[Repeater-Builder] Re: pre-amp placement

[skipp025]

Hello John, 

> "W3ML"  wrote:
> Hi, 

not since high school... :-) 

> I have now read two different things about where to put 
> the pre-amp.

Only two?

> One says before the Bandpass and one after.
> What I have now is the 6 can duplexer is hooked to the 
> bandpass and then on the other side the pre-amp is 
> connected and then a cable goes from preamp to radio.

> The other article I read this past week says the preamp 
> should go between the cans and the bandpass.

> Which is right?  Or does it matter?

Depends and it does matter... based on how busy your radio 
site is, where any other rf activity is relative to your 
frequency, the type of preamplifier, how it's constructed, 
your receiver front end, your duplexer type with number of 
cavities, your Tx Power level and a few other tidbits... 

got a headache yet?   

I'd venture to say... if your receiver front end is 
of decent Q (quality) and reasonably narrow band-width 
along with a decent duplexer... then the preamp might 
best go after the duplexer, between it and the band-pass 
cavity. 

If your receiver front end is average or fairly broad (a 
few MHz band-width) there might be a case to include the 
extra band pass cavity after the preamp before the 
receiver input. Some of this option depends on the duplexer 
and TX Power Level. 

The point of what I write above is about trying to obtain 
the best overload prevention performance and or damage 
control when the preamplifier is overloaded and generating 
unwanted signals. 

Many but not all the variables are are in the list. 

You could of course try both positions and measure the 
system performance. 

s. 

[Repeater-Builder] Re: setting up a repeater for dispatch

[skipp025]

> Most (even so-called "Public Safety ready") IP linking 
> systems DO NOT have ANY way to notify the dispatcher 
> that their transmissions are NOT going out over the air, 
> or that the link coming in from the field radio units is down.

... and most regular conventional Public Safety Systems do 
not normally have any way to notify dispatch their transmissions 
are not going out over the air. 

So... in each example I deal with... we figure out a practical 
way. We removed that ideal reverse burst in a Major Fire 
Dispatch System because they want to hear the repeater squelch 
close crash noise. 

We have on channel different location monitor receivers 
(normally cross muted console audio) flashing a status active 
light when ever an on-channel signal is received. 

There are many tricks of the trade to ensure systems are 
on the air. 

> The system used Multicast IP (mistake number one), UDP (maybe
> mistake number two), 

Both Multicast and UDP are not to blame... someone didn't 
engineer the system properly. 

> and when I said, "Unplug the Ethernet jack from the 
> repeater" while the dispatch console was "transmitting"... 
> there was ZERO alarm indication ANYWHERE to tell either 
> the dispatcher, the officers in the field, or the
> technicians -- THAT THE SYSTEM WAS DOWN.

Once again...someone didn't engineer the system properly. 

Wow Nate... now how do you really feel about VoIP/RoIP?  

:-) 

cheers, 
s. 

Re: [Repeater-Builder] Re: $2000 Motrac era repeater!

[Rev. Robert P. Chrysafis]

the stupidity on craigslist and ebay never ceases to amaze me :)


- Original Message - 
From: "JOHN MACKEY" 
To: 
Sent: Wednesday, November 25, 2009 11:35 PM
Subject: Re: [Repeater-Builder] Re: $2000 Motrac era repeater!


> I'll undercut you and give the bargain basement sale of a Micor repeater 
> ready
> to go on the 2 meter channel of choice with Zetron 38max controller & 
> duplexer
> for $4500.00!!
>
> -- Original Message --
> Received: Wed, 25 Nov 2009 06:49:06 PM PST
> From: "kc7stw" 
> To: Repeater-Builder@yahoogroups.com
> Subject: [Repeater-Builder] Re: $2000 Motrac era repeater!
>
>>
>>
>> --- In Repeater-Builder@yahoogroups.com, "JOHN MACKEY"  
>> wrote:
>> >
>> > http://portland.craigslist.org/clc/ele/1477806751.html
>> >
>>
>>
>> Well in this case.  I have a Motorola Micor Base repeater ready to go on
> 145.270 100watts with Sinclair duplexers for 5000.0 ?!?!  ;)
>>
>> I will throw in the Zetron 38max for a extra grand..
>>
>> LMFAO!
>>
>>
>
>
>
>
>
> 
>
>
>
> Yahoo! Groups Links
>
>
>
> 

Re: [Repeater-Builder] Re: $2000 Motrac era repeater!

[JOHN MACKEY]

I'll undercut you and give the bargain basement sale of a Micor repeater ready
to go on the 2 meter channel of choice with Zetron 38max controller & duplexer
for $4500.00!!

-- Original Message --
Received: Wed, 25 Nov 2009 06:49:06 PM PST
From: "kc7stw" 
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] Re: $2000 Motrac era repeater!

> 
> 
> --- In Repeater-Builder@yahoogroups.com, "JOHN MACKEY"  wrote:
> >
> > http://portland.craigslist.org/clc/ele/1477806751.html
> >
> 
> 
> Well in this case.  I have a Motorola Micor Base repeater ready to go on
145.270 100watts with Sinclair duplexers for 5000.0 ?!?!  ;)
> 
> I will throw in the Zetron 38max for a extra grand..
> 
> LMFAO!
> 
> 

Re: [Repeater-Builder] pre-amp placement

[Glenn Little WB4UIV]

If the preamp has helical resonators on the input, it should not matter.
If the preamp does not have preselection, after the bandpass filter, 
unless you like the intermod that will be generated in the preamp.

73
Glenn
WB4UIV

At 10:46 PM 11/25/2009, you wrote:
>Hi,
>
>I have now read two different things about where to put the pre-amp.
>
>One says before the Bandpass and one after.
>
>What I have now is the 6 can duplexer is hooked to the bandpass and 
>then on the other side the pre-amp is connected and then a cable 
>goes from preamp to radio.
>
>The other article I read this past week says the preamp should go 
>between the cans and the bandpass.
>
>Which is right?  Or does it matter?
>
>73
>John
>
>
>
>
>
>
>
>
>
>
>Yahoo! Groups Links
>
>
>

[Repeater-Builder] pre-amp placement

[W3ML]

Hi,

I have now read two different things about where to put the pre-amp.

One says before the Bandpass and one after.

What I have now is the 6 can duplexer is hooked to the bandpass and then on the 
other side the pre-amp is connected and then a cable goes from preamp to radio.

The other article I read this past week says the preamp should go between the 
cans and the bandpass.

Which is right?  Or does it matter?

73
John

[Repeater-Builder] Re: $2000 Motrac era repeater!

[kc7stw]

--- In Repeater-Builder@yahoogroups.com, "JOHN MACKEY"  wrote:
>
> http://portland.craigslist.org/clc/ele/1477806751.html
>


Well in this case.  I have a Motorola Micor Base repeater ready to go on 
145.270 100watts with Sinclair duplexers for 5000.0 ?!?!  ;)

I will throw in the Zetron 38max for a extra grand..

LMFAO!

Re: [Repeater-Builder] Another unknown duplexer

[Paul Holm]

I didn't measure the wall thickness.  They are relatively thin and 
lightweight, while the flange is thick.  Definitely aluminum or some other 
very lightweight metal.


- Original Message - 
From: "Joe"  I've never seen a set like that, but the cans look like they are made
> out of rigid coaxial line, the kind used for high power FM and TV
> broadcast stations.  I'm guessing that is what it is made out of because
> of the flange on the top.  I'm curious, what is the thickness of the
> outer walls on the cans?  Rigid coax was thick walled compared to
> regular hardline.
>
> Joe
>

>
>
>
>
>
> 

Re: [Repeater-Builder] $2000 Motrac era repeater!

[Jim WB5OXQ inb Waco, TX]

I have 3 Motorola high band transmitters of anyone is interested.  these were 
paging transmitters on 152.240 and put out 275 watts I believe.  Any of these 
could be teamed up with a vhf receiver to make a repeater.  Now they have 70mhz 
receivers in them with the necessary controls to make them repeat what they 
hear on the link frequency.  They also have hi stability oscillators.  I 
believe they are Micor type units and each has a pair of 4cx250 tubes in them.  
7' cabinets at over 300 pounds each.  Located in Waco, TX.  If anyone wants one 
let me know.  They are doing me no good.  WB5OXQ  I am good in QRZ.

  - Original Message - 
  From: JOHN MACKEY 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Wednesday, November 25, 2009 1:44 AM
  Subject: [Repeater-Builder] $2000 Motrac era repeater!



  http://portland.craigslist.org/clc/ele/1477806751.html



  

Re: [Repeater-Builder] Another unknown duplexer

[Joe]

I've never seen a set like that, but the cans look like they are made 
out of rigid coaxial line, the kind used for high power FM and TV 
broadcast stations.  I'm guessing that is what it is made out of because 
of the flange on the top.  I'm curious, what is the thickness of the 
outer walls on the cans?  Rigid coax was thick walled compared to 
regular hardline.

Joe

Paul Holm wrote:
>
>
> This set of cans has been in our club since before I was involved.  
> None of us seem to recall where this thing came from or who made it.  
> Does anyone recognize this one?
>  
> 
>  

RE: [Repeater-Builder] Spectra Audio Popping after Capacitor replacement

[Tim Ahrens]

Hi Mike,

Thanks for the info. 

Yes, I've cleaned it up good... I use a q-tip with
a baking soda/water combo, then wick solder on
the pad till it flows... sometimes gotta scrape a
shiny spot first.  Then soldersuck the pad &
clean up with wick.  Then another qtip with
lacquer thinner (contains MEK) - does great job
of cleaning the flux.  Nice & sparkly clean.

The smell of the solder on the corroded pad
reminds me of some solder I have that has
a water soluble rosin.  Kinda smells like fish.

It's probably the audio amp, but it's not
objectionable enough to make me want to
change it out.

It's amazing how many dead radios are coming
back to life after re-capping!  Of course some of
the problems were traces that had disappeared!

Thanks,

Tim

[Repeater-Builder] Re: 900mhz MASTR II Parts

[n0fpe]

NO LONGER AVAIABLE AT THIS TIME>






--- In Repeater-Builder@yahoogroups.com, "n0fpe"  wrote:
>
> Ok I am going to start parting out the 3 900mhz MASTR II repeaters I have. I 
> will have high power PA's <24volt ya know> transmitters, receivers, GETC 
> controllers . I think I even have the master ocsillator in 
> the pile someplace. I have the 24 volt power supplies but there is no way I 
> am going to ship those monsters. Feel free to drop me a note if there is 
> something you want and we will see if we can work a deal.
> 
> Email to  n0...@...
> 
> 73  Dan/NØFPE
>

RE: [Repeater-Builder] Spectra Audio Popping after Capacitor replacement

[Mike Morris WA6ILQ]

>-Original Message-
>From: Repeater-Builder@yahoogroups.com 
>[mailto:repeater-buil...@yahoogroups.com] On Behalf Of tahrens301
>Sent: Tuesday, November 24, 2009 2:43 PM
>To: Repeater-Builder@yahoogroups.com
>Subject: [Repeater-Builder] Spectra Audio Popping after Capacitor replacement
>
>Hi Folks,
>
>I've been working on these Spectras, and so far,
>the capacitors have done the trick.
>
>But on this last radio, the speaker pops whenever
>the audio path is open (unsquelched, signal, mode
>change, etc).
>
>Just curious if there's something I've missed.
>
>Thanks,
>
>Tim

The popping is due to a DC voltage change at the input to the
speaker amp.   Leaky caps are the most common cause of
this, but if you've changed the caps and not cleaned up the cap
residue on the board the crud can be conductive and essentially
shunt the new cap with a resistor.   So cleaning the board of all
leftover residue may help.   I've been told the residue contains
boric acid, I'm not a chemist, does anybody know what a good
neutralizer is for that ?  If I knew, I'd use that, then some MEK
(which you can find in cans in the paint section at Home Depot).

Mike WA6ILQ

RE: [Repeater-Builder] $2000 Motrac era repeater!

[Chris Quirk]

Just surprised it did not end up on Ebay

--- On Wed, 11/25/09, JOHN MACKEY  wrote:


From: JOHN MACKEY 
Subject: RE: [Repeater-Builder] $2000 Motrac era repeater!
To: Repeater-Builder@yahoogroups.com
Date: Wednesday, November 25, 2009, 12:50 PM


I hope your thanksgiving is also well!

-- Original Message --
Received: Wed, 25 Nov 2009 06:49:22 AM PST
From: 
To: 
Subject: RE: [Repeater-Builder] $2000 Motrac era repeater!

> Hi John,
> 
>  
> 
> Now that is funny, I got quite a chuckle out of that post. 
> 
>  
> 
> I hope you and your family have a happy Thanksgiving.








Yahoo! Groups Links






  

RE: [Repeater-Builder] $2000 Motrac era repeater!

[JOHN MACKEY]

I hope your thanksgiving is also well!

-- Original Message --
Received: Wed, 25 Nov 2009 06:49:22 AM PST
From: 
To: 
Subject: RE: [Repeater-Builder] $2000 Motrac era repeater!

> Hi John,
> 
>  
> 
> Now that is funny, I got quite a chuckle out of that post. 
> 
>  
> 
> I hope you and your family have a happy Thanksgiving.

Re: [Repeater-Builder] 900mhz MASTR II Parts

[Reid Brandon]

Hi, what do you want for a 900 MHz rcvr?Also is there a low pass
filter available from one of the transmitters or does GE use an internal one
like on the Mastr II? Reid  W6MTFQuoting n0fpe
:
 



  





  Ok I am going to start parting out the 3 900mhz MASTR II repeaters I
have. I will have high power PA's <24volt ya know> transmitters,
receivers, GETC controllers . I think I even have the master ocsillator in
the pile someplace. I have the 24 volt power supplies but there is no way I am
going to ship those monsters. Feel free to drop me a note if there is something
you want and we will see if we can work a deal.

Email to  n0...@cox.net

73  Dan/NØFPE














  

Re: [Repeater-Builder] Another unknown duplexer

[N9LLO]

Don't know where they came from but our club has one just like it on a 100w 
 MSF5000.
Works very well
 
Chris
N9LLO
 
 
In a message dated 11/25/2009 9:52:05 A.M. Eastern Standard Time,  
p...@chargertech.com writes:

 
 
 
This set of cans has been in our club since  before I was involved.  None 
of us seem to recall where this thing came  from or who made it.  Does anyone 
recognize this one?
 
<_http://groups.http://grohttp://groups.http://groups.http://groups.http://groups.yahoo.com/group/Repeater-Builder/photos/album/700689718/pic/list)
 >
 
The cavities are about 4" in diameter and are 23"  long.  The top plate is 
heavy brass and is made to fit 6 spaces in a 19"  rack.  At first glance it 
almost looks like it is homebrewed.  The  cavities are not silver plated.  
But some things make it appear to be of  commercial origin.  The aluminum 
cavities have very neatly welded top  mounting flanges and bottom endcaps, and 
are anodized/alodized.  Also,  the tuning rod lock nut assemblies appear to 
be custom fasteners, and the  center elements have nice fingerstock at the 
bottom.
 
We used this on a temporary, low-power machine a  few years ago.  Now, we'd 
like to really go through it and tune it up for  a another machine.  While 
I had it here, I thought I'd try to figure out  where it came from.  Thanks.
 
 
73  Paul - KC0HST
 
 

[Repeater-Builder] DB-224 Phasing Harness

[Michael Ryan]

Good morning.

I recall some discussion from the group about obtaining a replacement
wiring/phasing harness for the DB-224.  I am trying to help a group using
one of these antennas that operates in the 150 - 159mhz band.  Can anyone
offer some information about obtaining the phasing harness?-  Thanks.

n  Mike

   

Re: [Repeater-Builder] Another unknown duplexer

[no6b]

At 11/25/2009 06:50, you wrote:


>This set of cans has been in our club since before I was involved.  None 
>of us seem to recall where this thing came from or who made it.  Does 
>anyone recognize this one?
>
><http://groups.yahoo.com/group/Repeater-Builder/photos/album/700689718/pic/list>
>

I've worked with a set of those once.  I was told they were made by "North 
Shore".  Never could get very good isolation out of them.  We ended up 
chopping them up into individual cans & converting them to pass only, & 
converting some of those to 220 by cutting down the center tube - wish I 
had some of those now.

Bob NO6B

RE: [Repeater-Builder] Another unknown duplexer

[k7pfj]

Well I haven't seen these cavities in some time. They look like an early
version of the Fred Voight series of filters. They seemed to work with a bit
more loss than your commercial Sinclair 6 can Bp/Br cans. 

 

Mike

 

 

Mike Mullarkey K7PFJ

 

 

  _  

From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Paul Holm
Sent: Wednesday, November 25, 2009 7:50 AM
To: Repeater Builder Reflector
Subject: [Repeater-Builder] Another unknown duplexer

 

  

This set of cans has been in our club since before I was involved.  None of
us seem to recall where this thing came from or who made it.  Does anyone
recognize this one?

 

 yahoo.com/group/Repeater-Builder/photos/album/700689718/pic/list>

 

The cavities are about 4" in diameter and are 23" long.  The top plate is
heavy brass and is made to fit 6 spaces in a 19" rack.  At first glance it
almost looks like it is homebrewed.  The cavities are not silver plated.
But some things make it appear to be of commercial origin.  The aluminum
cavities have very neatly welded top mounting flanges and bottom endcaps,
and are anodized/alodized.  Also, the tuning rod lock nut assemblies appear
to be custom fasteners, and the center elements have nice fingerstock at the
bottom.

 

We used this on a temporary, low-power machine a few years ago.  Now, we'd
like to really go through it and tune it up for a another machine.  While I
had it here, I thought I'd try to figure out where it came from.  Thanks.

 

 

73  Paul - KC0HST

 

 



No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.425 / Virus Database: 270.14.80/2523 - Release Date: 11/24/09
07:46:00

[Repeater-Builder] Another unknown duplexer

[Paul Holm]

This set of cans has been in our club since before I was involved.  None of us 
seem to recall where this thing came from or who made it.  Does anyone 
recognize this one?



The cavities are about 4" in diameter and are 23" long.  The top plate is heavy 
brass and is made to fit 6 spaces in a 19" rack.  At first glance it almost 
looks like it is homebrewed.  The cavities are not silver plated.  But some 
things make it appear to be of commercial origin.  The aluminum cavities have 
very neatly welded top mounting flanges and bottom endcaps, and are 
anodized/alodized.  Also, the tuning rod lock nut assemblies appear to be 
custom fasteners, and the center elements have nice fingerstock at the bottom.

We used this on a temporary, low-power machine a few years ago.  Now, we'd like 
to really go through it and tune it up for a another machine.  While I had it 
here, I thought I'd try to figure out where it came from.  Thanks.


73  Paul - KC0HST

RE: [Repeater-Builder] $2000 Motrac era repeater!

[k7pfj]

Hi John,

 

Now that is funny, I got quite a chuckle out of that post. 

 

I hope you and your family have a happy Thanksgiving.

 

Mike

 

 

Mike Mullarkey K7PFJ

 

 

  _  

From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of JOHN MACKEY
Sent: Wednesday, November 25, 2009 12:44 AM
To: Repeater-Builder@yahoogroups.com
Subject: [Repeater-Builder] $2000 Motrac era repeater!

 

  

http://portland. 
craigslist.org/clc/ele/1477806751.html



No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.425 / Virus Database: 270.14.80/2523 - Release Date: 11/24/09
07:46:00

RE: [Repeater-Builder] Spectra Audio Popping after Capacitor replacement

[David Murman]

Yes, you are correct. The hear clear is only used in the 900 mhz
spectra. Changing the CAPS should help especially aroung the audio amp
chip. I have not had any issues with the VHF Spectras giving a popping
sound except I had to replace the audio amp chip in one. It was fun to
do but at the same time I replaced the capacitors.
 
I purchased the audio amp chips from Motorola and they weren't too
expensive. Sounds like you may have found your problem with the audio.
Good luck in the repair of the Spectra.
 
 
 
David 
 
-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of Tim Ahrens
Sent: Tuesday, November 24, 2009 10:32 PM
To: Repeater-Builder@yahoogroups.com
Subject: RE: [Repeater-Builder] Spectra Audio Popping after Capacitor
replacement
 
  
Hi David,

Is the Hear Clear board only on the 900 mhz spectras?

I was looking in my service manual, and it talks about
the board plugging into P501, but on my VHF spectras,
this plug is unpopulated..

As a side note, when I went to replace the capacitors,
I noticed that a fire ant had given it's life while spanning
a couple of pins on the audio output TDAxxx part. There
seemed to be some 'liquid ant residue' remaining, so perhaps
it damaged the audio amp. I guess I'll have to look at
the thing with the scope & see what's going on in comparison
to one that works 'correctly'.

Thanks!

Tim

Re: [Repeater-Builder] Re: Cheap: Canadian Marconi Repeater.

[Tedd Doda]

va...@rogers.com wrote:
> I'll be in probably next Tuesday afternoon, Tedd...

Hi Keith,

Did you want the repeaters as well? A couple guys from VE2 land
were interested, but as soon as they saw your post thought they
were sold.

Thanks,


Tedd Doda, VE3TJD

Lazer Audio and Electronics
http://www.ve3tjd.com

My idea of a symphony: 8 pistons playing the tune
my right foot tells them to.

Re: [Repeater-Builder] Best coax for marine use

[Eric Lowell]

He'll get as far or further than the hundreds of RG58 installations I've seen. 
I was at least attempting to offer a helpful opinion rather than trolling.
 Eric Lowell
Eastern Maine Electronics Inc.
48 Loon Road
Wesley ME 04686
eme@starband.net
www.satnetmaine.com
207-210-7469 





From: Vernon Densler 
To: Repeater-Builder@yahoogroups.com
Sent: Tue, November 24, 2009 1:14:09 PM
Subject: RE: [Repeater-Builder] Best coax for marine use

  
But how far can you get on the less than 9 watts you will have left after using 
a cable with that much loss?  
 
From:Repeater-Builder@ yahoogroups. com [mailto:Repeater- buil...@yahoogro 
ups.com] On Behalf Of Eric Lowell
Sent: Tuesday, November 24, 2009 12:39 PM
To: Repeater-Builder@ yahoogroups. com
Subject: Re: [Repeater-Builder] Best coax for marine use
 
  
The only issue I would have with Heliax is the possiblity of cracked and broken 
solid conductors due to vibration and repeated flexing. If I were the vessel 
owner, I'd use a good grade (Belden or equivalent) of RG-8 (X if you want). 
There are not a lot of terrain features out there. I'd think you could talk 
quite a ways on 25 watts at 70 feet HAAT. 75-100 miles?
 
GL, Eric
 
Eric Lowell
Eastern Maine Electronics Inc.
48 Loon Road
Wesley ME 04686
eme@starband. net
www.satnetmaine. com
 



From:Vernon Densler 
To: Repeater-Builder@ yahoogroups. com
Sent: Tue, November 24, 2009 11:17:45 AM
Subject: [Repeater-Builder] Best coax for marine use

  
I have been in a big discussion with the guys on my boat list about the right 
coax for running up the mast for VHF marine radio.
 
Keeping in mind that we are talking about a 70’ or so run going up the center 
of an aluminum mast, in a salt water environment, and the radio is limited to 
25 watts.  
Also keep in mind that when off shore this is a life line and the best possible 
send and receive is needed in an emergency situation.  
 
So given the criteria what is the best possible coax to use knowing that 
thickness matters and bend radiuses may be tight?  Others on the list are 
saying “just grab any old 8X type cable and you will be fine”.  I say use 
something with very low loss and suggested small heliax.
 
Any suggestions?
 
Vern
s/v Nirvelli
KI4ONW
 



  

[Repeater-Builder] Re: MASTER II TO RC-210

[n3ssl]

Hi Group,

Perform a Search on www.youtube.com for GE Mastr A guy from Allentown PA has a 
good videos on what it takes to convert a mobile and do the controller install. 
Very informative


Ryan n3ssl