1.1 GENERAL. THE MULTI-ELMAC AF-67 Trans-Citer is a ten-tube variable frequency or crystal controlled seven band transmitter or exciter. All circuits are simultaneously switched to the desired band by a single bandswitch lever.Designed as a complete transmitter for mobile or fixed installations, or an exciter to drive a higher power transmitter. When used as an exciter the 500 ohm tap on modulation transformer can be used to drive the higher power modulators.
1.2 DIMENSIONS. The maximum external dimensions of the AF-67 Trans-citer, excluding projections of control knobs, is 11 1/4 inches wide, 7 inches high, and 8 1/2 inches deep behind panel. Approximate weight is 18 pounds.
1.3 CIRCUIT DESCRIPTION. The AF-67 Trans-citer employs a variable frequency oscillator with output on wither 1.75 to 2.0 Mc. or 3.5 to 4.0 Mc. In addition to the V.F.O. feature, two crystal positions are included for operation on two spot frequencies. Any crystal that will work straight through, double of quadruple to the desired frequency may be used. The oscillator circuit employs a voltage regulator tube to maintain the plate voltage at a constant level.
The multiplier stages are broad tuned with a front panel control for peaking the final grid, insuring best performance on all bands. The audio circuit is designed to use either a carbon microphone or a low output microphone such as a crystal or dynamic. A slide switch on the rear apron on the AF-67 Trans-citer sets up the circuit for use with either type of microphone. A reactance tube modulator is incorporated in the variable frequency oscillator circuit for narrow-band-frequency-modulation. The variable frequency oscillator dial scale is directly calibrated in megacycles for each of the amateur bands.
1.4 TUBE COMPLIMENT. The AF-67 Trans-citer is supplied complete with all tubes, tested in the individual unit, as follows:
1.5 OUTPUT. The AF-67 Trans-citer is designed for use with a resonant antenna coupled to its output with a transmission line of 50 to 300 ohms impedance. Other impedance or balanced lines can be coupled through the use of an antenna tuning device. When used as an exciter the coupling link of the high powered final can be directly connected to the AF-67 with a suitable length of coaxial cable. The MULTI-ELMAC AF-67 is designed for a maximum plate power input of 60 (sixty) watts. Maximum ratings for this Trans-citer are 600 volts at 100 milliamperes; or 500 volts at 120 milliamperes. Full 100% modulation occurs when the modulator plate current swings to about 60% of the final plate current with normal voice frequencies.
1.6 AUDIO. The modulation transformer is provided with a 500 ohm output tap brought to the power plug for driving the grids of high powered modulators. The 5881's will deliver approximately 40 watts of audio with a plate supply of 500 volts.
1.7 POWER SUPPLY. The AF-67 Trans-citer was intentionally designed to use an external power supply in order to permit (a) use of PMR-6A receiver power supply to supply the low level stages, (b) use of the AF-67 Trans-citer with an AC operated power supply at a fixed or portable location, (c) use of a dynamotor or vibrator supply in mobile installations, or (d) use of the Trans-citer as a driver-exciter for high powered transmitters. A suitable MULTI-ELMAC power supply MODEL PS-2V for portable or fixed station operation from 115 volt AC lines is available.
1.8 POWER CONNECTOR. A 15 prong female connector is provided with each unit. The 15 prong connector allows all circuits to be arranged for maximum flexibility. Making it possible to use the AF-67 Trans-citer in various types of installations.1.9 ACCESSORIES. The following accessories are available for use with the AF-67 Trans-citer:
PS-2V --- A universal 115 volt AC power supply. (Supplies 6 or 12 volts AC for filaments and two separate high voltages.)CFS-1 --- Cable with a 15 prong female connector and fanning strip to connect the AF-67 to the PS-2V power supply.
AF-67 Mods & Maintenance by John Conley, W7ZFB
1.1 GENERAL. The MULTI-ELMAC PMR-7 RADIO RECEIVER is a ten tube double conversion superheterodyne covering the 160, 80, 40, 20, 15, and 10 meter amateur bands, plus the standard broadcast band. Designed primarily as an efficient communications receiver for mobile use, it is also especially suitable, because of its small size, for (1) marine and aircraft installations; (2) portable operation; and (3) as a fixed station or monitoring receiver. It is not intended as a converter to accessory to another unit, but a complete receiver, employing a separate power supply and speaker as described in this manual. Every effort has been made to furnish the user with an extremely stable receiver of rugged construction, compact layout, and high sensitivity.
1.2 DIMENSIONS. The maximum external dimensions of the PMR-7 receiver, including the control knobs are: height 4 5/8", width, 7", and depth, 11 1/2". The depth behind the panel is 9 7/8". The net weight of the receiver is 8 1/2 pounds.
The ESS-3 "S" Meter is an accessory external 0 - 1 milliampere meter calibrated in "S" units for use with the Multi-Elmac PMR-7 receivers.
Designed for use with the Multi-Elmac AF-67 Trans-Citer or a variety of other applications.
Wednesday Nights at 7:00 PM CST, 3.880 MHz (except for first Wednesday of month).
Electric Radio Magazine - Article Title
Chenoweth,John,W8CAE, and the R.L. Drake Co.
Drake Tube and Antique Radio Net
Cooling The Drake TR-4
Drake Equipment List
Drake RV-6 Remote VFO, The
Drake 2B Receiver, The
Drake TR-6, The
Adding an AM Filter to a Drake TR-4CW
Adding AM Filter to a Drake TR-4C
New Filters for the Drake TR-4 Transceiver
Ham Radio Magazine - Article Title
Drake W-4 Directional Wattmeter
Frequency Synthesizer for the Drake R-4
Using Shure 401A mic. with Drake TR-4
Bandpass Tuning Electronic in the Drake R-4C
Frequency Synthesizer for the Drake R-4 (mod. letter)
Simple tune-up for Drake Gear
Cleaner Audio for R-4C
New Product Detector for R-4C
Improved Tuning on T-4X xmtrs on 160-meters
New Audio Amplifier for R-4C
Split Frequency operation R-4B and TR-4
Backlash Cure for Drake R-4C
Sensitivity Improvement for TR-22C
Improving Drake R-4C Product Detector
Drake R-4C Audio Improvements
Woodpecker Noise Blanker of TR-7
Improving Drake R-4C Power Supply
Better Frequency Stability for the Drake TR-7
QST Magazine - Article Title
TR-4, detailed description (pages 80-83)
L-4B Linear Amplifier; Lange, Walter W1YDS
ML-2 Marker Luxury FM Transceiver; Campbell, Laird W1CUT
MN-2000 Matching Network; Lange, Walter W1YDS
MN-4 Matching Network; Grammer, George W1DF
R-4C Communications Receiver; Myers, Robert W1FBY
R7 Receiver; DeMaw, Doug W1FB
R8 Shortwave Receiver; Kearman, Jim KR1S
RCS-4 Remote Coax Switch; Cain, Jim K1TN
SC-2 2-Meter Converter;Tilton, Edward W1HDQ
SC-6 50-Mc Converter; Tilton, Edward W1HDQ
SPR-4 Receiver; Blakeslee, Douglas W1KLK
SW1 Shortwave Receiver;Lindquist,Rick KX4V
SW8 General-Coverage Receiver; Kearman, Jim KR1S
T-4 Transmitter; Grammer, George W1DF
T-4X Transmitter; Grammer, George W1DF
T-4XC Transmitter; Sumner, Dave K1ZND
TR-6 50-MHz Transceiver; Tilton, Edward W1HDQ
TR-7 HF Transceiver; Sumner, Dave K1ZZ
TR270 FM Transceiver; Ford, Steve WB8IMY
UV-3 VHF FM System; Kearman, Jim W1XZ
Communications Quarterly Summer-92
TR-7 Modifications (4 Board Set)
Better Frequency Stability For Drake TR7
WARC and LF on the TR-7
R. L. Drake Co.
Drake Amateur Radio Club - W8CYE
Drake List Home Page
R. L. Drake Virtual Museum - Sindre Torp
BAMA - Drake Manual and Schematic Archive
Cin-Tran, Inc. - A Company that manufactured transformers for Drake (purchased by Standex International in 2002)
EB5AGV / EC5AAU Drake C Line Repair and Mods page
(877) 372-2341; FAX (701) 378-2551
International Radio - Crystal Filters for R-4C and TR-7/R7
Drake Service CDs - By Garey Barrell, K4OAH
K5DKZ - Convert your T-4 to 6146 with mod kit and more!
NU0C - TR-7 Extender Boards
Radiophile.com - W1JA's Vintage Drake Station
Sherwood Engineering - Modification Kits and Installations for R-4C
T & T Drake Repair - Larry Taft, K2LTand Henry Turner, KC5FLJ
WB4HFN - Lots of information on Drake gear
2B Radio Parts - Don Garrett - Replacement Parts for Drake Radio Equipment
B D Crystals1438 Cox AvenueErlanger, Ky. 41018Phone 606-283-5000
Velco Electric, Inc.611 Wangum RoadFishers, NY 14453Phone: 716-924-2073Fax: 716-924-2136
Drake User's Net - Tuesday nights, 2000 EST 3865 kHz; technical net on Sunday 2000 EST 7238 kHz
73, Bruce WC1E
I received numerous requests for Bill Frost's description of a procedure to match the 6JB6 finals in 4-line equipment. Rather than send to many individuals, I think the interest is high enough to share the procedure with everyone. It is brief. By the way, I am told by others that Sylvania 6JB6's don't require matching because of their quality.
73, Wayne, KG5BI
Thanks for the e-mail. The 6JB6 tubes were matched on cathodecurrent. A fixture was designed and built by the Engineering Dept. thatkept the operating voltages constant while measuring the cathodecurrent. A similiar test can be preformed by using the T-4X or TR-4 asthe test fixture.
1. Turn unit off and disconnect power supply. Place the unit upsidedown and remove the bottom cover. Re-connect power supply.
2. Key the transmitter, with the transmitter gain control at minimum (thetransmitter should only be drawing idle current).
3. Measure the voltage at pin 3 of each final tube. The voltage should bewithin .1 or .2 volts to be "matched". Substitute tubes and re-measureuntil all tubes are "matched."
Bill FrostR.L. Drake Service Manager
Drake List at QTH.NET