My Ambulance District got a new Repeater installed and the thing works horribly. The repeater is a Vertex VX-7000 VHF that is fed into a TPL Repeater Amp that boosts the Wattage up to 130 Watts. The Volume of the Audio across the channel is Really Crappy. We sound like we are down in a well when we talk and everybody else blows us out of the trucks on there channel. Now here is what i have discovered, i did a wattage check on the output side of the repeater and it was putting out 48 watts (repeater is rated for 50 so thats pretty good) it is fed into a TPL amp that is only rated for 20-30 Watts in 130 Watts out; not 48 watts, is there such a thing as Over Modulating the TPL Amp? Am i looking in the right direction when looking at the Amp as a potential source of our problems? i Don't have a high enough wattage slug for my Bird meter to check the output of the AMP so i cannot tell what it is sending out to the Antenna. Thanks for your help
Mikey
Repeater Help!!!
Moderator: Queue Moderator
-
Mikey
- Posts: 410
- Joined: Wed Sep 05, 2001 4:00 pm
- What radios do you own?: CDM1550 LS+, HT1250, MCS2000
The Company that instaled the equiptment doesn't care how it works, he got his money and that is all that matters to him. I use the exact same repeater at my house but without the TPL Amp and i can out talk there repeater like crazy, so i know its not the brand of repeater cause mine sounds great.
Mikey
Mikey
The best equipment in the world will work like crap if it's installed that way. Your department should be more discerning when it comes to choosing their service provider. We offer a 1-year warranty on the installation (antenna/cabling/grounding/programming/alignment/etc) for any base station/repeater we install. Any reputable shop should be willing to do the same. If this joker won't set it straight, get a reputable shop to do it. I'd even send him the bill. He likely won't pay it, but he might think twice about screwing his next 'customer'.Mikey wrote:The Company that instaled the equiptment doesn't care how it works, he got his money and that is all that matters to him. I use the exact same repeater at my house but without the TPL Amp and i can out talk there repeater like crazy, so i know its not the brand of repeater cause mine sounds great.
Mikey
If your power measurements are correct, the power amp is definitely being over driven. It'll burn out much quicker that way, you should definitely get that taken care of. It shouldn't have anything to do with your audio problems though. I'd give the repeater a try on it's own to see how things sound, just to be sure. If it still sounds like crap, I'm willing to bet he either misprogrammed it for narrowband, or screwed the alignment...or both.
Todd
No trees were harmed in the posting of this message...however an extraordinarily large number of electrons were horribly inconvenienced.
Welcome to the /\/\achine.
Welcome to the /\/\achine.
Where does the output of the amp go to, if it goes to a duplexer is the duplexer rated for 130 or more watts. If not some of the xmit could be geting back into the receiver.
Remove the amp, if it works better then find someone who can set it up properly. Do you realy need 130 watts, are you licensed for it?
You need someone who knows repeaters to set this up properly
Remove the amp, if it works better then find someone who can set it up properly. Do you realy need 130 watts, are you licensed for it?
You need someone who knows repeaters to set this up properly
Cause Motorola said so that's why
-
Mikey
- Posts: 410
- Joined: Wed Sep 05, 2001 4:00 pm
- What radios do you own?: CDM1550 LS+, HT1250, MCS2000
Yes, We are Licensed for 110 Watts, he said that by the time youfigure in Cable Loss, it is putting out 110 watts at the antenna (200 Ft. up on Water Tower) And to answer your question yes we need all 110 watts of it to penetrate the massive hills and valleys in this rural community. I got a chance to poke around in the programming tonight, and he hasn't set the narrrowband for the channel, he has it on Wideband. I think his Duplexers are WAY off though, The repeater didn't work any better with the Amp removed from the system. Let me know what you think guys
Mikey
Mikey
HI:
I am sorry to hear you communication system
was not well designed.
That is the reason its does not work well.
I would seriously either consider hiring the right
people to due the job, or you can just live with
the results.
Here are a few things you need to be aware of:
1. Over Driving a Power Amp WILL cause very
serious problems ! ( If it has not already blown )
Just because your " Analog " Power meter may " Show "
you are Transmitting RF energy, it could be spread
all over the spectum. A good Spectrum Analizer will
give you a good idea how the Power Amp is performing.
Solid State Power Amps are known to be sensitive
to problems. For them to work properly " Everything "
in the system MUST BE PERFECT. ( Period )
NEVER overdrive the PA they can be expensive
to fix ( If anything, under drive it )
2. Always consider......with 200 feet of transmission line,
you will suffer alot of receiver performance loss since the Rx
Signal is very week, and it too has to travel down that
200 foot transmission line. If you are using 1-5/8" Celwave
Line, that would be a plus...Anything less ( Well, you have
been warned )
I also doubt you are truly seeing 100 watts ( At where the
Antenna is mounted )
3. As far as the " Audio " is concerned, that too can be
compromised with a sloppy installation, and with what
you have presented, makes me very skeptical that the
persons did not do a good job on the other areas of the
system
Sounds like they did a good job on your pocket book, but
that's about it.
Untill some of the above issues are addressed, your system
most likely will be " Short Changed " as any " Repeater " or
" Remote Base" is only as good as the persons who installed
it.
If you have a " Good Antenna System " one could
hook up a 5 Watt HT, and it would sound great ( Even
at Low Power )
I have seen many cases like the one you have decribed,
and the only solution is to deisgn the system properly to
your needs....
Depending on where you are located, there should be
" at least someone local " if not, well, there are persons
here on the board that are more than qualified if you
have Plane Tickets and accomodations for them.
I can offer some services for free, but you must have
Photos, and good documents about your system
I would offer my services, however with the damage left
over here in Southern California, we are addressing a number
of site restorations here, and we suspect it will take 3 ~ 6 months
to correct.
MS
I am sorry to hear you communication system
was not well designed.
That is the reason its does not work well.
I would seriously either consider hiring the right
people to due the job, or you can just live with
the results.
Here are a few things you need to be aware of:
1. Over Driving a Power Amp WILL cause very
serious problems ! ( If it has not already blown )
Just because your " Analog " Power meter may " Show "
you are Transmitting RF energy, it could be spread
all over the spectum. A good Spectrum Analizer will
give you a good idea how the Power Amp is performing.
Solid State Power Amps are known to be sensitive
to problems. For them to work properly " Everything "
in the system MUST BE PERFECT. ( Period )
NEVER overdrive the PA they can be expensive
to fix ( If anything, under drive it )
2. Always consider......with 200 feet of transmission line,
you will suffer alot of receiver performance loss since the Rx
Signal is very week, and it too has to travel down that
200 foot transmission line. If you are using 1-5/8" Celwave
Line, that would be a plus...Anything less ( Well, you have
been warned )
I also doubt you are truly seeing 100 watts ( At where the
Antenna is mounted )
3. As far as the " Audio " is concerned, that too can be
compromised with a sloppy installation, and with what
you have presented, makes me very skeptical that the
persons did not do a good job on the other areas of the
system
Sounds like they did a good job on your pocket book, but
that's about it.
Untill some of the above issues are addressed, your system
most likely will be " Short Changed " as any " Repeater " or
" Remote Base" is only as good as the persons who installed
it.
If you have a " Good Antenna System " one could
hook up a 5 Watt HT, and it would sound great ( Even
at Low Power )
I have seen many cases like the one you have decribed,
and the only solution is to deisgn the system properly to
your needs....
Depending on where you are located, there should be
" at least someone local " if not, well, there are persons
here on the board that are more than qualified if you
have Plane Tickets and accomodations for them.
I can offer some services for free, but you must have
Photos, and good documents about your system
I would offer my services, however with the damage left
over here in Southern California, we are addressing a number
of site restorations here, and we suspect it will take 3 ~ 6 months
to correct.
MS
Last edited by Monty on Sat Dec 06, 2003 12:53 pm, edited 1 time in total.
Need help on a Program Cable or (/\/\) Rib Box ?
Contact me anytime/All availible / Free Support Info !
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Contact me anytime/All availible / Free Support Info !
mail to: MSisco9939@aol.com
PLease avoid PM's whenever possible. Box gets too full.
-
radiomidwest
- Posts: 31
- Joined: Wed Mar 19, 2003 4:45 am
repeater
I have 3 VXR-7000's configured the exact same way with the same amp. They all work really great. I love the VXR7000. A lot of bang for the buck. But as stated in previous posts, don't over drive the amp. the drive level should be brought down to about 25 watts as I recall, to deliver 105-110 watts out. No reason to drive it to the max.
Is this rack mounted or in a cabinet? The two should be connected via 1/4" superflex without any adapters. The same goes for the duplexer. What is the model of duplexer?
The audio problem may be that the repeater is programmed for 12.5K narrowband rather than 25K wideband.
Either way, it's an easy fix.
Is this rack mounted or in a cabinet? The two should be connected via 1/4" superflex without any adapters. The same goes for the duplexer. What is the model of duplexer?
The audio problem may be that the repeater is programmed for 12.5K narrowband rather than 25K wideband.
Either way, it's an easy fix.
Is that 110 watts ERP? What is the gain of the antenna? If it is a 6 dB gain antenna then the power @ the antenna should be 27.5 watts to give you 110 watts ERP.
George
George
Mikey wrote:Yes, We are Licensed for 110 Watts, he said that by the time youfigure in Cable Loss, it is putting out 110 watts at the antenna (200 Ft. up on Water Tower) And to answer your question yes we need all 110 watts of it to penetrate the massive hills and valleys in this rural community. I got a chance to poke around in the programming tonight, and he hasn't set the narrrowband for the channel, he has it on Wideband. I think his Duplexers are WAY off though, The repeater didn't work any better with the Amp removed from the system. Let me know what you think guys
Mikey
-
kb4mdz
- Posts: 282
- Joined: Tue Oct 02, 2001 4:00 pm
- What radios do you own?: Too many for the time I have.
Repeater Help!!
Let's back up a step; give the board a listing of your frequencies in the repeater, model of duplexer, type of antenna and length of cable, and yes, how it's interconnected with the amplifier; cable type, connectors, etc. As you may have guessed, there are dozens of items, some interrelated, that could be the crux of the problem.
If the system does not meet your purchase requirements, you can take the dealer in, to court if necessary. It will be a lot of work, probably more than getting it fixed properly, but that is always an option. But to be avoided until the last resort.
It's an old joke in shops:
"My radiod don't work"
What's wrong with it?
"It's broke."
What kind of radio are you using?
"It's a GE/Motorola/Vertex/Kenwood/Aerotron/..."
(tech mentally curses never having taken those mind-reading lessons..)(and contemplates that box of stupid-seeking missiles in the stock room)
If the system does not meet your purchase requirements, you can take the dealer in, to court if necessary. It will be a lot of work, probably more than getting it fixed properly, but that is always an option. But to be avoided until the last resort.
It's an old joke in shops:
"My radiod don't work"
What's wrong with it?
"It's broke."
What kind of radio are you using?
"It's a GE/Motorola/Vertex/Kenwood/Aerotron/..."
(tech mentally curses never having taken those mind-reading lessons..)(and contemplates that box of stupid-seeking missiles in the stock room)
HI:
Thought we would add something for you
to consider depending on the terrain and
conditions.
If your Antenna Structure is on a Water Tower
200 ~ 250 ft AGL, and lets say the nearest land
mass is 10 ~ 20 miles away at / about the same
level consider the following:
1. Antenna ( Super Station Master w/ 7 degree vertical beamwidth ( These are 8 ~ 10 Db Gain UHF Antennas ) Stay away from " Cheap Antenna" unless you plan on replacing them every 2 ~ 3 Years.
2. Transmission line...Lots of variables, however, 200 feet ( and Up ) I would only recommend 1-5/8" Transmission Line.....7/8 would be more economical ( BUT NOTHING LESS than 7/8" ) Celwave is a good choice.
3. Use " Water Proof ( NOT weather Resistant ) Cold or Hot
Shrink Sleaving at the top ! ( This is REQUIRED to keep mosture
from getting into the top of the line )
4. Use Good Jumpers ( heliflex or suitable ) in areas to jumper from the Line to the Load or Source.
5. Make sure you " Repeater " is set up properly for the
Bandwidth you are using....As others have indicated, if
they " Selected " the Narrow bandwidth on the repaeter,
and you radios are wide band, you will hear " Distorition "
when most talk.....And that is a easy correction.
6. MAKE VERY SURE, the drive levels are properly set ! ( You
should be able to " Reduce " the Power Level from the " Repeater"
to Drive the Amp Properly.....Again, make sure the " Jumpers"
from the Repeater are RG-142B/U or Suitable. {NO RG-58 or RG-8}
If there are no Power Adjustments, use a Power Antenuator
7. Take a look at how the Extarnal panel was installed....Nice
and Neat ? or just wired in. That is a good indication of installation
quality, and a poor wiring job could spell trouble in the future.
8. Very Important Data ( and Write it down for the future )
Measure the [ Input Power to the Transmission Line @ where
the Repeater is located ]
And this is the rough part, as someone will have to climb the
structure, is to ALWAYS measure the Power [ INTO ] the Antenna
where { Its Mounted }
9. The use of a " High Quality " Band Pass / Band Reject Duplexer
would be a PLUS, and I would have that professionaly tuned
and installed.
As time passes, if there is " Any Noticable " difference, you can
then " Recheck " later in 1 ~ 2 years.
This is " Especially Important " to the Receiver Performance ! Too many timesI have seen cases where a person will run a 100 ~ 150 Watt Repeater, and it works great with a 100 Watt Spectra, BUT then they want the " Same Results " with a 5 Watt Portable 50 ~ 100 miles away.....Sometimes it will work, but the 100 Watt Spectra ( or other high Power radio ) will ALWAYS outperform a HT....
Many times I see where a " Portable " hears the Repeater just
fine, but the Repater does not hear the Portable....Reason?
Portable HT only runs 4 ~ 5 Watts, and maybe 50 ~ 100 Miles
away from the repeater...Sorta like trying to see a Christmas
Tree Lamp blub 50 miles away.
A nice " Professional Receiver Pre-Amp " can do wonders
in improving a Repeater System ( great for HT usage )
Other than Installation Protection from lightning, and other
elements, it should be OK if those areas are covered.
Any " Weak Link " Cable, Connector, Adjustment, programming anywhere in the chain will make a repeater
perform very poorly.
And just because you make get it working by addressing a few
areas, think about 6 ~ 12 months down the line...
Setting up a " Good Repeater " is more than just taking a
couple of Mobile Radios and running them back to back...
MS
Thought we would add something for you
to consider depending on the terrain and
conditions.
If your Antenna Structure is on a Water Tower
200 ~ 250 ft AGL, and lets say the nearest land
mass is 10 ~ 20 miles away at / about the same
level consider the following:
1. Antenna ( Super Station Master w/ 7 degree vertical beamwidth ( These are 8 ~ 10 Db Gain UHF Antennas ) Stay away from " Cheap Antenna" unless you plan on replacing them every 2 ~ 3 Years.
2. Transmission line...Lots of variables, however, 200 feet ( and Up ) I would only recommend 1-5/8" Transmission Line.....7/8 would be more economical ( BUT NOTHING LESS than 7/8" ) Celwave is a good choice.
3. Use " Water Proof ( NOT weather Resistant ) Cold or Hot
Shrink Sleaving at the top ! ( This is REQUIRED to keep mosture
from getting into the top of the line )
4. Use Good Jumpers ( heliflex or suitable ) in areas to jumper from the Line to the Load or Source.
5. Make sure you " Repeater " is set up properly for the
Bandwidth you are using....As others have indicated, if
they " Selected " the Narrow bandwidth on the repaeter,
and you radios are wide band, you will hear " Distorition "
when most talk.....And that is a easy correction.
6. MAKE VERY SURE, the drive levels are properly set ! ( You
should be able to " Reduce " the Power Level from the " Repeater"
to Drive the Amp Properly.....Again, make sure the " Jumpers"
from the Repeater are RG-142B/U or Suitable. {NO RG-58 or RG-8}
If there are no Power Adjustments, use a Power Antenuator
7. Take a look at how the Extarnal panel was installed....Nice
and Neat ? or just wired in. That is a good indication of installation
quality, and a poor wiring job could spell trouble in the future.
8. Very Important Data ( and Write it down for the future )
Measure the [ Input Power to the Transmission Line @ where
the Repeater is located ]
And this is the rough part, as someone will have to climb the
structure, is to ALWAYS measure the Power [ INTO ] the Antenna
where { Its Mounted }
9. The use of a " High Quality " Band Pass / Band Reject Duplexer
would be a PLUS, and I would have that professionaly tuned
and installed.
As time passes, if there is " Any Noticable " difference, you can
then " Recheck " later in 1 ~ 2 years.
This is " Especially Important " to the Receiver Performance ! Too many timesI have seen cases where a person will run a 100 ~ 150 Watt Repeater, and it works great with a 100 Watt Spectra, BUT then they want the " Same Results " with a 5 Watt Portable 50 ~ 100 miles away.....Sometimes it will work, but the 100 Watt Spectra ( or other high Power radio ) will ALWAYS outperform a HT....
Many times I see where a " Portable " hears the Repeater just
fine, but the Repater does not hear the Portable....Reason?
Portable HT only runs 4 ~ 5 Watts, and maybe 50 ~ 100 Miles
away from the repeater...Sorta like trying to see a Christmas
Tree Lamp blub 50 miles away.
A nice " Professional Receiver Pre-Amp " can do wonders
in improving a Repeater System ( great for HT usage )
Other than Installation Protection from lightning, and other
elements, it should be OK if those areas are covered.
Any " Weak Link " Cable, Connector, Adjustment, programming anywhere in the chain will make a repeater
perform very poorly.
And just because you make get it working by addressing a few
areas, think about 6 ~ 12 months down the line...
Setting up a " Good Repeater " is more than just taking a
couple of Mobile Radios and running them back to back...
MS
Need help on a Program Cable or (/\/\) Rib Box ?
Contact me anytime/All availible / Free Support Info !
mail to: MSisco9939@aol.com
PLease avoid PM's whenever possible. Box gets too full.
Contact me anytime/All availible / Free Support Info !
mail to: MSisco9939@aol.com
PLease avoid PM's whenever possible. Box gets too full.
As usual Monty offers a lot of really good advice. If you listen to him I think you'll end up with very good results. However there is one area I'd like to comment on:
Sorry this is way off topic, but I had to put my $0.02 here...
--z
I specified the use of 3M Cold Shrink tubing for years but stared getting reports that in certain cases it was leaking. I'm not sure if it's an installation issue, quality control on 3M's part (doubtful), or what but since I can't gurantee results I no longer recommend Cold Shrink. I'm now back to recommending a layer of quality electrical tape like Scotch 33+, followed by a layer of Butyl mastic (also known as Vapor Wrap), covered with another layer of electrical tape. This method is messy as hell to get back into, but is very reliable. Andrew has a special publication that goes into detail including a lot of good photos on how to do this; search for Publication Number SP50375 on Andrew's website if you're interested.Monty wrote: 3. Use " Water Proof ( NOT weather Resistant ) Cold or Hot
Shrink Sleaving at the top ! ( This is REQUIRED to keep mosture
from getting into the top of the line )
[MS
Sorry this is way off topic, but I had to put my $0.02 here...
--z
To make it easier to take apart the connector without the mess I start with a layer of electrical cloth friction tape, followed by the rest.
You can carefully make a cut through the tape layers with a boxcutter or other razor knife and peel the tape and sealents away, leaving a nice clean connector without any sticky adhesives.
George
You can carefully make a cut through the tape layers with a boxcutter or other razor knife and peel the tape and sealents away, leaving a nice clean connector without any sticky adhesives.
George