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.
Turn on the K1. Make sure the attenuator is off (as indicated by the yellow LED).
Plug in a pair of sensitive headphones, and adjust the AF GAIN control until you hear some
background noise. If you don't hear any noise at all, refer to Appendix E of the owner's manual.
i
There are four trimmer capacitors to adjust on each band (two in the premix filter, two in the RF
filter). The large circled numbers in Figure 11 show the order in which the bands will be aligned:
(1)
10 MHz;
(2)
7 MHz;
(3)
18 or 21 MHz;
(4)
14 MHz.
Note: If touch-up of the trimmer settings is ever
required, always adjust the 10 MHz trimmers before the 7 MHz trimmers, since the capacitance on 7 MHz
is the sum of the two. For the same reason, 18/21 MHz settings must be aligned before 14 MHz.
Figure 11
Using a small flat-blade screwdriver or tuning tool, set all sixteen trimmers so that their adjustment
slots are roughly perpendicular to their flat sides (see Figure 11).
You'll need one of the following in order to do K1 receiver alignment (in order of preference):
1.
A signal generator
that covers all four bands, connected directly to the antenna jack. A
noise generator
can also be used, but there is a small risk of peaking the filters at the wrong frequency.
2.
A ham-band transmitter or transceiver
connected to a dummy load. Use a low power output setting.
Connect a short wire (3' [1 m]) to the K1 antenna jack and drape it near the dummy load.
3.
An antenna
. Use a resonant antenna if possible, or a wire at least 20-30 ft (6 to 9 m) long. In general,
the longer and higher the antenna, the more signal strength that you'll have available during alignment.
