CA
Clay Autery
Sat, Sep 2, 2017 6:57 PM
Having decision-making problems for the materials for my GPS main
feedline. Going to use a TM LMR stock, just can't decide how big to go
with it...
26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
inside/center of mast and exit near the bottom, thence routed through a
window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
Blitzortung System Blue station, and one other device TBD.
Just cannot decide how big to go with the antenna to distro amp feed...
Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
(closest to 1725 MHz), here are the losses from just this piece
(ignoring the amp to device jumpers):
-240 = 5.45 dB XXX - too much loss?
-400 = 2.85 dB
-500 = 2.30 dB XXX - too hard to find
-600 = 1.85 dB
-900 = 1.25 dB
Money not necessarily a consideration as this is a short run for a
permanent installation. Don't anticipate ever moving the GPS antenna to
the tower.
For 900 and likely 600, likely would not be able to do it in one piece
as routing it out of the mast and into the shack would get complicated.
Would likely bring it out of the mast at the bottom with a right angle
connector, and then use a smaller diameter jumper for the last 12 feet.
500 is pretty uncommon stock wise and it and connectors are harder to find.
I already have the tooling for both 240 and 400... but I definitely
don't want to challenge ANY of the devices for signal gain.
So it mostly boils down to easy vs. more effort ($$ aside).... Is it
worth the additional trouble to move from -400 to -600 or -900? To NOT
lose the 1-1.6 dB additional?
I'd appreciate your recommendation and reasoning. Thanks in advance!
73,
--
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389
Having decision-making problems for the materials for my GPS main
feedline. Going to use a TM LMR stock, just can't decide how big to go
with it...
26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
inside/center of mast and exit near the bottom, thence routed through a
window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
Blitzortung System Blue station, and one other device TBD.
Just cannot decide how big to go with the antenna to distro amp feed...
Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
(closest to 1725 MHz), here are the losses from just this piece
(ignoring the amp to device jumpers):
-240 = 5.45 dB XXX - too much loss?
-400 = 2.85 dB
-500 = 2.30 dB XXX - too hard to find
-600 = 1.85 dB
-900 = 1.25 dB
Money not necessarily a consideration as this is a short run for a
permanent installation. Don't anticipate ever moving the GPS antenna to
the tower.
For 900 and likely 600, likely would not be able to do it in one piece
as routing it out of the mast and into the shack would get complicated.
Would likely bring it out of the mast at the bottom with a right angle
connector, and then use a smaller diameter jumper for the last 12 feet.
500 is pretty uncommon stock wise and it and connectors are harder to find.
I already have the tooling for both 240 and 400... but I definitely
don't want to challenge ANY of the devices for signal gain.
So it mostly boils down to easy vs. more effort ($$ aside).... Is it
worth the additional trouble to move from -400 to -600 or -900? To NOT
lose the 1-1.6 dB additional?
I'd appreciate your recommendation and reasoning. Thanks in advance!
73,
--
______________________
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389
BK
Bob kb8tq
Sat, Sep 2, 2017 8:26 PM
Hi
A lot depends on what comes after the feed cable. The “disto amp” will determine
a lot. You likely need 10 db of net gain in front of it to keep things running ok. For an
antenna that is really 26 db (as opposed to 26 db +/- 6 db), that would come out to
16 db of feed line loss. This isn’t a terribly surprising outcome. The antennas are designed
for installations that run 150’ or more of coax ….
Bob
On Sep 2, 2017, at 2:57 PM, Clay Autery cautery@montac.com wrote:
Having decision-making problems for the materials for my GPS main
feedline. Going to use a TM LMR stock, just can't decide how big to go
with it...
26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
inside/center of mast and exit near the bottom, thence routed through a
window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
Blitzortung System Blue station, and one other device TBD.
Just cannot decide how big to go with the antenna to distro amp feed...
Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
(closest to 1725 MHz), here are the losses from just this piece
(ignoring the amp to device jumpers):
-240 = 5.45 dB XXX - too much loss?
-400 = 2.85 dB
-500 = 2.30 dB XXX - too hard to find
-600 = 1.85 dB
-900 = 1.25 dB
Money not necessarily a consideration as this is a short run for a
permanent installation. Don't anticipate ever moving the GPS antenna to
the tower.
For 900 and likely 600, likely would not be able to do it in one piece
as routing it out of the mast and into the shack would get complicated.
Would likely bring it out of the mast at the bottom with a right angle
connector, and then use a smaller diameter jumper for the last 12 feet.
500 is pretty uncommon stock wise and it and connectors are harder to find.
I already have the tooling for both 240 and 400... but I definitely
don't want to challenge ANY of the devices for signal gain.
So it mostly boils down to easy vs. more effort ($$ aside).... Is it
worth the additional trouble to move from -400 to -600 or -900? To NOT
lose the 1-1.6 dB additional?
I'd appreciate your recommendation and reasoning. Thanks in advance!
73,
--
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Hi
A lot depends on what comes after the feed cable. The “disto amp” will determine
a lot. You likely need 10 db of net gain in front of it to keep things running ok. For an
antenna that is *really* 26 db (as opposed to 26 db +/- 6 db), that would come out to
16 db of feed line loss. This isn’t a terribly surprising outcome. The antennas are designed
for installations that run 150’ or more of coax ….
Bob
> On Sep 2, 2017, at 2:57 PM, Clay Autery <cautery@montac.com> wrote:
>
> Having decision-making problems for the materials for my GPS main
> feedline. Going to use a TM LMR stock, just can't decide how big to go
> with it...
>
> 26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
> inside/center of mast and exit near the bottom, thence routed through a
> window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
> Blitzortung System Blue station, and one other device TBD.
>
> Just cannot decide how big to go with the antenna to distro amp feed...
> Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
> (closest to 1725 MHz), here are the losses from just this piece
> (ignoring the amp to device jumpers):
>
> -240 = 5.45 dB XXX - too much loss?
> -400 = 2.85 dB
> -500 = 2.30 dB XXX - too hard to find
> -600 = 1.85 dB
> -900 = 1.25 dB
>
> Money not necessarily a consideration as this is a short run for a
> permanent installation. Don't anticipate ever moving the GPS antenna to
> the tower.
> For 900 and likely 600, likely would not be able to do it in one piece
> as routing it out of the mast and into the shack would get complicated.
> Would likely bring it out of the mast at the bottom with a right angle
> connector, and then use a smaller diameter jumper for the last 12 feet.
> 500 is pretty uncommon stock wise and it and connectors are harder to find.
>
> I already have the tooling for both 240 and 400... but I definitely
> don't want to challenge ANY of the devices for signal gain.
>
> So it mostly boils down to easy vs. more effort ($$ aside).... Is it
> worth the additional trouble to move from -400 to -600 or -900? To NOT
> lose the 1-1.6 dB additional?
>
> I'd appreciate your recommendation and reasoning. Thanks in advance!
>
> 73,
>
> --
> ______________________
> Clay Autery, KY5G
> MONTAC Enterprises
> (318) 518-1389
>
> _______________________________________________
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
PL
Pete Lancashire
Sat, Sep 2, 2017 8:38 PM
What are you using for a distribution amplifier ?
On Sat, Sep 2, 2017 at 11:57 AM, Clay Autery cautery@montac.com wrote:
Having decision-making problems for the materials for my GPS main
feedline. Going to use a TM LMR stock, just can't decide how big to go
with it...
26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
inside/center of mast and exit near the bottom, thence routed through a
window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
Blitzortung System Blue station, and one other device TBD.
Just cannot decide how big to go with the antenna to distro amp feed...
Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
(closest to 1725 MHz), here are the losses from just this piece
(ignoring the amp to device jumpers):
-240 = 5.45 dB XXX - too much loss?
-400 = 2.85 dB
-500 = 2.30 dB XXX - too hard to find
-600 = 1.85 dB
-900 = 1.25 dB
Money not necessarily a consideration as this is a short run for a
permanent installation. Don't anticipate ever moving the GPS antenna to
the tower.
For 900 and likely 600, likely would not be able to do it in one piece
as routing it out of the mast and into the shack would get complicated.
Would likely bring it out of the mast at the bottom with a right angle
connector, and then use a smaller diameter jumper for the last 12 feet.
500 is pretty uncommon stock wise and it and connectors are harder to find.
I already have the tooling for both 240 and 400... but I definitely
don't want to challenge ANY of the devices for signal gain.
So it mostly boils down to easy vs. more effort ($$ aside).... Is it
worth the additional trouble to move from -400 to -600 or -900? To NOT
lose the 1-1.6 dB additional?
I'd appreciate your recommendation and reasoning. Thanks in advance!
73,
--
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/
mailman/listinfo/time-nuts
and follow the instructions there.
What are you using for a distribution amplifier ?
On Sat, Sep 2, 2017 at 11:57 AM, Clay Autery <cautery@montac.com> wrote:
> Having decision-making problems for the materials for my GPS main
> feedline. Going to use a TM LMR stock, just can't decide how big to go
> with it...
>
> 26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
> inside/center of mast and exit near the bottom, thence routed through a
> window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
> Blitzortung System Blue station, and one other device TBD.
>
> Just cannot decide how big to go with the antenna to distro amp feed...
> Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
> (closest to 1725 MHz), here are the losses from just this piece
> (ignoring the amp to device jumpers):
>
> -240 = 5.45 dB XXX - too much loss?
> -400 = 2.85 dB
> -500 = 2.30 dB XXX - too hard to find
> -600 = 1.85 dB
> -900 = 1.25 dB
>
> Money not necessarily a consideration as this is a short run for a
> permanent installation. Don't anticipate ever moving the GPS antenna to
> the tower.
> For 900 and likely 600, likely would not be able to do it in one piece
> as routing it out of the mast and into the shack would get complicated.
> Would likely bring it out of the mast at the bottom with a right angle
> connector, and then use a smaller diameter jumper for the last 12 feet.
> 500 is pretty uncommon stock wise and it and connectors are harder to find.
>
> I already have the tooling for both 240 and 400... but I definitely
> don't want to challenge ANY of the devices for signal gain.
>
> So it mostly boils down to easy vs. more effort ($$ aside).... Is it
> worth the additional trouble to move from -400 to -600 or -900? To NOT
> lose the 1-1.6 dB additional?
>
> I'd appreciate your recommendation and reasoning. Thanks in advance!
>
> 73,
>
> --
> ______________________
> Clay Autery, KY5G
> MONTAC Enterprises
> (318) 518-1389
>
> _______________________________________________
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>
CA
Clay Autery
Sat, Sep 2, 2017 8:47 PM
PCTEL GPS-TMG-HR-26NCM Antenna.
http://www.neobits.com/pctel_maxrad_gps_tmg_hr_26ncm_high_rejection_gps_p2769137.htm
Can't say what the gain tolerances are, but it appears to be a pretty
decent quality part.
The distribution amp is an HP 58516A GPS L1 Distribution Amp with the
external power supply tap which will be fed with an ultras stable/clean
adjustable linear power supply. As I understand it, this is a unity
gain amp, so there should be little to no insertion loss or distro losses.
The distribution amp will be mounted near the devices such that amp to
device jumpers will all be < 1 meter/3.28 feet. Likely a lot less. ALL
Times N-connectors until reaching a connector TM doesn't make.
Clay Autery, KY5G
On 9/2/2017 3:26 PM, Bob kb8tq wrote:
Hi
A lot depends on what comes after the feed cable. The “disto amp” will determine
a lot. You likely need 10 db of net gain in front of it to keep things running ok. For an
antenna that is really 26 db (as opposed to 26 db +/- 6 db), that would come out to
16 db of feed line loss. This isn’t a terribly surprising outcome. The antennas are designed
for installations that run 150’ or more of coax ….
Bob
On Sep 2, 2017, at 2:57 PM, Clay Autery cautery@montac.com wrote:
Having decision-making problems for the materials for my GPS main
feedline. Going to use a TM LMR stock, just can't decide how big to go
with it...
26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
inside/center of mast and exit near the bottom, thence routed through a
window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
Blitzortung System Blue station, and one other device TBD.
Just cannot decide how big to go with the antenna to distro amp feed...
Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
(closest to 1725 MHz), here are the losses from just this piece
(ignoring the amp to device jumpers):
-240 = 5.45 dB XXX - too much loss?
-400 = 2.85 dB
-500 = 2.30 dB XXX - too hard to find
-600 = 1.85 dB
-900 = 1.25 dB
Money not necessarily a consideration as this is a short run for a
permanent installation. Don't anticipate ever moving the GPS antenna to
the tower.
For 900 and likely 600, likely would not be able to do it in one piece
as routing it out of the mast and into the shack would get complicated.
Would likely bring it out of the mast at the bottom with a right angle
connector, and then use a smaller diameter jumper for the last 12 feet.
500 is pretty uncommon stock wise and it and connectors are harder to find.
I already have the tooling for both 240 and 400... but I definitely
don't want to challenge ANY of the devices for signal gain.
So it mostly boils down to easy vs. more effort ($$ aside).... Is it
worth the additional trouble to move from -400 to -600 or -900? To NOT
lose the 1-1.6 dB additional?
I'd appreciate your recommendation and reasoning. Thanks in advance!
73,
--
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389
PCTEL GPS-TMG-HR-26NCM Antenna.
http://www.neobits.com/pctel_maxrad_gps_tmg_hr_26ncm_high_rejection_gps_p2769137.htm
Can't say what the gain tolerances are, but it appears to be a pretty
decent quality part.
The distribution amp is an HP 58516A GPS L1 Distribution Amp with the
external power supply tap which will be fed with an ultras stable/clean
adjustable linear power supply. As I understand it, this is a unity
gain amp, so there should be little to no insertion loss or distro losses.
The distribution amp will be mounted near the devices such that amp to
device jumpers will all be < 1 meter/3.28 feet. Likely a lot less. ALL
Times N-connectors until reaching a connector TM doesn't make.
______________________
Clay Autery, KY5G
On 9/2/2017 3:26 PM, Bob kb8tq wrote:
> Hi
>
> A lot depends on what comes after the feed cable. The “disto amp” will determine
> a lot. You likely need 10 db of net gain in front of it to keep things running ok. For an
> antenna that is *really* 26 db (as opposed to 26 db +/- 6 db), that would come out to
> 16 db of feed line loss. This isn’t a terribly surprising outcome. The antennas are designed
> for installations that run 150’ or more of coax ….
>
> Bob
>
>> On Sep 2, 2017, at 2:57 PM, Clay Autery <cautery@montac.com> wrote:
>>
>> Having decision-making problems for the materials for my GPS main
>> feedline. Going to use a TM LMR stock, just can't decide how big to go
>> with it...
>>
>> 26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
>> inside/center of mast and exit near the bottom, thence routed through a
>> window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
>> Blitzortung System Blue station, and one other device TBD.
>>
>> Just cannot decide how big to go with the antenna to distro amp feed...
>> Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
>> (closest to 1725 MHz), here are the losses from just this piece
>> (ignoring the amp to device jumpers):
>>
>> -240 = 5.45 dB XXX - too much loss?
>> -400 = 2.85 dB
>> -500 = 2.30 dB XXX - too hard to find
>> -600 = 1.85 dB
>> -900 = 1.25 dB
>>
>> Money not necessarily a consideration as this is a short run for a
>> permanent installation. Don't anticipate ever moving the GPS antenna to
>> the tower.
>> For 900 and likely 600, likely would not be able to do it in one piece
>> as routing it out of the mast and into the shack would get complicated.
>> Would likely bring it out of the mast at the bottom with a right angle
>> connector, and then use a smaller diameter jumper for the last 12 feet.
>> 500 is pretty uncommon stock wise and it and connectors are harder to find.
>>
>> I already have the tooling for both 240 and 400... but I definitely
>> don't want to challenge ANY of the devices for signal gain.
>>
>> So it mostly boils down to easy vs. more effort ($$ aside).... Is it
>> worth the additional trouble to move from -400 to -600 or -900? To NOT
>> lose the 1-1.6 dB additional?
>>
>> I'd appreciate your recommendation and reasoning. Thanks in advance!
>>
>> 73,
>>
>> --
>> ______________________
>> Clay Autery, KY5G
>> MONTAC Enterprises
>> (318) 518-1389
CA
Clay Autery
Sat, Sep 2, 2017 8:49 PM
HP 58516A GPS L1 Disribution Amplifier ( 4-way with external power
supply input)
Clay Autery, KY5G
On 9/2/2017 3:38 PM, Pete Lancashire wrote:
What are you using for a distribution amplifier ?
On Sat, Sep 2, 2017 at 11:57 AM, Clay Autery cautery@montac.com wrote:
Having decision-making problems for the materials for my GPS main
feedline. Going to use a TM LMR stock, just can't decide how big to go
with it...
26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
inside/center of mast and exit near the bottom, thence routed through a
window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
Blitzortung System Blue station, and one other device TBD.
Just cannot decide how big to go with the antenna to distro amp feed...
Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
(closest to 1725 MHz), here are the losses from just this piece
(ignoring the amp to device jumpers):
-240 = 5.45 dB XXX - too much loss?
-400 = 2.85 dB
-500 = 2.30 dB XXX - too hard to find
-600 = 1.85 dB
-900 = 1.25 dB
Money not necessarily a consideration as this is a short run for a
permanent installation. Don't anticipate ever moving the GPS antenna to
the tower.
For 900 and likely 600, likely would not be able to do it in one piece
as routing it out of the mast and into the shack would get complicated.
Would likely bring it out of the mast at the bottom with a right angle
connector, and then use a smaller diameter jumper for the last 12 feet.
500 is pretty uncommon stock wise and it and connectors are harder to find.
I already have the tooling for both 240 and 400... but I definitely
don't want to challenge ANY of the devices for signal gain.
So it mostly boils down to easy vs. more effort ($$ aside).... Is it
worth the additional trouble to move from -400 to -600 or -900? To NOT
lose the 1-1.6 dB additional?
I'd appreciate your recommendation and reasoning. Thanks in advance!
73,
--
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/
mailman/listinfo/time-nuts
and follow the instructions there.
HP 58516A GPS L1 Disribution Amplifier ( 4-way with external power
supply input)
______________________
Clay Autery, KY5G
On 9/2/2017 3:38 PM, Pete Lancashire wrote:
> What are you using for a distribution amplifier ?
>
> On Sat, Sep 2, 2017 at 11:57 AM, Clay Autery <cautery@montac.com> wrote:
>
>> Having decision-making problems for the materials for my GPS main
>> feedline. Going to use a TM LMR stock, just can't decide how big to go
>> with it...
>>
>> 26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
>> inside/center of mast and exit near the bottom, thence routed through a
>> window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
>> Blitzortung System Blue station, and one other device TBD.
>>
>> Just cannot decide how big to go with the antenna to distro amp feed...
>> Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
>> (closest to 1725 MHz), here are the losses from just this piece
>> (ignoring the amp to device jumpers):
>>
>> -240 = 5.45 dB XXX - too much loss?
>> -400 = 2.85 dB
>> -500 = 2.30 dB XXX - too hard to find
>> -600 = 1.85 dB
>> -900 = 1.25 dB
>>
>> Money not necessarily a consideration as this is a short run for a
>> permanent installation. Don't anticipate ever moving the GPS antenna to
>> the tower.
>> For 900 and likely 600, likely would not be able to do it in one piece
>> as routing it out of the mast and into the shack would get complicated.
>> Would likely bring it out of the mast at the bottom with a right angle
>> connector, and then use a smaller diameter jumper for the last 12 feet.
>> 500 is pretty uncommon stock wise and it and connectors are harder to find.
>>
>> I already have the tooling for both 240 and 400... but I definitely
>> don't want to challenge ANY of the devices for signal gain.
>>
>> So it mostly boils down to easy vs. more effort ($$ aside).... Is it
>> worth the additional trouble to move from -400 to -600 or -900? To NOT
>> lose the 1-1.6 dB additional?
>>
>> I'd appreciate your recommendation and reasoning. Thanks in advance!
>>
>> 73,
>>
>> --
>> ______________________
>> Clay Autery, KY5G
>> MONTAC Enterprises
>> (318) 518-1389
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/
>> mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
> _______________________________________________
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
W
Wes
Sat, Sep 2, 2017 11:02 PM
This is just a cascaded noise figure situation.
The first stage is the antenna (preamp) which has 26 dB gain (assumed) and an
unknown noise figure. Assume it's a dB or so. Let the second stage gain be a
negative value equal to the cable loss and the second stage noise figure be
equal to the cable loss in dB. Assume a lousy 10 dB NF and 10 dB gain for the
distribution amp.
If the cable loss is 5 dB then the cascaded noise figure and gain are: 1.26 dB,
31 dB gain.
If the cable loss is 2 dB then the cascaded noise figure and gain are: 1.13 dB,
33 dB gain.
I would use RG-6.
See: https://www.pasternack.com/t-calculator-noise-figure.aspx
The secret here is the 26 dB gain.
Wes N7WS
On 9/2/2017 11:57 AM, Clay Autery wrote:
Having decision-making problems for the materials for my GPS main
feedline. Going to use a TM LMR stock, just can't decide how big to go
with it...
26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
inside/center of mast and exit near the bottom, thence routed through a
window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
Blitzortung System Blue station, and one other device TBD.
Just cannot decide how big to go with the antenna to distro amp feed...
Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
(closest to 1725 MHz), here are the losses from just this piece
(ignoring the amp to device jumpers):
-240 = 5.45 dB XXX - too much loss?
-400 = 2.85 dB
-500 = 2.30 dB XXX - too hard to find
-600 = 1.85 dB
-900 = 1.25 dB
Money not necessarily a consideration as this is a short run for a
permanent installation. Don't anticipate ever moving the GPS antenna to
the tower.
For 900 and likely 600, likely would not be able to do it in one piece
as routing it out of the mast and into the shack would get complicated.
Would likely bring it out of the mast at the bottom with a right angle
connector, and then use a smaller diameter jumper for the last 12 feet.
500 is pretty uncommon stock wise and it and connectors are harder to find.
I already have the tooling for both 240 and 400... but I definitely
don't want to challenge ANY of the devices for signal gain.
So it mostly boils down to easy vs. more effort ($$ aside).... Is it
worth the additional trouble to move from -400 to -600 or -900? To NOT
lose the 1-1.6 dB additional?
I'd appreciate your recommendation and reasoning. Thanks in advance!
73,
This is just a cascaded noise figure situation.
The first stage is the antenna (preamp) which has 26 dB gain (assumed) and an
unknown noise figure. Assume it's a dB or so. Let the second stage gain be a
negative value equal to the cable loss and the second stage noise figure be
equal to the cable loss in dB. Assume a lousy 10 dB NF and 10 dB gain for the
distribution amp.
If the cable loss is 5 dB then the cascaded noise figure and gain are: 1.26 dB,
31 dB gain.
If the cable loss is 2 dB then the cascaded noise figure and gain are: 1.13 dB,
33 dB gain.
I would use RG-6.
See: https://www.pasternack.com/t-calculator-noise-figure.aspx
The secret here is the 26 dB gain.
Wes N7WS
On 9/2/2017 11:57 AM, Clay Autery wrote:
> Having decision-making problems for the materials for my GPS main
> feedline. Going to use a TM LMR stock, just can't decide how big to go
> with it...
>
> 26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
> inside/center of mast and exit near the bottom, thence routed through a
> window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
> Blitzortung System Blue station, and one other device TBD.
>
> Just cannot decide how big to go with the antenna to distro amp feed...
> Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
> (closest to 1725 MHz), here are the losses from just this piece
> (ignoring the amp to device jumpers):
>
> -240 = 5.45 dB XXX - too much loss?
> -400 = 2.85 dB
> -500 = 2.30 dB XXX - too hard to find
> -600 = 1.85 dB
> -900 = 1.25 dB
>
> Money not necessarily a consideration as this is a short run for a
> permanent installation. Don't anticipate ever moving the GPS antenna to
> the tower.
> For 900 and likely 600, likely would not be able to do it in one piece
> as routing it out of the mast and into the shack would get complicated.
> Would likely bring it out of the mast at the bottom with a right angle
> connector, and then use a smaller diameter jumper for the last 12 feet.
> 500 is pretty uncommon stock wise and it and connectors are harder to find.
>
> I already have the tooling for both 240 and 400... but I definitely
> don't want to challenge ANY of the devices for signal gain.
>
> So it mostly boils down to easy vs. more effort ($$ aside).... Is it
> worth the additional trouble to move from -400 to -600 or -900? To NOT
> lose the 1-1.6 dB additional?
>
> I'd appreciate your recommendation and reasoning. Thanks in advance!
>
> 73,
>
MN
Mike Naruta AA8K
Sat, Sep 2, 2017 11:07 PM
On 09/02/2017 02:57 PM, Clay Autery wrote:
Having decision-making problems for the materials for my GPS main
feedline. Going to use a TM LMR stock, just can't decide how big to go
with it...
26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
inside/center of mast and exit near the bottom, thence routed through a
window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
Blitzortung System Blue station, and one other device TBD.
I'd appreciate your recommendation and reasoning. Thanks in advance!
73,
Clay, you may wish to consider using a quality RG-6 with F
connectors. Grounding blocks are readily available for the base
of your mast and the entrance to your house. Also,
off-the-shelf over-voltage protectors (Zap-Tech) are available.
I even found an F-to-N adapter for the antenna on Amazon. Watch
out for the ones with metric N threads though.
For my 25 meter run I was going to use an existing one inch
Heliax, but pulled a run of Belden RG-6 instead after learning
that Trimble used RG-6.
It worked well directly connected to a Trimble Thunderbolt; now
it is connected to a Symmetricon 58535A GPS L1 distribution
amplifier.
My Blitzortung System Red station has been running fine in my
attic (Michigan) on a Motorola 97 Oncore patch antenna fastened
against the roof underside. It is looking through wood,
shingles, and nails (and a tree and antennas and utility lines).
How are you planning to do strain-relief on the vertical run of
coax inside of your mast?
Mike - AA8K
On 09/02/2017 02:57 PM, Clay Autery wrote:
> Having decision-making problems for the materials for my GPS main
> feedline. Going to use a TM LMR stock, just can't decide how big to go
> with it...
>
> 26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
> inside/center of mast and exit near the bottom, thence routed through a
> window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
> Blitzortung System Blue station, and one other device TBD.
>
...
>
> I'd appreciate your recommendation and reasoning. Thanks in advance!
>
> 73,
>
Clay, you may wish to consider using a quality RG-6 with F
connectors. Grounding blocks are readily available for the base
of your mast and the entrance to your house. Also,
off-the-shelf over-voltage protectors (Zap-Tech) are available.
I even found an F-to-N adapter for the antenna on Amazon. Watch
out for the ones with metric N threads though.
For my 25 meter run I was going to use an existing one inch
Heliax, but pulled a run of Belden RG-6 instead after learning
that Trimble used RG-6.
It worked well directly connected to a Trimble Thunderbolt; now
it is connected to a Symmetricon 58535A GPS L1 distribution
amplifier.
My Blitzortung System Red station has been running fine in my
attic (Michigan) on a Motorola 97 Oncore patch antenna fastened
against the roof underside. It is looking through wood,
shingles, and nails (and a tree and antennas and utility lines).
How are you planning to do strain-relief on the vertical run of
coax inside of your mast?
Mike - AA8K
BK
Bob kb8tq
Sat, Sep 2, 2017 11:31 PM
Hi
Modern distribution amp chips are likely to be sub 2 db NF. Gain is generally just a bit more than
the loss through any post filtering and the passive power splitter after it.
Bob
On Sep 2, 2017, at 7:02 PM, Wes wes@triconet.org wrote:
This is just a cascaded noise figure situation.
The first stage is the antenna (preamp) which has 26 dB gain (assumed) and an unknown noise figure. Assume it's a dB or so. Let the second stage gain be a negative value equal to the cable loss and the second stage noise figure be equal to the cable loss in dB. Assume a lousy 10 dB NF and 10 dB gain for the distribution amp.
If the cable loss is 5 dB then the cascaded noise figure and gain are: 1.26 dB, 31 dB gain.
If the cable loss is 2 dB then the cascaded noise figure and gain are: 1.13 dB, 33 dB gain.
I would use RG-6.
See: https://www.pasternack.com/t-calculator-noise-figure.aspx
The secret here is the 26 dB gain.
Wes N7WS
On 9/2/2017 11:57 AM, Clay Autery wrote:
Having decision-making problems for the materials for my GPS main
feedline. Going to use a TM LMR stock, just can't decide how big to go
with it...
26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
inside/center of mast and exit near the bottom, thence routed through a
window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
Blitzortung System Blue station, and one other device TBD.
Just cannot decide how big to go with the antenna to distro amp feed...
Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
(closest to 1725 MHz), here are the losses from just this piece
(ignoring the amp to device jumpers):
-240 = 5.45 dB XXX - too much loss?
-400 = 2.85 dB
-500 = 2.30 dB XXX - too hard to find
-600 = 1.85 dB
-900 = 1.25 dB
Money not necessarily a consideration as this is a short run for a
permanent installation. Don't anticipate ever moving the GPS antenna to
the tower.
For 900 and likely 600, likely would not be able to do it in one piece
as routing it out of the mast and into the shack would get complicated.
Would likely bring it out of the mast at the bottom with a right angle
connector, and then use a smaller diameter jumper for the last 12 feet.
500 is pretty uncommon stock wise and it and connectors are harder to find.
I already have the tooling for both 240 and 400... but I definitely
don't want to challenge ANY of the devices for signal gain.
So it mostly boils down to easy vs. more effort ($$ aside).... Is it
worth the additional trouble to move from -400 to -600 or -900? To NOT
lose the 1-1.6 dB additional?
I'd appreciate your recommendation and reasoning. Thanks in advance!
73,
Hi
Modern distribution amp chips are likely to be sub 2 db NF. Gain is generally just a bit more than
the loss through any post filtering and the passive power splitter after it.
Bob
> On Sep 2, 2017, at 7:02 PM, Wes <wes@triconet.org> wrote:
>
> This is just a cascaded noise figure situation.
>
> The first stage is the antenna (preamp) which has 26 dB gain (assumed) and an unknown noise figure. Assume it's a dB or so. Let the second stage gain be a negative value equal to the cable loss and the second stage noise figure be equal to the cable loss in dB. Assume a lousy 10 dB NF and 10 dB gain for the distribution amp.
>
> If the cable loss is 5 dB then the cascaded noise figure and gain are: 1.26 dB, 31 dB gain.
>
> If the cable loss is 2 dB then the cascaded noise figure and gain are: 1.13 dB, 33 dB gain.
>
> I would use RG-6.
>
> See: https://www.pasternack.com/t-calculator-noise-figure.aspx
>
> The secret here is the 26 dB gain.
>
>
> Wes N7WS
>
> On 9/2/2017 11:57 AM, Clay Autery wrote:
>> Having decision-making problems for the materials for my GPS main
>> feedline. Going to use a TM LMR stock, just can't decide how big to go
>> with it...
>>
>> 26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
>> inside/center of mast and exit near the bottom, thence routed through a
>> window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
>> Blitzortung System Blue station, and one other device TBD.
>>
>> Just cannot decide how big to go with the antenna to distro amp feed...
>> Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
>> (closest to 1725 MHz), here are the losses from just this piece
>> (ignoring the amp to device jumpers):
>>
>> -240 = 5.45 dB XXX - too much loss?
>> -400 = 2.85 dB
>> -500 = 2.30 dB XXX - too hard to find
>> -600 = 1.85 dB
>> -900 = 1.25 dB
>>
>> Money not necessarily a consideration as this is a short run for a
>> permanent installation. Don't anticipate ever moving the GPS antenna to
>> the tower.
>> For 900 and likely 600, likely would not be able to do it in one piece
>> as routing it out of the mast and into the shack would get complicated.
>> Would likely bring it out of the mast at the bottom with a right angle
>> connector, and then use a smaller diameter jumper for the last 12 feet.
>> 500 is pretty uncommon stock wise and it and connectors are harder to find.
>>
>> I already have the tooling for both 240 and 400... but I definitely
>> don't want to challenge ANY of the devices for signal gain.
>>
>> So it mostly boils down to easy vs. more effort ($$ aside).... Is it
>> worth the additional trouble to move from -400 to -600 or -900? To NOT
>> lose the 1-1.6 dB additional?
>>
>> I'd appreciate your recommendation and reasoning. Thanks in advance!
>>
>> 73,
>>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
CA
Clay Autery
Sat, Sep 2, 2017 11:48 PM
Thanks for the response...
Not sure why you and the other guy both recommended RG-6 75-Ohm cable
and F-connectors, when the nominal impedance of literally everything
else in the system is 50 Ohm, including the antenna and the HP GPS
Distribution Amp.... And then adding N to F adapters?
Doesn't make any sense unless one has $$ as a top priority, already has
a spool of RG-6 quad shield, etc... but I specifically stated that $$
is not a top priority.... Not really even in the top 5 or 10...
The whole point of this exercise is to put up a semi-permanent SINGLE
antenna/feed-line install that will supply all 4 ports of the HP amp
with the least compromised signal within reason.... 4 now, and 8
whenever I can find the HP 8-way distro amp with external power input.
Strain relief solution: Really depends upon which cable stock I end up
using.... Obviously, the larger the cable, the more weight will be
suspended under the antenna (approx. 38 feet, depending on where I pull
the cable out of the mast at the bottom. (The mast is on a tilt-base of
my own construction.... which brings up a valid consideration. it is
already a chore to walk the mast up manually. The more weight added at
the top and inside the mast, the more difficult a manual walk-up will
be. I'd prefer to keep this a manual tilt for now... at least until I
add the tri-band vertical dipole)
LMR-400 would be less than 4 lbs total weight... I'd likely suspend the
cable by the connector alone. (although, it wouldn't be JUST the
crimp... The connector would have at a minimum, 1 layer of
adhesive-lined shrink tube... probably 2, with the second, overlapping.
Then a nice wrap of self-fusing tape and then electrical tape over that.
Even LMR-600 could be suspended by the connector alone, at 5 lbs max in
the 38 foot max vertical section.
I do have several methods of secondary suspension within the top (and/or
second) mast section though if I decide I need it.
Also prefer to keep all the connectors N-type as much as possible since
that is the station standard.
73,
Clay Autery, KY5G
On 9/2/2017 6:07 PM, Mike Naruta AA8K wrote:
Clay, you may wish to consider using a quality RG-6 with F
connectors. Grounding blocks are readily available for the base of
your mast and the entrance to your house. Also, off-the-shelf
over-voltage protectors (Zap-Tech) are available. I even found an
F-to-N adapter for the antenna on Amazon. Watch out for the ones with
metric N threads though.
For my 25 meter run I was going to use an existing one inch Heliax,
but pulled a run of Belden RG-6 instead after learning that Trimble
used RG-6.
It worked well directly connected to a Trimble Thunderbolt; now it is
connected to a Symmetricon 58535A GPS L1 distribution amplifier.
My Blitzortung System Red station has been running fine in my attic
(Michigan) on a Motorola 97 Oncore patch antenna fastened against the
roof underside. It is looking through wood, shingles, and nails (and
a tree and antennas and utility lines).
How are you planning to do strain-relief on the vertical run of coax
inside of your mast?
Mike - AA8K
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Thanks for the response...
Not sure why you and the other guy both recommended RG-6 75-Ohm cable
and F-connectors, when the nominal impedance of literally everything
else in the system is 50 Ohm, including the antenna and the HP GPS
Distribution Amp.... And then adding N to F adapters?
Doesn't make any sense unless one has $$ as a top priority, already has
a spool of RG-6 quad shield, etc... but I specifically stated that $$
is not a top priority.... Not really even in the top 5 or 10...
The whole point of this exercise is to put up a semi-permanent SINGLE
antenna/feed-line install that will supply all 4 ports of the HP amp
with the least compromised signal within reason.... 4 now, and 8
whenever I can find the HP 8-way distro amp with external power input.
Strain relief solution: Really depends upon which cable stock I end up
using.... Obviously, the larger the cable, the more weight will be
suspended under the antenna (approx. 38 feet, depending on where I pull
the cable out of the mast at the bottom. (The mast is on a tilt-base of
my own construction.... which brings up a valid consideration. it is
already a chore to walk the mast up manually. The more weight added at
the top and inside the mast, the more difficult a manual walk-up will
be. I'd prefer to keep this a manual tilt for now... at least until I
add the tri-band vertical dipole)
LMR-400 would be less than 4 lbs total weight... I'd likely suspend the
cable by the connector alone. (although, it wouldn't be JUST the
crimp... The connector would have at a minimum, 1 layer of
adhesive-lined shrink tube... probably 2, with the second, overlapping.
Then a nice wrap of self-fusing tape and then electrical tape over that.
Even LMR-600 could be suspended by the connector alone, at 5 lbs max in
the 38 foot max vertical section.
I do have several methods of secondary suspension within the top (and/or
second) mast section though if I decide I need it.
Also prefer to keep all the connectors N-type as much as possible since
that is the station standard.
73,
______________________
Clay Autery, KY5G
On 9/2/2017 6:07 PM, Mike Naruta AA8K wrote:
>
> Clay, you may wish to consider using a quality RG-6 with F
> connectors. Grounding blocks are readily available for the base of
> your mast and the entrance to your house. Also, off-the-shelf
> over-voltage protectors (Zap-Tech) are available. I even found an
> F-to-N adapter for the antenna on Amazon. Watch out for the ones with
> metric N threads though.
>
> For my 25 meter run I was going to use an existing one inch Heliax,
> but pulled a run of Belden RG-6 instead after learning that Trimble
> used RG-6.
>
> It worked well directly connected to a Trimble Thunderbolt; now it is
> connected to a Symmetricon 58535A GPS L1 distribution amplifier.
>
>
> My Blitzortung System Red station has been running fine in my attic
> (Michigan) on a Motorola 97 Oncore patch antenna fastened against the
> roof underside. It is looking through wood, shingles, and nails (and
> a tree and antennas and utility lines).
>
>
> How are you planning to do strain-relief on the vertical run of coax
> inside of your mast?
>
>
> Mike - AA8K
>
> _______________________________________________
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
BH
Bill Hawkins
Sun, Sep 3, 2017 5:37 AM
My HP conical antennas had N connectors, so I used 50 feet of RG-8.
Z3801 receivers never had a problem.
RG-8 is a sturdy cable, which may be the primary consideration for a 38
foot drop unsupported through the mast.
Don't have any comparison to lighter cable, though.
Bill Hawkins
-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Clay
Autery
Sent: Saturday, September 02, 2017 1:57 PM
To: Time Nuts
Subject: [time-nuts] GPS Antenna Feed Line Decision
Having decision-making problems for the materials for my GPS main
feedline. Going to use a TM LMR stock, just can't decide how big to go
with it...
26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
inside/center of mast and exit near the bottom, thence routed through a
window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
Blitzortung System Blue station, and one other device TBD.
Just cannot decide how big to go with the antenna to distro amp feed...
Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
(closest to 1725 MHz), here are the losses from just this piece
(ignoring the amp to device jumpers):
-240 = 5.45 dB XXX - too much loss?
-400 = 2.85 dB
-500 = 2.30 dB XXX - too hard to find
-600 = 1.85 dB
-900 = 1.25 dB
Money not necessarily a consideration as this is a short run for a
permanent installation. Don't anticipate ever moving the GPS antenna to
the tower.
For 900 and likely 600, likely would not be able to do it in one piece
as routing it out of the mast and into the shack would get complicated.
Would likely bring it out of the mast at the bottom with a right angle
connector, and then use a smaller diameter jumper for the last 12 feet.
500 is pretty uncommon stock wise and it and connectors are harder to
find.
I already have the tooling for both 240 and 400... but I definitely
don't want to challenge ANY of the devices for signal gain.
So it mostly boils down to easy vs. more effort ($$ aside).... Is it
worth the additional trouble to move from -400 to -600 or -900? To NOT
lose the 1-1.6 dB additional?
I'd appreciate your recommendation and reasoning. Thanks in advance!
73,
--
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
My HP conical antennas had N connectors, so I used 50 feet of RG-8.
Z3801 receivers never had a problem.
RG-8 is a sturdy cable, which may be the primary consideration for a 38
foot drop unsupported through the mast.
Don't have any comparison to lighter cable, though.
Bill Hawkins
-----Original Message-----
From: time-nuts [mailto:time-nuts-bounces@febo.com] On Behalf Of Clay
Autery
Sent: Saturday, September 02, 2017 1:57 PM
To: Time Nuts
Subject: [time-nuts] GPS Antenna Feed Line Decision
Having decision-making problems for the materials for my GPS main
feedline. Going to use a TM LMR stock, just can't decide how big to go
with it...
26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the
inside/center of mast and exit near the bottom, thence routed through a
window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
Blitzortung System Blue station, and one other device TBD.
Just cannot decide how big to go with the antenna to distro amp feed...
Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
(closest to 1725 MHz), here are the losses from just this piece
(ignoring the amp to device jumpers):
-240 = 5.45 dB XXX - too much loss?
-400 = 2.85 dB
-500 = 2.30 dB XXX - too hard to find
-600 = 1.85 dB
-900 = 1.25 dB
Money not necessarily a consideration as this is a short run for a
permanent installation. Don't anticipate ever moving the GPS antenna to
the tower.
For 900 and likely 600, likely would not be able to do it in one piece
as routing it out of the mast and into the shack would get complicated.
Would likely bring it out of the mast at the bottom with a right angle
connector, and then use a smaller diameter jumper for the last 12 feet.
500 is pretty uncommon stock wise and it and connectors are harder to
find.
I already have the tooling for both 240 and 400... but I definitely
don't want to challenge ANY of the devices for signal gain.
So it mostly boils down to easy vs. more effort ($$ aside).... Is it
worth the additional trouble to move from -400 to -600 or -900? To NOT
lose the 1-1.6 dB additional?
I'd appreciate your recommendation and reasoning. Thanks in advance!
73,
--
______________________
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389
_______________________________________________
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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