Table of Contents
Advertisement
Quick Links
E
L E C R A F T
Revision B, December 7, 2011. Copyright © 2011, Elecraft; All Rights Reserved
Important Manual Note
Assembly, alignment, and other information about the 4-band Filter board is covered in this manual, not in
the K1 Owner's Manual. Wherever the owner's manual mentions the 2-band module, you'll need to refer to
the applicable sections of this manual instead.
Please read the K1 Owner's Manual Errata Sheet now and make all corrections listed. The errata
sheet provides notations that will tell you when to refer to the KFL1-4 manual. Also, if you're just starting
to build your K1, read the first three chapters of the owner's manual before assembling this board.
Introduction
The KFL1-4 Filter board provides four of the most popular HF QRP bands on a single plug-in module: 40,
30, 20, and either 17 or 15 meters. The KFL1-4 is the same size as the 2-band K1 filter board (KFL1), and
can simply be plugged into the K1 transceiver with no other required changes.
The 4-band filter board is fully compatible with the KBT1 battery option and the KAT1 automatic antenna
tuner (ATU). With most antennas, the ATU will find a good match on all four bands.
The KFL1-4 covers the frequency ranges listed below. These ranges are approximate, and depend on which
VFO range the builder chooses during assembly (80 or 150 kHz). The builder must also select either 17 m
or 15 m band coverage. These topics are covered later in the manual.
Band
40 m
30 m
20 m
17 m
15 m
i
Caution: Some parts in this kit can be damaged by static discharge or by dropping them
onto a hard surface. Before handling the integrated circuit (U1), put on an anti-static wrist strap, or
touch a grounded, unpainted metal surface. When handling crystals and toroid cores, be careful not
to drop them onto a hard surface.
KFL1-4
F O U R - B A N D F I L T E R B O A R D
Assembly and Operating Instructions
80 kHz VFO Range
7.0-7.08
10.1-10.18
14.0-14.08
18.05-18.13
21.0-21.08
Elecraft
•
www.elecraft.com
150 kHz VFO Range
7.0-7.15
10.0-10.15
14.0-14.15
18.05-18.20
21.0-21.15
•
831-763-4211
Advertisement
Table of Contents
Related Manuals for ELECRAFT KFL1-4
Summary of Contents for ELECRAFT KFL1-4
- Page 1 The KFL1-4 Filter board provides four of the most popular HF QRP bands on a single plug-in module: 40, 30, 20, and either 17 or 15 meters. The KFL1-4 is the same size as the 2-band K1 filter board (KFL1), and can simply be plugged into the K1 transceiver with no other required changes.
- Page 2 The table below lists all parts in four-band filter board kit. The photographs in Appendix A of the K1 owner's manual may be helpful in identifying components. If anything is missing, contact Elecraft. Note: Some capacitors use lettered reference designators, e.g. "CA". This is explained later in the manual.
- Page 3 (Builder Resources page) for suggested models. A higher-wattage iron or one with a wide tip may damage components, pads, or traces. Locate the KFL1-4 PC board and identify the top and bottom sides. The side of the board with the label "KFL1-4" is the top.
- Page 4 The approximate locations of the 16 trimmer capacitors on the Filter board are shown in Figure 1. Relays K3-K6 are shown for reference. Note that each trimmer's body has a narrow end, and that they are not all oriented in the same direction. The trimmers must be oriented as shown to keep their rotor terminals at ground potential.
- Page 5 When handling capacitors in the following steps, do not pull on the leads or bend them excessively, since they can be quite fragile. In the case of capacitors with pre-formed leads, there is no need to remove any bends. The short, pre-formed portion of the leads can remain exposed (above the board) after installation.
- Page 6 Install the capacitors listed below, which are all located on the bottom side of the board. Do not solder yet. __ C46, 0.1 ("104") __ C42, .001 ("102") __ C41, .001 ("102") __ C40, .001 ("102") __ C39, .001 ("102") __ C38, .001 ("102") __ C37, .001 ("102") __ C19, .001 ("102")
- Page 7 Two different crystals, X1A and X1B, are supplied for the highest-frequency band, which can be either 15 or 17 meters (21.0 or 18.05 MHz, respectively) . Identify the desired crystal using the table below, and store the unneeded crystal. (X1 will be installed in the next step.) Band Crystal 15 meters...
- Page 8 All the toroid cores used on the KFL1-4 board are type T37-6 (yellow, 0.37" [19 mm] in diameter). If you aren't yet familiar with toroidal inductors, please read the information on page 13 of the K1 owner's manual titled "Identifying Toroid Cores."...
- Page 9 Cut a 9" (23 cm) length of the red enamel-coated wire. To wind L1, "sew" the long end of the wire through the core 11 times, spacing the turns as shown in the left-hand drawing of Figure 4. Each pass through the core counts as one turn. Leave at least 1/2" (12 mm) of extra wire for each lead, and trim off the excess.
- Page 10 Install L1 vertically as shown by its component outline. Pull the leads taut on the bottom of the board and bend them slightly to hold the toroid in place. Use the magnifying glass again to verify that the part of each lead that extends from the pad is tinned and shiny.
- Page 11 Cut two 14" (36 cm) lengths of red enamel-coated wire. Cut two 4" (10 cm) lengths of green enamel-coated wire. The first of T3's windings requires 21 turns of red enamel wire (see Figure 5a). Wind the turns as close together as possible to leave room for the smaller winding.
- Page 12 The remaining two inductors on the Filter board, T1 and T2, both use the two-layer winding shown in Figure 6a. The 16-turn winding will be completed first, then the 8-turn winding will be wound over about half of it. The 8-turn winding should interleaved with the 16-turn winding as shown. Figure 6b shows lead 2 folded down in preparation for stripping and tinning.
- Page 13 The connectors to be installed in the following steps must be positioned correctly to avoid intermittent or unreliable operation. Also, they have plastic bodies that can melt if too much heat is applied, causing the pins to be mis-positioned. Limit soldering time for each pin to 2 to 3 seconds. Review Figure 3-3 in the K1 Owner's Manual (page 7), which shows how the Filter board plugs into the RF board.
- Page 14 A wire jumper will be inserted into J2 in the following steps to act as an antenna tuner bypass during Filter board alignment. The jumper can be removed later when the KAT1 auto-tuner option is installed. If the jumper is left in, make sure it is fully inserted into J2 so it won't fall out. (The jumper can optionally be soldered permanently into place on the bottom of the Filter board.) Cut a 1"...
- Page 15 Insert U1 into its socket, with the notched or dimpled end of the IC aligned with the notched end of the PC board outline. Make sure all pins of U1 are lined up with the socket. (Figure 10 shows an 8-pin IC; U1 is similar but has 18 pins.) Press U1 down into the socket as far as it will go.
- Page 16 Locate C57 on the K1 RF board (near U9, back-left corner). Fold C57 down towards U9 at about a 45- degree angle. This will prevent C57 from interfering with C39 on the bottom of the KFL1-4 board. Plug in the 4-band Filter board (KFL1-4). The connectors on the Filter board must be fully inserted into J6, J7, and J8 on the RF board.
- Page 17 4-Band Receiver Alignment If you have not completed BFO alignment (page 40 of the owner's manual, right column): Set the BFO trimmer capacitor, C20, so that its adjustment slot is parallel to the nearby crystal. (C20 is located near the front edge of the RF board.) The final setting of C20 will be determined later.
- Page 18 quickly one or more times until the 10-MHz band is selected. B AN D Set the VFO to about mid-band. Tap once if necessary to verify that you're in the right 100- B AN D kHz band segment. Note: Your VFO dial could be off by as much as +/- 10 kHz at this point. Operating frequency calibration will be completed after filter alignment.
- Page 19 4-Band Transmitter Alignment This step depends upon the revision of your K1’s RF board. The revision is silkscreened on the board. Perform only the following step for the RF board in your K1: a) If your K1’s RF board is revision E or later, move the RF DET jumper (on 3-pin header P3) to the K1 position.
- Page 20 Note: The optimal setting for RF filter trimmer CB (18/21 MHz) is slightly different for receive and transmit. If you have excess power output on this band, you may want to re-peak CB on receive, or choose a compromise setting between receive and transmit. If your K1 is already fully assembled, go on to Re-installing Option Modules (next page).
- Page 21 Troubleshooting No relays heard when changing bands: U1 on the Filter board may have a bent pin, be installed backwards, or not be programmed. Ceramic resonator Z1 may be damaged or not soldered properly. Also try swapping in a different band module (if available) to verify that the K1 itself is working. Difficulties with receiver alignment: 1.
- Page 22 Circuit Details Note: The schematic for the 4-band Filter board appears on the following two pages. The schematics for the K1 RF and Front Panel boards can be found in Appendix B of the K1 Owner's Manual. Sheet 1 One of crystals X1-X4 is selected for premixing by relays K1 and K2 (there are four possible settings of the two relays).
- Page 23 = On bottom of PC board 3. K1-K8 are latching relays, shown in the RESET position. The selected band determines which if any relays are in the SET position: Elecraft KFL1-4 15 m: none 30 m: K1, K3, K4, K5, K6, K7, K8 Rev.
- Page 24 .001 ATTN RY .001 .001 .001 RFC1 .001 .001 100µH RY COM RY COM .001 .001 .001 .001 .001 .001 6R/AUX Elecraft KFL1-4 To ATU-P1 1 2 3 Rev. Date Sht. W. Burdick (Note 1) 2 of 2 10/09/01 E.Swartz...
Need help?
Do you have a question about the KFL1-4 and is the answer not in the manual?
Questions and answers