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scriber line in the United States now has a nominal 900-ohm impedance. This fact will probably be a surprise to most pho ne patch manufacturers, also. However, t he 600-ohm equipment has worked well in t he past. There are other restrictions on what yo u can fced to the jack supplied by the telephone company. ...Power of the signal at the central office (must) not exceed 12 db below 1 milliwatt averaged over any 3 second intcrva!....The power of the signal which may be applied by the customer-provided equipment to the Telephone Company interface located on the customer's premises will be specified for each type of co nnecting arra ngement bu t in no case shall it exceed one milliwatt. In other words, you are not allowed to over-d rive the telephone company lines. T his is a reasonable provision, and should be t he basis for providing a meter on your phone patch, alt hough most patches don't have meters. It is not too like ly that your patch will provide more than a legal signal. If it does, the "network control signaling unit" has some built-in compensation. Of co urse, the telephone company could specify an un· reasonably low input level. Line loss can be as high as 10 db. Be suspicious in this area, but don't leave yourself open to that $10 charge. The power in the band 3995 to 4005 Hertz shall be at least 18 db below the limit (that is. 18 db below the 12 db below 1 milliwatt at the central office)....T he power in the band 4 .000 Hertz to 10.000 Hertz shall not exceed 16 db below I milliwatt....l 0.000 Hertz to 25,000 Hertz- 24 db below ... 25,000 Hertz to 40,000 Hertz- 36 db below ...above 40.000 Hertz- 50 db below... These figures give the " low-pass" filter req uirements which your phone patch must meet. They should not cause any difficulty. To prevent interruption...(the) signal (wi ll) at no time have energy solely in tile 2450 to 2750 lIertz band. If signal power is in (the) band, it must not e xceed the power prese nt at the same time in the 800 to 2450 Hertz band. This rat her simple restriction is the reason for the occasional unexplained disco nnection of an apparently-good phone-patch circuit. The telepho ne companies use special signals in the 2450-2750 band which are the equivalent of a " hang up" command, and the call is cut off. An occasional hetrodyne at the wrong freque ncy can cause this problem, bu t there is not mu ch you can do about it. Other Methods There is one other way to accomplish a phone patch, and it can be done at a saving. 58 Section 20 of the tariff provides restrictions on " Inductive or Acoustic Coupline," which can be used without charge. I suspect that there will be quite a bit of amateur develo p ment effort toward developing inductive or acoustic phone patches. The restrictions are as follows : " ...Network control signaling shall be performed by equipment furnished, installed, and maintained by the Telephone Company. In other words, you have to have a telephone. No fair just inductively coupling the patch to the telephone company lines. .....Connection is made externally to a Telephone Company net work control signaling unit." You can't put part of the patch inside the telephone. The inductive coupler or acoustic arra ngement must be outside the phone. ...Equipment mu st comply with the following minimu m network protection criteria: ...The power of the signal which is applied by the customer-provided equipment to the network co ntrol signaling unit located on the customer's pre mises be limited so that the signal power at the output of the network control signaling unit (i.c. at the input to the telephone company line) docs not exceed 9 db below I milliwatt when averaged over any three second intcrval....(and)....Ifrequcncyjpower limits). Notice that the signal power restriction is 9 db below I mw at the line input. rather than at the cent ral office. If your line happens to be among the worst, your signal could be 19 db down at the central office, rather than the 12 db allowed for an electrically (QKT) connected system. This is rat her restrictive, and again industry has objected. The frequency{power limits are the same as listed before, except that they are referred to the minus 9 db figure. Now What? With pho ne patches now legal, the amateur "fraternity" should take so me positive action. Each of us with a phone patch must make sure that the patch is operated properly and that it is not harming the telephone e quipment. Since a tariff now exists for customerprovided equipment, the telephone companies can no longer t urn a blind eye o n phone patches. The cost is really very reasonable, and the peace of mind is worth it. Call the local company and get " legal" yourself. Since the ARRL now recognizes phone patches, we should urge the ARRL and any other interested amateur groups to present the amateur views on this subject to the FCC 73 MAGAZINE
and the state regulating agencies. I fee l that a well-designed phone patch should not be subjected to the additional restrictions of a "network control signaling unit ," and should be allowed to provide dialing, answering, and control functions if properly constructed. If you support this view, write the ARRL. The FCC sometimes listens to the voice of amateur radio. Possibly, a good quality phone patch could be used as a supporting exhibit. In any case, make your opinions known. The phone patch is a useful piece of equipment, and now it's legal. Let's keep it that way. ...W5LHG Will Amateur Radio Win the Technology Race? Ham radio is becoming extremely technical, what with SSB, VHF, UHF, SHF, Moonbounce, Pulse, Masers, Lasers, etc. Unless the convictions of most amateur radio operators change drastically, technology may destroy ham radio. As an IS-year old electronics engineering student, I have been observing the more experienced operators above the age of thirty, most of whom have become content to possess their general license and just chew the rag. Few will admit their stagnation, but only a handful of "go-getters" are advancing ham radio technically. And even fewerare keeping up with the advancement. Many SSB operators really do not even understand the technique of SSB generation! Just take a look at the bands above 50 MHz. Only on the frequencies where commercial equipment is available are there any large-scale operations. The majority of ham radio is not willing to explore the upper region, either duo to lack of knowledge or lack of initiative. Now I am not professing to be an electronics genius, but I am not content to pass the test and fake a rest! After four to eight years of college, I plan extensive study of radio technology, far beyond what is expected of the average ham . What I am advocating, however, is not for all amateurs to study college courses. This is too much to expect. But at least be able to understand your present rig. Try to keep pace with the moderate theory. Maybe, if you keep active, both on electronics t heory and on the air, you'll be a better ham. Remember, amateur radio is not CB. We are supposed to lead in technology and experimentation, not fo llow. Roy C. Pollill, WA3IID TORO ID CORES Red " E" C ores·500 kHl to 30 MHl- P. = 10 :# 00 10 T-200-2 2.00" 1.25" T-94-2 .94 .56 T-80-2 .80 .50 T-68-2 .68 .17 T-50-2 .50 .30 T-37-2 .37 .21 T-25· 2 .25 .12 T-12-2 .125 .06 Ye llow " SF" C orel- IO MHI to 90 MHl- 1J. = 8 T·94-& .94 T·80-6 .80 T-68·6 .68 T-50·& .50 T-2S-6 .25 T- 12·6 .125 Bla ck " W " Cores-30 MHI to 200 MHl- = 7 .56 .50 .31 .30 .12 .06 H -:55" .lI •25 . 19 . 19 . 12 ." .05 .J I .25 .19 . 19 ." .05 EACH $3.00 .75 .. .50 .4, .40 .30 .25 .95 .80 .65 .50 .35 .25 T·50- 10 .50 .30 . 1'1 .&0 T·J7- IO .37 .21 .12 .45 T-25-10 .25 .12 .0'1 .40 T- 12- 10 .125 .0& .05 .25 FERRITE BEADS : .1 25" x . 125" . 1J. = '100 . W ith Spec Sheet & Applica ti on Notes Pkg of 12. $2.00 KILOWATT TORO ID BALUN KIT : Stilt only $5.00 EXPE RIMENTER 'S 2 CORE TOROID KIT-This famous kit cc oteles cores. wire, e nd charts so that you c oi n make you r own high ~ modern ind uctors fo r hun dreds of prdctical a p p lica tions.: $ 1.50 MINIMUM OROER : 51.00 Please Add 25¢ per order for Packing & Shipping AMIDON ASSOCIATES 12033 Otsego Street North Hollywood, Calif. 91607 CAMP ALBERT BUTLER I NVITES HAM RADIO ENHU5'ASTS OF ALL AGES TO TRY FOR YOUR GENERAL CLASS TICKET THIS SUMMERI OUR 8th SEASON NOV ICES, TECHNICIANS AND C.B.·.rs ESPECIALLY TAKE NOTE Thl, eo-ed Ama teur n adio Camp. Y.M.C.A. owned and operated. can aeoommodate 60 campen. There II no age li mit. We bave had nmpen from 1 througb 14 r ei n ot lI'e. It II vel'f hel pfu l It rcu een COpy 5W1lm ')r hIVe a l"ol'lce or Teehnld ln t1cket. but 1t II not n&l.'fluary. Time I, dIvided between radio claue. In code and theory and the usual nmp act" utee. such II Iwlmm1n l'. archery. rHlery. hiking. etc. Golf prlvllegel are Included It the beauLIful l"ew River Country Club course. Entire ' tatl' l.'OllIl!ta of IlcelUed haml who are Inltructon In electrical en dneerlng In lOme or OUr ftne1t college-s and un tr er I ILIN. Camp ope", August 2 and cloles AUl'\Ut 16lh.Tultiotl of 5185.001neludes a ll camp expenses : room. meall. notebookl. te xt boob . and Inauranee, Send tor ou r brochure. - - - - ---- --- - -- - - - - - --...." , C. L. Pet ers. K4DNJ I n.n.ral Gllyi_ Rotfl 8 8C" y [ ....C (l1'1/ I I .A•• Elkin. North Carolina P le" e u nd mil t hll Booklet and Applll.'ltion Blank tor
Page 1 and 2:
WORLD'S LARGEST INDEPENDENT HAM MAG
Page 3 and 4:
MAGAZINE 73 Magazine 11'104 , May 1
Page 5 and 6:
.. .. .... .", , , .. ...... ."'"".
Page 7 and 8: Here are several hams who have achi
Page 9 and 10: New 500-Watt 5-Bander from NRCI You
Page 11 and 12: , I ....- , 0 0 ====j .- .'Q ' 0, .
Page 13 and 14: ohm coaxial cable off ce nte r will
Page 15 and 16: Now your transmitter can work . •
Page 17 and 18: e AC and DC SUPPLI ES BU ILT IN! e5
Page 19 and 20: If you're thinking about boning up
Page 21 and 22: y t hose whom I thought were of hig
Page 23 and 24: (Sometimes, when I make like an SWL
Page 25 and 26: -e,-,"' '.-- j - - , . .... .' 1 ,.
Page 27 and 28: preselectors, it is a fine investme
Page 29 and 30: WHAT IS THE BEST ". CO'. TO SET ,,'
Page 31 and 32: I ,~ - Gel more receiver than you p
Page 33 and 34: the boom, shorting all loops so tha
Page 35 and 36: The lassie 36 With Patent Approved'
Page 37 and 38: look (electrical) at il. I took my
Page 39 and 40: ROHN, as the largest tower manufaot
Page 41 and 42: • ,~, • • • ••• 1>00"
Page 43 and 44: transmission line or the rf voltage
Page 45 and 46: sumed. A signal generator of suffic
Page 47 and 48: may not have enough rf available to
Page 49 and 50: cuitry developed through the earlie
Page 51 and 52: The Super SS Clifford Klinert 520 D
Page 53 and 54: present one, a boornless quad, was
Page 55 and 56: HOWARD W. SAMS Famous Editors & Eng
Page 57: declared that they " are and have s
Page 61 and 62: '0' '" '0. Fig. 2. T he direct r ea
Page 63 and 64: 2 A 7/ I 1/2 ). ----~I/~--- 2 1/ 8
Page 65 and 66: 0000 O' A"'( TE ll " • "'''''' 10
Page 67 and 68: Add This Simple Decimal Readout to
Page 69 and 70: THE STELLAR - CASE STATION IS NOW A
Page 71 and 72: \ 1/ r------- - TO l(lollTlil " P I
Page 73 and 74: Step 4: In actual practice, VBE wil
Page 75 and 76: F ig. 1A (II SPLIC E C E ~ T E R CO
Page 77 and 78: How to Fly YOur Kite M. B. Crowley,
Page 79 and 80: Boulder Antenna 18 28 38 48 58 Tabl
Page 81 and 82: MH z. and consequently less paths a
Page 83: 30 a ~ ~ , I , I ~ V ' - 0 z I .' <
Page 86 and 87: 0 2 1!i0 'O!iV 8+ F ig. 2 . GAG7 Am
Page 88 and 89: I Telephone Beeper The following is
Page 90 and 91: the 20's and 30's the phone transmi
Page 92 and 93: • A Kilowatt Dummy Antenna •
Page 94 and 95: Mini-Bomb • Bill Brown 11".pSYK 2
Page 96 and 97: • DX'ing rom Joseph D. Burn ett ,
Page 98 and 99: Kalashi Nose, KH6IJ/l J0 Cam bridge
Page 100 and 101: Getting Your Extra Class License Pa
Page 102 and 103: - stage o f the game, it's a major
Page 104 and 105: e-radiation produced by the molecul
Page 106 and 107: and direction usually undergo chang
Page 108 and 109:
Just to complicate things, most aur
Page 110 and 111:
----- ---- o F[EO------- - - ---- -
Page 112 and 113:
corner reflector is sometimes incor
Page 114 and 115:
known that almost any spaci ng (wit
Page 116 and 117:
NEW BOOKS Electronics for Technicia
Page 118 and 119:
Economy Ed Baker, W0EDO 993 7 Truma
Page 120 and 121:
4 x 150 Sockets Larry Jack, WA3AQS
Page 122 and 123:
Alan Shawsmith. V K 4SS 35 Whynol S
Page 124 and 125:
Handbook is easy to use and accurat
Page 126 and 127:
TEST E UIPMENT 'IIi\IATUHE TEST L\U
Page 128 and 129:
SQUEEZE ACTION TOOL A MUST FOR THE
Page 130 and 131:
Adapting A Mobile Antenna System or
Page 132 and 133:
LETTERS This is in response to your
Page 134 and 135:
Also, I thought that the ta x-exemp
Page 136 and 137:
--r..ta U 8H NEW G&G CATALOG! MILIT
Page 138 and 139:
we would retain responsibility for
Page 140 and 141:
LARGEST SELECTION In United State.
Page 142 and 143:
HAMFEST sponsored by Lancaster & Fa
Page 144 and 145:
JOHN MESHNA JR. 19 ALLERTON. ST., L
Page 146 and 147:
LIBERTY PAYS MORE! LIBERTY OFFERS M
Page 148:
NEW DRAKE MODEL • TR·B 6-M SIDEB
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