paluzzi@pioneer.arc.nasa.gov (Peter Paluzzi ZeroOne) (05/25/90)
I am looking for some information on the new Kenwood TH-26AT 2m
handheld transceiver.
I recently purchased this unit from AES in Milwaukee WI. On the whole I
like it very much. Once one gets used to the key sequences to work the
various functions, I found it reasonably easy to use. However I have
noticed one problem with the TH-26AT.
When I disconnect the "rubber ducky" antenna and attach a roof mounted
American Legion J-Pole at the QTH, I get a minimum S5 to S9 +30 reading
across the 2m band on what sounds like background noise! Most repeaters
still come in loud and clear although I seem to lose some of the more distant
stations in this "noise" (receiver desensing?). I also noticed that some very
wide band interference (10s of kHz) which carries what sounds like either a
FM Broadcast Program or TV center about 147.570 (local ARES simplex
channel). Again, with the rubber ducky, the errant S meter readings go away.
I called Kenwood and they said that since the rubber ducky is very
inefficient, they make the receiver front end extremely sensitive and
the use of external antennas in rf saturated urban areas like the Bay
Area could result in the capture of interference from other services. In
other words, don't use an external antenna. One of the reasons I want
to use an external antenna is to improve my outgoing signal as well as
pull in the weak simplex stations. Not much help here.
I later called the dealer (AES in Wisconsin) and they said that Kenwood
may have put the S meter circuit in one of the earlier stages which is
less selective hence making the unit more apt to getting peculiar readings.
If so, why is it that the S meter still goes crazy even when there is,
in my opinion, lots of clear space surrounding a vacant channel.
Still no help.
While talking on one of the local repeaters, one ham encouraged me to get a
helical resonator filter to limit out of band signals which may be causing
intermodulation interference from other services. He further said that
he uses one on his ht and hasn't had a problem since.
Are there any suppliers of 2m helical resonators which can be used for both
transmitting and receiving? If so any info on contacting them would be
appreciated since I cannot think of another solution. I noted there was
some discussion of helical resonators on this new category recently but
I didn't follow it (I had neither license or ht at the time). Was this
discussion archived or can someone summarize. BTW the Kenwood guy said an
external helical resonator wouldn't work because it wouldn't be inside the
ht!
Any information on how to deal with this problem other than returning
the unit will be appreciated.
Thanks in advance...
Peter Paluzzi, Sr. Graphics Analyst, Sterling Software, ZeroOne Group
Advanced Computing Facility, NASA/Ames Research Center
Mail Stop 233-3, Moffett Field, CA 94035
(415) 604-4589 paluzzi@ames.arc.nasa.gov N6YEO (FTS) 464-4589