Hey Ron,    How about setting your Font back to at least 10 for all the 
senior citizens who like to read your stuff   :-))

73 John VE3AMZ
  ----- Original Message ----- 
  From: Ron Wright 
  To: Repeater-Builder@yahoogroups.com 
  Sent: Monday, May 12, 2008 9:34 AM
  Subject: RE: [Repeater-Builder] Re: Adding Control Receiver without Separate 
Antenna


  I would recommend not using a 12.5 kHz spacing freq in this case of a control 
receiever, a receiver that is only 12.5 kHz away from your regular repeater 
input.


  With typical good FM analog receivers these would both have overlapping 
passbands and an input signal on the repeater input would interfer with the 
control input.  With som many using IC type DTMF decoders any interference, 
just over lapping distorted voice would hender the decoder decoding.


  A typical UHF duplexer would have a notch wide enough for a freq +/-25 kHz 
away.  Know this is going to be another repeaters input, but with some research 
could find is close in distance to you.


  I have used control UHF freq that are 6.25 kHz spacing, but these were in the 
446 range and on separate antenna.  Just had access to this.  I used this freq 
to give some added security.


  73, ron, n9ee/r




  Ron Wright, N9EE


  727-376-6575


  MICRO COMPUTER CONCEPTS


  Owner 146.64 repeater Tampa Bay, FL


  No tone, all are welcome.








  On Sun, May 11, 2008 at 10:24 PM, Laryn Lohman wrote:


  --- In Repeater-Builder@ yahoogroups. com, "John Transue" <[EMAIL PROTECTED] 
.> 
  wrote: 
  > 
  > Laryn K8TVZ, 
  > 
  >   So, if I understand, I should put a splitter after the pre-amp, and 
  > the control frequency should be a split channel. Does this mean that I 
  > use half way between two channels? 


  Right, one of the 12.5 kc. in-between channels would be less likely to 
  have something on them. 


  > 
  >   Another question, who makes a good splitter, and how can I know I am 
  > getting a good splitter? 


  Well, I've seen 50 ohm splitters quite often at hamfests.  I don't 
  have a good brand name to point you to.  I am, however, using a 75 ohm 
  TV splitter.  Purists will hate this, but especially, if you are after 
  a preamp, I don't see this as a big deal.  It works just fine here 
  with no measured loss in repeater receiver sensitivity through the 
  system.  Use quality coax and fittings.  I've found that RG142 works 
  reasonably well with the TV splitters since it has a solid center 
  conductor. 


  If you are not using a preamp, then you really need to do things 
  right, using a proper splitter, and still you may lose some sensitivity. 


  Some of you are saying, where's the quality in that splitter scheme? 
  Well, experimentally I've found it works well here, so after initial 
  measurements showed me that things were still the same, I'll tend to 
  stay with what works, but ready to ditch the whole thing if needed and 
  go another route.  Sometimes <quality> takes the form of performance, 
  not looks or perfection.  If system sensitivity had suffered it 
  wouldn't be there for more than 15 minutes. 


  Laryn K8TVZ 


   

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