--- In BITX20@..., kumar gautam <fromgautam@y...> wrote:
Hello,
In my bitx20 BFO shows 9.995 MHz. and in VFO section when i add 2j
gang capacitor my VFO shows 4.000 to 4.180 MHz(when trimmer shifted to
4.000MHz) and after tuning Trimmer(shifted to 4.150MHz) it shows 4.180
to 4.410Mhz.
After trying various type of variable capacitors i coul'd not find
entire range i.e. 4.000 to 4.400MHz.
Kindly help me in this regard i.e.
1. what is the exact frequency of BFO.
Varies depending on the crystal filter characteristics. Ideally
it should be tuned to 300hz down the lower frequency edge (assuming
upper sideband) of the filter slope. To do that precisely you have
to know the filter shape. The alternate way is to listen to good
signals and start with the bfo low and tune it up for natural
sounding recieve signal. Then there may be some fine tuning of the
BFO once you have a QSO for best TX sound.
2. What modification should i do for correcting the VFO.
Try fewer turns on VFO coil. The tuning diode the 22pf capacitor
connected to the tuning diode may need a slight increase in value.
also could i connect T1,T2 and T3 legs in any direction or it is
coneected in any direction.
?? I am not certain what you are asking.
Allison
KB1GMX
