Ramsey Electronics FZ-146 Specifications

FX-146 • 1 2 METER AMATEUR PLL SYNTHESIZED FM TRANSCEIVER 140 - 180MHz Ramsey Electronics Model No. FX-146 Published in Three Sections: • FX-ser

FX 146 • 10 ENCLOSURE & HARDWARE CONSIDERATIONS: The companion CFX case and knob kit is sold as a separate option ONLY as an accommodation to tho

FX 146 • 100 Stage G: The PLL Synthesizer: Understanding and Assembly

FX-146 • 101 Stage G: The FX- Transceiver PLL Synthesizer A reassuring feature of the FX Transceiver is that if you build it correctly and make just

FX 146 • 102 Inserted into this circle is the frequency synthesizer (U6 with U3), which compares the output of the VCO with the output of its own 10.2

FX-146 • 103 soon as both strings are exactly on the same frequency. By tuning the one string to the exact pitch of the other, you have corrected the

FX 146 • 104 work together for channel programming. • The Phase Detector (or "phase corrector") which compares the 5 KHz Reference Frequen

FX-146 • 105 Unlike simpler PLL IC's, U6's phase detector has TWO outputs at pins 7 and 8. These outputs go through very simple low pass fi

FX 146 • 106 R48 and C85 form yet another low pass filter to ensure that any 5 KHz "whine" will not get into the VCO. Because the DC charge

FX-146 • 107 finish or review your work.  G1a. Insert the 28-pin DIP socket for U6 into its PC board position and slightly bend the 4 outermost pins

FX 146 • 108  G18a. Insert and solder U10 as in step G15a. Soldering the remaining pins for U7, U8, U9 and U10 may be done either as a single operat

FX-146 • 109 Stage H: Frequency Programming, Understanding and Building your Diode Matrix

FX-146 • 11 This $16 to $18 (plus tax) in basic hardware also presumes availability of all needed drill bits and/or a reamer or punches of sufficien

FX 146 • 110 Stage H: FREQUENCY PROGRAMMING: Understanding and Building the Diode Matrix The labeling of the 16 parallel programming inputs of U6 shou

FX-146 • 111 "N" for 146.52 MHz = 146520 ÷ 5 = 29,304 Now, install Programming Diodes at all YES positions and we're done! The pra

FX 146 • 112 before doing any further work on your transceiver. Freq N= 32K 16K 8K 4K 2K 1K 512 256 128 64 32 16 8 4 2 1 144.00 28,800

FX-146 • 113 Even though there are 16 matrix positions to program, there are some shortcuts to make your job easier for normal ham band operation. Le

FX 146 • 114 THE RX/TX OFFSET PROGRAMMING MATRIX Diode placement in this matrix follows the same binary number principles as used for frequency progr

FX-146 • 115 Easy enough! Whenever you want a transmit offset that is higher than the receiver or repeater output frequency, simply find the the N nu

FX 146 • 116  H2: R69, 1K (brown-black-red).  H3: R114, 1K (brown-black-red).  H4: R65, 1K (brown-black-red).  H5: R67, 10K (brown-black-

FX-146 • 117  H41. Form one diode matrix "bridge" for the RECV row of holes. Using the heavier gauge bare wire in your kit, shape, insert

FX 146 • 118 Frequency Programming and Channel Switch Preparation Before completing the transmit functions of this VHF FM transceiver, we should now

FX-146 • 119 programming explained in detail in the first pages of this Section. In lieu of constructing diode bridges and wiring the channel selecto

FX 146 • 12 THE RAMSEY CFX TRANSCEIVER ENCLOSURE KIT: The CFX Kit is very obviously a fair value and solid investment for the long term performance a

FX 146 • 120 C60 until instructed to do so. Adjustment Procedure: 1. Check PC board carefully for missed connections, wire trimmings or untrimmed

FX-146 • 121 If the receiver section is not working, going ahead with Stage M or Stage TX is very unlikely to fix the problem. Nor is there much poin

FX 146 • 122 Stage M: Microphone Amplifier and PTT Circuit If you have studied all preceding circuit explanations, you have a good idea of what the Mi

FX-146 • 123 assures that the otherwise-silent PTT circuitry is indeed functioning and obviously has nothing to do with the RF output of the transmit

FX 146 • 124  M18. Install Q11, NPN transistor type 2N3904. Be sure to orient flat side as shown.  M19. Identify and install R46, the yellow color

FX-146 • 125 during transmit.  M35: R107, near Y1, 10K (brown-black-orange).  M36: D22, near VR1, type 1N914 or 1N4148. Orient the banded end cor

FX 146 • 126 background noise is audible.

FX-146 • 127 6. Press the microphone button: the TX LED should light, and the receiver should be silenced. 7. Touch a wire from ground to pin 3

FX 146 • 128 Stage TX: Transmitter, Buffer and Final Amplifier

FX-146 • 129 Stage TX: Transmitter Buffer, Driver and Final The transmitter section, Q10, Q9 and Q8, is conventional VHF RF circuitry that has proven

FX-146 • 13 resoldered after passing through the grommet. Snap in the locking section of the relief grommet only AFTER both the red and black wires

FX 146 • 130 IMPORTANT: DO NOT install any parts near Q8 until after Q8 has been installed in accord with the explicit directions in Step TX2. If you

FX-146 • 131 B. Unpack and study the design of the chip, noting both ends are metallic. C. Lightly pre-tin both PC board points. D. Holding C75 i

FX 146 • 132 However, DO NOT INSTALL L9, R32 or L10 UNTIL AFTER ALIGNMENT HAS BEEN COMPLETED. Whether you test now or later depends on how anxious you

FX-146 • 133 8. While speaking in the microphone, adjust modulation level (R46) for the best sounding speech. "Best" is not necessarily th

FX 146 • 134  TX26: C58, the last .1 uf capacitor.  TX27: C59, .001 uf.  TX28: L13, 1.5 turn hand-wound coil. Review "TC" and TX16.

FX-146 • 135 the lead preventing a good solder connection, you may wish to slightly scrape away this coating on some parts.  TX35. Install R119a, 1K

FX 146 • 136 main PC board. 1 02 #4-40 nutsSpacer nut C7 #4-40 Screw SO-239 Female Case PanelGro und Jum pe r

FX-146 • 137 This completes the assembly of the low pass filter PC board. Inspect the board to be sure all leads on the bare side of the board are tr

FX 146 • 138 good 50 ohm load. Keep these key-down tests as brief as possible.  TX52. If you are observing at least 4 watts of RF output, transmitte

FX-146 • 139 FX-146 TECHNICIAN’S NOTES Throughout production of the “FX” series transceivers, the technicians here at Ramsey have been speaking with

FX 146 • 14 GUIDE TO PC BOARD I/O CONNECTIONS: In addition to primary interconnections required for jacks and controls, etc., your FX-series Transcei

FX 146 • 140 help after all. VCO & PLL Faults: (manual pages ref. 21-24, assm.35-36, 43-48, 52-57) 1. PLL not locking. (L7 will not set correct

FX-146 • 141 back to the manual, isn’t our “n” number for 10 Khz right about 2? c. Some coincidence! Now we can guess that our fault is between the

FX 146 • 142 output by spreading the coils.) *Common faults: • Low supply voltage. • Improper tuning. • Improper output power measurement. Receiv

FX-146 • 143

FX 146 • 144

FX-146 • 145

FX-146 • 15 1. PRIMARY CONNECTIONS: PWR (near L20): +12-15 volts DC from S1. GROUND: - DC from battery or power supply. SPEAKER: both connections nea

FX 146 • 16 MICROPHONE & SPEAKER INFORMATION The FX transceivers with the hardware supplied are designed to accept standard ICOM or ICOM-compatib

FX-146 • 17 VHF PACKET DATA OPERATION Your FM transceiver was planned and designed to accommodate easy and reliable VHF packet radio operation. The

FX 146 • 18 RAMSEY FX-SERIES FM TRANSCEIVER (With emphasis on the PLL and VCO) MC13135

FX-146 • 19 FX-146 CIRCUIT OVERVIEW The FX-146 VHF FM Transceiver circuit theory is explained in progressive stages and in some detail as part of our

FX 146 • 2 A DEDICATION The Ramsey FX-series FM Transceiver Kits are writing a truly NEW chapter in the annals of the ham radio story. Growing number

FX 146 • 20

FX-146 • 21 Stage CR: Integrated FM Receiver The MC13135 is a complete FM narrowband receiver from antenna input (pin 22) to audio output (pin 17).

FX 146 • 22 connection as well as +DC, D6 is grounded through RF choke L17, which prevents the antenna RF from being shorted to ground. During Transm

FX-146 • 23 thereby increasing available modulation voltage. The VCO requires a very pure source of well-filtered DC, free of AC hum, alternator whin

FX 146 • 24 R48 and C85 form yet another low pass filter to ensure that any 5 KHz "whine" will not get into the VCO. Because the DC charge d

FX-146 • 25 There are several methods for quickly finding the required binary code for a particular frequency and its "N" number: 1. Desce

FX 146 • 26 Stage M: Microphone Amplifier and PTT Circuit U4 is a LM324 quad op amp: two are used as a conventional microphone gain amplifier, and the

FX-146 • 27 Using the FX-series FM Transceiver Quick Reference Programming Guide: In addition to "pencil & paper math" calculation dir

FX 146 • 28 FX-146 Quick Program Reference Standard 2 Meter band repeater pairs and selected frequencies Program as follows: 1. Install diodes a

FX-146 • 29 145.49 - 29,098 0 1 1 0 1 0 1 0 1 0 146.61 - 29,322 1 0 1 0 0 0 1 0 1 0 146.64 - 29,328 1 0 1 0 0 1 0 0 0 0

FX-146 • 3 TABLE OF CONTENTS: The Ramsey FX-146 Tranceiver Manual is organized into three sections: General Reference Information, Kit Assembly Phase

FX 146 • 30 Freq = Receive frequency/Repeater output N = Frequency (KHz) ÷ 5 KHz

FX-146 • 31 Let's try doing an example. We want to receive 146.520 MHz: N = 146520 ÷ 5 = 29,304 Now, convert to

FX 146 • 32 +RPT or -RPT positions. Using Computer BASIC as a Diode Matrix Programming Aid The purpose of the following BASIC program is to be as CL

FX-146 • 33 50 PRINT “Enter Receiver Frequency as 6 digits with NO decimal!” 52 INPUT “For example: 146520. Enter here: “; F 55 N = F/5

FX 146 • 34 326 IF NL < 8 THEN NM = NL 330 IF NM => 4 THEN NN = 1 335 IF NM > 4 THEN NX = NM - 4 336 IF NM < 4 THEN NX = N

FX-146 • 35 0 1 1 1 0 0 1 0 1 0 1 1 1 1 0 1 >>> Enter Next Frequency for Programming: Enter Receiver

FX 146 • 36 PROGRAMMING THE 'MINUS' OFFSETS We showed the Plus offsets first to prepare you for the Minus offsets. The offsets are enter

FX-146 • 37 EXAMPLE 2: RECEIVER OSCILLATOR FREQUENCY We know from previous circuit discussion that the PLL synthesizer must run 21.4 MHz lower whe

FX 146 • 38 FX-146 PROGRAMMING SUMMARY Programming your FX-146 is really quite simple; all it takes is a clear mind, a scratch pad and a calculator.

FX-146 • 39 4. DON'T run switching cables across the VCO and Transmit RF side of the PC board. 5. Please DO submit successful frequency contr

FX 146 • 4 IMPORTANT NOTICE The Ramsey FX-146 VHF FM Transceiver is capable of TRANSMITTING as well as receiving on any frequency in the range of

FX 146 • 40 FX-SERIES TRANSCEIVER GLOSSARY The following is a deliberately INFORMAL collection of: • Technical terms useful to know in understa

FX-146 • 41 CCW = see CW below. COR = "Carrier Operated Relay," a switching circuit activated by the detection of a carrier signal in a r

FX 146 • 42 elements connected to RF ground, the horizontal elements are called a "groundplane." HIGH = In solid-state circuitry, to say a

FX-146 • 43 magic number (decimal) to understand in FX binary frequency programming. N = the frequency in KHz divided by 5 KHz. NBFM = "Narro

FX 146 • 44 controlled, compared with another frequency, as is done in a PLL circuit. See PHASE DETECTOR, PLL. RSSI = "Received Signal Strength

FX-146 • 45 amount of DC voltage applied to it. The higher the voltage, the lower the capacitance. See also VCO. VCO = "Voltage Controlled Osc

FX 146 • 46 FX- TROUBLESHOOTING GUIDE The FX- transceiver is designed to W-O-R-K with a minimum of adjustment or alignment. By imprinting the loca

FX-146 • 47 despite the detail of our explanations, be sure you set one channel up for 146.52 MHz Simplex before you pursue troubleshooting. It is ve

FX 146 • 48 NOTE ON REPLACEMENT PARTS: If you lose or damage parts during assembly or testing, you may, of course, order any needed replacement par

FX-146 • 49 FX-146 MASTER COMPONENT INDEX The following pages were prepared to serve these purposes: 1. A general cross-reference for c

FX-146 • 5 SPECIFICATIONS FOR THE RAMSEY FX-146 General: Frequency Range: Any 20 MHz segment between 140 and 180 MHz Tuning: Diode-programmable

FX 146 • 50 G: PLL Frequency Synthesizer H: Diode Matrix, Frequency Programming M: Microphone Amplifier and PTT TC: Transmit Coil and R

FX-146 • 51 [ ] [ ] C24 .001 M16 [ ] [ ] C25 100 pF DR6 [ ] [ ] C26 .01 CR14 [ ] [ ] C27 8.2 pf DR8

FX 146 • 52 [ ] [ ] C53 .01 D10 [ ] [ ] C54 56 pf E3 [ ] [ ] C55 .01 TX30 [ ] [ ] C56 10 pf TX5 [ ]

FX-146 • 53 D: DIODES (All Types) [ ] [ ] C82 10 pf TX10 [ ] [ ] C83 .001 M2 [ ] [ ] C84 35 pf trimmer TX32 TX

FX 146 • 54 FL: FILTERS [ ] [ ] D7 BA482 PIN M34b See T-R switch theory [ ] [ ] D8 1N914 or 1N4148 G34 works with D10,C85: see PLL t

FX-146 • 55 L: INDUCTORS (Coils, Transformers, Chokes): Q: TRANSISTORS (All Types): [ ] [ ] L1 455 KHz LB53303HK CR23 FM quadrature adjust [

FX 146 • 56 R: RESISTORS (Fixed, Trimmers, and Panel-Mounted) [ ] [ ] Q5 2SC2498 NPN RF F8 VCO common base buffer [ ] [ ] Q6 2N3904 NP

FX-146 • 57 [ ] [ ] R16 47K DR13 [ ] [ ] R17 470 ohm DR14 [ ] [ ] R18 270 ohm E7 [ ] [ ] R19 10K E13b [ ] [ ] R2

FX 146 • 58 [ ] [ ] R43 10K G26 [ ] [ ] R44 22K G20 [ ] [ ] R45 82 ohm 1/2W TX23 [ ] [ ] R46 10K trimpot M19 [ ]

FX-146 • 59 [ ] [ ] R71 100K H22-H40 U6 counter input pulldowns [ ] [ ] R72 "

FX 146 • 6 INTRODUCTION to FX-series VHF Transceiver Kit Assembly For the 1990's, Ramsey Electronics has adopted a "Learn As You Build

FX 146 • 60 V: VOLTAGE REGULATORS [ ] [ ] R103 47K G28 [ ] [ ] R104 10K G29 [ ] [ ] R105 100 ohm F16 [ ] [ ] R106 10K F

FX-146 • 61 [ ] [ ] S1 on R7 (volume) A2 DC on-off [ ] [ ] S2 12 position "H" Frequency selection [ ] [ ] TP1 F20

FX 146 • 62 The RAMSEY FX Transceiver Kit WARRANTY Please read carefully BEFORE calling or writing in about your Kit. Most problems can be solved

FX-146 • 63 KIT ASSEMBLY PHASE 1: Stage A: DC Power Regulation & Distribution Plus Packet Data I/O Connector Stage B: Receiver A

FX 146 • 64 FX-146 Transceiver Assembly Phase 1: Circuit stages A through E-F FX-146 MASTER PARTS LIST Before beginning assembly, take some time to

FX-146 • 65 CRYSTALS:  1 10.240 MHz, has 2 leads (Y2, PLL reference frequency)  1 21.855 MHz, has 2 leads (Y1, receiver IF oscillator)  1 21.4

FX 146 • 66  4 47 pf (C12,28,30,C31)  2 56 pf (C19,54)  10 100 pf (may be marked 100 or 101) (C17,20,22,25,32,35,45,46,47,50) ADDITIONAL DISC

FX-146 • 67 CONTROLS, HARDWARE AND MISC.:  1 volume control potentiometer with switch (may be any value from 10K to 100K) (R7,S1)  1 10K squelch

FX 146 • 68 VERY IMPORTANT PC BOARD ASSEMBLY INFORMATION FOR A-L-L OUR BUILDERS! 1. Your FX- transceiver PC board is double-clad with plated- throu

FX-146 • 69 at the factory have tried to help by grouping similar or related parts in individual sealed bags. Sorting organizers popular among kit bu

FX-146 • 7 parts as a finished product! For a minimal investment of your time as well as your well-earned money, you will have a VHF FM voice-data tr

FX 146 • 70 21. Use the extra spaces provided throughout this manual to write down the details of any changes or revisions noted on additional sheets

FX-146 • 71 STAGE A: DC POWER INPUT REGULATION & DISTRIBUTION and PACKET RADIO I/O CONNECTOR (J1) The "power supply" for your FX- trans

FX 146 • 72 STAGE A: DC POWER INPUT REGULATION & DISTRIBUTION and PACKET RADIO I/O CONNECTOR (J1)

FX-146 • 73 Stage A: ASSEMBLY STEPS  A1. Strip 1/8" of insulation from the heavier-gauge black wire, insert and solder in the GROUND hole. Th

FX 146 • 74  A10. Study the PC board, locate the triangular set of 3 holes for VR2 (type 7805), and insert VR2 so that the flat metal tab side is tow

FX-146 • 75  A13. Install C2, .001 uf disc capacitor. It may be marked .001 or 1 nf or 102. (102 means a one, a zero and two zeros which equals: 10

FX 146 • 76 Stage B: Receiver Audio Amplifier The secret to the fine performance of the LM380 audio amplifier lies in careful selection and physica

FX-146 • 77 Stage B: AUDIO AMPLIFIER CIRCUIT ASSEMBLY: Some of the Stage "A" steps required more detailed explanation than simply inserti

FX 146 • 78  B3. Install R108, 2 ohm (red-black-gold).  B4. Install C33, .01 uf disc capcitor (marked .01 or 103).  B5. Install C41, .1 uf disc c

FX-146 • 79 Optional: To a test speaker, temporarily or to a speaker intended for regular use inside or along with your FX- Transceiver.  B16. Sol

FX 146 • 8 A MESSAGE TO HAM RADIO BEGINNERS: If you have just earned your Novice or Technician license, or are studying for either of them right now,

FX 146 • 80 STAGE CR: FM RECEIVER CIRCUIT DUAL CONVERSION SUPERHET WITH IF FILTERS

FX-146 • 81 Stage CR: Integrated FM RECEIVER (with Squelch Control) This step is named "CR" so that the assembly step numbers do not r

FX 146 • 82 "DR" of this project. The purpose of the "DR" circuitry is to filter out or at least diminish other signals while boos

FX-146 • 83 ADDITIONAL RECEIVER IC FUNCTIONS AND FEATURES In addition to audio output at pin 17, a separate high speed data output (up to 35000 baud

FX 146 • 84  CR11. Install C8, .1 uf disc capacitor (marked .1 or 104).  CR12. Install C13, .1 uf disc capacitor (marked .1 or 104).  CR13. Insta

FX-146 • 85  CR29. Install FL1, the 21.4 MHz IF filter. Its 3 wires may be inserted either way; make sure its body is snug against the top of the bo

FX 146 • 86 frequency of the signal generator frequency plus 21.4 MHz. Because we have not yet constructed any of the input circuitry (Stage DR), you

FX-146 • 87 FX SERIES TRANSCEIVER Simplified Receiver Block Diagram LOW PASS FILTER HIGH PASS FILTER Q3 RECEIVE PRE-AMP BAND PASS FILTER Q2 RECEIVE

FX 146 • 88 Stage DR: Receiver Tuned RF Input and Preamp

FX-146 • 89 Stage DR: Antenna Input and RF Preamplifier The operation of the FM receiver IC was discussed in Stage CR. The purpose of the following

FX-146 • 9 DC POWER SUPPLY CONSIDERATIONS : Your Ramsey FM Transceiver is designed to operate from any stable DC voltage source in the 12 to 15 volt

FX 146 • 90 STAGE DR ASSEMBLY: Be very attentive to capacitor values (in picofarads) and to coil descriptions throughout this section.  DR1. Correc

FX-146 • 91 Install the following resistors, each in upright position:  DR13: R16, 47K ohm (yellow-violet-orange).  DR14: R17, 470 ohm (yellow-v

FX 146 • 92 Stages E - F: Transceiver VCO (Voltage Controlled Oscillator) and Buffer Stages

FX-146 • 93 Stage E-F: The FX Transceiver VCO The VCO (Voltage Controlled Oscillator) provides basic frequency control for both transmit and receive

FX 146 • 94 VCO CIRCUIT SUMMARY: The control voltage for the D3 and D23 varactor diodes is supplied through R47 and R25 by the output of U5:A in the

FX-146 • 95 Stage E: BASIC VCO ASSEMBLY In this Stage, we will assemble the basic VCO (Voltage Controlled Oscillator) circuit. Understanding the fu

FX 146 • 96  E20. Install R35, upright, 100K ohm (brown-black-yellow). R35 is between positions for D5 and C62. Steps E1-E20 are presented as a gro

FX-146 • 97  F18. Install C35, 100 pf disc capacitor (marked 100 or 101). C35 couples the VCO buffer to the receiver IC.  F19. Install C94, a 3.

FX 146 • 98 VCO AND RECEIVER TEST PROCEDURE:  1. Make sure work area is tidied up and that the PC board has been checked for stray scraps of wire, e

FX-146 • 99 RAMSEY FX-146 VHF FM TRANSCEIVER KIT ASSEMBLY PHASE 2: • Stage G: Understanding and Building the PLL Frequency Synthesizer • Sta