On (19 Aug 96) Ke4oqo Mike wrote to All...
 KM>  I have a Alinco DR-119T mobile two meter radio that seems to have a
 KM> problem recieving clearly. intermitently it will recieve voice but
 KM> with low audio and about 20% noise mixed in with it, even on strong
 KM> signals. The S meter fluctuates with the signal when recieving aswell.
 KM> I spoke to a local Alinco owmer and he suggested that maybe the
 KM> crystal filters are gone "to pot!" any input on this would be greatly
 KM> appreciated... 73 de ke4oqo mike
I doubt the "crystal filters" are at fault. Sounds more like a poor
connection, probably in the feedline connectors or at the antenna. A
received signal is a *very* low level voltage, in the order of a few
micro volts. Your transmit power, on the other hand is much stronger.
Thus an intermittent or high resistance contact would cause your receive
problem, but not appear to affect the transmitted signal because the
transmit signal will "jump" the poor connection.
Try putting a 1/4 wave homebrew antenna directly on the SO-239 output
connector. Make one using a PL-259 with a piece of wire (like a hunk
of coat hanger wire) about 19 inches long soldered in the male stem of
the PL-259, sticking out the end of the connector where the coax
normally is. Bend the wire at 90 degrees just outside the end of
the connector (don't let it touch the "shell" of the connector!) and
connect it to the Alinco (of course you will have to have the radio out
from underneath the dash of the car) so with the radio setting on the
seat (or on a bench connected to a power supply) the antenna is pointing
up. If the receive problem is cured, you have isolated it to the other
antenna and/or feedline.
BTW the 19 inch long "stinger" will provide near resonance, at 146
Mhz and thus is a "tuned" antenna. You can transmit with it as well.
I have one of these homebrew antennas for both 2 meters and 70 cm (6"
instead of 19" for this band) to quickly find out if my problem is in
the radio, or in the antenna. I stuff some scrap rubber or plastic
around the wire to keep it centered in the shell of the connector
*before* I bend the wire at 90 degrees. I also form a very small (1/8")
"loop" using needle nose pliers at the "top" end so keep it from
"stabing" me if I get careless. Very handy diagonstic tool.
... Fer sell cheep: IBM spel chekker. Wurks grate.
--- PPoint 2.00
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