ELECRAFT® K3 HIGH-PERFORMANCE 160 – 6 METER TRANSCEIVER KBPF3 GENERAL COVERAGE RECEIVE OPTION INSTALLATION INSTRUCTIONS Rev D, June 24, 2008 Copyright © 2008, Elecraft, Inc.
Contents Introduction............................................................................................................................................... 3 Customer Service and Support............................................................................................................................ 3 Technical Assistance ....................................................................................................................................... 3 Repair / Alignment Service ....
Introduction This manual covers the installation of the KBPF3 General Coverage Receive option in your K3 transceiver. The KBPF3 provides the proper input filters to optimize receiver sensitivity outside of the Ham bands over the tuning range of 500 KHz to 30 MHz and from 48 MHz through 54 MHz. Either the main K3 receiver or the optional KRX3 subreceiver may be equipped with the KBPF3. The KBPF3 consists of a single circuit board supported by two threaded standoffs.
Elecraft 1-Year Limited Warranty This warranty is effective as of the date of first consumer purchase. It covers both our kits and fully assembled products. For kits, before requesting warranty service, you should fully complete the assembly, carefully following all instructions in the manual. What is covered: During the first year after date of purchase (or if shipped from factory, date product is shipped to customer), Elecraft will replace defective or missing parts free of charge (post-paid).
Inexpensive static dissipating work mats are readily-available that will steadily and safely drain off any charges built up on parts or circuit boards placed on them. They are supplied with a lead that connects the mat to the common workbench ground. Also, metal cabinets on test equipment used on the bench should be tied together and connected to the common ground. Most importantly, you must have a way of continuously draining off any static charges that occur on your body.
Parts Included The following parts should be included in your kit. Check to ensure you have them all. If any parts are damaged or missing, contact Elecraft for replacements (see Customer Service and Support, page 3). QTY. ELECRAFT PART NO. ESD Sensitive. Follow ESD safe handling procedures. Keep in ESD-safe bag until installed. 1 E850269 Standoff, 4-40, 1/2” (13 mm) 2 E700061 Screw, 4-40, 1/4” (6.
Figure 1. Removing K3 Top Cover. CAUTION: Touch an unpainted metal ground or wear a grounded wrist strap before touching components or circuit boards inside the K3. See Preventing ESD Damage on page 4 for more information. Removing the KRX3 Subreceiver Module If your K3 is equipped with the optional KRX3 Subreceiver, you must remove the subreceiver module to install the KBPF3 in either the main receiver or the subreceiver. The KRX3 subreceiver module is the “L” shaped metal enclosure (see Figure 2).
In the following steps you will handle small TMP coaxial connectors. These are frictionfit connectors shown in Figure 3. Handle the connectors by the grips as shown. Do not pull on the coaxial cable. Figure 3. TMP Coaxial Connectors. Hold the KRX3 module by the two brass knurled nuts on the top, and lift it straight up to gain access to the small TMP coaxial connectors plugged into the module. There are two along the front. There may be one at the back as well, depending upon the options installed.
Check to see if the KBPF3 standoffs are already mounted at the locations shown in Figure 5. if so, go directly to Installing the KBPF3 on the KRX3 Board on page 10 Otherwise continue with Installing KBPF3 Standoffs on KRX3 Board below. Figure 5. KRX3 PC Board Installing KBPF3 Standoffs on KRX3 Board Remove the two unthreaded sleeves over the long screws shown in Figure 5, then remove the two PC board mounting screws. Each screw has a split lock washer under it.
Place the KRX3 main circuit board in the bottom shield so that the 1-1/2” screws extend through holes E7 and E13 on the KRX3 board. Press the KRX3 main circuit board down against the standoffs. The board will “snap” into position as the small bumps along the edges of the board slip into the holes in the sides of the shield.
If you removed them, place the 7/8” (22 mm) unthreaded sleeves over the long screws so they rest against the top of the circuit board (see Figure 5). Place the top shield over the assembly and adjust its position so the edge of the top fits inside the bottom and rests against the KRX3 main board on all sides. The long screws will pass through holes in the top cover. Secure the top with the knurled nuts, tightened only enough to hold the cover in place so it isn’t loose.
Remove both bottom covers from the K3 by removing the screws shown in Figure 10. REMOVE ALL THE SCREWS INDICATED AND LIFT THE BOTTOM COVERS OFF. ESD SENSITIVE! WEAR A GROUNDED WRIST STRAP OR TOUCH AN UNPAINTED METAL GROUND BEFORE HANDLING THE RF BOARD. SEE NOTE SEE NOTE SEE NOTE NOTE: THESE THREE SCREWS ARE 1/4" (6.4 mm) LONG AND HAVE INSIDE TOOTH LOCK WASHERS UNDER THE SCREW HEADS. ALL THE OTHER SCREWS ARE 3/16" (4.8 mm) LONG AND HAVE NO LOCK WASHERS. Figure 10. Removing K3 Bottom Cover.
Installing the KBPF3 Board on the K3 RF Board There are three connectors on the bottom of the KBPF3 board that must be properly mated to P44A, P44C and P44E on the RF board (see Figure 12). Even though the connectors may be hard to see as they are mated, especially if the KPA3 shield is installed, they can be aligned as follows: Set the KBPF3 board in place over the standoffs, aligning it so the holes in the KBPF3 board are aligned with the screw holes in the tops of the standoffs.
Reassembly If your K3 is equipped with the KRX3 Subreceiver, turn to your KRX3 Subreceiver Installation and Operation manual, Installing the KRX3 Subreceiver Module section to replace the KRX3 module. Be especially careful to do the following as described in that procedure: Be sure the cover on battery BT1 on the K3 RF board is in place. The cover is essential to avoid shorting the battery.
Hold the top cover above the K3, route the speaker wire under the stiffener bar and plug it into P25 on the KIO3 board at the left rear of the K3 as shown in Figure 14. Figure 14. Connecting Speaker Cable. Position the top cover on the K3. Note that the tab on the back center goes under the rear lip of the K3 rear panel. Secure the top cover with the nine 4-40 3/16” (4.8 mm) black flat head screws you removed earlier.
