Hamtronics R144 Vhf Receiver Installation And Maintenance Manual

©1999 Hamtronics, Inc.; Hilton NY; USA.  All rights reserved.  Hamtronics is a registered trademark.    Manual revised: 1/1/00 Page 1
FUNCTIONAL DESCRIPTION.
The R144 is a premium commercial
grade single-channel vhf fm receiver.
It features a helical resonator front
end with low-noise dual gate fets, an
8-pole crystal filter plus a ceramic fil-
ter for superior i-f selectivity, and
hysteresis squelch circuit to lock onto
fading signals.  The R144 kit is avail-
able for the 143-150 MHz band, and
wired...

©1999 Hamtronics, Inc.; Hilton NY; USA.  All rights reserved.  Hamtronics is a registered trademark.    Manual revised: 1/1/00 Page 2
necting the receiver from the antenna
must be provided, and we recommend
our TRR Coax Relay Module if the
power level is under 25 Watts. Other-
wise, a larger coax relay will be re-
quired.
Discriminator Meter.
If you wish to use a discriminator
meter and you are handy in designing
with op-amps, you can run a sample
of the dc voltage at DISCRIMINATOR
output terminal E5 to...

©1999 Hamtronics, Inc.; Hilton NY; USA.  All rights reserved.  Hamtronics is a registered trademark.    Manual revised: 1/1/00 Page 3
list of typical audio levels are given to
act as a guide to troubleshooting.
Although voltages may vary widely
from set to set and under various op-
erating and measurement conditions,
the indications may be helpful when
used in a logical troubleshooting pro-
cedure.
The most common troubles in all
kits are interchanged components,
cold solder joints, and solder
splashes....

©1999 Hamtronics, Inc.; Hilton NY; USA.  All rights reserved.  Hamtronics is a registered trademark.    Manual revised: 1/1/00 Page 4
PARTS LIST FOR R144
Note: Capacitor values and helical
resonator vary with frequency seg-
ments.  Above 150 MHz, values may
vary.
Ref #          Value                  (marking)
C1 18 pf
C2 62 pf
C3 .001 uf chip capacitor
C4 not assigned
C5 .001 uf (1nK or 1nM)
C6 4 pf
C7-C8 .001 uf chip capacitor
C9 .01 uf disc (103)
C10 .001 uf (1nK or 1nM)
C11 2 pf
C12 2 pf
C13 2 pf
C14...

©1999 Hamtronics, Inc.; Hilton NY; USA.  All rights reserved.  Hamtronics is a registered trademark.    Manual revised: 1/1/00 Page 5 

©1999 Hamtronics, Inc.; Hilton NY; USA.  All rights reserved.  Hamtronics is a registered trademark.    Manual revised: 1/1/00 Page 6