EA3GCY EGV-40, Инструкция по сборке

Страница: 26 / 35

EGV-40 CW QRP Transceiver Page 26
Lower limit of frequency.
You may change the tuning coverage by spreading or compressing the turns. When the turns are
compressed, the inductance increases and, thus, the coverage is larger
(the lower limit decreases).
When turns are spread, the inductance and, thus, the coverage diminishes. Spreading or compressing
the turns a variation of a few kHz may be achieved.
The EGV-40 has been designed to have a lower limit of the tuning range around 7.000 MHz.
Higher limit of frequency.
In the back of the polyvaricon there are two padders (adjusting trimmers) “X” and “Z” to be used for the
fine tuning. The one below, “X”, goes in parallel with CV2 (J1-B) and the one on top, “Z”, is for CV3 (J1-
A). These padders may move the upper limit up to about 10-20 kHz! Make this adjustment with the
polyvaricon on its minimum capacity (all the way clockwise). The EGV-40 has been designed to allow
the adjustment of the upper limit of the coverage to 7.040 MHz.
Please see some examples as an orientation:
CV3 L6= T68-2 48 turns
.
Minimum Maximum
X5-X6 = 11.981Mhz. MHz MHz MHz MHz
VXO RF VXO RF Range
Turns widely spread 11.925 7.010 11.950 7.035 30 kHz
Turns less spread 11.915 7.000 11.958 7.043 43 kHz
Turns compressed 11.900 6.090 11.955 7.040 50 kHz
When the turns spread is changed, you may need to readjust slightly the “padder” on the polyvaricon to
keep the tuning upper limit near 7.040MHz.