4SQRP Bayou Jumper 40 Meter CW Transceiver, Руководство по сборке и инструкция

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revised 3 Feb 2021 Bayou Jumper revB Assembly Manual page 23 of 46
If the tuning range is too low
– below the 7000-7150 kHz range – and you
have spread out the turns of the 19 turn winding as far as possible, you will
need to remove a turn from that winding. Just cut the wire where it emerges
from the PCB on the outside of the core and pull the wire out from under the
core to remove one turn. Use a solder sucker or solder wick to clean out the
hole, and feed the wire back through to gauge its new length. Pull it back out to
strip and tin the end then re-insert, snug it up, and solder in place.
If the tuning range is too high
– and you have squeezed the 19 turn winding
as tightly as possible there are two possible actions, to be taken only after you
have verified that C4 and C20 have not been accidentally swapped . C20 should
be 120
pF (marked “121”)
1) Add some additional capacitance to the tank circuit by installing the capacitor
C20a. A 10 pF capacitor is supplied with the kit in case it is needed.
2) Or, you may add a turn to the main winding of L1. This probably requires
completely removing the toroid
– though, with care, you could re-wind 20 turns
while the core is still attached by the other two windings.
Adding more capacitance will have the additional effect of slightly reducing the
width of the tuning range, while adding inductance (extra turn) has the opposite
effect. The tuning range in either case should still be more than adequate to
cover the portions of the band needed.
Once one of these processes has been done, repeat the calibration steps to set
the range of the tuning control.
Regeneration Setup
□
The next step in receiver setup is to adjust the regeneration control range.
Check out the MP3 audio clips posted in the Files area of the Bayou Jumper
Yahoo Group if you are unfamiliar with how a regen receiver should sound.
Set the TUNING control to the middle of its range, the VOLUME control to mid-
range, and listen to the headphone audio. It may help if an antenna is
connected to the Bayou Jumper. Rotate the REGEN control knob from
maximum to minimum, and back. You should notice a marked change in the
audio hiss in the headphones at some point along the knob travel, as the
detector JFET Q2 enters and exits oscillation. This should occur near the
midpoint of its travel. If this is not the case there are two likely scenarios: