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Tuners, Wattmeters calibration procedure
CALIBRATION:       The mfj-xxx has been calibrated at the factory.  IF it should ever need to be recalibrated, then follow this procedure:   EQUIPMENT NEEDED: &...
MFJ-1025/MFJ-1026 Notes
Noise Phasing and MFJ-1025/1026 Data The original concept of the 1025 is based on a bridge phasing system. Many phasing boxes, such as the QRN Squasher, do not rotate phase. They are based ...
MFJ-1025/1026 Notes
the current requirement for the mfj-1026 noise cancelling antenna is: less than 100 mA.   L1 and L2 on the 1026 pc board are the same value.  each is a 100 uH surface mounted ind...
MFJ-1025/1026 Notes
type: 2N5109, cost: $2.85 each, mfj p/n: 305-5109.  send personal check or money order to: mfj, 300 industrial park road, starkville, ms 39759 or call the techline, 1-800-647-8324 to order with a...
MFJ-1768 overall view
This diagram was left out of the MFJ-1768 manual (inside front cover) for some owners.    
Current requirement for 1025/1026
the current requirement for the mfj-1026 noise cancelling antenna is: less than 100 mA.   Richard C. Stubbs, Jr., KC5NSZMFJ Customer Services
1026 Q4
type: 2N5109, cost: $2.85 each, mfj p/n: 305-5109.  send personal check or money order to: mfj, 300 industrial park road, starkville, ms 39759 or call the techline, 1-800-647-8324 to order with a...
1270 kiss mode
Turn KISS on.  Type restart.  should go back into KISS mode.   some units actually do not have kiss mode anymore, some of the newer ones.  the new ones have a vectronics firmwar...
MFJ-1272M to IC-2100H
Dear Sir, Pin-Outs for IC-2100H Pin 1   +8VDC                     Pin 5   Mic ...
MFJ-1274 TNC chip
looking for a z80(Z0844004PSC) chip for the mfj 1274 tnc...mark marsh p/n: 327-840004, $6.75 each plus $5.00 minimum mailing fee.  send personal check or money order to: mfj part request, 300 i...
1317/4103 Specifications
1317 specs: Input voltage: 100-240 VAC (limits: 90-264 VAC) Input frequency: 47 to 63 Hz (limits: 47-440 Hz) Input current: 0.8A(rms) - 115 VAC; 0.6A(rms) - 230 VAC Safety ground leakage...
1622 counterpoise wire lengths
(1:50:01 PM) Chad Butler: yes, they are cut to cover the 3.5-30 MHz...6, 14 and 26 ft wires...26ft for 3.5MHz and 7.0MHz, 14ft for 10MHz, 14MHz and 18MHz, and 6 for 21, 24 and 28MHz
1728 radiator length
yes, 144-174 MHz, is currently 49 inches.   Thanks for your business! We appreciate your Support!Richard C. Stubbs, Jr.KC5NSZ
1775 balun problems
If there is a problem with the balun it can be tested this way. Attached are photos of how the balun should be assembled on the inside of the box. You may test the balun with a ohm meter.   ...
201 circuit description
4. CIRCUIT DESCRIPTION The RF oscillator is a Colpitts type using a silicon transistor.  The RF voltage is rectified with a diode and the current is indicated on the meter. When the dip meter fr...
2012 OCFD Antenna
It's fed 1/3 of the way the total length -- roughly 22/44 feet. The attached file has SWR curves and more specific info. -- Rick
202B box test/calibration
MFJ-202B Box Test   Set-UP: Radio, Ohm Meter, 50 Ohm Load   Use AM   1.  Attach Ohm Meter (-) on third leg of power switch, (+) on (+) of air variable capacitor.   2.&...
MFJ-2289 Big Ear Feed Block Assembly
The BigEARTM Center Block assembly is p/n: 80-2289-1, retail $59.95.
MFJ-229 Test Procedure
MFJ-229 Test Procedure   1.  Attach trimpot to chassis 2.  Mount board and solder trimpot 3.  Solder Antenna jack to board 4.  Solder Display (*display and jack attach to...
MFJ-269 N-connector
p/n: 610-2003, mfj-269 N connector with socket pin, $3.62 plus $5.00 minimum mailing charge.  send personal check or money order or call the techline, 1-800-647-8324 to order with a credit card. ...
MFJ-259B on/off bypass
to bypass the on/off switch for the 259b, ground out the bottom four pins at the switch.   Richard C. Stubbs, Jr., KC5NSZMFJ Customer Services
MFJ-259/269 power switch
p/n: 504-2022, 23 cents each, add $5.00 minimum mailing charge.  send personal check or money order to: mfj, 300 industrial park road, starkville, ms 39759 or call the techline, 1-800-647-8324 to...
MFJ-269 Sign of Reactance
It is good to know that you have been directly involved with several technical sessions ("Circuits in Motion", "Capacitors and Oscillators"....) where building circuits was an enjoyable task.   ...
MFJ-259B usage -- 7 MHz traps
Dear Hans,   I do not believe that you can get the trap resonance frequency with a 80 kHz resolution (7.00 MHz, 7.08 MHz) following the method that you described. Even though the numbers that y...
Trimmer resistors in the MFJ-259B
  I guess that the basic function for the MFJ259B, MFJ269 trimmers, could be extracted from the calibration procedures http://www.mfjenterprises.com/MFJ-259Bcalibration.php and http://www.m...
MFJ-259B/MFJ-269 Distance to Fault Procedure
Before to try to clearify your doubs about the MFJ-259B Distance to Fault methodology I should apologize for the 5.5, Distance to Fault mode "To measure fault distance" confusing text. I think that ...
MFJ-269 Bridge Voltage
  To access to the bridge voltage reading the unit should be set first to the TEST mode:             -  Immediately after turnin...
MFJ-259B Diodes
p/n: 302s-2820, 66 cents each plus $5.00 minimum mailing fee.  send personal check or money order to: mfj parts request, 300 industrial park road, starkville, ms 39759 or call the techline, 1-800...
MFJ-269 Parts
p/n: 305-6310, Transistor FET, To-92 Siliconix J310 . . . . 32 cents each   p/n: 305-6005, Transistor FET, Switching, VN10KM . . . . 32 cents each   p/n: 305-0017 (has been changed t...
Microwave Diodes for MFJ-259B
here is the information requested on diodes used in the mfj-259b.  thanks for your inquiry.   p/n: 300S-0914, switching diode, SOT-3, CMPD914 (four); D10, D11, D14, D15; ---- p/n: 300...
MFJ-267 Calibration Procedure
mfj-267 calibration procedure: items needed: 100 watt output exciter, minimum 500 watt output amplifier, bird wattmeter, external dummy load, mfj-267, and tuning wand.   CONNECT AS SHOWN: E...
269 reviews
eham.net reviews: 19, bad reviews 3 or lower: 6 31% say it's bad.  69% say it's great!    go back and read all of the good reviews.  then read the bad reviews.  note the a...
4225mv voltage adjust
you can adjust trimmer capacitor VR1 to vary the voltage up or down.  17 volts is the high end and will cut off automatically.   note that when you adjust the low end, your high end wil...
MFJ-434 with Heil microphone
To make the 434 work with a Heil microphone:   The Heil mic is an electret mic and requires voltage to work.    On the MFJ-434 pc board, find jumper JMP6, (located next to the PLAY...
MFJ-4416B Troubleshooting Guide
MFJ-4416 Troubleshooting Guide     1.         For any failure Check Pin 2 of U1.  This is the 5.2 Volt reference voltage used by most of the c...
MFJ-447 Self Test
When performing the Self Test, make sure to release the paddles before the copyright message completes.  Also, make sure NOT to double press the dot or dash paddle when testing them.&nb...
MFJ-451/452 Keyer restore
jimmy allen, our repair technician on the keyer line says you need to reset your keyer by doing the following task.  the "long beep without power led illuminating," means that your keyer has lock...
MFJ-4602 Binding Post Assembly
4602 binding post assembly   screw (1), p/n: 660-3500S, $1.16 each nut (2), p/n: 705-1032, .05 cents each flat washer (4), p/n: 710-1043, .10 cents each split washer (2), p/n: 711-1037-SL, ....
MFJ-464 Hyperterminal for Windows
To setup and run HyperTerminal for Windows:   *) Click Start, point to Programs, point to Accessories,    point to Communications, and then click HyperTerminal.*) Connection Des...
MFJ-492 Battery Type
CR2430, $2.61 plus $5.00 minimum s/h.  can probably be found at radio shack also.    it is a 3 Volt Lithium button battery.   Thanks for your business! We appreciate your Sup...
MFJ-493 Message
I did not work on the MFJ-493, but from my understanding of page 7 of the manual.  To upload a message to the MFJ-493 keyer, type and save your text file like this:   {#MESSAGE T...
MFJ-495 L4
The L4 is used to prevent RF, if any, from getting into the ground plane of the Keyer.  In most cases, you probably don't need it, but if there are a lot of RF around, it helps.  If needed, ...
MFJ-495 Running a Prosign
To send the prosign BT as one key, type the equal sign "=".  All standard prosigns are listed on the "Morse Code Character Set" section of the manual on page 48.   >When I am typing ahe...
MFJ-495 Weight Increment
On the MFJ-495, the weight increment is 1% in the range of 25% to 75%.  We define the weight as the duty cycle of a continuous string of dots, where 50% for perfect code.  Weight is independ...
MFJ-495 Memory
From your email, I'm assuming you will use two-level paddle with your MFJ-495.  To get to memory 1: 1. Press the POWER button to turn on the MFJ-495. 2. Press the MENU button briefly, as n...
MFJ-624DM to Yaesu FT-857D
Jumper settings:   Jumper # 4   mike audio       pins 4   Jumper # 3   Through pass   pins 1,2,3,5,6,7,8   Jumper # 2&n...
MFJ-784B center frequency
The bandpass filter in the MFJ-784B has adjustable center frequency of 300 to 3400 Hz and adjustable bandwidth of 30 to 2100 Hz. This filter has attenuation of 47 dB at 60 Hz outside the passband. ...
MFJ-784B B1 FAIL
The message "B1 FAIL" means either the first button (hence B1) on the left side is shorted to ground, not connected correctly, or you have pressed the wrong button during the self test.   ...
MFJ-801 Diode Type
P/N: 302-0270 dIODE, SCHOTTKY CDSH270 D1   Richard C. Stubbs, Jr., KC5NSZMFJ Customer Services
MFJ-815 Calibration
the pc board should already be labeled with the appropriate designations.  there four trimpots side by side, R201, R203, R205, R207.  they should be labeled HI FOR, LO FOR, HI REF, LO REF.&n...
MFJ-8621 Data Radio Recrystalling
to install new crystals in your 8621 do the following: 1. remove 8621 cabinet lid (one screw on each side). 2. locate and remove the existing transmit crystal (Y3) from its socket. 3. carefully p...
MFJ-888 Time Base frequency
thanks for your inquiry.  internal  time base reference frequency is: 4.1943 MHz.   Richard C. Stubbs, Jr., KC5NSZMFJ Customer Services
MFJ-890 Beacon Monitor
the 890 is not a receiver.  it does not receive the beacons directly.  you must use this unit in conjunction with your transceiver in order to fully understand the beacon network.   t...
MFJ-890 World Change
turns out the 890 modification is not really a modification at all, so i have chosen to detail this in an email rather than mail it to you.   1. open the unit to expose the pc board of the 890...
MFJ-9440 -- changing frequency for UK
to change the 9440 frequency range, like getting it ready for uk receivability, adjust L3 VFO coil.   Richard C. Stubbs, Jr., KC5NSZMFJ Customer Services
MFJ-9420 Adjustment
With antenna hooked to 9420, hit tune.  adjust L3 until unit is heard on a reference receiver.  L3 is the large silver coil labeled VFO CAL on side.  below C43 green capacitor, above v...
MFJ-9406 Fuse Location
the 9406 fuse is actually a trace on the pc board.  it is located at the back of the pc board behind the power jack J3.   Richard C. Stubbs, Jr., KC5NSZMFJ Customer Services
MFJ-9040 Tuning Cap
p/n: 204-5050, 90 series tuning cap, $15.42 plus $7.00 s/h.  send personal check or money order to: mfj, 300 industrial park road, starkville, ms 39759 or call the techline, 1-800-647-8324 to or...
MFJ-9420 -- Reducing Output
the newer radios have trimpots to adjust specifically for that purpose.  but the 9420 is the original band coverage model, the only way to adjust it is on R61.  turn it a little bit counter ...
MFJ-9020 Technical Questions
I just bought a used MFJ-9020 QRP CW transceiver, and I have some questions.             I’ll do my best—I no longer work for MFJ an...
MFJ-941E Inductor Switch
p/n: 500-2026, $23.10; add $7 minimum s/h.  send personal check or money order to: mfj part request, 300 industrial park road, starkville, ms 39759 or call the techline, 1-800-647-8324 to order w...