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 )
REMOVE THE "S" FROM netS in email address to respond.

Photoman 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 )
REMOVE THE "S" FROM netS in email address to respond.

Why not list the frequency of the pager transmitters here? Also, I
don't see what type duplexers that you have? Are they pass/pass,
pass/reject, what do you have?

If you think the paging transmitter may be mixing with your signal,
what about a circulator or isolator on your transmitter? I don't see
that listed in your equipment list.

Photoman 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 )
REMOVE THE "S" FROM netS in email address to respond.

Why not list the frequency of the pager transmitters here? Also, I
don't see what type duplexers that you have? Are they pass/pass,
pass/reject, what do you have?

If you think the paging transmitter may be mixing with your signal,
what about a circulator or isolator on your transmitter? I don't see
that listed in your equipment list.

You may also want to make sure that the paging transmitters have some
soft of filter cavities on their outputs.

Photoman 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 )
REMOVE THE "S" FROM netS in email address to respond.

Why not list the frequency of the pager transmitters here? Also, I
don't see what type duplexers that you have? Are they pass/pass,
pass/reject, what do you have?

If you think the paging transmitter may be mixing with your signal,
what about a circulator or isolator on your transmitter? I don't see
that listed in your equipment list.

You may also want to make sure that the paging transmitters have some
soft of filter cavities on their outputs.

On Mon, 20 Dec 2004, Photoman 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.

If the pager is only 600 kHz off your frequency, then it is in the amateur band
and is therefore illegal and needs to be shut down (since paging is a
commercial service, it violates 97.113). I'm willing to suspect that your
computation is wrong. It's more likely that the pager is near your frequency
plus twice your IF frequency, and your duplexer and system cabinet aren't
providing enough shielding.

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.

That is much more likely than what you said in your first paragraph.

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.

Have you contacted the pager company and alerted them of this problem? Maybe
there's something THEY can do, such as swap a transmitter with one at a
different location that uses a different frequency so that the mix doesn't
cause a 600 kHz difference.

Jam it! hahahahaha!

"Photoman" wrote in message
...
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 )
REMOVE THE "S" FROM netS in email address to respond.