruction Manual that includes sections on con
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