Advertisement
TRC-70
CIRCUIT DESCRIPTION
The TRC-70 operates as a double conversion sys-
tem for both transmission and reception. (See Figure
1.)
*
Receiver system
The receive signal from the ANT terminal passes
through the final unit and the TX-RX unit LPF and is
applied directly to mixers Q9 and Q10 (2SK125-5).
Here the signal is mixed with the first local oscillator
frequency (71.395~101.295 MHz) from the PLL in or-
der to generate the first IF signal of 71.295 MHz.
The
receive frequency may be fine tuned with the clarifier
by varying the first local oscillator frequency.
The 71.295 MHz first IF signal passes through a
monolithic filter (MCF) and is mixed with the second
local oscillator frequency (60.6 MHz) by MIX FETs 013
and O14 (2SK520(K44)) to generate a 10.695 MHz
second IF signal. The second local oscillator signal is
generated by the TX-RX unit Q90 and Q91 (2SC2714(Y))
and is then doubled by Q56 (2SC2714(Y)).
* Transmitter system
The audio signal from the microphone is amplified
by mic amplifiers O37 and 038 : 2SC3324(G), and is
then combined with the carrier oscillator in the bal-
anced modulator, (IC6 : 4PC1037A) to generate the TX
first IF (10.695 MHz).
In the H3E mode, a carrier signal is added to the TX
first IF (10.695 MHz). The TX first IF is then mixed win
the second local oscillator frequency (60.6 MHz) by |C7
: SN16913P in the same manner as the receiver sys-
tem, to produce a 71.295 MHz signal.
This signal is
then mixed with the PLL first local oscillator frequency
in order to generate a transmit signal.
10.695MHz
SSB.CW.XF2
SP
Q29:2$C332.4
(GR) IC2:KCOO03
Q13.14:2SK520(K44)
= 71.295MHz
Q9.10:2SK125-5
LPF
IC5:pPC1242H
OFT
2nd MIXER
MCF
ist MIXER
AF
10.695MHz
AMP
H3E_XF
BPF
ANT
0.\~3OMHz
XF3
TT
~~
7
ist Local freq.
CAR
71.395~101.295
MHz
USB | 10.6965 MHz
|
|
USB: +1.5 KHz
LSB :10.6935MHz
PLL
LSB: —1 5 KHz
RX:
CW:4+0.7KHz
CW-RxX : 10.69 65MHz
osec2sceTiacy)
|
SYSTEM
|
|
CW-TX: 10.6957MHz
Q90.9I: 27iay)
H3E-RX:
O KHz
H3E~-TX:
10.6965MHz
Zz
9
(x2) |_|
|
HSE-TX: 445.5 KHz
=
a
2nd local
|
|
" a
G0. 6MHz
L_.
—_ —_J
10.695MHz SSB.CW
H3E:ON
XF (Shored by receiver
ystem)
—
71.295 MHz
MCF (Shored by receiver
10.695MHz H3E
+
y
=
FINAL.
MIC
XF (Shared by
:
+
NIT
pL P.F }—
AMP
receiver
system)
Thess
U
MIC
Q37.38
TX BM
MIXER
MIXER
Qi
Q4.5: 28028791(0,Y)
[28C3324(G)
!c6
=
IC7 : SN16913P
Q51.52
: 2SC197I
1 PCIO37HA
:3SKI7T9(L) 022 3 CSI33
Fig. 1 Frequency configuration
Advertisement
