[App_rpt-users] MSF to RTCM Wiring

Thu Sep 18 09:31:58 UTC 2014

OT :: I absolutely agree that the tower companies should be more ham
friendly and it would be great if the ARRL could help. But a large part of
the issue is that there are some enterprising hams that have managed to get
their own structures and either don’t have the room or they share with just
their friends. I am fortunate to pay $50 for one site and only $140 for the
second site. But the truly awesome sites controlled by the power houses
demand $700 for a ¼ of a rack.

I would love to learn from you the art of syncing the TX audio. I have a
natural cutoff where a normally full scale signal begins to drop and what we
call site #2 can naturally come in and take over. Site #3 is either going to
be on the same pair, or a different pair. I’m not sure yet. Because site #1
straddles both sides of the mountain voting does not seem to be an option.
The repeaters sites can see one another. A major part of our mission is as a
true ECOMM repeater that can disconnect Allstar nodes if a regional
emergency takes place. Because of our 6,400 foot altitude and the ability to
talk and listen over the majority of So. California site selection and power
level are key.

I’ll read and hope to learn how to connect the Motorola GPS units that pop
right into the MSF 5000’s.

Thank you for sharing your advice with me.

  _____  

From: KJ6KO [mailto:kj6ko at innercite.com] 
Sent: Wednesday, September 17, 2014 10:32 PM
To: Robert
Subject: Re: [App_rpt-users] MSF to RTCM Wiring

My friend has a GPS connected to every RTCM so the TX audio is time coded
and all repeaters TX at exactly the same time in sync.  Not sure about how
he connects the GPS to the RTCM, but I just helped him put one in a couple
weeks ago!  Guess I should have asked more about it, but I remember him
dialing into the RTCM to see if it was GPS locked!  Probably part of the
reason they are so much!

  I was thinking about writing the ARRL to complain about the tower
companies (ATC, SBA, Crown Castle etc) not being "Ham Friendly" and see if
they could lean on them!  Couldn't be worse than doing nothing!

----- Original Message ----- 

From: Robert <mailto:robert at controlservers.net>  

To: app_rpt-users at ohnosec.org 

Sent: Wednesday, September 17, 2014 3:54 PM

Subject: Re: [App_rpt-users] MSF to RTCM Wiring

The Moto modules ARE the GPS units :-) But I’ve still never done this. But
are you saying that the RTCM has a built-in GPS or that one may be
connected?

Mark called me today and said my RTCM missed shipping but is leaving today.
<silly teen-aged girl happy dance goes here >

I looked at the #2 and #3 MSF 5000 and it says that it is a C73 CBX and not
CLB’s. Hmm
 maybe the one on the hill is a CLB.

OT: Right now I am desperately looking for someone that has a small space on
Strawberry Peak in the San Bernardino Mountains. American Tower is a joke
and SubCarrier hasn’t replied. I wonder if anyone in the group has a
suggestion? Heap’s Peak is raining down on Pali Mountain with -1dBm of 99.1
on your FM freakin’ dial. If I add the Angle Linear dual cavity back in it
reduces it by 99dB (-67dBm). It’s a sharp 1MHz window.

Strawberry sees the coastal side AND the high desert side. Will $$$.

Thank you for the replies. You are all appreciated.

  _____  

From: KJ6KO [mailto:kj6ko at innercite.com] 
Sent: Tuesday, September 16, 2014 11:12 PM
To: robert at controlservers.net
Subject: Re: [App_rpt-users] MSF to RTCM Wiring

Not sure what "Moto Modules" you are talking about, but the RTCM will do
that with a GPS antenna.  No need for any special modules.  Control, repeat
and sync'd TX audio can all be done by the RTCM.  Freq can be done by GPS
also.  Maybe that's the module you are talking about?

Sounds like fun!

----- Original Message ----- 

From: Robert <mailto:robert at controlservers.net>  

To: 'KJ6KO' <mailto:kj6ko at innercite.com>  ; app_rpt-users at ohnosec.org 

Sent: Tuesday, September 16, 2014 9:16 AM

Subject: RE: [App_rpt-users] MSF to RTCM Wiring

The repeater will be one of three. Each will communicate with a master
server in a commercial data center where our business is located. If I have
read correctly this is a hub? At any rate the CLB’s will be run with RTCM as
non-voted but with synchronized TX. I have the Motorola modules for this.

  _____  

From: KJ6KO [mailto:kj6ko at innercite.com] 
Sent: Tuesday, September 16, 2014 8:27 AM
To: Robert
Subject: Re: [App_rpt-users] MSF to RTCM Wiring

Hi Robert,

  It mainly depends on how you are going to use the system.  If it is just a
stand alone repeater, the RTCM is a bit of overkill, but will work fine.  I
have done a couple of MSF's.

  Assuming this is just a standalone CLB repeater (the one with the EPROM),
and not a voted system, I like to keep things as simple as possible.
Program the repeater to be a "Base Station", NOT a repeater!.  Pull RX audio
from the DISCRIMINATOR output of the MSF and make sure the RTCM is set to
PLFILTER=YES  and  DEEPPHASIS=YES.  The COR/PL Detect on a MSF is a bit
trickey.  You have to pull it off of a chip and use a transistor to switch
it.  For TX, just use the PTT and MIC Input.  That is the simplest way.  You
can also feed raw TX audio directly into the modulator from the RTCM and
have the RTCM generate the TX PL if you like, but that is a bit more
complicated.  I have done it, but I don't really see much of an advantage.
ALl these connections are Test Points on the MSF, (Except the COR/PL) and
that makes connection easy.  ALSO, set the squelch on the RTCM a bit high!
The RTCM's squelch circuit is a bit touchy.

  NOW, if you have a CXB (programmable MSF) it is all basically the same
except that you can program an output of the MSF for "Valid PL Signal" and
use that as the COR/PL input to the RTCM.

I don't use the internal controller as the repeater.  I have never been real
satisfied with the audio quality of the MSF repeated audio.  Best to let the
RTCM do all the work and digitally filter the DISC audio rather than let the
MSF do it!  The RTCM will do all the controlling, tail, ID and courtesy
tones for you.   Also, don't forget to disable the MSF's TX Timer!  

 Unless you are using a voting system, the URI is a MUCH cheaper source and
does everything you want for just a standalone repeater, assuming you have a
computer to go with it.  I use the Beaglebone!  The URI as it will also act
as the controller, filter the DISC audio and one thing it does that the RTCM
won't do is you have REMOTE audio control!  That way, after you install the
repeater on a hilltop, and you think the audio is a bit high or low, you can
remotely bump it up or down to your hearts content!   The RTCM is all manual
control!

Good luck and 73...

Greg   KJ6KO

----- Original Message ----- 

From: Robert <mailto:robert at controlservers.net>  

To: app_rpt-users at ohnosec.org 

Sent: Monday, September 15, 2014 11:01 PM

Subject: [App_rpt-users] MSF to RTCM Wiring

I have seen so many different ways of how to wire a controller / RTCM to a
MSF 5000 – is there one sure fired way to do this? Poor eyesight on my part.
I hate being the new guy

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