[Repeater-Builder] Re: Radio for repeater use

[W3ML]

Thanks to all that replied.

This is a club repeater and I am under pressure to fixed the de-sense.  So far, 
everything/trick I have been told really didn't help the de-sense until now.

I turned up the power all the way and it appears to be a 110 watt radio. I say 
appears as there are no markings to ID what model it is.

Anyway, I turned it back down to 55 out and the Daiwa CN-801HP swr/wattmeter 
shows on the reflected side that there is just a little bit of swr.  The needle 
moves just off the zero, not enough even to say that it reads 0.1.

So it appears that this radio, which is a GE Mastr II mobile, doesn't like to 
run at the lower wattage of 10 to 20 watts out.

One more question.

One of you said that the G7-144 is not a very good antenna. I can not put up a 
DB 224 type antenna as we only have access to a Rohn BX tower and the DB will 
not fit on it where the tower is located.
We must have an antenna that someone can man handle to put it on top of a mast.

Any other antenna suggestions that might work better than the used G7-144 we 
are now using?

Thanks again and 73
John, W3ML

 

--- In Repeater-Builder@yahoogroups.com, n...@... wrote:
>
> At 10/4/2009 11:24, you wrote:
> >Hi All,
> >
> >I am looking at the changing radios on our repeater because of the 
> >problems we are having.
> >
> >We are using a GE Mastr II into a 6 can duplexer and up via 1/2 hardline 
> >to a G7-144.
> >
> >However, we can not raise the power above 10 watts before de-sense sets in.
> 
> What makes you think the problem is the TX?  I can't even remember a case 
> I've seen where a problem similar to what you describe turned out to be due 
> to a bad TX.
> 
> >  Also the radio will climb in power level as it gets hot.
> >
> >I set it at 5 watts out and by the end of a half hour net it is up to 12 
> >watts out.
> >
> >In my opinion this is not right.
> 
> Sounds exactly like what a 75 or 110 watt Mastr II RFPA would do.  You need 
> to run it at a power level closer to its rated power.  If you need less 
> power, you need a PA with lower output.  I'm about to throw a 110 W VHFHB 
> Mastr II mobile on my bench that's going to have it's final PA bypassed: 
> routing the 25 W driver board straight over to the harmonic filter input.
> 
> >What radio would be good for a 2 meter repeater.
> 
> If you don't like the GE Mastr II, how about a GE MVP?  ;)
> 
> Seriously, if you feel you must use current production equipment, the 
> Kenwood TKR series seems to perform the best.
> 
> Bob NO6B
>

[Repeater-Builder] Re: Radio for repeater use

[W3ML]

No, except when it was at the 2o watts the swr was almost 1 and someone said 
that was the problem causing the de-sense.  So we were afraid to run it higher.

Like you said guess it was only a problem from running too little of power.


Thanks and 73
John


--- In Repeater-Builder@yahoogroups.com, W9SRV  wrote:
>
> You answered your own question :
> 
> "So it appears that this radio, which is a GE Mastr II mobile, doesn't like 
> to run at the lower wattage of 10 to 20 watts out."
> 
> 110w radio will not be stable at 10-20w. If you look at your output on a 
> spectrum you probably have spurs all over the place. Any reason you cannot 
> run it at least 1/2-2/3 power?
> 
> Tom
> W9SRV
> 
> Sent from my iPhone
> 
> On Oct 4, 2009, at 4:46 PM, "W3ML"  wrote:
> 
> So it appears that this radio, which is a GE Mastr II mobile, doesn't like to 
> run at the lower wattage of 10 to 20 watts out.
>

[Repeater-Builder] Re: Radio for repeater use

[W3ML]

--- In Repeater-Builder@yahoogroups.com, Ralph Mowery  wrote:
>
> You should be able to run the mobile unit around 90 watts without any 
> problems if it is the 110 watt unit. The very first GE Mastr ll I converted 
> was a unit like that over 10 years ago.  I did raise it off the table it was 
> sitting on about an inch and put a muffin fan blowing from the back to the 
> frount of the unit.  One thing to look at is to see if  the jumper wire from 
> the amp to the otuput filter.  If so replace it with a small flexiable piece 
> like the shiled of a piece of small coax.  That wire has a tendency to flex 
> under heating and cooling and breaking loose.  Make sure you are using double 
> shielded coax from the receiver to the duplexer. Also for the transmitter.
>
All coax is double shielded from radio to the hardline.

I have three fans on it now. One blowing down through holes in the lid and two 
sitting on top of the heat sink. They are hooked to a circuit the runs off of a 
heat sensor, so they do not run all the time.

I will look for that wire.

Sorry, if I sounded dumb about some of the things. This is my first time 
working with old GEs and repeaters. I mostly work HF and have not bother to 
learn about repeaters over the years.

Thanks everyone,
73
John

[Repeater-Builder] Re: Radio for repeater use

[W3ML]

Again let me say thanks for all the help.

In the 30 years of hamming, this is all new to me and I am learning something 
new every day I play with this.  And yes, it is really fun, to be able to learn 
something new about our hobby.

I have all RG 213 coax as harness cable for the cans and to the radio for 
transmit and from radio through bandpass to the can on receive.

I have been measuring the swr out of the radio. One of you said that I need to 
move the meter to the other side of the duplexer and check it there. I will do 
that again. I did check it there before, but have been leaving the meter in 
line between the radio and duplexer.

Right now we have it running at 55 watts (out of radio) and everyone sounds 
great, except one and that may be his antenna as there is a little frying noise 
on him.

One ham on the other side of county did say the reading went up from S2 to S5 
so he was happy and a ham in another county about 27 miles away said we are 20 
over at his place.


This is a great improvement, because when it was ran around 10 to 20 watts the 
noise covered everyone up.

Thanks gain, I really do appreciate the help. I hope everyone has a great week.

73
John 

--- In Repeater-Builder@yahoogroups.com, "Chuck Kelsey"  wrote:
>
> Double shielded -- specifically what type?
> 
> Chuck
> WB2EDV
> 
> 
> - Original Message - 
> From: "W3ML" 
> To: 
> Sent: Sunday, October 04, 2009 6:52 PM
> Subject: [Repeater-Builder] Re: Radio for repeater use
> 
> 
> >>
> > All coax is double shielded from radio to the hardline.
> > 
> >
>

[Repeater-Builder] Re: Radio for repeater use

[W3ML]

I was Wrong.  I have RG-214 double shielded coax running throughout.

John


--- In Repeater-Builder@yahoogroups.com, "W3ML"  wrote:
>
> Again let me say thanks for all the help.
> 
> In the 30 years of hamming, this is all new to me and I am learning something 
> new every day I play with this.  And yes, it is really fun, to be able to 
> learn something new about our hobby.
> 
> I have all RG 213 coax as harness cable for the cans and to the radio for 
> transmit and from radio through bandpass to the can on receive.
> 
> I have been measuring the swr out of the radio. One of you said that I need 
> to move the meter to the other side of the duplexer and check it there. I 
> will do that again. I did check it there before, but have been leaving the 
> meter in line between the radio and duplexer.
> 
> Right now we have it running at 55 watts (out of radio) and everyone sounds 
> great, except one and that may be his antenna as there is a little frying 
> noise on him.
> 
> One ham on the other side of county did say the reading went up from S2 to S5 
> so he was happy and a ham in another county about 27 miles away said we are 
> 20 over at his place.
> 
> 
> This is a great improvement, because when it was ran around 10 to 20 watts 
> the noise covered everyone up.
> 
> Thanks gain, I really do appreciate the help. I hope everyone has a great 
> week.
> 
> 73
> John 
> 
> --- In Repeater-Builder@yahoogroups.com, "Chuck Kelsey"  wrote:
> >
> > Double shielded -- specifically what type?
> > 
> > Chuck
> > WB2EDV
> > 
> > 
> > - Original Message - 
> > From: "W3ML" 
> > To: 
> > Sent: Sunday, October 04, 2009 6:52 PM
> > Subject: [Repeater-Builder] Re: Radio for repeater use
> > 
> > 
> > >>
> > > All coax is double shielded from radio to the hardline.
> > > 
> > >
> >
>

Re: [Repeater-Builder] Re: Radio for repeater use

[W9SRV]

You answered your own question :

"So it appears that this radio, which is a GE Mastr II mobile, doesn't like to 
run at the lower wattage of 10 to 20 watts out."

110w radio will not be stable at 10-20w. If you look at your output on a 
spectrum you probably have spurs all over the place. Any reason you cannot run 
it at least 1/2-2/3 power?

Tom
W9SRV

Sent from my iPhone

On Oct 4, 2009, at 4:46 PM, "W3ML"  wrote:

So it appears that this radio, which is a GE Mastr II mobile, doesn't like to 
run at the lower wattage of 10 to 20 watts out.



  

Re: [Repeater-Builder] Re: Radio for repeater use

[John]

Have thought about getting a lower PA module

John, K4AG

Re: [Repeater-Builder] Re: Radio for repeater use

[Lee Pennington]

John, W3ML.,
Let'r rip,  two meters needs repeaters folks can hear. !!  After the cans,
you"ll still have at least 80 watts to play with, why go half steppin'??
Your properly tuned Hustler ant will handle it
Also, did you ever think of sidemounting a DB 224E with two stand offs. Just
my 2 cents worth.
de Lee
K4LJP
73

On Sun, Oct 4, 2009 at 6:15 PM, John  wrote:

>
>
> Have thought about getting a lower PA module
>
> John, K4AG
>
>  
>



-- 
"Always drink upstream from the herd."

Re: [Repeater-Builder] Re: Radio for repeater use

[Ralph Mowery]

--- On Sun, 10/4/09, W3ML  wrote:

> From: W3ML 
> Subject: [Repeater-Builder] Re: Radio for repeater use
> To: Repeater-Builder@yahoogroups.com
> Date: Sunday, October 4, 2009, 5:46 PM
> Thanks to all that replied.
> 
> This is a club repeater and I am under pressure to fixed
> the de-sense.  So far, everything/trick I have been
> told really didn't help the de-sense until now.
> 
> I turned up the power all the way and it appears to be a
> 110 watt radio. I say appears as there are no markings to ID
> what model it is.
> 
> Anyway, I turned it back down to 55 out and the Daiwa
> CN-801HP swr/wattmeter shows on the reflected side that
> there is just a little bit of swr.  The needle moves
> just off the zero, not enough even to say that it reads
> 0.1.
> 
> So it appears that this radio, which is a GE Mastr II
> mobile, doesn't like to run at the lower wattage of 10 to 20
> watts out.
> 
>

You should be able to run the mobile unit around 90 watts without any problems 
if it is the 110 watt unit. The very first GE Mastr ll I converted was a unit 
like that over 10 years ago.  I did raise it off the table it was sitting on 
about an inch and put a muffin fan blowing from the back to the frount of the 
unit.  One thing to look at is to see if  the jumper wire from the amp to the 
otuput filter.  If so replace it with a small flexiable piece like the shiled 
of a piece of small coax.  That wire has a tendency to flex under heating and 
cooling and breaking loose.  Make sure you are using double shielded coax from 
the receiver to the duplexer. Also for the transmitter.



  

Re: [Repeater-Builder] Re: Radio for repeater use

[Ken Arck]

At 03:46 PM 10/4/2009, W3ML wrote:
>
>
>No, except when it was at the 2o watts the swr was almost 1 and 
>someone said that was the problem causing the de-sense. So we were 
>afraid to run it higher.

Re: [Repeater-Builder] Re: Radio for repeater use

[James Adkins]

I agree with Ken.  You simply cannot run a 100w GE Master II at low power,
spurs everywhere.  If you need to run lower power, find a lower power unit
or throw an attenuator in line.

On Sun, Oct 4, 2009 at 5:58 PM, Ken Arck  wrote:

>
>
> At 03:46 PM 10/4/2009, W3ML wrote:
> >
> >
> >No, except when it was at the 2o watts the swr was almost 1 and
> >someone said that was the problem causing the de-sense. So we were
> >afraid to run it higher.
>
>  products too. In fact, most of that power was probably at THOSE
> frequencies, hence the high SWR as the antenna couldn't deal with 'em
> --
> President and CTO - Arcom Communications
> Makers of repeater controllers and accessories.
> http://www.arcomcontrollers.com/
> Authorized Dealers for Kenwood and Telewave and
> we offer complete repeater packages!
> AH6LE/R - IRLP Node 3000
> http://www.irlp.net
> "We don't just make 'em. We use 'em!"
>
>  
>



-- 
James Adkins, KB0NHX
Vice-President -- Nixa Amateur Radio Club, Inc. (KC0LUN)

Southern Missouri Frequency Coordinator - Missouri Repeater Council
www.nixahams.net

The Nixa Amateur Radio Club - "There is no charge for awesomeness!" (Well,
only $1.00 per month)

Re: [Repeater-Builder] Re: Radio for repeater use

[W9SRV]

Ok-

1. Where are you checking the swr at in the chain? Make sure you bypass the 
duplexers to check the antenna, the cans can throw off the reading on some 
meters like you describe using. If you are less than 1.5:1 I would not worry 
too much more about it, any reflected power will get eaten up back in the cans. 
If you are really concerned about protecting the TX put a circulator in-line 
with it. 

2. Make sure all the interconnecting cables are good shielded and not foil/ 
braid type. RG-213 and RG-400 are good choices, though there are a few more.

3. Terminate into a good dummy load. Set you output power to 80-90W. Then run 
thru the duplexer and check the power coming out of the cans. You should see 
something like 60-70w, depending on the spec of the duplexer. If your seeing 
much less than you may have a duplexer tuning issue.

Figure out the real problem, let the radio run at a real spec power output, 
than absorb the title of "far lord" as every one thanks you for giving the 
repeater twice as many s-units. (then be prepared for the next round of 
complaints that become your problem)

Tom
W9SRV

Sent from my iPhone

On Oct 4, 2009, at 5:46 PM, "W3ML"  wrote:

No, except when it was at the 2o watts the swr was almost 1 and someone said 
that was the problem causing the de-sense.  So we were afraid to run it higher.

Like you said guess it was only a problem from running too little of power.


Thanks and 73
John


--- In Repeater-Builder@yahoogroups.com, W9SRV  wrote:

You answered your own question :

"So it appears that this radio, which is a GE Mastr II mobile, doesn't like to 
run at the lower wattage of 10 to 20 watts out."

110w radio will not be stable at 10-20w. If you look at your output on a 
spectrum you probably have spurs all over the place. Any reason you cannot run 
it at least 1/2-2/3 power?

Tom
W9SRV

Sent from my iPhone

On Oct 4, 2009, at 4:46 PM, "W3ML"  wrote:

So it appears that this radio, which is a GE Mastr II mobile, doesn't like to 
run at the lower wattage of 10 to 20 watts out.









Yahoo! Groups Links






  

Re: [Repeater-Builder] Re: Radio for repeater use

[Chuck Kelsey]

Double shielded -- specifically what type?

Chuck
WB2EDV


- Original Message - 
From: "W3ML" 
To: 
Sent: Sunday, October 04, 2009 6:52 PM
Subject: [Repeater-Builder] Re: Radio for repeater use


>>
> All coax is double shielded from radio to the hardline.
> 
> 

Re: [Repeater-Builder] Re: Radio for repeater use

[Paul Plack]

John,

SWR for a given feedline and load doesn't change with power level unless 
something starts arcing or melting somewhere. If you're seeing a change in SWR 
at various power settings, probably because the final has gone spurious and is 
putting out lots of energy at frequencies other than that for which the load is 
resonant.

Back in my days playing with CB rigs converted to 10m, I bought one outboard 
amplifier off a flea market table. The seller said he'd gone in with his little 
screwdriver to "peak" it for his favorite channel, (this on an amp which is 
broadbanded for 3 - 30 MHz,) and it now stuck in transmit after the exciter was 
unkeyed. (Note - these amps have variable caps inside, but they're for 
balancing and neutralization, not for "tuning.")

When I brought it home and ran it into an antenna cut for 29.6, I observed that 
when I transmitted and the amp keyed, the SWR measured between the output of 
the amp and the antenna was about 1.1-to-1. When I unkeyed, the reflected power 
pinned the meter! Long-story-short, the thing was so unstable that when drive 
was removed, it became a 40-watt oscillator somewhere in the 50 MHz region, 
where the antenna had a really bad SWR. A careful alignment of the little amp 
to spec restored proper operation.

Unfortunately, as others have noted, a Mastr II PA's output will get ugly if 
run too low, even when it's properly aligned. The 35-watt Mastr II UHF mobile I 
converted for repeater use started getting measureably dirtier at anything 
below about 22 watts. I can only imagine how bad a 110-watt PA run at 5 watts 
will be.

The rise you're seeing to 12 watts as temps rise may be spurious emissions that 
aren't even in the ham band.

Bypassing the driver stage straight to the filter, and removing the final 
altogether, as has been mentioned, would be a great improvement, but even then, 
you'll want to run it near its full power. As a bonus, you'll use way less 
power and dump way less heat than trying to run a 110-watt PA at 5W out.

73,
Paul, AE4KR


  - Original Message - 
  From: W3ML 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Sunday, October 04, 2009 4:46 PM
  Subject: [Repeater-Builder] Re: Radio for repeater use


No, except when it was at the 2o watts the swr was almost 1 and someone 
said that was the problem causing the de-sense. So we were afraid to run it 
higher.

  Like you said guess it was only a problem from running too little of power.

  Thanks and 73
  John

  --- In Repeater-Builder@yahoogroups.com, W9SRV  wrote:
  >
  > You answered your own question :
  > 
  > "So it appears that this radio, which is a GE Mastr II mobile, doesn't like 
to run at the lower wattage of 10 to 20 watts out."
  > 
  > 110w radio will not be stable at 10-20w. If you look at your output on a 
spectrum you probably have spurs all over the place. Any reason you cannot run 
it at least 1/2-2/3 power?
  > 
  > Tom
  > W9SRV
  > 
  > Sent from my iPhone
  > 
  > On Oct 4, 2009, at 4:46 PM, "W3ML"  wrote:
  > 
  > So it appears that this radio, which is a GE Mastr II mobile, doesn't like 
to run at the lower wattage of 10 to 20 watts out.
  >



  

Re: [Repeater-Builder] Re: Radio for repeater use

[Chuck Kelsey]

OK, that's good.

Chuck
WB2EDV


- Original Message - 
From: "W3ML" 
To: 
Sent: Sunday, October 04, 2009 8:03 PM
Subject: [Repeater-Builder] Re: Radio for repeater use


>I was Wrong.  I have RG-214 double shielded coax running throughout.
> 
> John
> 

Re: [Repeater-Builder] Re: Radio for repeater use

[W9SRV]

Right message this time.

214 will work fine. Glad to hear your making progress!

Tom
W9SRV

Sent from my iPhone

On Oct 4, 2009, at 7:03 PM, "W3ML"  wrote:

I was Wrong.  I have RG-214 double shielded coax running throughout.

John


--- In Repeater-Builder@yahoogroups.com, "W3ML"  wrote:

Again let me say thanks for all the help.

In the 30 years of hamming, this is all new to me and I am learning something 
new every day I play with this.  And yes, it is really fun, to be able to learn 
something new about our hobby.

I have all RG 213 coax as harness cable for the cans and to the radio for 
transmit and from radio through bandpass to the can on receive.

I have been measuring the swr out of the radio. One of you said that I need to 
move the meter to the other side of the duplexer and check it there. I will do 
that again. I did check it there before, but have been leaving the meter in 
line between the radio and duplexer.

Right now we have it running at 55 watts (out of radio) and everyone sounds 
great, except one and that may be his antenna as there is a little frying noise 
on him.

One ham on the other side of county did say the reading went up from S2 to S5 
so he was happy and a ham in another county about 27 miles away said we are 20 
over at his place.


This is a great improvement, because when it was ran around 10 to 20 watts the 
noise covered everyone up.

Thanks gain, I really do appreciate the help. I hope everyone has a great week.

73
John 

--- In Repeater-Builder@yahoogroups.com, "Chuck Kelsey"  wrote:

Double shielded -- specifically what type?

Chuck
WB2EDV


- Original Message - 
From: "W3ML" 
To: 
Sent: Sunday, October 04, 2009 6:52 PM
Subject: [Repeater-Builder] Re: Radio for repeater use



All coax is double shielded from radio to the hardline.












Yahoo! Groups Links






  

Re: [Repeater-Builder] Re: Radio for repeater use

[Lee Pennington]

John,
Now if you'll just consider Letting the big dog eat ( turn it up to full
power), and mounting a 224E on the side of your tower as high as possible,
you'll be talking. Remember height is might, it's also "free" gain. One more
thing,  get yourself a Bird Watt Meter!!
de Lee
K4LJP
73

On Sun, Oct 4, 2009 at 8:35 PM, W9SRV  wrote:

>
>
> Right message this time.
>
> 214 will work fine. Glad to hear your making progress!
>
>
> Tom
> W9SRV
>
> Sent from my iPhone
>
> On Oct 4, 2009, at 7:03 PM, "W3ML" >
> wrote:
>
> I was Wrong. I have RG-214 double shielded coax running throughout.
>
> John
>
> --- In Repeater-Builder@yahoogroups.com,
> "W3ML"  wrote:
>
> Again let me say thanks for all the help.
>
> In the 30 years of hamming, this is all new to me and I am learning
> something new every day I play with this. And yes, it is really fun, to be
> able to learn something new about our hobby.
>
> I have all RG 213 coax as harness cable for the cans and to the radio for
> transmit and from radio through bandpass to the can on receive.
>
> I have been measuring the swr out of the radio. One of you said that I need
> to move the meter to the other side of the duplexer and check it there. I
> will do that again. I did check it there before, but have been leaving the
> meter in line between the radio and duplexer.
>
> Right now we have it running at 55 watts (out of radio) and everyone sounds
> great, except one and that may be his antenna as there is a little frying
> noise on him.
>
> One ham on the other side of county did say the reading went up from S2 to
> S5 so he was happy and a ham in another county about 27 miles away said we
> are 20 over at his place.
>
> This is a great improvement, because when it was ran around 10 to 20 watts
> the noise covered everyone up.
>
> Thanks gain, I really do appreciate the help. I hope everyone has a great
> week.
>
> 73
> John
>
> --- In Repeater-Builder@yahoogroups.com,
> "Chuck Kelsey"  wrote:
>
> Double shielded -- specifically what type?
>
> Chuck
> WB2EDV
>
> - Original Message -
> From: "W3ML" 
> To: 
> >
> Sent: Sunday, October 04, 2009 6:52 PM
> Subject: [Repeater-Builder] Re: Radio for repeater use
>
> All coax is double shielded from radio to the hardline.
>
> 
>
> Yahoo! Groups Links
>
>  
>



-- 
"Always drink upstream from the herd."

[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[W3ML]

Hi Tom,



I did crank up the power to 55 watts out of radio and that gives me 45 out of 
the duplexer.  Decided on this wattage until I can figure the problem better. 
It is working better than before, but still having trouble.

So from what you said about power coming out duplexer, the duplexer must still 
be okay.

However, during the day today there were 3 hams talking and they said (later) 
that all of them were loud and clear. But, when I got home and tried to call 
one of them, he was covered in noise.

Later one of the others called in and he would be clear, then the repeater 
would cut out and his signal would be gone, then it would come back with noise 
on his signal and then clear again.

Then the other one came in with a lot of noise, then he would come in with a 
little noise and then no noise at all and then back again through this cycle.
 
This cycle of noise and then no noise is driving me crazy.

The set up is this:

GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs with a 
service monitor prior to bringing it here. 

There is a bandpass filter on the receive side after the duplexer and before 
the radio.

We have used 1/2 inch hardline going up to the used G7-144.

Then only thing I can think of is the radio is bad, the antenna is no good and 
the coax is shot.

Now, the radio was given to us by a group that had used it, but decided to 
replace it with a Kenwood.

I am thinking that they had the same problem and that is why they gave it away.

Any advice would be greatly appreciated. 

73
John, W3ML


- In Repeater-Builder@yahoogroups.com, W9SRV  wrote:
>
> Ok-
> 
> 1. Where are you checking the swr at in the chain? Make sure you bypass the 
> duplexers to check the antenna, the cans can throw off the reading on some 
> meters like you describe using. If you are less than 1.5:1 I would not worry 
> too much more about it, any reflected power will get eaten up back in the 
> cans. If you are really concerned about protecting the TX put a circulator 
> in-line with it. 
> 
> 2. Make sure all the interconnecting cables are good shielded and not foil/ 
> braid type. RG-213 and RG-400 are good choices, though there are a few more.
> 
> 3. Terminate into a good dummy load. Set you output power to 80-90W. Then run 
> thru the duplexer and check the power coming out of the cans. You should see 
> something like 60-70w, depending on the spec of the duplexer. If your seeing 
> much less than you may have a duplexer tuning issue.
> 
> Figure out the real problem, let the radio run at a real spec power output, 
> than absorb the title of "far lord" as every one thanks you for giving the 
> repeater twice as many s-units. (then be prepared for the next round of 
> complaints that become your problem)
> 
> Tom
> W9SRV
> 
> Sent from my iPhone
> 
> On Oct 4, 2009, at 5:46 PM, "W3ML"  wrote:
> 
> No, except when it was at the 2o watts the swr was almost 1 and someone said 
> that was the problem causing the de-sense.  So we were afraid to run it 
> higher.
> 
> Like you said guess it was only a problem from running too little of power.
> 
> 
> Thanks and 73
> John
> 
> 
> --- In Repeater-Builder@yahoogroups.com, W9SRV  wrote:
> 
> You answered your own question :
> 
> "So it appears that this radio, which is a GE Mastr II mobile, doesn't like 
> to run at the lower wattage of 10 to 20 watts out."
> 
> 110w radio will not be stable at 10-20w. If you look at your output on a 
> spectrum you probably have spurs all over the place. Any reason you cannot 
> run it at least 1/2-2/3 power?
> 
> Tom
> W9SRV
> 
> Sent from my iPhone
> 
> On Oct 4, 2009, at 4:46 PM, "W3ML"  wrote:
> 
> So it appears that this radio, which is a GE Mastr II mobile, doesn't like to 
> run at the lower wattage of 10 to 20 watts out.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Yahoo! Groups Links
>

[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[W3ML]

Thanks Tom,

The wind was calm today and knowing that the sections tend to work loose, we 
screwed them together with sheet metal screws. 
I would like to get a DB antenna but 700 bucks is not in our budget.

73
John

--- In Repeater-Builder@yahoogroups.com, Tom Parker  wrote:
>
> Hello W3ML,
> 
> I've been following this thread over the weekend and I think the issue 
> has been addressed.  I would check the antenna and related connectors.  
> In fact, for my 2 cents, I'd replace the G7 with a commercial grade 
> antenna, such as a DB product or equal.  Now, to your scenario today, I 
> would ask what the wind was like?  If memory serves me correctly, that 
> G7 has a couple of joints and is somewhat flimsy in terms of material 
> strength and antenna height. 
> 
> There ya go,
> 
> thp
> 
> W3ML wrote:
> >  
> >
> > Hi Tom,
> >
> > I did crank up the power to 55 watts out of radio and that gives me 45 
> > out of the duplexer. Decided on this wattage until I can figure the 
> > problem better. It is working better than before, but still having 
> > trouble.
> >
> > So from what you said about power coming out duplexer, the duplexer 
> > must still be okay.
> >
> > However, during the day today there were 3 hams talking and they said 
> > (later) that all of them were loud and clear. But, when I got home and 
> > tried to call one of them, he was covered in noise.
> >
> > Later one of the others called in and he would be clear, then the 
> > repeater would cut out and his signal would be gone, then it would 
> > come back with noise on his signal and then clear again.
> >
> > Then the other one came in with a lot of noise, then he would come in 
> > with a little noise and then no noise at all and then back again 
> > through this cycle.
> >
> > This cycle of noise and then no noise is driving me crazy.
> >
> > The set up is this:
> >
> > GE Mastr II VHF mobile running into a 6 cavity duplexer set to our 
> > freqs with a service monitor prior to bringing it here.
> >
> > There is a bandpass filter on the receive side after the duplexer and 
> > before the radio.
> >
> > We have used 1/2 inch hardline going up to the used G7-144.
> >
> > Then only thing I can think of is the radio is bad, the antenna is no 
> > good and the coax is shot.
> >
> > Now, the radio was given to us by a group that had used it, but 
> > decided to replace it with a Kenwood.
> >
> > I am thinking that they had the same problem and that is why they gave 
> > it away.
> >
> > Any advice would be greatly appreciated.
> >
> > 73
> > John, W3ML
> >
> > - In Repeater-Builder@yahoogroups.com 
> > , W9SRV  wrote:
> > >
> > > Ok-
> > >
> > > 1. Where are you checking the swr at in the chain? Make sure you 
> > bypass the duplexers to check the antenna, the cans can throw off the 
> > reading on some meters like you describe using. If you are less than 
> > 1.5:1 I would not worry too much more about it, any reflected power 
> > will get eaten up back in the cans. If you are really concerned about 
> > protecting the TX put a circulator in-line with it.
> > >
> > > 2. Make sure all the interconnecting cables are good shielded and 
> > not foil/ braid type. RG-213 and RG-400 are good choices, though there 
> > are a few more.
> > >
> > > 3. Terminate into a good dummy load. Set you output power to 80-90W. 
> > Then run thru the duplexer and check the power coming out of the cans. 
> > You should see something like 60-70w, depending on the spec of the 
> > duplexer. If your seeing much less than you may have a duplexer tuning 
> > issue.
> > >
> > > Figure out the real problem, let the radio run at a real spec power 
> > output, than absorb the title of "far lord" as every one thanks you 
> > for giving the repeater twice as many s-units. (then be prepared for 
> > the next round of complaints that become your problem)
> > >
> > > Tom
> > > W9SRV
> > >
> > > Sent from my iPhone
> > >
> > > On Oct 4, 2009, at 5:46 PM, "W3ML"  wrote:
> > >
> > > No, except when it was at the 2o watts the swr was almost 1 and 
> > someone said that was the problem causing the de-sense. So we were 
> > afraid to run it higher.
> > >
> > > Like you said guess it was only a problem from running too little of 
> > power.
> > >
> > >
> > > Thanks and 73
> > > John
> > >
> > >
> > > --- In Repeater-Builder@yahoogroups.com 
> > , W9SRV  wrote:
> > >
> > > You answered your own question :
> > >
> > > "So it appears that this radio, which is a GE Mastr II mobile, 
> > doesn't like to run at the lower wattage of 10 to 20 watts out."
> > >
> > > 110w radio will not be stable at 10-20w. If you look at your output 
> > on a spectrum you probably have spurs all over the place. Any reason 
> > you cannot run it at least 1/2-2/3 power?
> > >
> > > Tom
> > > W9SRV
> > >
> > > Sent from my iPhone
> > >
> > > On Oct 4, 2009, at 4:46 PM, "W3ML"  wrote:
> > >
> > > So it appears that this radio, wh

[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[W3ML]

I probably will turn it up more to see what happens.  When I had it at 5 watts 
out we had no problems at all.

Over the 10 watts is when the noise was really bad.  Now at 55 it works and 
then it doesn't and then it works again.

So, yes I still have something wrong and maybe one of  these days I will get 
another grant and convince the club to buy another GE Mastr II and and a new 
antenna and coax. Maybe that will fix it.  

People we got radio from are not answering.

John


--- In Repeater-Builder@yahoogroups.com, "Chuck Kelsey"  wrote:
>
> I'd suggest turning the power up more. You have it set at about 50% and the 
> transmitter may be intermittently spurious at that level.
> 
> Watch the wattmeter when things act up and see if anything changes when you 
> notice the desense happening. You can also pull the TX ICOM when the problem 
> is happening and see if the receive clears up on the local speaker.
> 
> There are so many things that could be at fault - loose connector, bad 
> antenna, problem with transmitter, problem with receiver, intermod issue, 
> etc.
> 
> Ask the people you got the radio from if they had the same problem with it.
> 
> Chuck
> WB2EDV
> 
> 
> 
> - Original Message ----- 
> From: "W3ML" 
> To: 
> Sent: Monday, October 05, 2009 8:33 PM
> Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's 
> comments
> 
> 
> > Hi Tom,
> >
> >
> >
> > I did crank up the power to 55 watts out of radio and that gives me 45 out 
> > of the duplexer.  Decided on this wattage until I can figure the problem 
> > better. It is working better than before, but still having trouble.
> >
> > So from what you said about power coming out duplexer, the duplexer must 
> > still be okay.
> >
> > However, during the day today there were 3 hams talking and they said 
> > (later) that all of them were loud and clear. But, when I got home and 
> > tried to call one of them, he was covered in noise.
> >
> > Later one of the others called in and he would be clear, then the repeater 
> > would cut out and his signal would be gone, then it would come back with 
> > noise on his signal and then clear again.
> >
> > Then the other one came in with a lot of noise, then he would come in with 
> > a little noise and then no noise at all and then back again through this 
> > cycle.
> >
> > This cycle of noise and then no noise is driving me crazy.
> >
> > The set up is this:
> >
> > GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs 
> > with a service monitor prior to bringing it here.
> >
> > There is a bandpass filter on the receive side after the duplexer and 
> > before the radio.
> >
> > We have used 1/2 inch hardline going up to the used G7-144.
> >
> > Then only thing I can think of is the radio is bad, the antenna is no good 
> > and the coax is shot.
> >
> > Now, the radio was given to us by a group that had used it, but decided to 
> > replace it with a Kenwood.
> >
> > I am thinking that they had the same problem and that is why they gave it 
> > away.
> >
> > Any advice would be greatly appreciated.
> >
> > 73
> > John, W3ML
> >
> >
> > - In Repeater-Builder@yahoogroups.com, W9SRV  wrote:
> >>
> >> Ok-
> >>
> >> 1. Where are you checking the swr at in the chain? Make sure you bypass 
> >> the duplexers to check the antenna, the cans can throw off the reading on 
> >> some meters like you describe using. If you are less than 1.5:1 I would 
> >> not worry too much more about it, any reflected power will get eaten up 
> >> back in the cans. If you are really concerned about protecting the TX put 
> >> a circulator in-line with it.
> >>
> >> 2. Make sure all the interconnecting cables are good shielded and not 
> >> foil/ braid type. RG-213 and RG-400 are good choices, though there are a 
> >> few more.
> >>
> >> 3. Terminate into a good dummy load. Set you output power to 80-90W. Then 
> >> run thru the duplexer and check the power coming out of the cans. You 
> >> should see something like 60-70w, depending on the spec of the duplexer. 
> >> If your seeing much less than you may have a duplexer tuning issue.
> >>
> >> Figure out the real problem, let the radio run at a real spec power 
> >> output, than absorb the title of "far lord" as every one thanks you for 
> >> giving the repeater twice as many s-units. (then be prepared for the next 
> &g

[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[W3ML]

Thanks Mark,

I will go read that article. Thought I read them all, since January, trying to 
learn all I can.

That is when I decided to get into this repeater business.  It has been a great 
learning experience for sure.

73
John, W3ML




--- In Repeater-Builder@yahoogroups.com, "Mark"  wrote:
>
> John,
> 
> I'll chime in here and agree with Chuck's suggestion to try a little more
> "fire in the wire"...  
> 
> It sounds as if your PA is less spurious now than before, but you need to
> dial it up more to eliminate all the spurious products.  Solid state PAs,
> especially mobiles, are noted for this when run at considerably less than
> rated output.  If I remember the beginning of the thread, this was a
> Mastr-II mobile...  
> 
> Seems as if I remember a rule of thumb that a solid state PA won't be stable
> beginning around 60-70% of its rated output.  If you're at 55W now, another
> 10-15W won't make much difference in the received signal strength, but will
> help a LOT to stabilize the PA.
> 
> This article: http://www.repeater-builder.com/ge/mastrIIgeneral.html says
> not to run Mastr-II PAs at less than 40%.  In your case, you're at about 50%
> now and still a little spurious, so... crank her up a tad more (to maybe
> 70W) and see if that clears it all up.  ;-)  The article also has other
> suggestions on how to deal with desense.
> 
> 73,
> Mark - N9WYS
> 
> -Original Message-
> From: Repeater-Builder@yahoogroups.com  On Behalf Of W3ML
> 
> I probably will turn it up more to see what happens.  When I had it at 5
> watts out we had no problems at all.
> 
> Over the 10 watts is when the noise was really bad.  Now at 55 it works and
> then it doesn't and then it works again.
> 
> So, yes I still have something wrong and maybe one of  these days I will get
> another grant and convince the club to buy another GE Mastr II and and a new
> antenna and coax. Maybe that will fix it.  
> 
> People we got radio from are not answering.
> 
> John
> 
> 
> --- In Repeater-Builder@yahoogroups.com, "Chuck Kelsey"  wrote:
> >
> > I'd suggest turning the power up more. You have it set at about 50% and
> the 
> > transmitter may be intermittently spurious at that level.
> > 
> > Watch the wattmeter when things act up and see if anything changes when
> you 
> > notice the desense happening. You can also pull the TX ICOM when the
> problem 
> > is happening and see if the receive clears up on the local speaker.
> > 
> > There are so many things that could be at fault - loose connector, bad 
> > antenna, problem with transmitter, problem with receiver, intermod issue, 
> > etc.
> > 
> > Ask the people you got the radio from if they had the same problem with
> it.
> > 
> > Chuck
> > WB2EDV
>

[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[W3ML]

Thanks Tom,

Getting help around here is the hard part.  I am the most experience and that 
is mostly from book reading and now a little playing around with the radio.  No 
one else knows anything about repeaters either.

We are just now getting into the repeater stage for our club. 

73
John


--- In Repeater-Builder@yahoogroups.com, Tom Parker  wrote:
>
> Mastr II is a good radio.  Likely not much wrong with it.  They're a 
> great deal better than most of what you buy today; however, we're pretty 
> impressed with the Kenwood TKR's in our shop for mid tier units.  Our 22 
> trunk sites are made up of Micors, Mastr II's, Johnsons, and one site of 
> MSR 2000's and one site of R1225's with Henry amps.  Most are five 
> channel and up.  The TKR's are in stand alone situations or conventional 
> users who own their on.
> 
> You ought to stick with what you have and work out the problems or get 
> some help.
> 
> thp
> 
> W3ML wrote:
> >  
> >
> > I probably will turn it up more to see what happens. When I had it at 
> > 5 watts out we had no problems at all.
> >
> > Over the 10 watts is when the noise was really bad. Now at 55 it works 
> > and then it doesn't and then it works again.
> >
> > So, yes I still have something wrong and maybe one of these days I 
> > will get another grant and convince the club to buy another GE Mastr 
> > II and and a new antenna and coax. Maybe that will fix it.
> >
> > People we got radio from are not answering.
> >
> > John
> >
> > --- In Repeater-Builder@yahoogroups.com 
> > <mailto:Repeater-Builder%40yahoogroups.com>, "Chuck Kelsey" 
> >  wrote:
> > >
> > > I'd suggest turning the power up more. You have it set at about 50% 
> > and the
> > > transmitter may be intermittently spurious at that level.
> > >
> > > Watch the wattmeter when things act up and see if anything changes 
> > when you
> > > notice the desense happening. You can also pull the TX ICOM when the 
> > problem
> > > is happening and see if the receive clears up on the local speaker.
> > >
> > > There are so many things that could be at fault - loose connector, bad
> > > antenna, problem with transmitter, problem with receiver, intermod 
> > issue,
> > > etc.
> > >
> > > Ask the people you got the radio from if they had the same problem 
> > with it.
> > >
> > > Chuck
> > > WB2EDV
> > >
> > >
> > >
> > > - Original Message -
> > > From: "W3ML" 
> > > To:  > <mailto:Repeater-Builder%40yahoogroups.com>>
> > > Sent: Monday, October 05, 2009 8:33 PM
> > > Subject: [Repeater-Builder] Re: Radio for repeater use Response to 
> > Tom's
> > > comments
> > >
> > >
> > > > Hi Tom,
> > > >
> > > >
> > > >
> > > > I did crank up the power to 55 watts out of radio and that gives 
> > me 45 out
> > > > of the duplexer. Decided on this wattage until I can figure the 
> > problem
> > > > better. It is working better than before, but still having trouble.
> > > >
> > > > So from what you said about power coming out duplexer, the 
> > duplexer must
> > > > still be okay.
> > > >
> > > > However, during the day today there were 3 hams talking and they said
> > > > (later) that all of them were loud and clear. But, when I got home 
> > and
> > > > tried to call one of them, he was covered in noise.
> > > >
> > > > Later one of the others called in and he would be clear, then the 
> > repeater
> > > > would cut out and his signal would be gone, then it would come 
> > back with
> > > > noise on his signal and then clear again.
> > > >
> > > > Then the other one came in with a lot of noise, then he would come 
> > in with
> > > > a little noise and then no noise at all and then back again 
> > through this
> > > > cycle.
> > > >
> > > > This cycle of noise and then no noise is driving me crazy.
> > > >
> > > > The set up is this:
> > > >
> > > > GE Mastr II VHF mobile running into a 6 cavity duplexer set to our 
> > freqs
> > > > with a service monitor prior to bringing it here.
> > > >
> > > > There is a bandpass filter on the receive side after the duplexer and
> > > &

[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[W3ML]

Thanks Tom,

Yes, the advice is all good and I have tried several of the suggestions and 
most, if not all, did help some.

Tomorrow, I will turn it up to 70 watts out, which should give me 60 out of the 
duplexer, if it works like it does not at 55 and 45 out.

Then we will see what happens.

In fact I did hook it up to another antenna on an adjacent tower.  It worked 
worse than the G7.

Funny thing is when I hook the G7 to a regular 2 meter radio and transmit on 
simplex, it works really well, hearing stations far a way and putting out a 
solid signal.

73
John



--- In Repeater-Builder@yahoogroups.com, Tom Parker  wrote:
>
> Well then, that's what everyone on this group is here for.  All you have 
> to do is ask, and you've done that.  All the advice tonight is valid, so 
> now you need to make some measurements.  You definitely need an iso-tee, 
> and good watt meter, i.e., Bird or Telewave, and a service monitor with 
> at least a spectrum analyser would be a good start.  Read the RB page 
> and follow the suggestions.  We actually had a couple of Mastr II 
> mobiles rigged as repeaters, but we didn't de-rate the PA's.  They saw 
> heavy use with zero problems for over ten years before we replaced them 
> with stations.  Of course the tower building was a constant 74oF in the 
> Texas sun and the A/C ran most of the winter.  It's a shame there's not 
> another antenna on the tower you could "borrow" for a few minutes.
> 
> thp
> 
> W3ML wrote:
> 
> >  
> >
> > Thanks Tom,
> >
> > Getting help around here is the hard part. I am the most experience 
> > and that is mostly from book reading and now a little playing around 
> > with the radio. No one else knows anything about repeaters either.
> >
> > We are just now getting into the repeater stage for our club.
> >
> > 73
> > John
> >
> > --- In Repeater-Builder@yahoogroups.com 
> > <mailto:Repeater-Builder%40yahoogroups.com>, Tom Parker  wrote:
> > >
> > > Mastr II is a good radio. Likely not much wrong with it. They're a
> > > great deal better than most of what you buy today; however, we're 
> > pretty
> > > impressed with the Kenwood TKR's in our shop for mid tier units. Our 22
> > > trunk sites are made up of Micors, Mastr II's, Johnsons, and one 
> > site of
> > > MSR 2000's and one site of R1225's with Henry amps. Most are five
> > > channel and up. The TKR's are in stand alone situations or conventional
> > > users who own their on.
> > >
> > > You ought to stick with what you have and work out the problems or get
> > > some help.
> > >
> > > thp
> > >
> > > W3ML wrote:
> > > >
> > > >
> > > > I probably will turn it up more to see what happens. When I had it at
> > > > 5 watts out we had no problems at all.
> > > >
> > > > Over the 10 watts is when the noise was really bad. Now at 55 it 
> > works
> > > > and then it doesn't and then it works again.
> > > >
> > > > So, yes I still have something wrong and maybe one of these days I
> > > > will get another grant and convince the club to buy another GE Mastr
> > > > II and and a new antenna and coax. Maybe that will fix it.
> > > >
> > > > People we got radio from are not answering.
> > > >
> > > > John
> > > >
> > > > --- In Repeater-Builder@yahoogroups.com 
> > <mailto:Repeater-Builder%40yahoogroups.com>
> > > > <mailto:Repeater-Builder%40yahoogroups.com>, "Chuck Kelsey"
> > > >  wrote:
> > > > >
> > > > > I'd suggest turning the power up more. You have it set at about 50%
> > > > and the
> > > > > transmitter may be intermittently spurious at that level.
> > > > >
> > > > > Watch the wattmeter when things act up and see if anything changes
> > > > when you
> > > > > notice the desense happening. You can also pull the TX ICOM when 
> > the
> > > > problem
> > > > > is happening and see if the receive clears up on the local speaker.
> > > > >
> > > > > There are so many things that could be at fault - loose 
> > connector, bad
> > > > > antenna, problem with transmitter, problem with receiver, intermod
> > > > issue,
> > > > > etc.
> > > > >
> > > > > Ask the people you got the radio from if they had

[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[W3ML]

I agree Eric, it might be the radio or it could be the old coax and old antenna.

Finding an spectrum analyzer is the trick. The one ham that I know who has one 
had a heart attack and won't be able to visit for some time. So, I keep trying 
the little suggestions without one to see how much I can improve it.

Thanks and 73
John


--- In Repeater-Builder@yahoogroups.com, "Eric Lemmon"  wrote:
>
> John,
> 
> One thing to keep in mind about a particular PA's tendency to "go spurious"
> is that it will probably be well-behaved when tested on the bench while
> feeding a dummy load.  A good dummy load is purely resistive, while a
> duplexer input is highly reactive- just what a flaky PA needs as a trigger
> to become unstable.  Any additional triggers, such as loose connections,
> aging coax, or an antenna with loose elements, can quickly become a
> nightmare.  It may be helpful to monitor your repeater's emissions on a
> spectrum analyzer when the noise occurs.  Use a short whip on the analyzer
> to pick up the signal- don't connect into the feedline at all, since doing
> so will upset the conditions you want to monitor.  It's possible that the
> radio itself may have a problem, and I don't think that has been ruled out
> yet.
> 
> 73, Eric Lemmon WB6FLY
> 
> 
> -Original Message-
> From: Repeater-Builder@yahoogroups.com
> [mailto:repeater-buil...@yahoogroups.com] On Behalf Of W3ML
> Sent: Monday, October 05, 2009 7:25 PM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's
> comments
> 
>   
> 
> Thanks Mark,
> 
> I will go read that article. Thought I read them all, since January, trying
> to learn all I can.
> 
> That is when I decided to get into this repeater business. It has been a
> great learning experience for sure.
> 
> 73
> John, W3ML
> 
> --- In Repeater-Builder@yahoogroups.com
> <mailto:Repeater-Builder%40yahoogroups.com> , "Mark"  wrote:
> >
> > John,
> > 
> > I'll chime in here and agree with Chuck's suggestion to try a little more
> > "fire in the wire"... 
> > 
> > It sounds as if your PA is less spurious now than before, but you need to
> > dial it up more to eliminate all the spurious products. Solid state PAs,
> > especially mobiles, are noted for this when run at considerably less than
> > rated output. If I remember the beginning of the thread, this was a
> > Mastr-II mobile... 
> > 
> > Seems as if I remember a rule of thumb that a solid state PA won't be
> stable
> > beginning around 60-70% of its rated output. If you're at 55W now, another
> > 10-15W won't make much difference in the received signal strength, but
> will
> > help a LOT to stabilize the PA.
> > 
> > This article: http://www.repeater-builder.com/ge/mastrIIgeneral.html
> <http://www.repeater-builder.com/ge/mastrIIgeneral.html>  says
> > not to run Mastr-II PAs at less than 40%. In your case, you're at about
> 50%
> > now and still a little spurious, so... crank her up a tad more (to maybe
> > 70W) and see if that clears it all up. ;-) The article also has other
> > suggestions on how to deal with desense.
> > 
> > 73,
> > Mark - N9WYS
> > 
> > -Original Message-
> > From: Repeater-Builder@yahoogroups.com
> <mailto:Repeater-Builder%40yahoogroups.com>  On Behalf Of W3ML
> > 
> > I probably will turn it up more to see what happens. When I had it at 5
> > watts out we had no problems at all.
> > 
> > Over the 10 watts is when the noise was really bad. Now at 55 it works and
> > then it doesn't and then it works again.
> > 
> > So, yes I still have something wrong and maybe one of these days I will
> get
> > another grant and convince the club to buy another GE Mastr II and and a
> new
> > antenna and coax. Maybe that will fix it. 
> > 
> > People we got radio from are not answering.
> > 
> > John
> > 
> > 
> > --- In Repeater-Builder@yahoogroups.com
> <mailto:Repeater-Builder%40yahoogroups.com> , "Chuck Kelsey" 
> wrote:
> > >
> > > I'd suggest turning the power up more. You have it set at about 50% and
> > the 
> > > transmitter may be intermittently spurious at that level.
> > > 
> > > Watch the wattmeter when things act up and see if anything changes when
> > you 
> > > notice the desense happening. You can also pull the TX ICOM when the
> > problem 
> > > is happening and see if the receive clears up on the local speaker.
> > > 
> > > There are so many things that could be at fault - loose connector, bad 
> > > antenna, problem with transmitter, problem with receiver, intermod
> issue, 
> > > etc.
> > > 
> > > Ask the people you got the radio from if they had the same problem with
> > it.
> > > 
> > > Chuck
> > > WB2EDV
> >
>

RE: [Repeater-Builder] Re: Radio for repeater use Response to Tom'scomments

[Thomas Oliver]

My thoughts exactly!  He should be losing around %35 through a six cavity
duplexer, my 4 can duplexer loses %29.

Tom, do you have a toggle switch in the PTT line and a local speaker you
can listen to the received signal with?  This is a must on repeaters to be
able to listen to a noisy signal and be able to turn off the transmitter to
check for a difference in signal quality.

You could also disable the transmitter and hook your mobile radio in its
place and transmit while another user is transmitting on the input to see
if the noise is still there.

I changed  to a hotter receiver one time that was almost totally  un usable
due to being noise even on a strong local signal. The problem was traced to
the transmitter seeing reflected power looking into the duplexer.  I added
short jumpers until the reflected power went away then made up a new jumper
with that new length.
It made all the difference in the world to the new receiver.  The old
receiver did not mind at all the extra noise that was being generated due
to reflected power.

G-7's are decent repeater antennas but they tend to pick up static
especially during thunderstorms. I started out with one on a water tower
and did not have much problem with performance except during thunderstorms
- there would be so much static even on a very strong signal that it was
almost totally un useable. 

My G-7 was tuned to have absolutely no reflected power at my TX Freq. and
joints were double hose clamped and gooped with silicone so as to keep the
moisture and corrosion out.  It worked for several years until it was blown
away by a direct lightning strike. all that was left of the vertical part
was the one inch wire from the center of the N connector.

Good luck on your project.




> [Original Message]
> From: Eric Lemmon 
> To: 
> Date: 10/5/2009 11:16:12 PM
> Subject: RE: [Repeater-Builder] Re: Radio for repeater use Response to
Tom'scomments
>
> Tom,
>
> You mentioned in an earlier posting that you had a six-cavity duplexer.
> Most six-cavity duplexers will have an insertion loss of about 2.25 dB,
> which means that with 70 watts in, you should see about 42 watts out.  If
> you actually were measuring 45 watts out with 55 watts in, your duplexer
has
> an insertion loss of only 0.9 dB.  If your measurements are accurate, the
> duplexer tuning seems to be way off.  What make and model duplexer is it?
> What instrument are you using to measure RF power?
>
> 73, Eric Lemmon WB6FLY
>  
>
> -Original Message-
> From: Repeater-Builder@yahoogroups.com
> [mailto:repeater-buil...@yahoogroups.com] On Behalf Of W3ML
> Sent: Monday, October 05, 2009 7:54 PM
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's
> comments
>
>   
>
> Thanks Tom,
>
> Yes, the advice is all good and I have tried several of the suggestions
and
> most, if not all, did help some.
>
> Tomorrow, I will turn it up to 70 watts out, which should give me 60 out
of
> the duplexer, if it works like it does not at 55 and 45 out.
>
> Then we will see what happens.
>
> In fact I did hook it up to another antenna on an adjacent tower. It
worked
> worse than the G7.
>
> Funny thing is when I hook the G7 to a regular 2 meter radio and transmit
on
> simplex, it works really well, hearing stations far a way and putting out
a
> solid signal.
>
> 73
> John
>
> --- In Repeater-Builder@yahoogroups.com
> <mailto:Repeater-Builder%40yahoogroups.com> , Tom Parker  wrote:
> >
> > Well then, that's what everyone on this group is here for. All you have 
> > to do is ask, and you've done that. All the advice tonight is valid, so 
> > now you need to make some measurements. You definitely need an iso-tee, 
> > and good watt meter, i.e., Bird or Telewave, and a service monitor with 
> > at least a spectrum analyser would be a good start. Read the RB page 
> > and follow the suggestions. We actually had a couple of Mastr II 
> > mobiles rigged as repeaters, but we didn't de-rate the PA's. They saw 
> > heavy use with zero problems for over ten years before we replaced them 
> > with stations. Of course the tower building was a constant 74oF in the 
> > Texas sun and the A/C ran most of the winter. It's a shame there's not 
> > another antenna on the tower you could "borrow" for a few minutes.
> > 
> > thp
> > 
> > W3ML wrote:
> > 
> > > 
> > >
> > > Thanks Tom,
> > >
> > > Getting help around here is the hard part. I am the most experience 
> > > and that is mostly from book reading and now a little playing around 
> > > with the radio. No one else knows anything about repeaters either.

Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom'scomments

[Nate Duehr]

On Oct 5, 2009, at 10:22 PM, Thomas Oliver wrote:

> My thoughts exactly! He should be losing around %35 through a six  
> cavity
> duplexer, my 4 can duplexer loses %29.
>
> Tom, do you have a toggle switch in the PTT line and a local speaker  
> you
> can listen to the received signal with? This is a must on repeaters  
> to be
> able to listen to a noisy signal and be able to turn off the  
> transmitter to
> check for a difference in signal quality.


Note for Tom, this is also needed if you ever have something like a  
Sinaddr or other way to measure 12 dB SINAD, to get an accurate base  
reading of how well/badly your receiver performs, and to see if it  
changes once the transmitter is turned on... or if you ever want  
maximum performance of your receiver by adding a pre-amp on the RX  
side.  You have to measure it to know if it's doing some good... or not.


> I changed to a hotter receiver one time that was almost totally un  
> usable
> due to being noise even on a strong local signal. The problem was  
> traced to
> the transmitter seeing reflected power looking into the duplexer. I  
> added
> short jumpers until the reflected power went away then made up a new  
> jumper
> with that new length.
> It made all the difference in the world to the new receiver. The old
> receiver did not mind at all the extra noise that was being  
> generated due
> to reflected power.


Professional/Commercial repeater operators use Isolators for this  
problem/reason.


> My G-7 was tuned to have absolutely no reflected power at my TX  
> Freq. and
> joints were double hose clamped and gooped with silicone so as to  
> keep the
> moisture and corrosion out. It worked for several years until it was  
> blown
> away by a direct lightning strike. all that was left of the vertical  
> part
> was the one inch wire from the center of the N connector.


Every fiberglass vertical deployed out here in the 2nd highest  
lightning strike prone State of the Union, dies this death.  They make  
pretty white confetti all over the top of the mountain and fit nicely  
into a kitchen trash bag, no matter how big they once were, when hit  
by lightning.

Blowing snow will make 'em crackle like a son-of-a-gun on receive  
too... and adding Kevin's favorite, those "static buster" things often  
makes that problem worse in our dry air out here.

Folded metal dipoles (preferably the type with all parts welded  
together, no screws, no moving parts, period...) are the only way to  
fly... once the budget allows.

I cringe when I hear folks are shooting sheet metal screws into multi- 
part antennas... if those are installed at high-RF sites along-side  
high-power broadcast, your antenna is very likely to become a source  
of Passive Intermod once something rusts or via dissimilar metals  
touching.  Slather on the NoOX, and/or use stainless steel screws,  
please.  Even then...

PIM is evil evil stuff to find and fix.  You'll spend hours on a tower  
with a non-conductive stick (broom-stick works well) banging on other  
people's antennas to find the culprit, and then you'll want to  
strangle whoever hung that crappy thing.

Of course, if the repeater's at a site with no high-RF nearby to  
"light up" those "rusty joint" problems... fine.  But verticals you  
can grab and bend over a few inches, let 'em go, and her bang, bang,  
bang, going on inside... really have no place on a busy commercial  
tower in the near-field of lots of transmitters... been there, done  
that.

--
Nate Duehr, WY0X
n...@natetech.com

[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Douglas]

Let me tell you a little story about this kind of problem. I had a similar 
situation on a VHF mastr II repeater where a signal sounded great one time and 
noisy the next. The problem turned out to be a hairline crack in a solder pad 
that was used to bridge two circuit boards and the output connectors to a 
circuit board, within the PA assembly. It would run great power and then low 
power from one transmission to the next. The output power would drop noticably 
as seen on a relative signal meter on my rig. That was how I localized it.

When we would put a meter on the output, it had just enough sstress on the 
cable to make a good connection and all was well, hookk it back to the 
duplexer, and the intermittant problem returned. 

I suspect that same kind of thing could happen on a receiver connection. 

The only real way to fix is to touch all the solder terminals that are used for 
primary signal in the input or output route. 

Good luck. I liked to have lost my brain over that one (what brain is left from 
the 60s).

Doug

KC0SDQ



--- In Repeater-Builder@yahoogroups.com, "W3ML"  wrote:
>
> Thanks Mark,
> 
> I will go read that article. Thought I read them all, since January, trying 
> to learn all I can.
> 
> That is when I decided to get into this repeater business.  It has been a 
> great learning experience for sure.
> 
> 73
> John, W3ML
> 
> 
> 
> 
> --- In Repeater-Builder@yahoogroups.com, "Mark"  wrote:
> >
> > John,
> > 
> > I'll chime in here and agree with Chuck's suggestion to try a little more
> > "fire in the wire"...  
> > 
> > It sounds as if your PA is less spurious now than before, but you need to
> > dial it up more to eliminate all the spurious products.  Solid state PAs,
> > especially mobiles, are noted for this when run at considerably less than
> > rated output.  If I remember the beginning of the thread, this was a
> > Mastr-II mobile...  
> > 
> > Seems as if I remember a rule of thumb that a solid state PA won't be stable
> > beginning around 60-70% of its rated output.  If you're at 55W now, another
> > 10-15W won't make much difference in the received signal strength, but will
> > help a LOT to stabilize the PA.
> > 
> > This article: http://www.repeater-builder.com/ge/mastrIIgeneral.html says
> > not to run Mastr-II PAs at less than 40%.  In your case, you're at about 50%
> > now and still a little spurious, so... crank her up a tad more (to maybe
> > 70W) and see if that clears it all up.  ;-)  The article also has other
> > suggestions on how to deal with desense.
> > 
> > 73,
> > Mark - N9WYS
> > 
> > -Original Message-
> > From: Repeater-Builder@yahoogroups.com  On Behalf Of W3ML
> > 
> > I probably will turn it up more to see what happens.  When I had it at 5
> > watts out we had no problems at all.
> > 
> > Over the 10 watts is when the noise was really bad.  Now at 55 it works and
> > then it doesn't and then it works again.
> > 
> > So, yes I still have something wrong and maybe one of  these days I will get
> > another grant and convince the club to buy another GE Mastr II and and a new
> > antenna and coax. Maybe that will fix it.  
> > 
> > People we got radio from are not answering.
> > 
> > John
> > 
> > 
> > --- In Repeater-Builder@yahoogroups.com, "Chuck Kelsey"  wrote:
> > >
> > > I'd suggest turning the power up more. You have it set at about 50% and
> > the 
> > > transmitter may be intermittently spurious at that level.
> > > 
> > > Watch the wattmeter when things act up and see if anything changes when
> > you 
> > > notice the desense happening. You can also pull the TX ICOM when the
> > problem 
> > > is happening and see if the receive clears up on the local speaker.
> > > 
> > > There are so many things that could be at fault - loose connector, bad 
> > > antenna, problem with transmitter, problem with receiver, intermod issue, 
> > > etc.
> > > 
> > > Ask the people you got the radio from if they had the same problem with
> > it.
> > > 
> > > Chuck
> > > WB2EDV
> >
>

[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[W3ML]

Doug,

Thanks for the story. This next weekend I will go over the inside with a fine 
tooth comb and see if I can find any cracks or bad solder joints.

My brain is going to but not just from this project.
73
John


--- In Repeater-Builder@yahoogroups.com, "Douglas"  wrote:
>
> 
> Let me tell you a little story about this kind of problem. I had a similar 
> situation on a VHF mastr II repeater where a signal sounded great one time 
> and noisy the next. The problem turned out to be a hairline crack in a solder 
> pad that was used to bridge two circuit boards and the output connectors to a 
> circuit board, within the PA assembly. It would run great power and then low 
> power from one transmission to the next. The output power would drop 
> noticably as seen on a relative signal meter on my rig. That was how I 
> localized it.
> 
> When we would put a meter on the output, it had just enough sstress on the 
> cable to make a good connection and all was well, hookk it back to the 
> duplexer, and the intermittant problem returned. 
> 
> I suspect that same kind of thing could happen on a receiver connection. 
> 
> The only real way to fix is to touch all the solder terminals that are used 
> for primary signal in the input or output route. 
> 
> Good luck. I liked to have lost my brain over that one (what brain is left 
> from the 60s).
> 
> Doug
> 
> KC0SDQ
> 
> 
> 
> --- In Repeater-Builder@yahoogroups.com, "W3ML"  wrote:
> >
> > Thanks Mark,
> > 
> > I will go read that article. Thought I read them all, since January, trying 
> > to learn all I can.
> > 
> > That is when I decided to get into this repeater business.  It has been a 
> > great learning experience for sure.
> > 
> > 73
> > John, W3ML
> > 
> > 
> > 
> > 
> > --- In Repeater-Builder@yahoogroups.com, "Mark"  wrote:
> > >
> > > John,
> > > 
> > > I'll chime in here and agree with Chuck's suggestion to try a little more
> > > "fire in the wire"...  
> > > 
> > > It sounds as if your PA is less spurious now than before, but you need to
> > > dial it up more to eliminate all the spurious products.  Solid state PAs,
> > > especially mobiles, are noted for this when run at considerably less than
> > > rated output.  If I remember the beginning of the thread, this was a
> > > Mastr-II mobile...  
> > > 
> > > Seems as if I remember a rule of thumb that a solid state PA won't be 
> > > stable
> > > beginning around 60-70% of its rated output.  If you're at 55W now, 
> > > another
> > > 10-15W won't make much difference in the received signal strength, but 
> > > will
> > > help a LOT to stabilize the PA.
> > > 
> > > This article: http://www.repeater-builder.com/ge/mastrIIgeneral.html says
> > > not to run Mastr-II PAs at less than 40%.  In your case, you're at about 
> > > 50%
> > > now and still a little spurious, so... crank her up a tad more (to maybe
> > > 70W) and see if that clears it all up.  ;-)  The article also has other
> > > suggestions on how to deal with desense.
> > > 
> > > 73,
> > > Mark - N9WYS
> > > 
> > > -Original Message-
> > > From: Repeater-Builder@yahoogroups.com  On Behalf Of W3ML
> > > 
> > > I probably will turn it up more to see what happens.  When I had it at 5
> > > watts out we had no problems at all.
> > > 
> > > Over the 10 watts is when the noise was really bad.  Now at 55 it works 
> > > and
> > > then it doesn't and then it works again.
> > > 
> > > So, yes I still have something wrong and maybe one of  these days I will 
> > > get
> > > another grant and convince the club to buy another GE Mastr II and and a 
> > > new
> > > antenna and coax. Maybe that will fix it.  
> > > 
> > > People we got radio from are not answering.
> > > 
> > > John
> > > 
> > > 
> > > --- In Repeater-Builder@yahoogroups.com, "Chuck Kelsey"  wrote:
> > > >
> > > > I'd suggest turning the power up more. You have it set at about 50% and
> > > the 
> > > > transmitter may be intermittently spurious at that level.
> > > > 
> > > > Watch the wattmeter when things act up and see if anything changes when
> > > you 
> > > > notice the desense happening. You can also pull the TX ICOM when the
> > > problem 
> > > > is happening and see if the receive clears up on the local speaker.
> > > > 
> > > > There are so many things that could be at fault - loose connector, bad 
> > > > antenna, problem with transmitter, problem with receiver, intermod 
> > > > issue, 
> > > > etc.
> > > > 
> > > > Ask the people you got the radio from if they had the same problem with
> > > it.
> > > > 
> > > > Chuck
> > > > WB2EDV
> > >
> >
>

[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[W3ML]

Well Chuck, there will be no new radio unless I buy it out of my pocket and 
that won't happen as I need a new rotor.

This club has no money. I was able to get a grant for emergency communications 
and that is how I ended up with the stuff we have now.

My big problem seems to be that I took this radio in for free instead of buying 
one from that ham in Florida that sells GEs for repeaters.

As I have said before being a ham for 30 years now has taught me nothing about 
the maintenance of a repeater. I have built rigs before and trouble shot many a 
good HF radio, and now I am actually somewhat having fun playing with this 
thing.

I have done more reading on repeaters than I have at my regular job and that is 
the Teaching of English Literature.

Of course if we were to buy a new one, hi hi, then there would  be nothing to 
learn and we all need to keep learning to keep our brains working.

I really appreciate everyone on here helping out not only myself, but the 
others that come on here who need help and are just starting out in this area 
of ham radio like me.

73
John

--- In Repeater-Builder@yahoogroups.com, "Chuck Kelsey"  wrote:
>
> John -
> 
> A word of caution may be in order since you are dealing with a club.
> 
> These days, the typical ham doesn't begin to comprehend the complexity of a 
> repeater system. To many, one simply needs to go out a purchase new 
> equipment, plug it all together, and it runs. Wrong!
> 
> Don't let your club go down that path. The end result will be lots of money 
> being spent and unhappy results. I've watched it happen.
> 
> If you are running a repeater, you WILL have problems with it, no matter 
> what brand of equipment you use, no matter if it's new or used.
> 
> You appear to be taking the steps to learn about it. It's the only way 
> you'll be able to cope unless the club pays a commercial two-way shop to 
> maintain the system.
> 
> In the meantime, keep plugging away. It can get very frustrating at times.
> 
> Chuck
> WB2EDV
> 
> 
> 
> - Original Message - 
> >>
> >> I will go read that article. Thought I read them all, since January, 
> >> trying to learn all I can.
> >>
> >> That is when I decided to get into this repeater business.  It has been a 
> >> great learning experience for sure.
> >>
> >> 73
> >> John, W3ML
> >
>

[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[W3ML]

Thanks Eric

I read that document that you speak of.  We cleaned it , re-fiber-glassed some 
of it and then sprayed it with polyurethane finish and screwed the sections so 
they would not move even though they had clamps on them.

But, like you I think with it being used there may be a problem inside that we 
can not see.

73
John


--- In Repeater-Builder@yahoogroups.com, Eric Lowell  wrote:
>
> Your antenna needs to come down and be gone over before you buy anything new. 
> Those G7s will get bad connections in them that act like diodes and rectify 
> all kinds of crud to desense your otherwise good system. I understand that 
> there is a document on the RB site about refurbing that antenna. You may have 
> heard this before.
>  
> Good Luck, Eric (W1EL)
> 
> Eric Lowell
> Eastern Maine Electronics Inc.
> 48 Loon Road
> Wesley ME 04686
> eme@...
> www.satnetmaine.com
> 
> 
> --- On Tue, 10/6/09, W3ML  wrote:
> 
> 
> From: W3ML 
> Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's 
> comments
> To: Repeater-Builder@yahoogroups.com
> Date: Tuesday, October 6, 2009, 5:36 PM
> 
> 
>   
> 
> 
> 
> Well Chuck, there will be no new radio unless I buy it out of my pocket and 
> that won't happen as I need a new rotor.
> 
> This club has no money. I was able to get a grant for emergency 
> communications and that is how I ended up with the stuff we have now.
> 
> My big problem seems to be that I took this radio in for free instead of 
> buying one from that ham in Florida that sells GEs for repeaters.
> 
> As I have said before being a ham for 30 years now has taught me nothing 
> about the maintenance of a repeater. I have built rigs before and trouble 
> shot many a good HF radio, and now I am actually somewhat having fun playing 
> with this thing.
> 
> I have done more reading on repeaters than I have at my regular job and that 
> is the Teaching of English Literature.
> 
> Of course if we were to buy a new one, hi hi, then there would be nothing to 
> learn and we all need to keep learning to keep our brains working.
> 
> I really appreciate everyone on here helping out not only myself, but the 
> others that come on here who need help and are just starting out in this area 
> of ham radio like me.
> 
> 73
> John
> 
> --- In Repeater-Builder@ yahoogroups. com, "Chuck Kelsey"  wrote:
> >
> > John -
> > 
> > A word of caution may be in order since you are dealing with a club.
> > 
> > These days, the typical ham doesn't begin to comprehend the complexity of a 
> > repeater system. To many, one simply needs to go out a purchase new 
> > equipment, plug it all together, and it runs. Wrong!
> > 
> > Don't let your club go down that path. The end result will be lots of money 
> > being spent and unhappy results. I've watched it happen.
> > 
> > If you are running a repeater, you WILL have problems with it, no matter 
> > what brand of equipment you use, no matter if it's new or used.
> > 
> > You appear to be taking the steps to learn about it. It's the only way 
> > you'll be able to cope unless the club pays a commercial two-way shop to 
> > maintain the system.
> > 
> > In the meantime, keep plugging away. It can get very frustrating at times.
> > 
> > Chuck
> > WB2EDV
> > 
> > 
> > 
> > - Original Message - 
> > >>
> > >> I will go read that article. Thought I read them all, since January, 
> > >> trying to learn all I can.
> > >>
> > >> That is when I decided to get into this repeater business. It has been a 
> > >> great learning experience for sure.
> > >>
> > >> 73
> > >> John, W3ML
> > >
> >
>

[Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[W3ML]

Thanks Nate,

I have read most all of the documents on RB and learned quite a bit about 
repeaters and the GEs.

73
John


--- In Repeater-Builder@yahoogroups.com, Nate Duehr  wrote:
>
> 
> On Oct 6, 2009, at 10:12 AM, Douglas wrote:
> 
> >
> > Let me tell you a little story about this kind of problem. I had a  
> > similar situation on a VHF mastr II repeater where a signal sounded  
> > great one time and noisy the next. The problem turned out to be a  
> > hairline crack in a solder pad that was used to bridge two circuit  
> > boards and the output connectors to a circuit board, within the PA  
> > assembly. It would run great power and then low power from one  
> > transmission to the next. The output power would drop noticably as  
> > seen on a relative signal meter on my rig. That was how I localized  
> > it.
> >
> > When we would put a meter on the output, it had just enough sstress  
> > on the cable to make a good connection and all was well, hookk it  
> > back to the duplexer, and the intermittant problem returned.
> >
> > I suspect that same kind of thing could happen on a receiver  
> > connection.
> >
> > The only real way to fix is to touch all the solder terminals that  
> > are used for primary signal in the input or output route.
> >
> > Good luck. I liked to have lost my brain over that one (what brain  
> > is left from the 60s).
> >
> > Doug
> >
> > KC0SDQ
> 
> MASTR II PA's can also make funny noises (really ugly stuff on a  
> spectrum analyzer) if they're experiencing this type of crack at the  
> PA output going into the harmonic filter board... you literally can  
> HEAR it happening on the repeater's output.  Often the arcing  
> happening over that joint "modulates" the FM signal in the form of a  
> low-level squeal in the background of the repeater's signal, and/or a  
> "frying" sound.  It's not pleasant, but also not always so bad you can  
> hear it.
> 
> http://www.repeater-builder.com/ge/pix/mvc-474f.jpg
> 
> From:
> 
> http://www.repeater-builder.com/ge/mastrIIparepair.html
> 
> Look carefully.  Sometimes it's hard to spot.  There's a little strip  
> of metal under that solder blob, that bridges that gap, which is  
> almost under that capacitor.  Re-heating this area, you'll often find  
> the problem, but be careful not to cook the cap.  We've done the  
> "bump" fix, and we've also done the "just clean up the pads and re-use  
> the factory metal strip" fix.  Can't say that either way is "better"  
> when the screws surrounding the joint are torqued to factory  
> specifications.  If either side is "loose", or "too tight" the boards  
> will flex during heating and cooling and break the connection again.  
> Had one that was so burnt the board itself and the "charcoal" became  
> conductive and it would visibly arc over every time it was keyed.   
> That one had to have both the final board and the harmonic filter  
> board replaced, and was stinky.  Usually they're sneakier than that,  
> though.
> 
> I was fighting with VHF PA's a couple of years ago, and when I finally  
> enlisted the help of someone FAR more patient than I to completely  
> rebuild one, including pulling ALL of the boards off the PA heatsink,  
> scraping all of the old/dead heatsink compound off of everything and  
> re-applying new, re-torquing all the screws to FACTORY specs (it's in  
> the LBI, and many late model repeater PA's, not the mobiles usually,  
> have stickers with the EXACT torque specs of all screw types on the PA  
> board), resoldering every joint with good quality solder... etc.  A  
> real "re-work" job.
> 
> This was done slowly and carefully by Scott W0KU... then following the  
> "rule" we've given ourselves that ALL MASTR II PAs get an isolator...
> 
> His rebuilt PA has gone through antenna hell (long story, but let's  
> just say it wasn't radiating, feeding into the isolator at 85W  
> continuous for hours and hours) plus has also worked great on-the-air  
> for three years now.
> 
> I now really believe that these 30 year old PA's just need a little  
> bench TLC before they go up to a site, and I'm MORE than willing to go  
> work them over thoroughly, and buy beers for Scott to enjoy in his  
> backyard shed after the soldering and tricky stuff is done with.
> 
> I rebuilt two, they died.  Scott rebuilt one, after I explained what I  
> thought I'd rushed through, or done badly, and how frustrating it was  
> to see two of them die... we made a plan to meet up and work slowly  
> and carefully and do a complete tear-down and rebuild on one utilizing  
> whatever boards/parts we had on-hand.  That rebuilt PA has kept  
> working now for a long time.
> 
> I definitely credit the removal and replacement of the completely  
> dried out, dead heatsink compound as a component of much of this  
> "success."  After seeing the flaky, useless "stuff" that came off the  
> heatsink (the date stamp read 1981 on this particular PA), I highly  
> recommend the full tear-down

Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Chuck Kelsey]

I'd suggest turning the power up more. You have it set at about 50% and the 
transmitter may be intermittently spurious at that level.

Watch the wattmeter when things act up and see if anything changes when you 
notice the desense happening. You can also pull the TX ICOM when the problem 
is happening and see if the receive clears up on the local speaker.

There are so many things that could be at fault - loose connector, bad 
antenna, problem with transmitter, problem with receiver, intermod issue, 
etc.

Ask the people you got the radio from if they had the same problem with it.

Chuck
WB2EDV



- Original Message - 
From: "W3ML" 
To: 
Sent: Monday, October 05, 2009 8:33 PM
Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's 
comments


> Hi Tom,
>
>
>
> I did crank up the power to 55 watts out of radio and that gives me 45 out 
> of the duplexer.  Decided on this wattage until I can figure the problem 
> better. It is working better than before, but still having trouble.
>
> So from what you said about power coming out duplexer, the duplexer must 
> still be okay.
>
> However, during the day today there were 3 hams talking and they said 
> (later) that all of them were loud and clear. But, when I got home and 
> tried to call one of them, he was covered in noise.
>
> Later one of the others called in and he would be clear, then the repeater 
> would cut out and his signal would be gone, then it would come back with 
> noise on his signal and then clear again.
>
> Then the other one came in with a lot of noise, then he would come in with 
> a little noise and then no noise at all and then back again through this 
> cycle.
>
> This cycle of noise and then no noise is driving me crazy.
>
> The set up is this:
>
> GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs 
> with a service monitor prior to bringing it here.
>
> There is a bandpass filter on the receive side after the duplexer and 
> before the radio.
>
> We have used 1/2 inch hardline going up to the used G7-144.
>
> Then only thing I can think of is the radio is bad, the antenna is no good 
> and the coax is shot.
>
> Now, the radio was given to us by a group that had used it, but decided to 
> replace it with a Kenwood.
>
> I am thinking that they had the same problem and that is why they gave it 
> away.
>
> Any advice would be greatly appreciated.
>
> 73
> John, W3ML
>
>
> - In Repeater-Builder@yahoogroups.com, W9SRV  wrote:
>>
>> Ok-
>>
>> 1. Where are you checking the swr at in the chain? Make sure you bypass 
>> the duplexers to check the antenna, the cans can throw off the reading on 
>> some meters like you describe using. If you are less than 1.5:1 I would 
>> not worry too much more about it, any reflected power will get eaten up 
>> back in the cans. If you are really concerned about protecting the TX put 
>> a circulator in-line with it.
>>
>> 2. Make sure all the interconnecting cables are good shielded and not 
>> foil/ braid type. RG-213 and RG-400 are good choices, though there are a 
>> few more.
>>
>> 3. Terminate into a good dummy load. Set you output power to 80-90W. Then 
>> run thru the duplexer and check the power coming out of the cans. You 
>> should see something like 60-70w, depending on the spec of the duplexer. 
>> If your seeing much less than you may have a duplexer tuning issue.
>>
>> Figure out the real problem, let the radio run at a real spec power 
>> output, than absorb the title of "far lord" as every one thanks you for 
>> giving the repeater twice as many s-units. (then be prepared for the next 
>> round of complaints that become your problem)
>>
>> Tom
>> W9SRV
>>
>> Sent from my iPhone
>>
>> On Oct 4, 2009, at 5:46 PM, "W3ML"  wrote:
>>
>> No, except when it was at the 2o watts the swr was almost 1 and someone 
>> said that was the problem causing the de-sense.  So we were afraid to run 
>> it higher.
>>
>> Like you said guess it was only a problem from running too little of 
>> power.
>>
>>
>> Thanks and 73
>> John
>>
>>
>> --- In Repeater-Builder@yahoogroups.com, W9SRV  wrote:
>>
>> You answered your own question :
>>
>> "So it appears that this radio, which is a GE Mastr II mobile, doesn't 
>> like to run at the lower wattage of 10 to 20 watts out."
>>
>> 110w radio will not be stable at 10-20w. If you look at your output on a 
>> spectrum you probably have spurs all over the place. Any reason you 
>> cannot run it at least 1/2-2/3 power?
>>
>> Tom
>> W9SRV
>>
>> Sent from my iPhone
>>
>> On Oct 4, 2009, at 4:46 PM, "W3ML"  wrote:
>>
>> So it appears that this radio, which is a GE Mastr II mobile, doesn't 
>> like to run at the lower wattage of 10 to 20 watts out.
>>
>>
>>
>>
>>
>> 
>>
>>
>>
>> Yahoo! Groups Links
>>
>
>
>
>
> 
>
>
>
> Yahoo! Groups Links
>
>
>
> 

Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Tom Parker]

Hello W3ML,

I've been following this thread over the weekend and I think the issue 
has been addressed.  I would check the antenna and related connectors.  
In fact, for my 2 cents, I'd replace the G7 with a commercial grade 
antenna, such as a DB product or equal.  Now, to your scenario today, I 
would ask what the wind was like?  If memory serves me correctly, that 
G7 has a couple of joints and is somewhat flimsy in terms of material 
strength and antenna height. 


There ya go,

thp

W3ML wrote:
 


Hi Tom,

I did crank up the power to 55 watts out of radio and that gives me 45 
out of the duplexer. Decided on this wattage until I can figure the 
problem better. It is working better than before, but still having 
trouble.


So from what you said about power coming out duplexer, the duplexer 
must still be okay.


However, during the day today there were 3 hams talking and they said 
(later) that all of them were loud and clear. But, when I got home and 
tried to call one of them, he was covered in noise.


Later one of the others called in and he would be clear, then the 
repeater would cut out and his signal would be gone, then it would 
come back with noise on his signal and then clear again.


Then the other one came in with a lot of noise, then he would come in 
with a little noise and then no noise at all and then back again 
through this cycle.


This cycle of noise and then no noise is driving me crazy.

The set up is this:

GE Mastr II VHF mobile running into a 6 cavity duplexer set to our 
freqs with a service monitor prior to bringing it here.


There is a bandpass filter on the receive side after the duplexer and 
before the radio.


We have used 1/2 inch hardline going up to the used G7-144.

Then only thing I can think of is the radio is bad, the antenna is no 
good and the coax is shot.


Now, the radio was given to us by a group that had used it, but 
decided to replace it with a Kenwood.


I am thinking that they had the same problem and that is why they gave 
it away.


Any advice would be greatly appreciated.

73
John, W3ML

- In Repeater-Builder@yahoogroups.com 
, W9SRV  wrote:

>
> Ok-
>
> 1. Where are you checking the swr at in the chain? Make sure you 
bypass the duplexers to check the antenna, the cans can throw off the 
reading on some meters like you describe using. If you are less than 
1.5:1 I would not worry too much more about it, any reflected power 
will get eaten up back in the cans. If you are really concerned about 
protecting the TX put a circulator in-line with it.

>
> 2. Make sure all the interconnecting cables are good shielded and 
not foil/ braid type. RG-213 and RG-400 are good choices, though there 
are a few more.

>
> 3. Terminate into a good dummy load. Set you output power to 80-90W. 
Then run thru the duplexer and check the power coming out of the cans. 
You should see something like 60-70w, depending on the spec of the 
duplexer. If your seeing much less than you may have a duplexer tuning 
issue.

>
> Figure out the real problem, let the radio run at a real spec power 
output, than absorb the title of "far lord" as every one thanks you 
for giving the repeater twice as many s-units. (then be prepared for 
the next round of complaints that become your problem)

>
> Tom
> W9SRV
>
> Sent from my iPhone
>
> On Oct 4, 2009, at 5:46 PM, "W3ML"  wrote:
>
> No, except when it was at the 2o watts the swr was almost 1 and 
someone said that was the problem causing the de-sense. So we were 
afraid to run it higher.

>
> Like you said guess it was only a problem from running too little of 
power.

>
>
> Thanks and 73
> John
>
>
> --- In Repeater-Builder@yahoogroups.com 
, W9SRV  wrote:

>
> You answered your own question :
>
> "So it appears that this radio, which is a GE Mastr II mobile, 
doesn't like to run at the lower wattage of 10 to 20 watts out."

>
> 110w radio will not be stable at 10-20w. If you look at your output 
on a spectrum you probably have spurs all over the place. Any reason 
you cannot run it at least 1/2-2/3 power?

>
> Tom
> W9SRV
>
> Sent from my iPhone
>
> On Oct 4, 2009, at 4:46 PM, "W3ML"  wrote:
>
> So it appears that this radio, which is a GE Mastr II mobile, 
doesn't like to run at the lower wattage of 10 to 20 watts out.

>
>
>
>
>
> 
>
>
>
> Yahoo! Groups Links
>

Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Lee Pennington]

I've been following it too. You can lead a horse to water, but you can't
make him drink.

K4LJP

On Mon, Oct 5, 2009 at 8:49 PM, Tom Parker  wrote:

>
>
> Hello W3ML,
>
> I've been following this thread over the weekend and I think the issue has
> been addressed.  I would check the antenna and related connectors.  In fact,
> for my 2 cents, I'd replace the G7 with a commercial grade antenna, such as
> a DB product or equal.  Now, to your scenario today, I would ask what the
> wind was like?  If memory serves me correctly, that G7 has a couple of
> joints and is somewhat flimsy in terms of material strength and antenna
> height.
>
> There ya go,
>
> thp
>
> W3ML wrote:
>
>
>
> Hi Tom,
>
> I did crank up the power to 55 watts out of radio and that gives me 45 out
> of the duplexer. Decided on this wattage until I can figure the problem
> better. It is working better than before, but still having trouble.
>
> So from what you said about power coming out duplexer, the duplexer must
> still be okay.
>
> However, during the day today there were 3 hams talking and they said
> (later) that all of them were loud and clear. But, when I got home and tried
> to call one of them, he was covered in noise.
>
> Later one of the others called in and he would be clear, then the repeater
> would cut out and his signal would be gone, then it would come back with
> noise on his signal and then clear again.
>
> Then the other one came in with a lot of noise, then he would come in with
> a little noise and then no noise at all and then back again through this
> cycle.
>
> This cycle of noise and then no noise is driving me crazy.
>
> The set up is this:
>
> GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs
> with a service monitor prior to bringing it here.
>
> There is a bandpass filter on the receive side after the duplexer and
> before the radio.
>
> We have used 1/2 inch hardline going up to the used G7-144.
>
> Then only thing I can think of is the radio is bad, the antenna is no good
> and the coax is shot.
>
> Now, the radio was given to us by a group that had used it, but decided to
> replace it with a Kenwood.
>
> I am thinking that they had the same problem and that is why they gave it
> away.
>
> Any advice would be greatly appreciated.
>
> 73
> John, W3ML
>
> - In Repeater-Builder@yahoogroups.com ,
> W9SRV  wrote:
> >
> > Ok-
> >
> > 1. Where are you checking the swr at in the chain? Make sure you bypass
> the duplexers to check the antenna, the cans can throw off the reading on
> some meters like you describe using. If you are less than 1.5:1 I would not
> worry too much more about it, any reflected power will get eaten up back in
> the cans. If you are really concerned about protecting the TX put a
> circulator in-line with it.
> >
> > 2. Make sure all the interconnecting cables are good shielded and not
> foil/ braid type. RG-213 and RG-400 are good choices, though there are a few
> more.
> >
> > 3. Terminate into a good dummy load. Set you output power to 80-90W. Then
> run thru the duplexer and check the power coming out of the cans. You should
> see something like 60-70w, depending on the spec of the duplexer. If your
> seeing much less than you may have a duplexer tuning issue.
> >
> > Figure out the real problem, let the radio run at a real spec power
> output, than absorb the title of "far lord" as every one thanks you for
> giving the repeater twice as many s-units. (then be prepared for the next
> round of complaints that become your problem)
> >
> > Tom
> > W9SRV
> >
> > Sent from my iPhone
> >
> > On Oct 4, 2009, at 5:46 PM, "W3ML"   wrote:
> >
> > No, except when it was at the 2o watts the swr was almost 1 and someone
> said that was the problem causing the de-sense. So we were afraid to run it
> higher.
> >
> > Like you said guess it was only a problem from running too little of
> power.
> >
> >
> > Thanks and 73
> > John
> >
> >
> > --- In Repeater-Builder@yahoogroups.com,
> W9SRV  wrote:
> >
> > You answered your own question :
> >
> > "So it appears that this radio, which is a GE Mastr II mobile, doesn't
> like to run at the lower wattage of 10 to 20 watts out."
> >
> > 110w radio will not be stable at 10-20w. If you look at your output on a
> spectrum you probably have spurs all over the place. Any reason you cannot
> run it at least 1/2-2/3 power?
> >
> > Tom
> > W9SRV
> >
> > Sent from my iPhone
> >
> > On Oct 4, 2009, at 4:46 PM, "W3ML"  wrote:
> >
> > So it appears that this radio, which is a GE Mastr II mobile, doesn't
> like to run at the lower wattage of 10 to 20 watts out.
> >
> >
> >
> >
> >
> > 
> >
> >
> >
> > Yahoo! Groups Links
> >
>
>
>



-- 
"Always drink upstream from the herd."

RE: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[David Murman]

Sounds like he has a noise source near by causing him his problems. Probably
not in the repeater at all.  Had similar experience with a 50 mhz repeater
located on a mountain top. Grounding wasn't the best and any noise generated
by the wind moving the towers made the repeater at times almost unusable.
Times signals were full quieting and then they were noisy.

 

 

 

David

 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Chuck Kelsey
Sent: Monday, October 05, 2009 7:47 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's
comments

 

  

I'd suggest turning the power up more. You have it set at about 50% and the 
transmitter may be intermittently spurious at that level.

Watch the wattmeter when things act up and see if anything changes when you 
notice the desense happening. You can also pull the TX ICOM when the problem

is happening and see if the receive clears up on the local speaker.

There are so many things that could be at fault - loose connector, bad 
antenna, problem with transmitter, problem with receiver, intermod issue, 
etc.

Ask the people you got the radio from if they had the same problem with it.

Chuck
WB2EDV

- Original Message - 
From: "W3ML" mailto:w3ml%40arrl.net> >
To: mailto:Repeater-Builder%40yahoogroups.com>
yahoogroups.com>
Sent: Monday, October 05, 2009 8:33 PM
Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's 
comments

> Hi Tom,
>
>
>
> I did crank up the power to 55 watts out of radio and that gives me 45 out

> of the duplexer. Decided on this wattage until I can figure the problem 
> better. It is working better than before, but still having trouble.
>
> So from what you said about power coming out duplexer, the duplexer must 
> still be okay.
>
> However, during the day today there were 3 hams talking and they said 
> (later) that all of them were loud and clear. But, when I got home and 
> tried to call one of them, he was covered in noise.
>
> Later one of the others called in and he would be clear, then the repeater

> would cut out and his signal would be gone, then it would come back with 
> noise on his signal and then clear again.
>
> Then the other one came in with a lot of noise, then he would come in with

> a little noise and then no noise at all and then back again through this 
> cycle.
>
> This cycle of noise and then no noise is driving me crazy.
>
> The set up is this:
>
> GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs 
> with a service monitor prior to bringing it here.
>
> There is a bandpass filter on the receive side after the duplexer and 
> before the radio.
>
> We have used 1/2 inch hardline going up to the used G7-144.
>
> Then only thing I can think of is the radio is bad, the antenna is no good

> and the coax is shot.
>
> Now, the radio was given to us by a group that had used it, but decided to

> replace it with a Kenwood.
>
> I am thinking that they had the same problem and that is why they gave it 
> away.
>
> Any advice would be greatly appreciated.
>
> 73
> John, W3ML
>
>
> - In Repeater-Builder@ <mailto:Repeater-Builder%40yahoogroups.com>
yahoogroups.com, W9SRV  wrote:
>>
>> Ok-
>>
>> 1. Where are you checking the swr at in the chain? Make sure you bypass 
>> the duplexers to check the antenna, the cans can throw off the reading on

>> some meters like you describe using. If you are less than 1.5:1 I would 
>> not worry too much more about it, any reflected power will get eaten up 
>> back in the cans. If you are really concerned about protecting the TX put

>> a circulator in-line with it.
>>
>> 2. Make sure all the interconnecting cables are good shielded and not 
>> foil/ braid type. RG-213 and RG-400 are good choices, though there are a 
>> few more.
>>
>> 3. Terminate into a good dummy load. Set you output power to 80-90W. Then

>> run thru the duplexer and check the power coming out of the cans. You 
>> should see something like 60-70w, depending on the spec of the duplexer. 
>> If your seeing much less than you may have a duplexer tuning issue.
>>
>> Figure out the real problem, let the radio run at a real spec power 
>> output, than absorb the title of "far lord" as every one thanks you for 
>> giving the repeater twice as many s-units. (then be prepared for the next

>> round of complaints that become your problem)
>>
>> Tom
>> W9SRV
>>
>> Sent from my iPhone
>>
>> On Oct 4, 2009, at 5:46 PM, "W3ML"  wrote:
>>
>> No, except wh

RE: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Mark]

John,

I'll chime in here and agree with Chuck's suggestion to try a little more
"fire in the wire"...  

It sounds as if your PA is less spurious now than before, but you need to
dial it up more to eliminate all the spurious products.  Solid state PAs,
especially mobiles, are noted for this when run at considerably less than
rated output.  If I remember the beginning of the thread, this was a
Mastr-II mobile...  

Seems as if I remember a rule of thumb that a solid state PA won't be stable
beginning around 60-70% of its rated output.  If you're at 55W now, another
10-15W won't make much difference in the received signal strength, but will
help a LOT to stabilize the PA.

This article: http://www.repeater-builder.com/ge/mastrIIgeneral.html says
not to run Mastr-II PAs at less than 40%.  In your case, you're at about 50%
now and still a little spurious, so... crank her up a tad more (to maybe
70W) and see if that clears it all up.  ;-)  The article also has other
suggestions on how to deal with desense.

73,
Mark - N9WYS

-Original Message-
From: Repeater-Builder@yahoogroups.com  On Behalf Of W3ML

I probably will turn it up more to see what happens.  When I had it at 5
watts out we had no problems at all.

Over the 10 watts is when the noise was really bad.  Now at 55 it works and
then it doesn't and then it works again.

So, yes I still have something wrong and maybe one of  these days I will get
another grant and convince the club to buy another GE Mastr II and and a new
antenna and coax. Maybe that will fix it.  

People we got radio from are not answering.

John


--- In Repeater-Builder@yahoogroups.com, "Chuck Kelsey"  wrote:
>
> I'd suggest turning the power up more. You have it set at about 50% and
the 
> transmitter may be intermittently spurious at that level.
> 
> Watch the wattmeter when things act up and see if anything changes when
you 
> notice the desense happening. You can also pull the TX ICOM when the
problem 
> is happening and see if the receive clears up on the local speaker.
> 
> There are so many things that could be at fault - loose connector, bad 
> antenna, problem with transmitter, problem with receiver, intermod issue, 
> etc.
> 
> Ask the people you got the radio from if they had the same problem with
it.
> 
> Chuck
> WB2EDV

Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Tom Parker]

Mastr II is a good radio.  Likely not much wrong with it.  They're a 
great deal better than most of what you buy today; however, we're pretty 
impressed with the Kenwood TKR's in our shop for mid tier units.  Our 22 
trunk sites are made up of Micors, Mastr II's, Johnsons, and one site of 
MSR 2000's and one site of R1225's with Henry amps.  Most are five 
channel and up.  The TKR's are in stand alone situations or conventional 
users who own their on.


You ought to stick with what you have and work out the problems or get 
some help.


thp

W3ML wrote:
 

I probably will turn it up more to see what happens. When I had it at 
5 watts out we had no problems at all.


Over the 10 watts is when the noise was really bad. Now at 55 it works 
and then it doesn't and then it works again.


So, yes I still have something wrong and maybe one of these days I 
will get another grant and convince the club to buy another GE Mastr 
II and and a new antenna and coax. Maybe that will fix it.


People we got radio from are not answering.

John

--- In Repeater-Builder@yahoogroups.com 
<mailto:Repeater-Builder%40yahoogroups.com>, "Chuck Kelsey" 
 wrote:

>
> I'd suggest turning the power up more. You have it set at about 50% 
and the

> transmitter may be intermittently spurious at that level.
>
> Watch the wattmeter when things act up and see if anything changes 
when you
> notice the desense happening. You can also pull the TX ICOM when the 
problem

> is happening and see if the receive clears up on the local speaker.
>
> There are so many things that could be at fault - loose connector, bad
> antenna, problem with transmitter, problem with receiver, intermod 
issue,

> etc.
>
> Ask the people you got the radio from if they had the same problem 
with it.

>
> Chuck
> WB2EDV
>
>
>
> - Original Message -
> From: "W3ML" 
> To: <mailto:Repeater-Builder%40yahoogroups.com>>

> Sent: Monday, October 05, 2009 8:33 PM
> Subject: [Repeater-Builder] Re: Radio for repeater use Response to 
Tom's

> comments
>
>
> > Hi Tom,
> >
> >
> >
> > I did crank up the power to 55 watts out of radio and that gives 
me 45 out
> > of the duplexer. Decided on this wattage until I can figure the 
problem

> > better. It is working better than before, but still having trouble.
> >
> > So from what you said about power coming out duplexer, the 
duplexer must

> > still be okay.
> >
> > However, during the day today there were 3 hams talking and they said
> > (later) that all of them were loud and clear. But, when I got home 
and

> > tried to call one of them, he was covered in noise.
> >
> > Later one of the others called in and he would be clear, then the 
repeater
> > would cut out and his signal would be gone, then it would come 
back with

> > noise on his signal and then clear again.
> >
> > Then the other one came in with a lot of noise, then he would come 
in with
> > a little noise and then no noise at all and then back again 
through this

> > cycle.
> >
> > This cycle of noise and then no noise is driving me crazy.
> >
> > The set up is this:
> >
> > GE Mastr II VHF mobile running into a 6 cavity duplexer set to our 
freqs

> > with a service monitor prior to bringing it here.
> >
> > There is a bandpass filter on the receive side after the duplexer and
> > before the radio.
> >
> > We have used 1/2 inch hardline going up to the used G7-144.
> >
> > Then only thing I can think of is the radio is bad, the antenna is 
no good

> > and the coax is shot.
> >
> > Now, the radio was given to us by a group that had used it, but 
decided to

> > replace it with a Kenwood.
> >
> > I am thinking that they had the same problem and that is why they 
gave it

> > away.
> >
> > Any advice would be greatly appreciated.
> >
> > 73
> > John, W3ML
> >
> >
> > - In Repeater-Builder@yahoogroups.com 
<mailto:Repeater-Builder%40yahoogroups.com>, W9SRV  wrote:

> >>
> >> Ok-
> >>
> >> 1. Where are you checking the swr at in the chain? Make sure you 
bypass
> >> the duplexers to check the antenna, the cans can throw off the 
reading on
> >> some meters like you describe using. If you are less than 1.5:1 I 
would
> >> not worry too much more about it, any reflected power will get 
eaten up
> >> back in the cans. If you are really concerned about protecting 
the TX put

> >> a circulator in-line with it.
> >>
> >> 2. Make sure all the interconnecting cables are good shielded and 
not
>

Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Tom Parker]

Well then, that's what everyone on this group is here for.  All you have 
to do is ask, and you've done that.  All the advice tonight is valid, so 
now you need to make some measurements.  You definitely need an iso-tee, 
and good watt meter, i.e., Bird or Telewave, and a service monitor with 
at least a spectrum analyser would be a good start.  Read the RB page 
and follow the suggestions.  We actually had a couple of Mastr II 
mobiles rigged as repeaters, but we didn't de-rate the PA's.  They saw 
heavy use with zero problems for over ten years before we replaced them 
with stations.  Of course the tower building was a constant 74oF in the 
Texas sun and the A/C ran most of the winter.  It's a shame there's not 
another antenna on the tower you could "borrow" for a few minutes.


thp

W3ML wrote:

 


Thanks Tom,

Getting help around here is the hard part. I am the most experience 
and that is mostly from book reading and now a little playing around 
with the radio. No one else knows anything about repeaters either.


We are just now getting into the repeater stage for our club.

73
John

--- In Repeater-Builder@yahoogroups.com 
<mailto:Repeater-Builder%40yahoogroups.com>, Tom Parker  wrote:

>
> Mastr II is a good radio. Likely not much wrong with it. They're a
> great deal better than most of what you buy today; however, we're 
pretty

> impressed with the Kenwood TKR's in our shop for mid tier units. Our 22
> trunk sites are made up of Micors, Mastr II's, Johnsons, and one 
site of

> MSR 2000's and one site of R1225's with Henry amps. Most are five
> channel and up. The TKR's are in stand alone situations or conventional
> users who own their on.
>
> You ought to stick with what you have and work out the problems or get
> some help.
>
> thp
>
> W3ML wrote:
> >
> >
> > I probably will turn it up more to see what happens. When I had it at
> > 5 watts out we had no problems at all.
> >
> > Over the 10 watts is when the noise was really bad. Now at 55 it 
works

> > and then it doesn't and then it works again.
> >
> > So, yes I still have something wrong and maybe one of these days I
> > will get another grant and convince the club to buy another GE Mastr
> > II and and a new antenna and coax. Maybe that will fix it.
> >
> > People we got radio from are not answering.
> >
> > John
> >
> > --- In Repeater-Builder@yahoogroups.com 
<mailto:Repeater-Builder%40yahoogroups.com>

> > <mailto:Repeater-Builder%40yahoogroups.com>, "Chuck Kelsey"
> >  wrote:
> > >
> > > I'd suggest turning the power up more. You have it set at about 50%
> > and the
> > > transmitter may be intermittently spurious at that level.
> > >
> > > Watch the wattmeter when things act up and see if anything changes
> > when you
> > > notice the desense happening. You can also pull the TX ICOM when 
the

> > problem
> > > is happening and see if the receive clears up on the local speaker.
> > >
> > > There are so many things that could be at fault - loose 
connector, bad

> > > antenna, problem with transmitter, problem with receiver, intermod
> > issue,
> > > etc.
> > >
> > > Ask the people you got the radio from if they had the same problem
> > with it.
> > >
> > > Chuck
> > > WB2EDV
> > >
> > >
> > >
> > > - Original Message -
> > > From: "W3ML" 
> > > To: <mailto:Repeater-Builder%40yahoogroups.com>

> > <mailto:Repeater-Builder%40yahoogroups.com>>
> > > Sent: Monday, October 05, 2009 8:33 PM
> > > Subject: [Repeater-Builder] Re: Radio for repeater use Response to
> > Tom's
> > > comments
> > >
> > >
> > > > Hi Tom,
> > > >
> > > >
> > > >
> > > > I did crank up the power to 55 watts out of radio and that gives
> > me 45 out
> > > > of the duplexer. Decided on this wattage until I can figure the
> > problem
> > > > better. It is working better than before, but still having 
trouble.

> > > >
> > > > So from what you said about power coming out duplexer, the
> > duplexer must
> > > > still be okay.
> > > >
> > > > However, during the day today there were 3 hams talking and 
they said
> > > > (later) that all of them were loud and clear. But, when I got 
home

> > and
> > > > tried to call one of them, he was covered in noise.
> > > >
>

RE: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Eric Lemmon]

John,

One thing to keep in mind about a particular PA's tendency to "go spurious"
is that it will probably be well-behaved when tested on the bench while
feeding a dummy load.  A good dummy load is purely resistive, while a
duplexer input is highly reactive- just what a flaky PA needs as a trigger
to become unstable.  Any additional triggers, such as loose connections,
aging coax, or an antenna with loose elements, can quickly become a
nightmare.  It may be helpful to monitor your repeater's emissions on a
spectrum analyzer when the noise occurs.  Use a short whip on the analyzer
to pick up the signal- don't connect into the feedline at all, since doing
so will upset the conditions you want to monitor.  It's possible that the
radio itself may have a problem, and I don't think that has been ruled out
yet.

73, Eric Lemmon WB6FLY


-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of W3ML
Sent: Monday, October 05, 2009 7:25 PM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's
comments

  

Thanks Mark,

I will go read that article. Thought I read them all, since January, trying
to learn all I can.

That is when I decided to get into this repeater business. It has been a
great learning experience for sure.

73
John, W3ML

--- In Repeater-Builder@yahoogroups.com
<mailto:Repeater-Builder%40yahoogroups.com> , "Mark"  wrote:
>
> John,
> 
> I'll chime in here and agree with Chuck's suggestion to try a little more
> "fire in the wire"... 
> 
> It sounds as if your PA is less spurious now than before, but you need to
> dial it up more to eliminate all the spurious products. Solid state PAs,
> especially mobiles, are noted for this when run at considerably less than
> rated output. If I remember the beginning of the thread, this was a
> Mastr-II mobile... 
> 
> Seems as if I remember a rule of thumb that a solid state PA won't be
stable
> beginning around 60-70% of its rated output. If you're at 55W now, another
> 10-15W won't make much difference in the received signal strength, but
will
> help a LOT to stabilize the PA.
> 
> This article: http://www.repeater-builder.com/ge/mastrIIgeneral.html
<http://www.repeater-builder.com/ge/mastrIIgeneral.html>  says
> not to run Mastr-II PAs at less than 40%. In your case, you're at about
50%
> now and still a little spurious, so... crank her up a tad more (to maybe
> 70W) and see if that clears it all up. ;-) The article also has other
> suggestions on how to deal with desense.
> 
> 73,
> Mark - N9WYS
> 
> -Original Message-
> From: Repeater-Builder@yahoogroups.com
<mailto:Repeater-Builder%40yahoogroups.com>  On Behalf Of W3ML
> 
> I probably will turn it up more to see what happens. When I had it at 5
> watts out we had no problems at all.
> 
> Over the 10 watts is when the noise was really bad. Now at 55 it works and
> then it doesn't and then it works again.
> 
> So, yes I still have something wrong and maybe one of these days I will
get
> another grant and convince the club to buy another GE Mastr II and and a
new
> antenna and coax. Maybe that will fix it. 
> 
> People we got radio from are not answering.
> 
> John
> 
> 
> --- In Repeater-Builder@yahoogroups.com
<mailto:Repeater-Builder%40yahoogroups.com> , "Chuck Kelsey" 
wrote:
> >
> > I'd suggest turning the power up more. You have it set at about 50% and
> the 
> > transmitter may be intermittently spurious at that level.
> > 
> > Watch the wattmeter when things act up and see if anything changes when
> you 
> > notice the desense happening. You can also pull the TX ICOM when the
> problem 
> > is happening and see if the receive clears up on the local speaker.
> > 
> > There are so many things that could be at fault - loose connector, bad 
> > antenna, problem with transmitter, problem with receiver, intermod
issue, 
> > etc.
> > 
> > Ask the people you got the radio from if they had the same problem with
> it.
> > 
> > Chuck
> > WB2EDV
>

Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Chuck Kelsey]

That's typical. Duplex is a different animal. If there's a slight problem 
with a connection in the antenna, it will show up in duplex service.

Chuck
WB2EDV


- Original Message - 
From: "W3ML" 
To: 
Sent: Monday, October 05, 2009 10:54 PM
Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's 
comments


> >
> Funny thing is when I hook the G7 to a regular 2 meter radio and transmit 
> on simplex, it works really well, hearing stations far a way and putting 
> out a solid signal.
>
> 73
> John
>
> 

RE: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Eric Lemmon]

Tom,

You mentioned in an earlier posting that you had a six-cavity duplexer.
Most six-cavity duplexers will have an insertion loss of about 2.25 dB,
which means that with 70 watts in, you should see about 42 watts out.  If
you actually were measuring 45 watts out with 55 watts in, your duplexer has
an insertion loss of only 0.9 dB.  If your measurements are accurate, the
duplexer tuning seems to be way off.  What make and model duplexer is it?
What instrument are you using to measure RF power?

73, Eric Lemmon WB6FLY
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of W3ML
Sent: Monday, October 05, 2009 7:54 PM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's
comments

  

Thanks Tom,

Yes, the advice is all good and I have tried several of the suggestions and
most, if not all, did help some.

Tomorrow, I will turn it up to 70 watts out, which should give me 60 out of
the duplexer, if it works like it does not at 55 and 45 out.

Then we will see what happens.

In fact I did hook it up to another antenna on an adjacent tower. It worked
worse than the G7.

Funny thing is when I hook the G7 to a regular 2 meter radio and transmit on
simplex, it works really well, hearing stations far a way and putting out a
solid signal.

73
John

--- In Repeater-Builder@yahoogroups.com
<mailto:Repeater-Builder%40yahoogroups.com> , Tom Parker  wrote:
>
> Well then, that's what everyone on this group is here for. All you have 
> to do is ask, and you've done that. All the advice tonight is valid, so 
> now you need to make some measurements. You definitely need an iso-tee, 
> and good watt meter, i.e., Bird or Telewave, and a service monitor with 
> at least a spectrum analyser would be a good start. Read the RB page 
> and follow the suggestions. We actually had a couple of Mastr II 
> mobiles rigged as repeaters, but we didn't de-rate the PA's. They saw 
> heavy use with zero problems for over ten years before we replaced them 
> with stations. Of course the tower building was a constant 74oF in the 
> Texas sun and the A/C ran most of the winter. It's a shame there's not 
> another antenna on the tower you could "borrow" for a few minutes.
> 
> thp
> 
> W3ML wrote:
> 
> > 
> >
> > Thanks Tom,
> >
> > Getting help around here is the hard part. I am the most experience 
> > and that is mostly from book reading and now a little playing around 
> > with the radio. No one else knows anything about repeaters either.
> >
> > We are just now getting into the repeater stage for our club.
> >
> > 73
> > John
> >
> > --- In Repeater-Builder@yahoogroups.com
<mailto:Repeater-Builder%40yahoogroups.com>  
> > <mailto:Repeater-Builder%40yahoogroups.com>, Tom Parker  wrote:
> > >
> > > Mastr II is a good radio. Likely not much wrong with it. They're a
> > > great deal better than most of what you buy today; however, we're 
> > pretty
> > > impressed with the Kenwood TKR's in our shop for mid tier units. Our
22
> > > trunk sites are made up of Micors, Mastr II's, Johnsons, and one 
> > site of
> > > MSR 2000's and one site of R1225's with Henry amps. Most are five
> > > channel and up. The TKR's are in stand alone situations or
conventional
> > > users who own their on.
> > >
> > > You ought to stick with what you have and work out the problems or get
> > > some help.
> > >
> > > thp
> > >
> > > W3ML wrote:
> > > >
> > > >
> > > > I probably will turn it up more to see what happens. When I had it
at
> > > > 5 watts out we had no problems at all.
> > > >
> > > > Over the 10 watts is when the noise was really bad. Now at 55 it 
> > works
> > > > and then it doesn't and then it works again.
> > > >
> > > > So, yes I still have something wrong and maybe one of these days I
> > > > will get another grant and convince the club to buy another GE Mastr
> > > > II and and a new antenna and coax. Maybe that will fix it.
> > > >
> > > > People we got radio from are not answering.
> > > >
> > > > John
> > > >
> > > > --- In Repeater-Builder@yahoogroups.com
<mailto:Repeater-Builder%40yahoogroups.com>  
> > <mailto:Repeater-Builder%40yahoogroups.com>
> > > > <mailto:Repeater-Builder%40yahoogroups.com>, "Chuck Kelsey"
> > > >  wrote:
> > > > >
> > > >

Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[TGundo 2003]

Well, you don't really need my input, you certainly have gotten plenty of 
quality responses tonight...

Don't let the flurry of ideas overwhelm you. Take it one step at a time. You 
still might be too low on the power output. I had a transmitter
that didnt like to be turned down less than 2/3 rated power, at 1/2
power it would create problems on the reciever, its spurs would mix
with some local 2-way stuff and come thru on the receiver from time to
time, had me convinced it was local interference and I needed
filtering. Turning up the power solved the problem. KISS method is
always a worth a try. There are way more qualified guys on the list here to 
help you, but here is what I would do (without having a spectrum analyzer to 
look at your output):

1. Terminate the TX into a dummy load. Turn the power up to 80W. Key the 
transmitter for a good long time and get it warmed up. Keep your wattmeter in 
line and watch it, make sure it stays stable at 80W. If you notice it acting up 
then you have a problem in the radio. If not- go to step two. 

2. Once the transmitter is nice and warmed up have someone with a weaker signal 
start giving you a signal on the input. Leave the transmitter hooked up to the 
dummy load for this test and the reciever hooked up to the antenna system. 
First, disable the transmitter and have them continue transmissions while you 
monitor the input. It may take several tests like this if it is outside 
interference, since it's likely not consistent. Try and notate any particular 
times of day the noise happens to get a better clue into this. If you do hear 
the noise, then you know its interference or something in the antenna system. 
If not, then move on to step three.

3. With your friend still sending a signal on the input enable the transmitter 
into the dummy load. If the noise appears then something in the radio is amiss, 
like the PA is going spurious or there's a bad jumper or connector somewhere . 
If not- move onto step four.

4. Reconnect everything back to normal. Leave the power level at 80W. If the 
noise re-appears then you still need to look into the antenna system. The G7 
could have a problem, or something in the feedline. If all is well then it was 
likely the power level of the PA was still too low. Problem solved!

Hopefully one of these steps without the proper test gear will get you pointed 
in the right direction. Let us know your findings!

Tom
W9SRV

--- On Mon, 10/5/09, W3ML  wrote:

From: W3ML 
Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's 
comments
To: Repeater-Builder@yahoogroups.com
Date: Monday, October 5, 2009, 7:33 PM

Hi Tom,



I did crank up the power to 55 watts out of radio and that gives me 45 out of 
the duplexer.  Decided on this wattage until I can figure the problem better. 
It is working better than before, but still having trouble.

So from what you said about power coming out duplexer, the duplexer must still 
be okay.

However, during the day today there were 3 hams talking and they said (later) 
that all of them were loud and clear. But, when I got home and tried to call 
one of them, he was covered in noise.

Later one of the others called in and he would be clear, then the repeater 
would cut out and his signal would be gone, then it would come back with noise 
on his signal and then clear again.

Then the other one came in with a lot of noise, then he would come in with a 
little noise and then no noise at all and then back again through this cycle.
 
This cycle of noise and then no noise is driving me crazy.

The set up is this:

GE Mastr II VHF mobile running into a 6 cavity duplexer set to our freqs with a 
service monitor prior to bringing it here. 

There is a bandpass filter on the receive side after the duplexer and before 
the radio.

We have used 1/2 inch hardline going up to the used G7-144.

Then only thing I can think of is the radio is bad, the antenna is no good and 
the coax is shot.

Now, the radio was given to us by a group that had used it, but decided to 
replace it with a Kenwood.

I am thinking that they had the same problem and that is why they gave it away.

Any advice would be greatly appreciated. 

73
John, W3ML


- In Repeater-Builder@yahoogroups.com, W9SRV  wrote:
>
> Ok-
> 
> 1. Where are you checking the swr at in the chain? Make sure you bypass the 
> duplexers to check the antenna, the cans can throw off the reading on some 
> meters like you describe using. If you are less than 1.5:1 I would not worry 
> too much more about it, any reflected power will get eaten up back in the 
> cans. If you are really concerned about protecting the TX put a circulator 
> in-line with it. 
> 
> 2. Make sure all the interconnecting cables are good shielded and not foil/ 
> braid type. RG-213 and RG-400 are good choices, though there are a few more.
> 
> 3. Terminate into a good dummy load. Set you output power to 80-90W. 

Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Nate Duehr]

Just throwing a side-comment in here...

How do you know if a PA is spurious or if you're bothering your  
spectrum neighbors?  You MUST MEASURE IT.

Beg, borrow, or steal the proper test gear for working on repeaters  
and this whole "process of elimination by e-mail" disappears...

Spectrum analyzer, and/or a good RF Service Monitor, a known good- 
quality dummy load, "bias T" or directional coupler, high-quality  
double-shielded test cables, Bird or other good quality Wattmeter...  
all these things really SHOULD make their way into any Repeater- 
Builder's box of tricks, sooner or later.

We've ALL seen repeaters that "worked the 1st time out" without  
measuring anything.  We've all also seen repeater owners fight and  
claw and struggle for months trying to figure out a problem, without  
the proper test gear, and wondering if they'll ever figure it out.

It's s much less time-consuming and easier to just measure the  
repeater and find the problem than to go back and forth with symptoms  
and possible solutions.

When I started reading this thread, my first thought was "desense  
isn't caused by changes in RF power".  Of course, I also thought, "The  
MASTR II PA is known for going spurious at low power settings, wonder  
which PA he has... the little one with only a driver, or a 110W one  
that could likely freak out at that low a power."  Then the new  
symptom that measured SWR was changing with power level... "Oh man,  
that thing's probably throwing spurs", I thought to myself... but...

I kinda refuse to get into guessing games.  It just leads to making  
more problems you have to fix later if we all guess wrong.

The way to find out if the PA is spurring, is to look at the output of  
the repeater on a Spectrum Analyzer.

(And if you don't know, how do you know you're within your coordinated  
repeater spectrum limits?  Is there an adjacent pair repeater above/ 
below you?  Do you owe it to them to KNOW and not be guessing?)

Trying to troubleshoot repeaters without begging, borrowing, or  
stealing the proper test gear, is kinda like shooting fish in a  
barrel, but in a dark cave with no lights on...

You might hit the fish, or you might blow your foot off.

Don't wait until the adjacent repeater pair repeater owner sends you  
and the coordinator a nasty-gram.  Ya know?  If you're throwing spurs,  
you need to fix your station... and if you don't know if you're  
throwing spurs, you need to find out... and the only way to do that  
is...

Measure it.

--
Nate Duehr, WY0X
n...@natetech.com

Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Nate Duehr]

P.S. Before I get flame-broiled by the group for "being mean"...

Realize that I'm not an ogre, and the answers you're getting from  
other folks might sound more friendly, and so far, they're all leading  
the right direction too, it'll just be a long "journey" to get there  
without the proper test gear.

None of the below is meant in anger or in any way "negative".  In  
fact, you MUST imagine me asking the questions below with a twinkle in  
my eye and a friendly inquisitive but forceful demeanor to "get" how I  
would ask the questions in person, if they were posed on the phone, or  
face-to-face.

A repeater guru who taught me once asked, with that same twinkle in  
his eye, right after I said that "I thought" XYZ was wrong with my  
repeater...

"Are you a thinkin' man, or are you a KNOWIN' man?"

:-) <--- NOTE BIG SMILE... and a real one on my face, typing this.

Here's something I've always wanted to do, but never had time... write  
up the learning process I personally went through, including ALL of  
the annoying things I've chased and troubleshot on repeaters that led  
me to buy (or beg, or steal... okay, not steal... but you know what I  
mean) the right test gear over the last number of years.  All those  
"learning experiences" put together in story format, might convince  
someone that:

a) Repeater operation just isn't for them.
b) Repeater operation is just bloody expensive to do right.
c) Repeater operators are crazy and often spend as much time/money/ 
effort on really well done repeaters as the most crazed HF contester  
does on his station.  (Yep! That's it!)

Nate WY0X

On Oct 5, 2009, at 11:37 PM, Nate Duehr wrote:

> Just throwing a side-comment in here...
>
> How do you know if a PA is spurious or if you're bothering your
> spectrum neighbors? You MUST MEASURE IT.
>
> Beg, borrow, or steal the proper test gear for working on repeaters
> and this whole "process of elimination by e-mail" disappears...
>
> Spectrum analyzer, and/or a good RF Service Monitor, a known good-
> quality dummy load, "bias T" or directional coupler, high-quality
> double-shielded test cables, Bird or other good quality Wattmeter...
> all these things really SHOULD make their way into any Repeater-
> Builder's box of tricks, sooner or later.
>
> We've ALL seen repeaters that "worked the 1st time out" without
> measuring anything. We've all also seen repeater owners fight and
> claw and struggle for months trying to figure out a problem, without
> the proper test gear, and wondering if they'll ever figure it out.
>
> It's s much less time-consuming and easier to just measure the
> repeater and find the problem than to go back and forth with symptoms
> and possible solutions.
>
> When I started reading this thread, my first thought was "desense
> isn't caused by changes in RF power". Of course, I also thought, "The
> MASTR II PA is known for going spurious at low power settings, wonder
> which PA he has... the little one with only a driver, or a 110W one
> that could likely freak out at that low a power." Then the new
> symptom that measured SWR was changing with power level... "Oh man,
> that thing's probably throwing spurs", I thought to myself... but...
>
> I kinda refuse to get into guessing games. It just leads to making
> more problems you have to fix later if we all guess wrong.
>
> The way to find out if the PA is spurring, is to look at the output of
> the repeater on a Spectrum Analyzer.
>
> (And if you don't know, how do you know you're within your coordinated
> repeater spectrum limits? Is there an adjacent pair repeater above/
> below you? Do you owe it to them to KNOW and not be guessing?)
>
> Trying to troubleshoot repeaters without begging, borrowing, or
> stealing the proper test gear, is kinda like shooting fish in a
> barrel, but in a dark cave with no lights on...
>
> You might hit the fish, or you might blow your foot off.
>
> Don't wait until the adjacent repeater pair repeater owner sends you
> and the coordinator a nasty-gram. Ya know? If you're throwing spurs,
> you need to fix your station... and if you don't know if you're
> throwing spurs, you need to find out... and the only way to do that
> is...
>
> Measure it.
>
> --
> Nate Duehr, WY0X
> n...@natetech.com

Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Chuck Kelsey]

John -

A word of caution may be in order since you are dealing with a club.

These days, the typical ham doesn't begin to comprehend the complexity of a 
repeater system. To many, one simply needs to go out a purchase new 
equipment, plug it all together, and it runs. Wrong!

Don't let your club go down that path. The end result will be lots of money 
being spent and unhappy results. I've watched it happen.

If you are running a repeater, you WILL have problems with it, no matter 
what brand of equipment you use, no matter if it's new or used.

You appear to be taking the steps to learn about it. It's the only way 
you'll be able to cope unless the club pays a commercial two-way shop to 
maintain the system.

In the meantime, keep plugging away. It can get very frustrating at times.

Chuck
WB2EDV



- Original Message - 
>>
>> I will go read that article. Thought I read them all, since January, 
>> trying to learn all I can.
>>
>> That is when I decided to get into this repeater business.  It has been a 
>> great learning experience for sure.
>>
>> 73
>> John, W3ML
> 

Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Eric Lowell]

Your antenna needs to come down and be gone over before you buy anything new. 
Those G7s will get bad connections in them that act like diodes and rectify all 
kinds of crud to desense your otherwise good system. I understand that there is 
a document on the RB site about refurbing that antenna. You may have heard this 
before.
 
Good Luck, Eric (W1EL)

Eric Lowell
Eastern Maine Electronics Inc.
48 Loon Road
Wesley ME 04686
eme@starband.net
www.satnetmaine.com


--- On Tue, 10/6/09, W3ML  wrote:


From: W3ML 
Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's 
comments
To: Repeater-Builder@yahoogroups.com
Date: Tuesday, October 6, 2009, 5:36 PM


  



Well Chuck, there will be no new radio unless I buy it out of my pocket and 
that won't happen as I need a new rotor.

This club has no money. I was able to get a grant for emergency communications 
and that is how I ended up with the stuff we have now.

My big problem seems to be that I took this radio in for free instead of buying 
one from that ham in Florida that sells GEs for repeaters.

As I have said before being a ham for 30 years now has taught me nothing about 
the maintenance of a repeater. I have built rigs before and trouble shot many a 
good HF radio, and now I am actually somewhat having fun playing with this 
thing.

I have done more reading on repeaters than I have at my regular job and that is 
the Teaching of English Literature.

Of course if we were to buy a new one, hi hi, then there would be nothing to 
learn and we all need to keep learning to keep our brains working.

I really appreciate everyone on here helping out not only myself, but the 
others that come on here who need help and are just starting out in this area 
of ham radio like me.

73
John

--- In Repeater-Builder@ yahoogroups. com, "Chuck Kelsey"  wrote:
>
> John -
> 
> A word of caution may be in order since you are dealing with a club.
> 
> These days, the typical ham doesn't begin to comprehend the complexity of a 
> repeater system. To many, one simply needs to go out a purchase new 
> equipment, plug it all together, and it runs. Wrong!
> 
> Don't let your club go down that path. The end result will be lots of money 
> being spent and unhappy results. I've watched it happen.
> 
> If you are running a repeater, you WILL have problems with it, no matter 
> what brand of equipment you use, no matter if it's new or used.
> 
> You appear to be taking the steps to learn about it. It's the only way 
> you'll be able to cope unless the club pays a commercial two-way shop to 
> maintain the system.
> 
> In the meantime, keep plugging away. It can get very frustrating at times.
> 
> Chuck
> WB2EDV
> 
> 
> 
> - Original Message - 
> >>
> >> I will go read that article. Thought I read them all, since January, 
> >> trying to learn all I can.
> >>
> >> That is when I decided to get into this repeater business. It has been a 
> >> great learning experience for sure.
> >>
> >> 73
> >> John, W3ML
> >
>

















  

Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Ralph Mowery]

--- On Tue, 10/6/09, W3ML  wrote:

> From: W3ML 
> Subject: [Repeater-Builder] Re: Radio for repeater use Response to Tom's 
> comments
> To: Repeater-Builder@yahoogroups.com
> Date: Tuesday, October 6, 2009, 5:36 PM
> Well Chuck, there will be no new
>> 
> As I have said before being a ham for 30 years now has
> taught me nothing about the maintenance of a repeater. I
> have built rigs before and trouble shot many a good HF
> radio, and now I am actually somewhat having fun playing
> with this thing.
> 
> I have done more reading on repeaters than I have at my
> regular job and that is the Teaching of English Literature.
> 
>

When getting into the ham radio repeater business, have a good hammer ready.  
Either hit the repeater, the users or just hit yourself in the head.  I have 
been messing with the repeaters for over 30 years and have felt like doing all 
three.



  

Re: [Repeater-Builder] Re: Radio for repeater use Response to Tom's comments

[Nate Duehr]

On Oct 6, 2009, at 10:12 AM, Douglas wrote:

>
> Let me tell you a little story about this kind of problem. I had a  
> similar situation on a VHF mastr II repeater where a signal sounded  
> great one time and noisy the next. The problem turned out to be a  
> hairline crack in a solder pad that was used to bridge two circuit  
> boards and the output connectors to a circuit board, within the PA  
> assembly. It would run great power and then low power from one  
> transmission to the next. The output power would drop noticably as  
> seen on a relative signal meter on my rig. That was how I localized  
> it.
>
> When we would put a meter on the output, it had just enough sstress  
> on the cable to make a good connection and all was well, hookk it  
> back to the duplexer, and the intermittant problem returned.
>
> I suspect that same kind of thing could happen on a receiver  
> connection.
>
> The only real way to fix is to touch all the solder terminals that  
> are used for primary signal in the input or output route.
>
> Good luck. I liked to have lost my brain over that one (what brain  
> is left from the 60s).
>
> Doug
>
> KC0SDQ

MASTR II PA's can also make funny noises (really ugly stuff on a  
spectrum analyzer) if they're experiencing this type of crack at the  
PA output going into the harmonic filter board... you literally can  
HEAR it happening on the repeater's output.  Often the arcing  
happening over that joint "modulates" the FM signal in the form of a  
low-level squeal in the background of the repeater's signal, and/or a  
"frying" sound.  It's not pleasant, but also not always so bad you can  
hear it.

http://www.repeater-builder.com/ge/pix/mvc-474f.jpg

From:

http://www.repeater-builder.com/ge/mastrIIparepair.html

Look carefully.  Sometimes it's hard to spot.  There's a little strip  
of metal under that solder blob, that bridges that gap, which is  
almost under that capacitor.  Re-heating this area, you'll often find  
the problem, but be careful not to cook the cap.  We've done the  
"bump" fix, and we've also done the "just clean up the pads and re-use  
the factory metal strip" fix.  Can't say that either way is "better"  
when the screws surrounding the joint are torqued to factory  
specifications.  If either side is "loose", or "too tight" the boards  
will flex during heating and cooling and break the connection again.  
Had one that was so burnt the board itself and the "charcoal" became  
conductive and it would visibly arc over every time it was keyed.   
That one had to have both the final board and the harmonic filter  
board replaced, and was stinky.  Usually they're sneakier than that,  
though.

I was fighting with VHF PA's a couple of years ago, and when I finally  
enlisted the help of someone FAR more patient than I to completely  
rebuild one, including pulling ALL of the boards off the PA heatsink,  
scraping all of the old/dead heatsink compound off of everything and  
re-applying new, re-torquing all the screws to FACTORY specs (it's in  
the LBI, and many late model repeater PA's, not the mobiles usually,  
have stickers with the EXACT torque specs of all screw types on the PA  
board), resoldering every joint with good quality solder... etc.  A  
real "re-work" job.

This was done slowly and carefully by Scott W0KU... then following the  
"rule" we've given ourselves that ALL MASTR II PAs get an isolator...

His rebuilt PA has gone through antenna hell (long story, but let's  
just say it wasn't radiating, feeding into the isolator at 85W  
continuous for hours and hours) plus has also worked great on-the-air  
for three years now.

I now really believe that these 30 year old PA's just need a little  
bench TLC before they go up to a site, and I'm MORE than willing to go  
work them over thoroughly, and buy beers for Scott to enjoy in his  
backyard shed after the soldering and tricky stuff is done with.

I rebuilt two, they died.  Scott rebuilt one, after I explained what I  
thought I'd rushed through, or done badly, and how frustrating it was  
to see two of them die... we made a plan to meet up and work slowly  
and carefully and do a complete tear-down and rebuild on one utilizing  
whatever boards/parts we had on-hand.  That rebuilt PA has kept  
working now for a long time.

I definitely credit the removal and replacement of the completely  
dried out, dead heatsink compound as a component of much of this  
"success."  After seeing the flaky, useless "stuff" that came off the  
heatsink (the date stamp read 1981 on this particular PA), I highly  
recommend the full tear-down and rebuild of MASTR II PA's before  
giving them a week long "stress test" at 110W into a dummy load in the  
basement for a week... before they ever go anywhere near a repeater  
site.

Also I mention this, but don't think from your symptoms it's what's  
happening, but it's good info for anyone taking over a MASTR II...  
since what you're fighting is on and off receiver