Elegant and wide functioning with many conveniences for a good price.
Alinco Electronics, Inc.. located in Torrance. California is besi known for its single- and duat-band VHF UHF handheld and mobile transceiver equipment, sold by over 80 amateur radio dealers throughout the United States. Certain Alinco radios have achieved tan ctub status because of their unique design and relatively low cost.
For instancet there are the Alinco 1200TH2 9r600 baud packet radio made popular by Buck Rogers packet column; the Alinco DJ-G1T, the first handheld ever with spectral channel-occupancy bar graph: and the Alinco DR-599 dual-band mobile with "secret" antenna |ack for public safety
While Alinco Electronics, Inc., does not possess the sales volume and market share that Kenwood, Yaesu, and JCOM have, the company does enjoy a reputation for well-performing VHF UHF equipment at prices slightly lower than the big three and a small but efficient service team who can turn around most repairs at the Torrance facility within 10 working days. Alinco's technician/ engineer Taka Nakayama AB6VEf is extremely active on the ham bands, and knows the equipment inside and our "1 love operating ham radio." comments Taka When rt comes to 9.600 baud packet cross-band duplexing, or driving in downtown areas where inter"modulation is a problem, I
know how well our Alinco radios work because Tm active on the air says Nakayama with a smite. He holds an Extra class United States amateur license and a Japanese license, too.
But Alinco Electronics really surprised the amateur radio community by coming out wiib a high-frequency transceiver ior the 1995 Dayton HamVention debut. First we have VHF/UHR and now we have high frequency, too." comments Alinco Electronics USA President Mark Morisato KC60CX "And our new high-frequency DX-70 does more!" adds Morisato, No doubt Mark is speaking ot the built-in, aJf-mode. 6 meter 50-54 MHz capabilities with 10 watts output that is included in the high-frequency package and is the same size as the very popular and successful Kenwood TS-50 mobile HF transceiver
The new Alinco DX-70 HF plus 50 MHz all-mode transceiver runs 100 watts out from 1.8 MHz to 28 MHz on ham bands, and tunes 150 kHz to 30 MHz continuously from its excellent general coverage receiver Plus, it covers 50-54 MHzT with ail modes, and 10 watts out. That s plenty of soup to kick a 6 meter power amplifier into QRQ'
Most unique is the detachable control head that allows the new Aiinco DX-70 to be separated so the head could go on the dashr and the transceiver under the seal The mike still plugs into the transceiver body, so separating the iwo won't be a tiunk-and-dash affair. But I don i recommend trunk mounting ot any remote-control transceiver because ot the long run of the DC power cable. This is just asking for trouble If you want a longer mike cord, they have an EDS-5 microphone extension cable that will handle Ihe job nicety, Keep in mind thai the extension cable will cost extra—probably about S40—so if you plan to run it remote, factor this in to the transceiver s street price which will probably
Photo A. The Aiinco DX-70 and the matching Alinco Antenna Tuner combine to form a compact JHeld" radio.
be around 51,250,
Yes, 6 meter fans, there is a separate output SO-239 antenna jack. When you switch to the 6 meter mode, you can hear several relays go klink." which sound tells you they are running an independent receiver and transmitter section for best performance on the 6 meter band.
t hooked the DX-70 to a three-element HF beam and regulated 12-volt power source with ihe 6 meter side over to a three-eiemenl 6 meter beam to see how the radio would perform in the real world. The display popped up with a bold numerical readout of frequency MHz kHz and hundredths. The numbers are slightly smaller than the Kenwood TS-50. but are much bolder, wider, and darker. And like the Kenwood TS-50, there is a busy" icon when the squelch is open along with an amber jewel LED that also tights up with recerve activity. The mode indicator appears in the upper right-hand corner and AGC fast or slow appears above the frequency display. Finally, the DX-70 has more than enough to drive the top-mounted speaker
As soon as t hooked into the three-eie-ment tribander. there was no mistaking that the Alinco DX-70 has a wonderful receiver. It is dual conversion, with sensitivity and selectivity numbers identical to what you might find on everyone's sales brochures for a $tT000 HF mobile SSB transceiver. But unique with the Alinco DX-70 is the bottom left RF button thai lets you switch in the 10 dB pre-amp, switch it out. or switch in -10 dB and -20 dB attenuation. 1 found that ihe attenuator was a big help when operating on 40 meters, with a neighbor one biocfc away just 75 kHz up the band. On 10 and 15 meters i switched the pre-amp on, which gave me a hot receiver,
The same button that controls ihe RF gain selection also has a sublunction it turns the noise blanker on and off. While the noise blanker does not have any timing or sensitivity adjustments, it did a nice job of killing the clatter of our nexi door neighbor s old Ford Thunderbrrd when he Irred up the engine Furthermore, the noise blanker did not garble on extremely strong signals. On many HF transceivers, engaging the noise blanker on 40 and 80 meters causes most signals over S9 lo become garbled. Not so with this noise blanker.
Selectivity on SSB is 2,4 kHz, and a convenient filter" button next to Ihe RF gain button allows you to kick in the 1-khz SSB filter. The 1-kHz filter is already built in, and not an added option for tightening up on an incoming weak signal. You can further home in on an elusive signal by rotating the IF shift knob to dodge the QRM This same filter network offers 1-kHz or 1/2-kHz CW passband, And if you re into shortwave listening, you can click in 2.4 kHz AM narrow, or 9 kHz AM wide—including FM—for full fi delity reception.
The first IF is at 71.75 MHz, the second \F at 4 55 kHz, and spurious/image rejection is listed as 70 dB. When I switched back and forth between several transceivers on tne bench, the Alinco was more sensitive and just as selective as the higher-pnced sets.
Everyone commented on Ihe recovered audio on SSB as being sharp/ Ifs the same-sounding audio I have heard from the Yaesu 900: impressive, full-fidelity treble without tightness or hiss, Listening to the DX-70, when tuned into a transmitting SSB station, is similar to hearing a hi-fi with bass, mid-range and tweeters as opposed Eo an audio system with [ust a mid-range speaker. It's difficult to describe; try to listen for your-sell.
The AGC is a function/AGC command on the same push button 3s the filter switch The function button is conveniently located to the left of the set, a natural arrangement for depressing it with your thumb, while using your forefinger for the other button.
I switched up to 6 meters to confirm that all fillers, noise blankers, AGC actions, and pre-amps wereiVl the same. I did notice on a big 6 meter antenna that 10 dB of pre-amp gain brought in a phantom sound of an FM or TV station way in the background that could never be tuned in. but didn t have that problem with the pre-amp turned on when we tested the unit on :he mobile 54-inch whip.
I also tested the Alinco 6 meter receiver performance against two other iime-tested ngs and found the Alinco actually hoiter on
"As soon as I hooked into the three-element tribander, there was no mistaking that the A Unco DX-70 has a wonderful receiver."
receive with the pre-amp clicked on than the other two units which were running with external amplifiers And since the other two ran only 10 watts out, t didn't find 10 watts from this Alinco to be out of fine. Mirage now sold by MFJ. offers a 10-watt in. 150-watt output, 6 meter amp that I ve seen selling tor under S350. so getting more power from the Alinco package is noi all lhat difficult.
The front panel of the Alinco features a main tuning dial along with a smaller tuning dial. The smaller dial is rotated for both memory channel select and megahertz or ham band select, and to change frequencies in specific kiiohertz steps Tike 2 5 kHz. 1 kHz. or 500 Hz. This sub-knob reminds me of the "click-click-dick" knob on the Kenwood TS-140. Its a handy feature. The main tuning knob resolves frequency down to 100 Hz (.1 kHz) dial indication in 25-Hz steps if you ever -so-carefully turn the big knob.
The multifunction knob Jets you quickly rotate through 100 memory channel locations that hold a surprising amount of memo-channel information: Receive frequency- mode, any split IX filter. AGO setting, RF-gain amps or attenuators. noise blanker on or off. This is a very smart memory that might allow you independently to select a CW frequency for fast AGC, narrow filter, no-noise blanker, and RF pre-amp. On an SS8 channel, you could memorize slow AGC. noise blanker, -10 dB attenuator, and the normal filter. I considered this versatile memory capability as a definite plus foi this very compact ng.
Another nice feature is the high/low power output button Unlike a slide switch or no power option al all, you can quickly reduce power to local stations or reduce the current consumption of the radio on a dying storage battery.
A dial lock key prevents you from accidentally turning the big knob when tuning channels in from memory. As m Icom transceivers, memory positions allow for instant QSY from the big knob This allows you to use the small memo knob to get you within a pre set spot on the dial, and then use the big frequency knob A quick flick of ihe small knob instantly puts you back to that original memory position And when operating from the memory position for the digital modes, you would lock (electronically) the big knob to insure you don't accidentally bump off frequency.
Other buttons and knobs on the front are the RIT capabilities; Ihe "MF SEL button to select memo, band, or trequency options; the little TX jewel LED that comes on for transnut: delta transmit; memory Lo permanent VFO selection; memory right, split, and priority—all the usual knobs on a HF transceiver.
M you press and hold the lunction key twice for longer than 2 seconds, "SE'1 will appear on the screen indicating you have set the Alinco DX-70 into the set mode, This procedure is similar lo thai of the Kenwood TS-50 in the menu mode. The small multifunction dial selects ihe many setup options.
The relaliveEy large Alinco DX-70 instruction manual also describes procedures regarding simply resetting the mode settings, resetting all memory channels or VFOs, or performing a major reset of everything as if you had just purchased the equipment new from the dealer.
and UHF bands included."
On the back of the transceiver are the customary jacks for speaker or headphones, featuring the common miniature jack (not subminiature). There is the common CW jack tor connecting a telegraph key or electronic keyer system It lacks a built-in electronic keyer but most hams prefer their own style of electronic keyer rather than any type of built-in keyer The CW key-jack is atso a miniature jack not the frg 1 4-mch jack you would rind on larger equipment.
There are also RCA jacks for ALC as well as relay. When the equipment is new out of the box, the relay is out of circuit Cutting an obvious internal jumper wire, detailed in the instruction manual lets the relay close when me microphone or key is depressed The ALC input voltage from the amp needs lo be zero to -3 VOC,
There is a small screw for connecting a ground foil tab, two antenna jacks plainly marked for HF and 6 meters, the heal sink, and then the power connector More good news: It's the common six-pin power plug that is used by Kenwood Yaesu and ICOM from a DC source
There is an external antenna tuner connection that the manual fully describes as being compatible with a Kenwood AT-50, a Kenwood AT-300. an Icom AH-3 or even an SGC 230 automatic long-wire antenna tuner for field day/maritime mobile/mobile home applications.
While I didn't see an accessory jack for going digital the microphone offers pin 6 as the detector output with associated pins for PTT, ground, mike ground, and 5 volts DC, Taka at Alinco. an avid HF digital operator, says this radio has full capabilities in the digital modes.
Power output on high frequency was a good 100 waits, and I noticed the average modulation level around 60 watts, indicating only slight ALC action. This gave me a good punchy signal that everybody commented about as being "hefty~ and sounding great. An SWR protection circuit throttles back output down to 25 watts with no antenna, and a momentary antenna short-out pulled the power down to a safe 5-watt level.
On 10 meters FM, power output was also 100 watts. This surprised me because throughout the bands AM was only 50 watts.. On 6 meters. Ihe power output was 15 watts SSB 11 watts FM, and 6 watts AM.
I then tried operating on 10 meter and 6 meter repeaters and everything was going along fine in entering the 10 meter 100-kHz offsets as well as the 6 mete: 500-kHz offsets. But where, oh, where was the almost-always-necessary CTCSS selections out of menu? Not there! What7 No subaudible tone encode? Oh yes. there is, but it uses dip-switch programming.
The CTCSS encode is on the bottom side of the transceiver, with no mention of it in the well-written and illustrated instruction manual The tone board is already installed, included with the package, but you need your trusty toothpick and peniight lo manipulate the eight different switches for any one ol 38 possible subaudible tones But besides that I enjoyed Operating the equipment. The only thing I couldn't figure out when running the unit and not reading the instruction manual was how to get it to go into the set mode. As soon as t cracked the books, it was right there.
tt has been many years since I have seen the high-frequency transceiver manufactured with VHF and UHF bands included When you get a chance, head on down to your local amateur radio dealer and take a listen to the sharp high-fidelity action on the new Alinco HF + 6 meter transceiver that has a very bright future.
"jIt has been many years since / have seen the high-frequency transceiver manufactured with VHF
Number 15 on your Feedback card
Michael J. Geier KB1UM co 73 Magazine 70 Route 202 North Peterborough NH 03458
You hear it all the time in ham publications: don r buy an HF amplifier. just gei a better antenna or raise the one you have up higher. It s basically good advice, but it doesn t always work, does it? Depending on your location, surrounding mountains, sunspot activity, GRM. QRN. and whatever you can find yourself unable to be heard, no matter what you stick up in the air Or, you may not be allowed lo have a tower . . , or you may not be abfe to afford one. Whatever ihe reason sometimes increasing your outpu. power is your only choice.
So, let's took at HF linear amplifiers. How to buy one. how they work, how you use themr how you don't use them, and how to best make use of the hot. glowmg buggers.
Enduring Technology i usualiy stay away from this subject, because I consider myself a transistor guy, and the vast majority ot amps are tube-based But, having just bought an amp at a local hamfest, I've had to take a look at the whole topic.
Yes, Ihere are some solid-state HF linear amps, but they're quite expensive andl relatively uncommon. For the most part, amplifiers haven't changed much in about 30 years! That isn't from lack of interest on the part of the manufacturers; there just isn't that much you can do lo such a simple beast. Probably the biggest innovation has been the no-tune amp, but even that never realty caught on in a big way. I don I know why it has remained obscure. but intuition suggests that sue*' a design would be significantly less efficient than one with a nice. high-G, tunable tank circuit, Another step forward has been the use of microprocessor control. Now there's an odd match, huh? Microprocessors and vacuum tubes. Actualty. using a micro to control and store tuning settings is a good idea which makes amplifier use much more convenient and lets you have the best of both worlds: a high-Q tank and freedom from the manual tune-up process. So
Your Tech Answer Man far. though, such fancy stuff is limited to rather expensive, highend gear.
Something Old, Something New
So should you buy a new amp or an old one? At first thought, it makes sense to buy an old one. since the new ones aren't functionally much different, if at all, and they cost quite a bit Lois of people do buy old amps: I just bought one myself But you can get into trouble that way if you re not careful, because tubes are getting expensive and hard to Find And, various amplifiers require different tubes, the price oi which can range from Si 5 to more than S800 each, Ouchf Here are some possibilities you may run jnto:
Many smaller amps of yesteryear used television sweep tubes For those too young to remember them, sweep tubes were the ones used to generate the beam-sweeping currents for the yoke coifs around the neck ol a picture tube. A very common one was the 6LG6. which also went by the number 6JE6C and a few others. This thing had nine pins on the bottom and an anode cap on top. It was never meant for RF transmitting service, but it could do the job, provided you didn't push too hard; the plate would glow red and melt down if you tried to dissipate tots of power through the tube. Still, you'll find 6LQ6 tubes in plenty of old amplifiers, like the DenTron GLA-1000 I just bought.
Using any amp requires careful attention to avoiding too much current through the tube, but with sweep lubes you need to be extra careful. You have to tune up quickly, and when running full-duty-cycle modes iike SSTV and RTTY you have to back off the power quite a bit, lest your tubes become smoldering paperweights. Still, for moderate power output levels oft say, 400-700 watts, sweep lube amps are a decent, cheap alternative to higher-priced units. The upside is that neither the amps nor ihe tubes cost a great deal I've seen small amps like mine going for S100-$200 at hamfests. Where else can you get hundreds of watts for that kind of minimal outlay?
The other problem with this kind of amp is that sweep tubes weren't designed for linear service. They will amplify in a linear manner, as will any tube, but even a little overdriving makes them distort a great deal. So, pay extra attention to your radio s output level, and don't push it too hard
You may also find older amps with 572B and 811A tubes. The 811A was a real transmitting tube but it s a very old type and not a tremendously powerful one. so you should treat such amps much iike sweep tube amps.
This Ermac tube is perhaps the most popular one used in more modern amplifiers, and many units in production today use it These tubes cost about $ 1 G0-$140 each. That may sound high for a glass bottle but it really isn't, when you compare its performance to other, more expensive iransmitting tubes. The 3-5Q0Z is a good choice. It's a fairly large, powerful tube. You can get full legal output power from one 3-5002. but that's pushing it and I wouldn't expect the tube to last a tong time under full load conditions. It's better to get an amp that uses two of them. That way, they'll be loafing along, so they should last for years.
Metal-ceramic transmitting tubes are used in very high-power commercial installations, and some big ham amplifiers. I once had a DenTron MLjí\-25Q0< and It used two 8875 tubes, which were small, metal-ceramic types. Wow. did thai thing put out! "he tubes were about 20 years oíd. but it bJasled the ether like gang-busters Although those tubes could dissipate lots of plate current they were fairly sensitive I o grid current and you could ruin them by overdriving them: or transmitting with the amplifier out of tune, because that caused excessive grid current. You sure didn't want lo do that, though, because new 8875s cost over S400 each' Used MLA-2500s and similar amps cost about S500-S600 on the hamfest marker If the amp and the tubes are working properly, they're worth it. 1 wish I still had mine.
Simifar metaf-ceramic tubes you might run into would be 8877 8873 3CX-10G0 and 4CX1500A. They all cost a mint, but they re real workhorses that can last the life of the amplifier, and perhaps even the operator, if properly cared for
If you re going to buy a new amp, you can pretty much just pick one from the ads and buy it. There's only a few HF amplifier manufacturers left, so the choice should be easy. Just pick one you like with the most power you can afford. Chances are, it'll use a 3-500Z or two. Be prepared to spend at least $1000. probably more. If you want to buy a used unit, you have many more choices. because there were lois more amp makers back when ham radio gear was made mostly in this country. Expect to pay from $150 to $600 or so. depending on the age and power of the amp. For a little sweep tube amp I wouldn t pay over $200. preferably around $125 to $150. For one of the very popular Heathkit SB-220s, around $350 lo $500 seems to be the going price. For the big guns, its $500 and up-
Some designs were prone to parasitic oscillations, which can blow tubes as well as scramble up the spectrum for many miles around, and there were aftermarket kils or factory mods available to fix ihe problem. When examining a potential purchase, it pays to ask what s been done to it As with anything, of course, always avoid a unit which appears slop-piiy modified.
If you buy a used amplifier be absolutely sure to see it putting out something near its rated power before you plunk your money down. That is. of course, unless the price is so low that you won't mind buying new tubes. I didn i listen to my own advice and the GLA-1000's seller smiled into my face as he lied and told me that the tubes were brand new and worked great, I got home and discovered the truth: the tubes had no emission at all—they were stone cold dead! Unlike with solid-state devices, tubes can have varying degrees of functionality, including zero. In this case, it wasn't the end of the world; J found a set of good, used tubes at the next fest for $15, again taking a chance on the seller s honesty This lime. I got lucky. Had rhey been 8875s, though, i d have been In deep doo doo. Be sure to keep the cost of a set of tubes in mind when haggling over a used amplifier'
Wow. this topic is bigger lhan I expected. Let s continue next time with a look at setting up and using a iinear amplifier. Until then, 73 from KB1UM. ES
Number 16 On your Feedback card number on your P-e
Above & beyond
VHF and Above Operation
C. L. Houghton WB6IGP San Diego Micron e Group 6345 Badger Lake Ave. San Dtego CA 92119
1691 GOES Converter, The Local Oscillator/Mixer
Welf, last month I described Ihe conversion of an LNA or an LNB [o cover useful frequencies jor 1691 in pariicutei This type of design does not have to be frequency specific, but the broadband nature of the converted TVRO converter amplifier lends itself to converters from 1.000 MHz to 3 5 GHz. Whatever your frequency of interest, the principal is the same. A good RF am-pliiiet is a mixer and a local oscillator to convert Ihe high frequency to a lower IF frequency tor reception
I have received several letters wondering where 1o pick up LNA amplifiers I got mine for this test project at a local hamfest swap meel Olher locations that might show promise is to look in your local telephone directory for satellite television installers. They usuatly have some of the older LNA amplifiers of ihe 50 io 100 degree -loise temperature units that have been replaced with lower noise figure units, like 20 to 25 degrees. The newer units are much hotter than the older units and are sought alter by TVRO users. The units ihat they replaced are what we want and usually they can be had tor about ftve dollars.
The conversion of these units Is not too difficult. Remove the cover and add a two to five pF chip capacitor to the input of the amp where the previous waveguide connection resided. To the olher end of this capacitor conned an input RF connecior usu ally a SMA qi whatever your favorite RF connector is. With an ExactoT" knife, remove ihe frequency-determining stubs, leaving the bias and main connecting 50-ohm slripline connecting all amplifiers- If you have an LNB, add capacitance to the interstage capacitors by doubling up cou-pfmg capacitors to lower the frequency response of the IF amplifier. See Figure 1 for more detail covering these modifications.
The mixer I discussed last month was the Mini Circuits SRA-11. which has good RF performance to 2,000 MHz. The units fhat J tested I modified by soldering SMA connectors to the mixer pins for quick adaptation to many of the differenl circuits that I tned. See Figure 2 for SRA-11 connections. Other mixers could be used; \ used the SRA-11 because M was available in surplus on a scrap PC board. Any other type of mixer could be used, even a home-brewed one similar to the one ihat I described in this column several years ago
The main thrust of this month's
Number 16 On your Feedback card
column is Ihe local oscillator. It normally would operate on 1554 MHz. using a 137 MHz IF system for weather data reception on 1691 MHz. We obtain 1554 MHz by subtracting the IF :rom the RF frequency to obtain 1554 MHz,
There are several methods that could be used. One idea would be to use a CATV tuner loca oscillator at 1/3 or 12 the re quired frequency. By operating at 1/3 the frequency of 518 MHz a simpie iripier stage aod buffer amplifier would be all that is required to be added to Ihe synthesizer-controlled CATV local oscii lator. Again, I am using the internal divide-by circuitry in the CATV tuner to mput a low-frequency Signal io the familiar Motorola MC-145106 synthesizer chip for
this type of circuit. See Frgure 3 for synthesizer circuilry. Multiplier circuits can be found in many different reference books, such as the ARRi Handbook's VHF and UHF sections. Take a fook at the designs for the 1296-MHz converter and portions of the circuitry can be adapted from them Other good sources are the RSGB (Radio Society of Great Britain j VHF. UHF handbook.
Of course, the local oscillator can take the form of a single crystal starting out at a fraction of the required frequency and going through several multipliers until 1554 MHz is obtained. Sort of like a crystal-controlled transmitter multiplier to the operating frequency for CW operation. This local oscillator operation is quite identical.
The scheme that I would prefer given a larger budget, is to use a fundamental frequency controlled local oscillator that is capable of operating on 1554 MHz directly, without multiplication, This type of oscillator is a VCO (Vanabie Controlled Osciiia^ tor), The reason that; I did not select a VCO is that most amateurs would have difficulty in obtaining these devices. They are noi commonly available, t suspect this project will be attempted by a large number of experimenters and I wanted to name parts easier to obtam. The type and availability of certain dedicated com ponents might hinder those trying to follow a cookbook adaptation of the local oscillator. Remember, I am trying to construct this con^ verier on a shoe-siring budget and still make a converter that will perform well.
With preferences aside, what is the simplest system that can be constructed and stilt do a reasonably good job? A synthesizer-controlled oscillator from a TV tuner with its internal divide-by i s t 14'
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