First, check the VFO frequencies. The picture above shows the access holes to reach the trimmer caps through the 2nd board. Picture A screwdriver with a 1/8" shaft 2-1/2" long with a small tip will reach the trimmers. The tip of the screwdriver will need to be modified. See "Picture of Modified Screwdriver" for instructions. If you lift the upper board, remember to do a test fit to see how much the VFO is offset, so that you can account for it before screwing everything back down. ____Connect a Frequency Counter to the output of the VFO labeled VFO OUT. There should be plenty of drive for any frequency counter at either location. Note: See "Troublshooting" if you do not get a readout at the VFO OUT box. 31 and 16 Meter Bands___Both VFO LEDs should be off. ____Set the 2/8 ceramic trim pot (labeled 14.068) to as close to 13.500 MHz as possible. 19 Meter BandTurn on the VFO SPST switch that turns on the 10.545 MHz LED and relay. If you connected the switches as suggested in the instructions, it will be the one on the left. One LED will be on in the VFO Section. ____Set the VFO frequency by adjusting the yellow trim cap next to the 10.545 relay to 11.453 MHz. 41 Meter Band____Turn on the VFO SPST switch that turns on the 10.455 MHz LED and relay. If you connected the switches as suggested in the instructions, it will be the one on the right. Both LEDs will be on in the VFO Section. Note: The 10.545 LED must be on for the 10.455 LED to turn on. Each relay adds more capacitance to the VFO as they are turned on lowering the VFO frequency. ____Set the VFO frequency by adjusting the yellow trim cap next to the 10.455 relay to 10.847 MHz (Band begins at 7.300) or to 10.647 MHz (Band begins at 7.100) if you installed the 20pf cap next to the yellow trimmer. Secure the VFO
____Secure the VFO toroid by whatever means you have decided. Some options are a small plastic wrap, a 4-40 screw/nut and 3/16" rubber grommet. Picture____Pour melted wax from a common household candle onto the toroid and ferrite core for maximum frequency stability. Picture ____After the wax has cooled, recheck the 13.500 MHz freqeuncy. |
Second, peak the 455 KHz IF Strip, and adjust the BFO Amplifier.
____Connect an SWL antenna to the receiver. A long wire strung outside as high as possible for 25 to 50 feet would be a good start. For best results, do these adjustments in the early evening, 8 to 10PM, when SWL reception is best. ____Set the receiver to 41 meters. Set both VFO switches so that both LEDs are on in the VFO section.____Set the Bandpass Filter switch to the 40/30 side. ____Set the Crystal Filter switch to the 40/20 side. ____Adjust the "Bandpass Filter Tune" pot on Board 1 clockwise left of center position until you hear a noise peak. ____Adjusting the Main Tuning Capacitor of the VFO should bring in some noise or stations. ____Peak the first two 455 KHz IF cans on the 455 KHz IF Strip for best reception/noise. Normally, the white core will be 3/4 turn down from the top (first IF can), and the yellow core will be two turns down from the top (second IF can) (approximately). The peak is not real sharp, but is easy to define. ____Run the core all the way up on the third 455 KHz can next to the AGC detector. There is tons of gain here, and it should not be adjusted for a peak until you start doing fine tuning on the receiver. ____Run the core all the way up on the 455 KHz IF can at the BFO Amplifier, next to the Product Detector. There is tons of gain here, and it should not be adjusted for a peak until you start doing fine tuning on the receiver. ____Check the "Gain Adjust" trim pot at the BFO amplifier for full brightness of the BFO amplifier LED. It should be at full brightness when the receiver is first fired up. Troubeshooting |
Third, Adjust the S-MeterDouble check that you have installed the proper MTR1 and MTR2 resistor values for the S-Meter you are using. 50uA Meter Multimeter - Values shown on the Board. Please Note: Turning the Zero Adjust pot all the way clockwise will turn off the LEDs in the IF strip. The adjustment for the Zero Adjust pot will be near 3/4 of the way counter-clockwise. Dimming the IF LEDs will shut off the IF strip! See "Picture Showing Adjustments". ____Disconnect the Antenna from the receiver.____Have a clip lead connected to one of the Bold AGC boxes, the other end will be grounded at the appropriate time to help adjust the S-Meter. ____Adjust both the Zero Adjust and the Sensitivity trim pots all the way counter clockwise. The S-Meter should be reading near zero. ____Move the Zero Adjust trim pot counter-clockwise until a zero reading is obtained. The adjustment for the Zero Adjust pot will be near 3/4 of the way counter-clockwise. Make sure the IF LEDs do not dim with this adjustment. NOTE! You may not get the S-meter all the way to zero until the Sensitivity pot is adjusted. ____Ground the AGC line with the clip lead, the S-Meter should be off scale to the right. ____Move the Sensitivity pot till full scale reading is obtained. ____Remove the clip lead from Ground. The S-Meter should be off scale to the left. ____Move the Zero Adjust pot counter clockwise until a zero reading is obtained. ____Ground the AGC line with the clip lead, the S-Meter should show full scale reading. Your S-Meter Zero and Sensitivity adjustments should be close to what is shown in the picture below. ____If more sensitivity is desired, turn the Sensitivity pot counter-clockwise until the desired sensitivity is obtained. Having a signal tuned in will make this adjustment easier. At the more sensitive positions, the S-Meter will read past full scale when the AGC is grounded. Readjust the Zero pot so that it reads zero at no signal. |
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