Ham Radio's

100 Pages·2006·14.04 MB·English

ham
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radio
the world's fines1_
Amateur linear amplifie
We think it is ...a nd we 'think you'll agree with us.
Ever since we made our first Amateur amplifier almost 20years ago, our goal has been to make the finest,
most rugged and reliable amplifier possible. Now with the 3~ Classic we have accomplished this. It
contains all of the famous Henry amplifier features plus the magnificent 8877 tube, rugged heavy duty
power supply components and advanced antenna switch relay for semi break-in on CW. This is the
amplifier of every Amateur's dreams! .\rrt~iect 10 I (:c rypc ~rcccplar>rc
The 3K Classic/X with heavy duty power supply and 10 meter operation is available for sale outside the
USA where FCC type acceptance is not required.
'h2/ K Cia s sn c The 2K Classic represents the culmination of years of
experience in developing, manufacturing and improving
the 2K series. It remainsasalwaysa "workhorse", engineered and built to loaf along at full legal
power for days or weeks without rest. A look inside shows why! It is truly a "Classic" amateur
amplifier. Heavy duty, top quality components along with its rugged construction assures you
trouble free operation. It will put your signal on the air with greater strength and clarity than
you ever dreamed possible. The 2K Classic operates on all Amateur bands, 80 through 15
meters (export models include 10 meters). Price 51295.00
145-, y<p-s. ..
Another fine member of the famous Henry Radio family of superlor
ampllflen. And we're stlll convlnced that It's the world's flnest llnear In
Its class. The 1KD-5 was designed for the amateur who wants the quallty and dependablllty of the
2KD-5 and 2K-4, who may prefer thermaller size, llghter welght and lower prlce and who wlll settle
for a llttle less power. But make no mlstake, the 1KD-5 is no slouch. Its 1200 watt PEP lnput (700
watt PEP nominal output) along with Its superb operatlng characteristics wlll still punch out clean
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powerful signals slgnals you'll be proud of. Compare Its speclflcatlons. Its features and Its flne
components and we're sure you wlll agree that the IUD-5 is a superb value at only $695.
-
, 5
, We have been suggesting that you look lnslde any ampllller before you
1
'd buy It. We hope that YOU wlll. If you "llft the Ild" on a 2KD-5 you wlll see
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only the hlghest quallty, heavy duty components and careful workmanshlp attributes that
promlse a long llfeotcontlnous operation In any mode at full legal power. The 2KD-5 Ira2 000 watt
PEP lnput (1200 watt PEP nominal output) RF llnear ampllfler, covering the 80,40,20, and 15 meter
amateur bands. It operates wlth two Elmac 3-5002 glass envelope triodes and a PI-L plate clrcult
wlth a rotary sllver plated tank coll. Prlce $945.
Henry amateur amplifiers are available from select dealers throughout the U.S. And don't ,*P
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forget the rest of the Henry family of amateur amplifiers the Tempo 2002 high power VHF
amplifier and the broad line of topquality solid state amplifiers. Henry Radio also offers the 4K-
Ultra and 3K ClassicfX su~erbhi a., h D. ower H.F. amolifiers and a broad line of commercial FCC AP 4 IC
type accepted amplifiers for two way FM commun~cattonsc ovenng the range to SOOMHz.
2050 S. Bundy Dr., Los ACnB e les, CA 90025 213 820-1234
931 N. Eucl~d,A nahelm. 92801 1714l 772-9200 CpF
Butler, M~ssour6~47 30 816 679-3127
TOLL FREE OROER NUMBER: IBM)I 421-6831
For all states except Caltlorn~a
Calif res~dentsp lease call collect on our regular numbers
MFJ-1200 GENERAL PURPOSE MFJ SWW
CW Computer Interface
Connects computer to transceiver. Converts received audio
MFJ SWRlWattrneter
to TTLIRS-232. Allows computer to key transmitter. For
reads SWR, forward, reflect-
use with your computer and CW KeyboardlReader program.
ed Dower from 1.8-30 MHz.
Allows your rig to
"talk CW" to your
MFJ-814
New low cost in-line HF SWRIWanmelr.
MFJ-814 lets you rnonltor SWR, forward,
...u
(I?* reflected averacle power ~n 2 ranqes from 1.8
to 30 MHz. Read 20012000 watts forward.
201200 watts reflected power. SWR. 1:l-6:l.
A personal computer with an appropriate aluminum cabinet Requires 6 9 VAC or 110 VAC
program can give you a complete and very ver- with optional AC adapter. MFJ.1309AC. $9.95. Easy push-button switch opcntion: has power1
-
satile CW KeyboardlReader. But you st111 need 'Order from MFJ and try it no obligation. If SWR, highllow range, forwardlreflected push-
interface electronics to provide compatible signals not del~ghted, return 11 within 30 days for refund button sw~tches.S WR sens~tivltyc ontrol.
between your transce~vera nd computer. (less sh~pp~ng)O. ne year unconditional guarantee. Lighted meter (requires 12V). Rugged alumi.
The MFJ-1200 CW Computer Interface pro- Older today. Call toll free 800.647 1800. Charge mrm eggshell white, black cabinet. 6l/4~3~kx4~/4".
cesses (no~seI lrnlts, filters, detects, post filters. VISA, MC or mail check, money order for $69.95 SO-239 coax connectors. 2 color meter scale.
shapes, level sh~fts)t he received CW audio from lor MFJ-t 200 plus $4.00 sh~ppinga nd handl~ng. MFJ W F SWRlWattmeterl
your transceiver to provlde a clean computer Use this MFJ-1200 to enjoy your computer as
compatible TTL or RS.232 level. Field Strength Meters
H also takes the keyboard generated CW
and drives high keying circuits to key derlrepalr status Also call 601-323-5869 outside
your tube or solid state transmitter (.300 V,
+ continental USA and In MISSISSIPPI,
10 mA max; 300 V, 100 mA max).
Has tuning, transmit. and "ON" LEDs. Revene- ENTERPRISES,
normal sw~tchi nverts output level to computer. INCORPORATED New low cost VHF operating aids.
ONIOFF switch. 6x13/4x3 in. Black. eggshell white BOX 494, ~i~slssipSptait e. MS 39762 MFJ.812, $29.95: Read SWR from 14 to
d 170 MHz to mon~tora ntenna and feedlines.
Read forward and reflected power at 2 meters
(144-148 MHz). 2 scales (30 and 300 watts).
MFJ DIGI-DIAL ADAPTER Read nlatlve field stnngth from 1 to 170
MHz. Bind~ng post lor held strength antenna
turns your frequency counter into a Easy push-bunon operation: has forwardlre
flected and SWRlfield strength push-buttons
DIGITAL FREQ. READOUT
Aluminum eggshell while, black cabinet.
41/4~21/4~23/4"S.O 239. 2 color meter scale.
1 Calibrate control MFJ-810. $24.95: similar to MFJ.812 les!
0 field strength function. ,
$ 95
compensates for heterodyne MFJZry" 300 W and
MFJ DIGI-DIAL error5s and 9mode offsets. 1 K Dummy Loads.
mom "~OIIALE e,,
.ma
-
CArLIBnRAT E
MOOEL MFJ-210 Air cooled, non-inductive 50 ohm resistor ir
perlwated rnetl hous~nqw ith S0239 connectors
/
The MFJ 41-DM Adapter turns your ireGcy with optional MFJ-1312 AC adapter, $9.95. Full load for 30 seconds, de-rat~ngc urves t(
counter ~ntoa n accurate digital frequency readout Order MFJ-210 for any rig with 5.5.5 MH: 5 minutes. MFJ-260 (300 W). SWR: t.l:t t(
for your transce~ver. Connects between external VFO (TS-520. S. SE: TR-3. 4; HW.100. 101; 30 MHz, 1.5.1 for 30 160 MHz. 2l/zx2lhx7".
VFO jack and frequency counter. SB-l0 1. 102; Tritons; etc.) Order MFJ-211 for MFJ-262 (1KW). SWR 1.5:l-30 MHz. 3x3~13".
Counter gives dinct frequency nadout to right Yaesu FT.101 series (8.7 to 9.2 MHz VFO).
- MFJ.10. 3 foot coax with connectors. $4.95.
of dec~malf or 7, 14, 21, 28 MHz bands. Mentally Order hnm MFJ and try it no obligation. If
replace dig~tst o left of decimal w~thM Hz band not delighted, return 11 within 30 days for refund ~lderfromM FJ and try it. If not del~qhted.
as you do now with your analog dial. For the 3.5 (less sh~pping).m year unconditional g@rante& return w~th~3n0 days for refund (less sh~pp~ng).
and 28.5 MHz band ignore d~g~ttos left of deck Order today. Call toll free 800 647-18 00. Charge One year unconditional guarantee.
ma1 and mentally add 3.5 or 28.5 MHz. respec. VISA. MC or mail check, money order for $59 95 Order youn today. Call ton free 800-647-1800.
lively, to counter reading. plus $4.00 shipping for MFJ-210 or MFJ-211. Charqe VISA. MC Or mall check, money order.
Calibnte for each band and mode (CW. USB. Don't wail anv longer to eniov diaital readout, Add $4 00 each for sh~pp~naan d handl~nq.
LSB. AM) to compensate for heterodyne oscillator
errors (does not read CW transm~to ffset).
C.111 601 323 5869 for techn~cal ~nlorrnation,o r
Digital mixer Inverts VFO frequency to give
C,ill 601 323 58119 lor lechnlcal ~nlor~nal~oorn derlrepalr status Also call 601 323 5869 out-
correct frequency readout. NormallReverse swltch
derlrepa~rs tatus Also call 601 323 5869 outs~df s~dac nntinental USA and ~n M~ssiss~oo~.
gives d~rectV FO lrequency readout (for some rigs
rnnbnental USA and ~n MISSISSIDOI
on some bands, like Drake TR-4).
RF buffer amplifier. Crystal reference oscillator.
I
WOfl sw~tch." On" LEO. Black, eggshell white al. Box 494. Mississippi State. MS 39762
\ pahinet .73/rxll/rx3'/r" 9-18 VDC or 110 VAC Box 494. Mississiool State. MS 39762
More Details?C HECK-OFF Page 94 October 1981 1
I
lnstant ~ccessD igital
I lnstant Fingertip ~u;in~-~o More Knobs! W
6 Memories for Any Mode (AM,SSBICW, & FM) A Enter Button F SSBlCW Compensator
Dual PLL Frequency Synthesized-No Drift! B Signal Strength G Execute Bar
Indicator
C Liquid Crystal Display H Manual Tuning Buttons
A WHOLE NEW BREED OF RADIO IS HERE NOW! No other D Memory Preset Buttons I Scan
short wave receiver comb~ness o many advanced features for
both operating convenlence and high performance as does the E Antenna Adjustment J HighlLow Limit Buttons
new Sony ICF-2001. Once you have operated th~se xcit~ngn ew Dial
radio, you'll be spoiled forever1 D~recat ccess tuning elim~nates
conventional tunina knobs and dials with a convenient dia~tal
keyboard and ~iqu1C2r ystal D~splay(L CD) for accurate freqien.
OPERATIONAL FEATURES
cy readout to w~thin1 KHz. lnstant f~ngerlipt uning. up to 8
INSTANT FINGERTIP TUNING w~thth e calculator-type key board
memory presets, and continuous scanning features make the
enables the operator to have lnstant access to any frequency in
ICF-2001 the ultimate in convenlence.
the LW. MW. SW, and FM bands. And the LCD digital frequency
Compare the following features against any receiver currently
d~splay confirms the exact, drift.free signal be~ngr eceived.
available and you will have to agree that the Sony ICF 2001 is the
AUTOMATIC SCANNING of the above banas. Continuous
best value in shortwave receivers today:
scannlng of any des~redp ortion of the band IS achieved by
DUAL PLL SYNTHESIZER CIRCUITRY covers entire 150 KHz to setting the "L," and "L2" keys to define the range to be scanned.
29.999 MHz band. PLL, circu~th as 100 KHz step while PLL2 The scanner can stop automatically on strong signals, or it can
handles 1 KHz step. both of which are controlled by separate be done manually. MANUAL SEARCH is sim~lart o the manual
quartz crystal oscillators for preclse, no-drift tunlng. DUAL CON- scan mode and is useful for qu~cks ~gnals earching. The "UP"
VERSION SUPERHETERODYNE circu~trya ssures superior AM and "DOWN" keys let the tuner search for you. The "FAST" key
reception and htgh image rejection characteristics. The 10 7 MHz increases the search rate for faster signal detection. MEMORY
IF of the FM band is ut~l~zeasd the2nd IF of the AM band. A new PRESETS. SIX memory keys hold desired stations for Instant
type of crystal f~lterm ade especially for this purpose realizes one-key tuning in any mode (AM. SSBICW, and FM), and also. the
clearer reception than commonly used ceramic filters. ALL FET "L," and "L2" keys can give you two more memory slots when
FRONT END for high sensitivity and interference rejection. Inter- not used for scanning. OTHER FEATURES: Local, normal, DX
modulation, cross modulation, and spurious interference are ef. sensitivity selector for AM; SSBlCW compensator; 90 min. sleep
fectively rejected. FET RF AMP contributes to superior image re. timer; AM Ant. Adjust.
jection, high sensit~vity,a nd good signal to noise ratio. Both
strong and weak stations are received with minimal distortion.
SPECIFICATIONS
CIRCUIT SYSTEM: Fm Superheterodyne; AM Dual conversion
superheterodyne. SIGNAL CIRCUITRY: 4 IC's. 11 FET's, 23
EXTENDED SPECTRUM CONTINUOUS TUNING
Transistors, 16 Diodes. AUXILIARY CIRCUITRY: 5 IC's, 1 LSI. 5
LED'S, 25 Transistors. 9 D~odes.F REQUENCY RANGE: FM
76.108 MHz; AM 150.29,999 KHz. INTERMEDIATE FREQUENCY:
FM 10.7 MHz.; AM 1st 66.35 MHz., 2nd 10 7 MHz. ANTENNAS: FM
telescop~c,e xt. ant. term~nal;A M telescop~cb, u~lt-infe rr~teb ar,
ext. ant. terminal. POWER: 4.5 VDCll2O VAC DIMENSIONS: 12th
(W) X 2% (H) X 6% (n).W EIGHT: 3 Ib. 15 or. (1.8 kg)
2 October 1981 Tell 'em you saw it in HAM RADIO1
magazine
incorporating
~lume1 4, number 10
T. H. Tenney. Jr.. WlNLB
publisher and
editor-in-chief
Alfred Wilson, WGNIF 10 trapping the mysteries
of trapped antennas
editorial staff Gary E. O'Neil, N3GO
Manin Hanft. WBlCHO
product~on& ,tor
18 using simulated carbon
JOSRP~J . Schroedar. WJUV
Leonard H Anderson microphones with Amateur
assoctate edttors
W.E. Scarborough. Jr . KAIDXO transmitters
graph!= product#onm anager
Frank S. Reid, W9MKV
Irene Holllngsw~nh
editorial assostant
.
w E Scarborough. JI KAIDXO 24 junk-box portable antenna
John J. Malarkey, W3SMT
publishing staff
J CralgClark. Jr.. NlACH 28 operation upgrade:
asmtant publisher and
advenlslng manager
Susan Shorrock
clrculatlon manager Robert Shrader, WGBNB
ham radio magazine 42 ham radio techniques
is publoshed monthly by
GreenCvotlmlem. Nuenw~ cHaatimonpssT heicreh n0o30lo9g8y-,0 4In9c8 Bill Orr, W6SAI
Telephone, 603-878-1441
50 avoiding built-in digital-
subscription rates
circuit problems, part two
United States: one year. $16 50
two years. $28.50:t hree years. $38 50 Penn Clower, WlB G
Carl ade and other countries lvia Surface Ma811
one year, 821.50; two years. $40 W
three years. 957.M) 56 ICOM 701 owners' report
Europe, Japan. Afrlca lvia Air
Forwarding Service] one year. $28 W Martin Hanh, WBlCHO
All subscription orders payable in
Unitad States funds, please
62 SWR meter for the
foreign subscription agents high-frequency bands
Foreign subscription asents are Ken Powell, WBGAFT
listed on page TI
66 locating geostationary
M ~cop,es ~ ~ ~ , ~ ~
are avallable from satellites
Un~versityM icrofilms. International
Ann Arbor. Mlchigan 48106 Walter E. Pfiester, Jr., W2TQK
Order publicallon number 3076
Cass~ltta~pe s of 981ected artlcles
from ham rod10 are avallable to the
blind and physically handicapped
from Recorded Perladicals
919 Walnut Street. 8th Floor
Philadelphia. Pennsylvania 19107 94 advertisers index 6 letters
Copyright 1581 by
CammunicationsTechnology.I nc 46 DX forecaster 81 new PI cts
Title registered at U.S. Patent Office 77 flea market 4 observ n and
second-class postage
paid at Greenv~lle.N H 03098-M98 91 ham calendar opinio~
and at &t,onal mailtng oftices 72 ham mart 9 presstc
ISSN 0148 5~
,stmastar sand Form 3679 to hmr ndlo 74 ham notes 94 reader rice
Greanvills, N.W Hampshlrs 0~0ls-04~
October 1981
9
Observation
& Opinion
From time to time I tune across the Novice bands just to see what's going on and to learn how the
beginners are developing their operating skills. I sometimes fire up my rig and work a few Novices. In
most cases the Novices appreciate a more experienced CW operator invading their territory, espe-
cially if the latter is patient and understanding. I recommend that all experienced CW operators take
the time to work a few Novices. It's a welcome change from fighting the pile-ups and gives a sense of
accomplishment, especially if you've helped a Novice improve his code proficiency and operating
procedures.
Listening on the Novice frequencies can be an interesting experience. The Novice portion of the
40-meter band is a good example. Here you'll find some operators who are pretty good - their send-
ing, although not fast, is clear and clean, and their operating techniques are on a par with those of
many General-class operators. A few have electronic keyers or keyboards, but most plod along with
a straight key. At the other end of the scale, you'll find Novices who just can't seem to break bad
operating habits. This is where an experienced CW operator can really help, but it takes a lot of
patience and, above all, tact.
Many Novices don't know what to do after they've called CQ. The over evening I heard a station
sending CQ continuously at a rapid rate for three minutes, followed by his call sign, which was sent
only once. After a pause of a few seconds, the CQing started again. This was repeated for another
-
three or four minutes still no response. Then I tuned up the band a few kilohertz, and there was
-
another Novice calling CQ. The same pattern was again repeated no response. All in all, I heard
perhaps ten stations across the Novice portion of the band calling CQ. One wonders if they had their
receivers turned on.
Then I tuned back to the first station and there he was, still at it. When he signed this time I gave
-
him a call, being particularly careful to match my sending speed to his. I signed over nothing.
Then, "QRZ? QRZ?" I sent my call again at his speed. Again, "QRZ?" This went on for a few min-
utes, then I reduced speed to about half and the Novice finally answered. We had a pleasant contact
for a while, with the Novice sending at a considerably slower rate than before, complete with all the
punctuation marks.
I mentioned earlier that many Novices don't know what to do after calling CQ. I find that many
Novices, after returning to the receive mode, don't tune around their transmitting frequency. Appar-
ently they expect the replying station to be exactly on their transmitting frequency, which is unlikely
in many cases. If the Novice is using a sharp CW filter in the receiver, the answering signal could be
outside the receiver i-f passband and will never be heard.
The best answer to the CQ problem is don't. Old-timers will recall a filler cartoon that used to run in
QST years ago. It showed a mama cat walking along the top of a fence, followed by three kittens.
The caption was, "If you wanna get results, you gotta make calls!" Not only did it mean CQ calls but
also calls to other stations.
Another recollection of bygone days is the series of pieces in QST by T.O.M. (The Old Man).
T.O.M. loved to write about "Rotten Radio." His poignant prose was directed to everything from
rotten spark sets to rotten operating. I think we could use more of T.O.M.'s scathing criticism. Al-
though he wrote in a humorous vein, there was a lot of truth in his observations. I'll bet if T.O.M.
were alive today, he would endorse my sentiments about the operating practices of some of our Nov-
ices. I feel it's the responsibility of the higher-class operators to give a little of themselves to assist
those Novices that need help.
Alf Wilson, WGNIF
editor
4 October 1981

filter design I
Radio applications than is table 1). ticle if they send me a stamped, self-
For example, on page 59 of his arti- addressed envelope.
Dear HR: cle, Mr. Fowler states he uses To further demonstrate how stan-
I am writing to tell you that I en- "seven-pole LC lowpass filters with dard-value capacitors can simplify fil-
joyed reading the "Rf Power Meter" cutoffs at 5.8, 9.6, 15.7, 23.1, and ter design and construction, I have
article by Ralph Fowler, NGYC, that 30.4 MHz" to attenuate the harmonic made minor modifications to Mr.
appeared in the June issue. I was par- amplitudes of his signal generator. Fowler's 5.3-MHz Butterworth band-
ticularly interested in Mr. Fowler's These designs can be conveniently pass filter (fig. 9, page 61 of his arti-
discussion of the directional bridge selected from my table 2 and only cle). The Butterworth design was
and its associated accessories. I standard-value capacitors are need- modified into a Chebyshev design
noted that several of Mr. Fowler's ac- ed. Also, all of the messy calculations that is easier to construct, and the
cessories were lowpass and bandpass are eliminated. For the previously passband and stopband performance
filters, and he referred the reader to listed cutoff frequencies used by Mr. of the two designs is very similar (see
the ARRL Handbook for lowpass filter Fowler, I suggest Filter Designs #207, my fig. 1 of bandpass filter re-
construction information. In my opin- 232, 138, 162, and 173, respectively. sponses). (The Chebyshev design
ion, there are more useful references These designs have reflection coeffi- was based on my tabulation of pre-
than the ARRL Handbook for the de- cients of less than 9.2 percent, and calculated five-element lowpass fil-
sign of the seven-pole LC lowpass fil- they should perform satisfactorily in ters that was published in June, 1978
ters used by Mr. Fowler, and I wish to this application. I will be happy to - see reference 6.) Note that the in-
bring these references to the atten- provide anyone with a copy of my ar- ductor values of the two different de-
tion of Mr. Fowler and the readers of
ham radio. fKvo
Since 1972, 1 have had many arti-
EUTTERWOR
cles published on passive LC filter de- (N6VC)
sign (references 1 through 8) in which
tables of pre-calculated designs re-
500hnn c1 C1 Cs Soohma 3
quired only standard-value capacitors 8
10
to simplify construction. The most re- nmdpw tinsf .sbsnuw~d homm ~ S S 5
cent articles on this design aid was lamb .IOw for mmPan.nt valun). so 3
Flrrna~.lorb andpsu 1f111. &suns by NLVC and WSNPN.
published in the January 7, 1981,
.WE Fc C1.5 -4 U 11.5 Ul L3
issue of EON. I recommend this last Bultrsvcp . E-W Wnr) ipfl CF) ipFJ im) (PW (PW 20 2
reference to Mr. Fowler and your wCohrothb yekr 5.3 ism m wm ar rao ar4 3
nc I LO* 1.16 5.u 2mo n woo asie 11.5 aiw 10
readers for the expeditious design Nok: TD. WJNPN Chsbphs. EPF d..bn ha. bwn
and construction of the seven-ele- 0pdknh.d M uro nly .Un&rbrahn CaPSCiion ! ! ! 1 !
!o
ment lowpass filters mentioned in the
article. (Table 2 of the reference is
fig. 1. Calculated bandpass filter responsesbasedonan
probably more useful for Amateur inductor Qof 100 at 5.3 MHz.
6 October 1981
signs are very similar, and therefore
the inductors of the Chebyshev de-
sign should be just as feasible to ob-
tain as the Butterworth designs. If the
bandwidth of the filter is made too
small, the ratio of inductance values
(L2 to L1,5) will become too large,
Join him in the incredible world of electronics with NRI's all-new
thus making it difficult to get good in- .
training in the career of the future.. Electronic Design Technology.
ductor Q and proper filter perform- a
It's an electronic world we live in. And the indicators. It handles almost any circuit you can
ance. The filter bandwidth selected
designers of electronic circuits, controls, and design.. .linear and digital integrated circuits as
by Mr. Fowler seems reasonable from systemsare the people who are shaping it. Take well as discrete components such as transistors
your place in this exclusive company with this and diodes.
a construction and performance
exciting new training from NRI. Analysis and design work is speeded
viewpoint. Capacitor values C2 are You can learn Electronic Design with the Texas InstrumentsTI-30scientific
Technology at home. in our spare time. calculator. This engineer's instrument
similar 470 pF compared with 75 pF)
without quitting your jox, tying up your includes full trigonometric functions.
but C1,5 and C3 are quite different. evenings at night school, or wasting gas logarithms. square root. squares,
traveling to classes. Because NRI powers, rnemoy, and more. All this fine
This difference is a consequence of comes to you, makes you a class / equipment is part of your training. yours
changing the Butterworth design into of one with a complete, effec- to keep and use in your work.
tive, low-cost learning pro- NRI Fast-Track
a Chebyshev design. Mr. Fowler's B ram designed exclusively Training
center frequency of 5.3 MHz was or home study. You get , This is the uniaue NRI
slightly increased to 5.42 MHz to iitt aallll ......aa tt yyoouurr lesson concept that
convenience. simplifies and speeds
make C2,4 come out to a standard Hands-on learning. From the
capacitor value 175). Training ve y basics toad-
NRI trains vanced. state-of-
Mr. Fowler was correct in his con- ;ou for action. the-art electronics.
cluding sentence that "improvements ou get real-life each lesson is espe-
experience that cially prepared for
doubtless can be made," and this I builds priceless individualized in-
have attempted to demonstrate as far cy.oo- nuf iwdoe~ rnkcien..g o uki vneosw ledyc of lab practices and ject is covered fully and thorsotruugchtliyo,n b. uEta ecxh tsruanbe- -
as the passive LC filter design aspect techniques. It's all built Into the NRI Design ous material is eliminated, language is clear and
is concerned. I am grateful to Mr. Lab? a complete combination of equipment, to the point, organization is logical and effective.
hardware. training, and reference materials. From Fundamentals of Electronic Circuits
Fowler for taking the time and effort You'll design your own circuits from the very through Microprocessors. our lessons are
to write his articles, and I thank ham beoinnina. ~rouressinqfr om basic passive net- designed with you in minx
wGks thk"ghlkey circuits like supplies, No Exyrience Necessary
radio for publishing them. I hope to amplifiers, osciilators, digital and logic circuits.
You don t ave to be an engineer (or even
read many more similar articles which phase-locked loops and more. You'll move a college student) to succeed. High school
on to linear and digital integrated circuits, the
will assist me and others in improving heart of modern electronic equipment. You'll graduates with some algebra handle it without
any trouble. We start you at the beginning, let
our technical expertise. prototype your designs and verify operation. you advance just as quickly as ou're ready. We
learning professional test and measurement
even include the NRI Math ~elesheMr odule to
procedures as you progress.
help you brush up on your math and teach you
references Professional Equipment Included
any new concepts you may need.
All the way, you work with professional-
1. E. Wetherhold, "Design Your Own Filters By Com- qualit instruments like the Beckman 6-func- Free Catawl yi
puter," Electmnic Design. Vol. 20. No. 2, January20. tion, z6-range LCD digital multimeter. It gives No Salesman Call
1972. vou fast. accurate measurements of voltages, Our free. 100-pagec ataloy gives you all the
2. E. Wetherhold, "Pick A Filter From This Chart,"
Uectronic Design, Vol. 20, No. 24, November 23.
1972.
3. E. Wetherhold, "Low-Pass Filters For Amateur
Radio Transmitters." OST, December, 1979. Ave., Washington, DC 20016.
4. E. Wetherhold, "Chebyshev Filters Using Stan- 1111.1111- 1
dard-Value Capacitors," RF Design, Vol. 3, NO. 2,
NRI Schools Please check for one free catalog only. I
February, 1980. McGraw-Hill Continuing Electronics Design Technology
5. E. Wetherhold, "Design 7-Element Low-Pass Fil- Color TV Audio. and Video I
ters Using Standard-Value Capacitors," EDN. Vol. System Servicing
Washington D C.2 0016 Computer Electronics including I
26, No. 1, January 7,1981. Microcomputers
6. E. Wetherhold, "Passive LC Filter Design (Part 1). 0D igital Electronics I
Home Study Course 69/51." Measurements & Con- CLiocmenmseusn icMatoiobnilse ElCecBtr oAniicrcsr aFftC CM arine I
W7. E,.a nWde MtheedrihcoalldU, e"cLtorownpiacsss, b Cohthe bJyusnhee, v1 9F7il8te. rs Use II NO SALESMAN WILL CALL. 0 BSmasaicll EElnecgtirnoen Sicesrv icing I
Standard-Value Capacitors," Engineer's notebook, I 0 AApuptolimanocteiv See Srevrivciicnign g I
8p.a gEe. 1W6e0t.h Eelerhcotmldn. ic"7s-, EJluenmee 1n9t . C19h8e0b.y shev Filters for I (Please Print) 0 AAiur tCo oAnird Citioonndinitgio. Hnienagr ing. Refrigeration. (
Name &Solar Technology I
TEMPEST Testing," ITEM. 1981, published by R b B 1 Building Construction
Enterprises, Plymouth Meeting, Pennsylvania. I Street I
Ed Wetherhold, W3NON
( City/State/Zip aGpI pbrioll.v ed under I
)
Accredited by the Accrediting Commission of the National Home I
Study Councll 20101
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the 440 band with style! The new extra cost, and the ST-71T8s op-
ST-7/T synthesizes the entire band tional synthesized subtone en-
in 5 kHz steps, works both up and coder is controlled by the radio's
down repeater splits and does it front panel switch.
all right from your hand, with ver-
satile power options of 3 watts, 1 All the regular SANTEC acces-
watt or even 50 milliwatts (all sories used with your HT-1200 fit
nominal), to reach out to where the ST-7/T as well, meaning that
you want. The high power mode you can enjoy both bands fully
of 3 watts radiates on 440 like 5 with a smaller cash investment.
watts on 2 meters . . . and that's a Grab the new SANTEC ST-7/T and
handfull! join the fun on 440 MHz. See your
SANTEC Dealer for delivery
Tones? This- one has them . .. tones details.
- -
and n The 16 button tone
-
a
- ..
SANTEC'S popular HT-1200 is the inco
parable 2 meter leader. This little rig is hand-
ing over quality, power and features that
you'd expect from something nearer the size
of a bread box. WTEC packs a 2 meter
ham shack into the palm of your hand!
You can carry scan, search, 10 memories and
fully synthesized key pad control around
with you and still get out with a big 3.5
watts (nominal). Compare them apples to
anything you want, and settle for nothing
less.
WNTEC radios exceed FCC regulatrons limiting spurlous emissions. _
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Both the SANTEC ST-7/T and the SANTEC HT-1200 I I
are certified under FCC Part IS. 1 - - I
A W S
61 1981, Encomm, Inc. I I
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