ELECRAFT K3 HIGH-PERFORMANCE 160 – 6 METER TRANSCEIVER KSYN3A SYNTHESIZER INSTALLATION INSTRUCTIONS Rev A, January 28, 2015 Copyright © 2015, Elecraft, Inc.
Contents Introduction............................................................................................................................................... 3 Checking Synthesizer Types ............................................................................................................................... 3 Customer Service and Support ................................................................................................................. 4 Technical Assistance ....................
Introduction This manual will guide you through the replacement of the KSYN3 synthesizer(s) in your K3 transceiver with the new KSYN3A synthesizer(s). No test equipment is required. Only a few hand tools are needed to assemble your kit (see page Tools Required on page 7). Should you have difficulty, you'll have our full support via phone and e-mail. In addition, we hope you'll join our growing and enthusiastic community of owner/builders via the Elecraft reflector. Basic K3s have one synthesizer.
The new KSYN3A boards are shipped in ESD-safe envelopes. Do not handle them without first taking the ESD precautions listed on page 6. Keep the synthesizers you remove in those envelopes. Like the original synthesizer, one pin of the multi-pin connector at the bottom has been cut and the corresponding opening in the socket on the K3 RF board has been plugged to assist in properly aligning the connectors when installing the board. Figure 2. Original and New Synthesizer Boards.
IMPORTANT: You must contact Elecraft before mailing your product to obtain authorization for the return, what address to ship it to and current information on repair fees and turnaround times. (Frequently we can determine the cause of your problem and save you the trouble of shipping it back to us.) Our repair location is different from our factory location in Aptos. We will give you the address to ship your kit to at the time of repair authorization.
Preventing Electrostatic Discharge Damage Sensitive components may be damaged by Electrostatic Discharge (ESD) simply by touching them or a circuit board containing them unless you take specific steps to prevent such damage. Damage may occur with static discharges far too little for you to notice. A damaged component may not fail completely at first. Instead, the damage may result in below-normal performance for an extended period of time before you experience a total failure.
Preparing for Installation Tools Required 1. ESD Protection (see Preventing Electrostatic Discharge Damage, pg 6) 2. #1 size Phillips screwdriver. Some makes of size #0 screwdriver may fit better. Always use the screwdriver that best fits the screw in each step. To avoid damaging screws and nuts, a power screwdriver is not recommended. 3. Side (diagonal) cutters, flush-cut type preferred. 4. Small needle nose pliers or tweezers for holding small parts in tight spaces (see Figure 7 on page 10). 5.
Installation Procedure Removing the Top Cover Disconnect power and all cables from your K3. Remove the nine screws to free the top cover as shown in Figure 3. After the cover is open, lift it gently to reach the speaker wire connector. Unplug the speaker then set the top cover aside in a safe place. Whenever you remove screws from a panel, if one screw seems too tight to loosen without damaging it, first loosen the other screws then try again.
Remove the stiffener as shown in Figure 4. It will be held in place by a flat head screw through each side panel. If the KPA3 100 watt amplifier option is installed, two screws securing it to the KPA3 shield. Some older K3s may use nuts and lock washers on the screws securing the stiffener to the KPA3 shield instead of PEM nuts. Figure 4. Removing the Chassis Stiffener. Remove the three screws that hold the K144XV module to the side panel (see Figure 5).
Replacing the Synthesizer(s) CAUTION: The synthesizer mounting screws use two lock washers, one between the pc board and the front panel shield and one under the screw head. Do not lose the lock washers inside the K3. Some builders find it easier to stand the K3 on one side so a dropped lock washer does not fall down onto the main RF board covering the bottom. Unplug the coaxial cables from the synthesizer(s). The connectors are a friction fit and pull apart.
Figure 8. K3EXREF Board Option. Remove the replacement KSYN3A synthesizers from their envelopes. You will have two synthesizers only if your K3 is equipped with the KRX3 Subreceiver option. Inspect the back of each board for long leads, especially those associated with the mini-connector and U8 near the top of the board. Carefully trim these leads flush with the board as shown in Figure 9. Figure 9. Trimming Synthesizer Leads.
Install the main KSYN3A board as shown in Figure 10. Use the interior tooth lock washers you removed earlier with the new screws that came with the synthesizer. Do not replace the lock washers behind the synthesizer board that you removed earlier. The KSYN3A board rests directly against the PEM nuts on the front panel shield. Figure 10. Mounting the Main Synthesizer Board.
If your K3 has the KRX3 sub receiver, install the auxiliary synthesizer as follows: 1. First attach two coaxial cables to the pc board before installing it as shown in Figure 11. Connecting these now will simplify connecting them later in the tight space between the sub receiver enclosure and the synthesizer. 2.
Complete installing the coaxial cables connected as shown in Figure 12, depending upon the options you have in your K3. Note that: 1. The cables shown in gray do not change. They are shown in case one becomes disconnected from the KREF3 board while you are working. 2. If you do not have the KRX3 subreceiver installed, only one coaxial cable is used to connect J2 on the KREF3 board to J83 on the main KSYN3A board. 3.
Reassembling the K3 If you have the K144XV 2-meter option installed: 1. Reconnect any coaxial cables you removed (see Figure 13), but do not connect the REF IN cable from the main KSYN3. 2. Replace the cover and attach with the five 4-40 1/4" (6.4 mm) zinc pan head screws and internal tooth lock washers you removed earlier. 3. If you removed the K144XV from the side panel, remount it with the three 6-32 black flat head screws you removed earlier. Figure 13. Replacing the K144XV Module.
If you have the K144XV 2-meter module installed, connect the coaxial cable from the main KSYN3A synthesizer board to REF IN as shown in Figure 14. Also reconnect the power cable as shown. If you have the KRX3 subreceiver installed, dress the coaxial and power cables as shown in Figure 14. The area on top of the KRX3 enclosure must be clear of all wires and cables as shown for the K3 top to fit properly. Figure 14. Connecting and Dressing the Cables.
If you have the K144XV option installed, hold the top cover above the K3, route the speaker wire under the stiffener bar at the depression in the top of the K144XV module as shown in Figure 15. Figure 15. Routing the Speaker Wire Under the Chassis Stiffener. Plug the speaker wire into P25 on the KIO3 board at the left rear of the K3 as shown in Figure 16. Figure 16. Plugging the Speaker Wire into the KIO3 Board. Position the top cover on the K3.
