Alinco_DX-70TH_review_1997.pdf
-Ifiiimiimiiii.-JI- TheAlincoDX-70TH HF/VHFTransceiver BY BUCK ROGERS,K4ABT TheA/inco OX-70TH HFNHFtransceiver. A crossthehalfcenturythatIvebeen an amateur radio operator, Ive operated just about every kind of amateur radio station tnat canbeimag- ined.Myfirst transmitter was a horne- brew rig constructed on an Atwater-Kent chassis that I cannibalized from a radio mygrandfather had stashed in the barn loft. The power transformer was not the rockem sockem type that was used in later models.Thisone was used10power the number 45 M audio output tube, and supply B+ to other plate circuits in this museum piece.Iwas able to get enough power out ofit10make more than 300 volts, but even then I had to use a bridge circuitandthecurrentwasquite low.What Ididnotknow was that the filament wind- ingdelivered approximately 4 volts AC! After putting the power to the 6AG7 oscillatorandthe 6F6linal,Iwasonlyable togetabout5wattsoutofthebeast. Isoon discoveredmyproblem:The tubes I was using needed a full 6.3 volts (AC) to kick theminto fullemission.Oncethis problem wascorrected,Ifoundmyselfwithakilter- wattthat was making almost 30 watts of RF.Well,okay,20 to 30 watts. As best as I can recall, it would illuminate a 25 watt bulb to fullbrilliance. Heaven only knows what the impedance of the bulb was.It didnt matter anyway, since I had noway of measuring it-whiteit was hotorcold. Iwent through a lew rock crushers (crystal controlled) rigs. Once I built a 304Tlrig that ran almost400watts.1had found a pole-pig (utility power company poretransformer)withahyper-sealcore. Iturned it around and fed the 220 volt AC drop sideandwas able toget 2700 volts out. After I built the 866A mercury vapor bridgerectifieraroundit, Iwasable to pro- vide power for just about any kilowatt ar- rangement I wanted. The problem was, I didnt have a more powerlul tube to drive nor the funds to get one. As time passed, a new firm called The Heath Company came into the amateur manufacturing marketplace. I had a Sky- Buddy receiver that did well. The Heath Company introduced a transmitter kit calledtheAT-1.Igazed at the AT-tphoto 211 Luenburg Dr.Evington,VA24550 e-mail: 18 co November1997 in an old issue ofCOmagazine for a long time. It hadsome features I liked-name- Iy,a meter!IIboasted apowerof 35watts, and they suppliedallthe parts and lubes to make it air worthy. Best of all, theprice waswell under$5O!Bytodaysstandards thats not a lot,soI wontsayhow much below $50 it was, because I dont like to see grown men and women cry. Iworked hardthatsummer,pickingcot- ton andhelpingonmygrandfathersfarm, and at the end of summer I had amassed a fortune-enough to send aUSPostal money order for the AT1 to the Heath Company in Benton Harbor, Michigan. Yes, it was the one with the black knobs (in later models, Heath used gray knobs witbtneAr -t ). The Best Partof The Story Now that the amateur radio history ses- sion is over.the focus of the article is just aboutto begin. The HF and VHF rigs and transceivers Ive owned and operated over the dec- ades all have been somewhat large and insomecaseshernia-makers.tosaythe least.Theywerenotthetypeandsizethat you would care to haul up the hillside to the fielddayor contestsite.Hereiswhere the best part of this story really begins. This week I experienced the most fun withthemost feature-filledHFNHFtrans- ceiver Ive ever owned, the Alinco OX- 70TH.This unit coupled with an automat- rcantennatunersuchastheAlincoEDX-2 will operate and tune into a wire or a mobile whip at the touch of a button. The AlincoOX-70 comesin two varl- ettes:the DX-70T and the DX-70TH.The OX-70T runs 100 watts on the HF bands and 10 watts out on 6 meters. The OX- 70TH runs a full 100 watts output on all bands,160through 6 meters. Having A Field Day The fun really began as I sat waiting for theclock tostrike2PMon Saturday,June Say You SawIt In CO TI8dof,ThePS-tl211l -Ywlye-wl tnlakerpd 3201lS) OpenHardware and Software Architecture M;.lIMMIo.rrTall. wiillDS RU1C<J11._1Ru.inl actical Sail InterNET ll,wardporuonbud;ofSG7:!OO SG-7200 DSP HF Modem withSmartEmailer CcJmmlIMlO stand,nl55h,:a<.!- aw<.leipmvcnIll llWi.-elVCl. Call Today! 1-800-259-7331 Web srte http:/ / E-mail SGC MKTGlAOL,CQM talionIi_I,available0I11001,;.,J, .W.,la._ LIMfaaFItItfS:TlIO IIIJd8lItla.oo.lrom, lP.11p1.8-lltotillrld LP50 1.85.,1,80Iholler UOItlentpelbiieUlWIt! MlllI.I8b1flOd:,Max IXMW1ooo.-s 28th, Reid Day. At almost thesamemo- ment as Field Day activities began, the6 meter band opened to the west and north- west. I was operating as 2EVAFM07. Power was from a 1400amp, 13.8 volt DC DynastyN oltex batterybank that waskept charged by a 4x8solar-panel array from Fowler Solar Electric. For the next 7 hours I had myamateur radio fun experience for the year,working stations inNevada, Wisconsin, North Da- kota, South Dakota, Minnesota, Missouri, IIltnois, Idaho, Oklahoma, Texas, and California. All this funwas being had with the AnncoOX-70TH, but the rest of the combowas nothing towrite homeabout. Thepart that leavesmeaghast is thepuny antenna support structure thatIused to temporarilyraise my three-element beam. Ihad not planned to do a lot of 6 meter work, so I placed an MFJ-1762 three-ele- ment beam on two 10 fool sections(20 feet) of light-duty mast. No rotor, only the arm-strong rotationmethod wasneeded. However, I did not have tomove the an- tenna all afternoon. The 100 warts SSB out of the Alinco OX-70TH took care01the rest.Ididmake one change in the default setup by pressing the function/H/L switch- es androtatingthe multi-function control knobto set the Digital Audio Processor ON. After Imadethis change, my signal reports began to reflect it. Iactuallygot hoarse answering all the calls. My log of contacts on 6 meters sidebandis a testi- monial to the performance of the DX- 70TH and the20 foot high MFJ-1762 three-elementbeam. Belore I get into how to interfacethe OX-70TH forpacket operation (and other digitalmodes), let me lilI you inona few of the features of this super-compact little box of amateur radio dynamite. Just For Openers The OX-70TH coverstheamateurbands HF1.8-30 MHz and VHF50-54MHz in the SSB, AM, FM, andCWmodes. Both the DX70T and DX70TH have separate antenna terminals for the HF and 50 MHz bands. The receiver of the DX-70 isgeneral coverage, coveringfrom 150kHz to 30 MHz and50to54MHz in all modes.The super-compact body size is approximate- ly 7RWx24 R Hx9R D (178 mmx58mm x 228 mm). The detachable control panel allows you to install the transceiver with greater flexibility, whether itbein yourcar or your ham shack. When itcomes to getting rid of theun- wantednoise,theinterference eliminators built into the unit standtall. The IF SHIFT function; built-in narrowfilter standard for SSB, CW, and AM modes: and RFatten- uator make up a very impressive means of rejecting unwanted signals. II you likeCWoperation, theDX-70TH Say You Saw It In CO CiRClE71ON READER SERVICE CARD November1997CO19 Shield AFFromCantroller - GND Push ToTalk Receive ALINCODX-70THIICPORT Turnyour excess Ham Radios and related items inlo a laxbreakfor you andlearning1001for kids. TIP BucKUBT 3.5mm EXT.SPKRLSLEEV&-J AlternateReceive AF method Fig.1-The Alinco OX70TH interlace. Donate your radio or related gear to anIRSapproved 501 (c)(3) charity.Get the tax credit and help a worthy cause. THERADIOCLUB OF JUNIOR HIGHSCHOOL22 P.O. Box1052 NewYork. NY10002 &4I9i9,uieati6lft6 tc6HSi,u1950 enables you to receiveCWsignals from either upperorlower sides of the carrier frequency.ASelectable Sidetone and Selectable Full Break-in (QSK), Semi Break-in (in 7 steps), and Auto Break-in (delaylimeautomatically adjusted with keying speed) place you in the class with the topCWcompetitors. Theres much more,butspace is limit- ed,so Ill stop with this one final feature note:The Alinco DX-70THhas 100mem- ory channels that enablethe user1 0 store modes,filters, split-frequencies, AGC,at- tenuatororpre-amplify.andnoiseblanker settings. Needless to say, I am truly im- pressed with the OX-70TH. Digilallnlerfacing Made Easy When the DX-70TH arrived, I read the manual-well, almost all of it. The manu- alwasclear,describingthefeature details within the unit itself. I set some of the features of theOX- 70TH into action and connected the an- tenna. Nexttattached the unit to myAs- tron 13.5 volt, 25ampDC supply.Iturned it on,tuned to a 75 meter SSB frequency, and tuned it. Within a short time I was in QSO (mid-day) with Jim, N4JA, in South CarolinaandBlant.WA4NRU,inGeorgia. Notbad when we consider they had nor- lzcntal antennas, my antenna was a 40 foot vertical length of wire, myOX-70TH wasbarefoot (nolinear/PAl,and myQTH is central Virginia. The opening bell with theOX-70TH was ringing clear. My next step was to turn on the solder station here inthelab10interlacethe OX 70THto my multi-mode digital controller. Iwas about to try theunitat HFinthe dig- ital modes. First I had tofindthe mic data I/O port instructions inthemanual. Aquicklook at thetableof contents revealed acomplete sectiondedicated todigital models) inter- lacing. A turn to section2-11, page 2-22 of the manual brought me10something similar to fig. 1. The line at the lap of the page readsRTTY,Packet, FAX, and SSTV Operation. That about covers it. unless you want to toss in the rest of my digital interests, such as AmTor, G-Tor, PacTor, and a lew other Tors. For nowwe arehavingfun withthe dig- ital modes and the Alinco OX-70TH.The OX-70THispricedat$1074,whiletheOX- 70T is $957. For more information about theOX-70series,contactAlincoElectron- ics,Inc.,438AmapolaAvenue,Suite 130, Torrance,CA 90501(telephone310-618- 8616,fax 310-618-8758). 20 CIRCLE 670fIREADER SERVICE CARD
