How true and the same is being seen here. With the reduced activity
we are seeing some hams come back to the 146.640 repeater. We can
thank cell phones for the demise of the pagers. Thank you for you
input on the situation.
Ken
--- In Repeater-Builder@yahoogroups.com, "Jim B." <[EMAIL PROTECTED]> wrote:
> All paging transmitters involved should have narrow bandpass
cavities
> and circulators on their outputs. That's usually considered a must
at
> any site. If the paging company isn't willing to spend the money
for
> that, then they aren't to serious about staying in business.
> The good news is that VHF common carrier paging is slowly going
away,
> and the remaining frequencies will likely be dropped and released
back
> into the general pool in a few years, or less.
> There is virtually no VHF paging here in NE Ohio anymore.
> --
> Jim Barbour
> WD8CHL
>
>
> kc4ih wrote:
>
> >
> >
> > We have 146.04/.64 repeater on a nearby mountain top. It worked
> > great for years with a range of 100 miles or more. Since the
phone
> > company and a pager company installed their high power
transmitters
> > near the site of the repeater (within 100 yards) the repeater is
> > virtually useless. After much head scratching I believe that the
> > difference in frequency of the pager transmitter of 600 khz is
the
> > problem but have no idea how to solve the problem without going
to
> > an odd split. The repeater coordinator for this area of Virginia
> > won't even consider that as an option.
> >
> > The equipment that we are using is excellent. The transmitter
and
> > receiver on the repeater are both Motorola Micor and were
modified
> > with to the repeater frequencies by FCC 1st class licensed hams
> > using Motorola parts. This is not an equipment problem. We are
> > running a set of Wacom cavities which were bought new and are
> > correctly tuned and the antenna is a Phelps-Dodge Stationmaster.
> > When the intermod occurs it is dependant on BOTH pagers
transmitting
> > at the same time. If only one pager is transmitting there is no
> > problem. This may at first sound unusual but the pagers are in
the
> > 150 mhz band and they are exactly 600 kc apart. These
transmitter
> > are both 250 watts or more output.
> >
> > My theory is that the 600 kc (difference of the 2 pagers) is
mixing
> > with the output of the repeater 146.64 and producing the 146.04
> > signal, the repeater input frequency. We are using sub-audible
tone
> > for repeater access and as soon as a station working the
repeater
> > drops carrier the repeater drops. The intermod cannot hold up
the
> > machine once the tone is removed. This may be happening in the
> > antenna or hardline connectors prior to the cavities. Every
> > test I have run, and there have been many, supports this
conclusion.
> >
> > We are not the only 2 meter repeater that has fallen victim of
this
> > problem and in every case we have found two pager transmitters
> > situated 600 kc apart near the repeater. Most of the other
machines
> > have been taken off the air, others just put up with it. No one
has
> > been able to solve the problem and many technicians have studied
it.
> >
> > Moving the repeater far enough away is not an option since the
peak
> > of the mountain is so small. Also we are using an existing tower
> > which we would not have access to at other locations. The
searches I
> > have done on Google has turned up the stock answer of helical
> > resonators which would apply to 2 meter radios but not
repeaters. If
> > you are familiar with the Micor equipment you know that the
receiver
> > has excellent helical resonators built in.
> >
> > Tonight I have considered the possibility of splitting the
receiver
> > and the transmitter of the repeater and linking the rx signal by
a
> > 220 mhz link. I am hoping that by reducing the level of the
146.64
> > signal by 50-60 db would alleviate the problem. Maybe not, but
I'm
> > out of ideas. This split would be only about 100 yards but could
> > that be sufficient to relieve the problem?
> >
> > Have any of you ever had this problem and solved it? Any input
(pun
> > intended) on this matter would be appreciated.
> >
> > Ken Sturgill, KC4IH
> > Marion VA
> > please reply to ([EMAIL PROTECTED])
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