BROADBAND CIRCUITRY Thanks to exclusive CENTRAL ELECTRONICS broadband circuitry, load im:x»drtnces of 52-72 ohms for coaxial cable are inherently matched without the need of tunin? or loading controls. Power output is essentially constant across each band. FREQUENCY COVERAGE 80 Meters — 3.G to 4.5 MC. 40 Meters —6.5 to 7.5 MC. 20 Meters- 1S.5 to 14.5 MC. 15 Meters. 20.5 to 21.5 MC. 10 Meter* — 27.7 to 29.7 MC. PLUS- A spare position to permit factory installation of broadband coils for 1.75 to 2 IC. 2 to 2.5 MC., or any 1 MC. portion of the spectrum between 2.5 and 25.5 MC. not already covered by amateur banda» For example: 2.5 to 3.5 MC. 1.5 t.. MC- 5.5 to 6.5 MC. etc. (Note that these portions must l>etfin and end at .5 MC. points only) OR: the 2 MC. portion 25.0 to 27.6 MC. not covered by the 10 meter band position (at additional cost). NOTE the generous overlap bevond the amateur bands, for MARS, CAP or COMMERCIAL applications. Ever beyond that, the VFO has 50 KC of overtravel (100 KC. above 25.6 MC.) at each end of the scales. Calibration accuracy and linearity of this overtravel ts not guaranteed put ¡t*K there in case you need it. SIX OPERATING MODES LSIJ Lower sideband suppressed carrier. USB Upper sideband suppressed carrier. AM Double sideband with pre-set carrier. PM Phase modulation with pre-set carrier. CW Four methods of keying with pre-set carrier. FSK Frequency-shift teletype with pre-set carrier and adjustable deviation. Power input 200 watts PEP on SSB; 100 watts on AM; 175 watts on PM. CW and FSK. TELEVISION INTERFERENCE: Conventional AM equipment utilizes Class C amplifiers that distort the RF output waveform, causing seven! harmonic TVL Since the output stage in the 200V operates in Class AB1 in all modes of transmission, excellent linearity and extremely low harmonic output is obtained. transmitter in which the Sideband signal h generated at a fixed crystal controlled frequency and thereafter heterodyned to different band». This feature eliminates the necessity of rebalancing the wideband generator when changing from band to band. In the 200V a NEW DOUBLE HETERODYNE system insurer extreme stability. The VFO lanes from 6 to G MC, Sideband generation is crystal controlled at 8 MC. All Heterodyne oscillators run continuously, are crystal controlled and temperature compensated for high ¿lability. Blocked m id keying of mixers and linear amplifier result* in essentially click less chirp free break-in operation. INVERSE AUDIO LIMITER Audio clipping allows an increase in the level of the weaker speech passages giving your signal that extra "punch'* required for increased readability under adverse conditions It maintains maximum speech level and prevents overloading of the balanced modulator, mixer* and RK amplifier stages. In the past, most clipping systems have contributed objectionable distortion to the output signal. In the 200V a new circuit utilises the clipped waves as inverse feedback to cancel an appreciable amount of distortion. We have called this improved clipper the “Inverse Limiter". In combination with the new 200V Audio Filter, this revolutionary system allows 10 I)B. of limiting with minimum effect on the speech quality. With about 3 DB. of speech limiting the front panel Limiter Indicator begins to flash. The amount of limiting may be determined by t he 6 I)B. calibrations of the Spcech Level control. No matter how loud you talk into the microphone or how far you turn up the Speech control, the peaks will not increase beyond approximately 1 DB above the pre-set level. PERFECTED AUDIO FILTER The 200V filter is composed entirely of RC elements, yet has the steep aide response and rejection characteristic* of a toroid filter. Since it is a degenerative RC bandpass (200-3800 cycles) type, it overcomes the harsh, ringing characteristics of conventional filters. It precedes the phase-shift network and will maintain 50 DB. unwanted sideband suppression even beyond the bandpass limits of the new PS-2 phase shift network. PHASE SHIFT NETWORK The new PS-2 is a ten element type unit constructed of heat cycled component-» matched to .1% accuracy. In combination with its associated circuitry and the fact that DB. of inverse feedback is applied around the modulator, it will maintain 50 DB. unwanted sideband suppression. This novel approach means that even the modulator tubes may be changed WITHOUT AFFECTING SIDEBAND SUPPRESSION. The RK phaseshift network is a new non» critical, low impedance, wide band type having extreme stability. POWER OUTPUT CONTROL In the 20*)V the power output may be adjusted to any level between 10 watts and full output. This new circuit eliminates the need for power consuming dissipative networks when driving linear amplifiers with lower drive requirements. The power output control does not affect the output load impedance of 52-72 ohms A matching network will lie required for grounded grid amplifiers having an input impedance above 100 ohms. POWER OUTPUT TUBES The broadband output circuit of the 200V uses a pair of 6550 tubes that are rated for continuous commercial service in ultra-linear UiFi applications. Our tests, have shown that the linearity of 6650's is far superior to that of the commonly used 6146’s at the power output level of 100 watts PLUS. Plate dissipation is H5 watts per tube and a pair will deliver OVER 100 WATTS of single tone power, even on ten meters, without griil current flow! Two tone third order distortion products are down in excess of 40 DB. NEW POWER SUPPLY Conventional rectifier tubes have been replaced in the 200V with SILICON RECTIFIERS. The result is considerably ¿ess heat and higher voltage output. The new power supply has extremely good regulation even under the higher input levels .used in the 200V output stage. 2" MONITORING SCOPE Gives an instantaneous visual trapefeoid check on non-linearity or flat-topping resulting from improper loading. Also indicates correct setting of pre-set carrier level control for 100^ AM modulation. LOAD MIS-MATCH PROTECTION In the event that an improper load causes excessive screen current in the power amplifier, an overcurrent relay in the 200V applies protective bias and flashes the front panel MISMATCH neon indicator. METER The illuminated meter indicates final amplifier DC power input on a 0-200 watt scale. SET AND FORGET CONTROLS Behind the two magnetic doors on the front panel are all the seldom used controls which are normally adjusted when first putting the 200V on the air. They include: Speech Level: VOX trip level; Antitrip (QT) level: VOX release time: KSK deviation; carrier null; pre-set AM carrier and DSB switch: pre-set CW earner; CW monitor level; VFO-XTAL switch and Power output control. OTHER OPERATING CONTROLS CALIBRATE LEVEL: Adjusts strength of calibrate signal to suit band conditions or individual installations. FUNCTION SWITCH: Power Off; Standby; VOX; Voice calibrate; Carrier calibrate; PIT; and Manual. BAND SWITCH: Selects 80, 40, 20, 15, 10 and X position for special frequencies. EMISSION SWITCH: Selects LSB, USB, AM <DSB>, PM, CW or FSK. NEW MIXER CIRCUITRY New FRAME GIUI) tulies (6EH7-6FJ7) are used in the new 200V. They have extremely high gain, run cool and their use assures that unwanted mixer products are down in excess of 50 DB.