Info

Fig. 55* This 6 meter transmitter provides up to 50 watts of power with very good efficiency and . very low harmonics. The 2N3950 in the final provides a minimum power gain of 8 dB on six and it rated at 50 watts continuous service. The six meter transmitter of Fig, 55 will provide 50 watts of power into the antenna with very good efficiency and very low harmonics. The second harmonic is suppressed on the order of 28 dB while the third harmonic is more than 34 dB down. The efficiency of the...

Radio Amateur

Caen Van Neck la un 227, Ji ijswijk, ZT H. Unnecessary ir> say, l7m as full of admiration for your fine paper as everybody else, but just this fact urges me the stronger to protest against onrj inaccuracy. Some time ago you pointed out to nil Itams that it is much better to speak about frequencies tlian wavelengths, and the whole world has followed your ex maple. Hut wlieu s eakm about frequencies, wo m8nn the number of eyries per second, in any rase the number of cycles in a rrrtain time and...

Herbert W Gordon Co

Helping hams to help themselves Woodchuck Hill, Harvard, Mass. 01451 understudy I think he said was Kyuku * one of I he natives of Kenya, George suddenly has left 5Z4 land you know for ZS6 land so 1 guess that 5Z4 fellow has stepped into his job. Boy I bet that Nairobi T,V. is not on the air 100* of the time. I guess being from ZS land (that s where George is from you know) is sort of tough on a fellow in 5Z4 land. Must be getting sort of tough all around now because Leny 5Z4GT) f understand...

Wdty

Low Power Attenuators for the Amateur Bands, WB6AXG and WA6RBZ. 73 Magazine, January 1967. 2. Transistor Meter Amplifiers, WA6BSO, 73 Magazine, January 1966. Tom tally KIUBA 28 Amory Ret. Waltham, Mass. Articles have already been written about building k supplies with TV power transformers, using voltage doubling and series capacitors. The solid state man, shunning the lethal voltage approach to rf power generation, looks for a way to lower the line voltage. With this in mind, and ith a junked...

Amcom

The Phil-Mont Mobile Radio Club, Inc. of Philadelphia and vicinity is endeavoring to complete the outfitting ol what it considers a communications facility second to none in AM COM, Amateur Moi> iie COMmunications. This is being accomplished through the equipping of an independently powered mobile communications trailer, W3RQZ port-able, with its own prime mover also fully equipped to operate as an independent mobile relay station, W 3RQ Z mobile. Photo I shows the com-truck, a 1949 In*...

Oaf

Layout for the e+ched cir eui+ board used by WB6CHQ. to the base pf Q2 and the signal should not exceed this value at the base of Ql, These values are valid for the circuit when it is correctly adjusted. To adjust the product detector, first set the litiearity pot to zero resistance (so that the base of Q2 is shorted to ground). With the BFO off, (making sure that the product detector is on adjust the linearity pot from zero until the signal to which your are tuned becomes slightly...

Am

Howard Laughrey. 2 Elizabeth St Chappaqua. N.Y. 10514, (914) CE 8 3683 Worlds Largest Distributors of Short Wave Receivers James Forney WB2CCM New Canaan, Conn. Having trouble getting those pretty pictures with your panadapter Vlay be you need an isolating amplifier. I recently got a panadaptei It worked fine with a signal generator, but gave pretty dismal results when I connected it to my receiver, A careful search through the literature turned up all sorts of interesting...

Vanguard Labs

Y. 11423 Jim Fiik WIDTY RFD I. Box 138 RIndge. N. H. 03461 The new dummy loads from Waters Manufacturing down in Way land, Massachusetts, nicely fill the amateur need for a dummy load and or wattmeter that he can depend upon. The two models are basically the same load, but the Model 374 has a built in wattmeter w iile the Model 384 does not. These loads consists of a structured monolithic 52 ohm non-inductive resistance unit designed to present a constant...

Manufacturing

CANADIAN HAMS You may now order direct irom M. J, Howard and Co Ltd., 1300 Carting Ave., Ottawa, Ontario. See you at the S. S. 6. Show, Statler Hilton Hotel, New York, March 2tst. Rod C. Rigg W6YGZ 1305 Occidental Ave. Stockton, Calif. 95203 Barry S. Todd K6ZCE 310 East 10th St. Corona, California 91720 Here s a description of an exotic, yet very desirable, unit that will send your call or other information automatically without any motors or other moving parts. It can be built for about 15....

Dual Vfo Adaptor

Model 22 25 PLUG-IN VOX UNIT Model VX-1 35 and more rhythmic like DA or BR or something ' How about BK, Gramps Judy broke No replied FN, BK is a radio abbreviation meaning break' and it would be confusing don't use anything which may have a double meaning like BT, AR, SK and such ' Judy pondered a few minutes and then came up with, I'd like to take the Continental code equivalent of your sine Cramps, making it . . how about that ' Looking smugly pleased FN replied, Sure - - it's OK with me I...

Low Noise

Also available for 150-170 MCS Add this Ameco Nuvistor Preamplifier to your re ceiver or converter to improve the sensitivity and noise figure. Two tuned circuits also improve rejection of image and spurious frequencies. Compact, easily connected and low power requirements, wired and tested with tube. Model PV 27 Models PV 28, 50, 144 amp 220 13.95 Write for details on 150-170 mcs and others. Ideal for improving performance of surplus FM Two-Way equipment for...

Jodat

Dip Meter 2n3819

Box 68003, New Augusta, lnd,f 46268 Ship me EE 167, the new 1 7th Edition of the RADIO HANDBOOK at 12.9 5 73 E-3 .enclosed. Chech Money Order FETs I tried the inexpensive Motorola FET's in a number of circuits and found them quite satisfactory. I would use them without hesitation in the second stage and mixer of the 2 meter converter described by K6HMO in the October issue, and would use them for all stages on six or below. They are about a decibel noisier at 220 MHz than the TI...

Response

It is a well known fact that the gain characteristics of an amplifier may be shaped by applying nonlinear feedback. In the amplifier of Fig, 6, the nonlinear feedback is furnished by two back to back diodes in the collector to base feedback path. When ever the signal at the collet tor is high enough to forward bias the diodes greater than approximately 0,6 volts peak to peak , negative feedback occurs and the gain of the amplifier is reduced. The gain of the stage may be further controlled by...

K

Timing diagram for generating the word at. lection of and and or circuits that have been arranged in an orderly manner. Obtaining the equations' for setting up the diodes in the natrix is the only complicated portion of the design of this unit. It is necessary to determine the arrangement of diodes such that either output line, dot or dash, has the proper signal or absence of signal for each individual state of the counter. Obviously it is desirous to do this with a minimum number of...

Nt

This ten meter linear amplifier for SSB service uses transistors which were designed specifically for single sideband linear operation. Many junction transistors cannot be used satisfactorily for this application, because linear amplification at low power levels is a serious problem, Vp until the present time transistors haven t been used too much in SSB transmitters because linear amplification at even low signal levels has been a serious problem, However, the transistors in the ten...

Index To Advertisers

Ameca, 109 American Crystal, 120 Amrad Electronic, 124 Antenna Mart, 103 A ,R .C. Safes, 120 Arrow Sales, 124 Atlantic Surplus, 118 B C Electronics. 125 Barber Travel, 118 Callbook Magazine, 110 Cleveland Institute, 117 Columbia Electronics, 121 Comdel, Inc., 45 CTK's Barbd Wire Ant,, 114 Peter W. Dahl Co., 120 Ted Dames Co t 120 Daveo Electronics, 31 Dayton Hamvention, 22 Dixon's Radio Key, 111 Dow Trading, 125 DPZ, Inc., 114 R. L. Drake Co., 17 Editors amp Engineers, 111 Electronic Center, 97...

Sensitive Rf Probe

Ham Radio Voltmeter

Jim Rsk WIDTY RFD I, Box 138 Rindge, N.H. 03461 One of the handiest test instruments around the ham shack is the rf probe or rf voltmeter. This almost indispensible unit may be used for neutralizing transmitters, tuning up oscillators and in many other general tasks around the shop. Most hams simply purchase an rf probe to go along with their VTVM, but these probes are usua IK limited to an upper frequency range of somewhere around 250 MHz. Another serious limitation of the familiar VTVM rf...

Audio Signal Tracer Circuit

Ham Radio Audio Circuit

Th s signal tracer provides more than adequate audio output with only J00 microvolts of modulated rf at the input. It may also be used for tracing audio circuits, but don't depend on its fidelity. All the transistors are germanium types such as the 2N404, 2NI450, 2N2953, SK3004,, GE-2 or HEP-253 the diode in the probe is a IN34A or IN67A or similar. i ier to t beck microphones and preamps and to detect noise and hum in amplifiers. The signal tracer shown in Fig. 57 uses a push pull...

Input

Fig. 40, This cascode video amplifier provides more than 6 MHz bandwidth with a voltage gain of 10. Both FET's are 2N38I9. MPFI05, TIS34 or HEP-801, A negative supply would permit the use of a 2N4360 or TIM 12. Fig. 40, This cascode video amplifier provides more than 6 MHz bandwidth with a voltage gain of 10. Both FET's are 2N38I9. MPFI05, TIS34 or HEP-801, A negative supply would permit the use of a 2N4360 or TIM 12. stage amplifier is being aligned, the tuning of one stage effects all the...

Owd

2n2646 Oscillator Circuits

F g. 66, This two meter band edge marker provides useful harmonics up to several hundred MHz with 18 or 24 M Hi crystals. If modulation is desired, the audio oscillator from the circuit of Fig. 65 may be coupled into the base. Ql is a 2NI745, 2N2362, or HEP-2. Fig. 67, A sweep frequency generator is a very handy gadget, but many times the commercial units are more complicated than the ham requires. This simple sweeper may be used at any spot frequency between 100 kHi and 60 MHr by simply using...

Amateur Radio Radio Amateur 03-1967 Mohican Product Detector

100 Khz Crystal Calibrator

With the values shown in the schematic, this circuit provides gains of 3, 10 and 30, which extend the 1.5 volt scale of the VOM to 500, 150 and 50 millivolts lull scale. There are two zero controls which must be adjusted when using this unit first the 500 kilohm pot HI in the base bias lead to transistor QI is adjusted to zero the output with no input and the base isolated from ground. The 1.5k zero adjust pot R2 is then adjusted for an output zero with the input leads shorted...

Mfc

Tuned Collector Oscillator

Fig, 28, 25 watt modulator uses readily available commercial transformers. Transistors QI and Q2 are 2NII72, 2N301, 2NI560, SK3009, GE-9 or HEP-232 Q3 and Q4 are 2N 74t 2N278, SK3012, GE-4 or HEP-233 The frequency response ol this circuit is quite good and is essentially flat from 200 Hz to 7 kHz. If you are interested in building a dual conversion receiver for single channel operation on MARS, 2 meter F 1 or WWV, the single oscillator circuit which provides two outputs illustrated in Fig. 29...

Wnsdi

1 see that ARRL is still leaving no stone unturned to try and kid off the Institute of Amateur Radio. They've done their usual thorough job of making sure that the League is the only national amateur organization. Not that the Institute is dead, by any means, its just a definite unsuccess. The responsibility for the failure of the Institute to succeed is largely mine. 1 know when I .started it that it would be fought bv every means possible by the ARRL and I was sure that CQ would be as...

Simple Transistor Push Pull Speaker

Direct Coupling Amp

Fig. 20- This complimentary amplifier provides up to 220 mW output with a frequency response from 90 Hz to 12.5 kHz. Although matched transistors are not required for Q2 and Q3t they are available as the 2N2707. in the preamplifier. Resistive pads may be used to increase the input impedance, but they greatly reduce stage gain and increase problems with signal to noise ratios. In the amplifier of Fig, 19 equalization is obtained by a frequency selective feedback path between the collector and...

Mohican Product Detector

Pentagrid Converter

Norwich Avenue Fresno, California Improve the performance of your receiver on SSB and CW with this simple transistor product detector. All receivers not specifically designed for SSB reception suffer, to some extent, in quality and ease of tuning when used for this mode. I istoition of the received signal occurs for a number of reasons. When this includes BFO pulling, reduction of the rf gain may prove necessary. This in turn leads to loss of sensitivity and does...