More great info from Frank @ SIMREX.

    Steve ~ KA1RCI

----- Original Message ----- 
From: Frank Neuperger 
To: fr...@simrex.com 
Cc: Steven M Hodell ; maqui >> Mike Aquilino ; sa...@simrex.com 
Sent: Thursday, July 29, 2010 4:15 PM
Subject: Re: [Repeater-Builder] Fw: TKR750 -Preamp


Steve,

That did not post to the list because I don't have membership.  I would 
appreciate if you would forward to the list on my behalf. 

Regards
Frank

On 7/29/2010 3:58 PM, Frank Neuperger wrote: 
  Steven,

  Thanks for the vote of confidence.       We sell them to Hams (Ham 
frequencies)  for $275($25 less than 2-way dealers)  as a gesture to Gil Boelke 
(silenet key) who developed the preselector and founded GLB (now owned by 
SIMREX).   

  Note that the standalone preselector is still made in house by staff that 
were trained by Gil and on tooling built by Gil.  
  It is also the front end of every SNRDS-II radio.  Same radios that are part 
of many FAA and other Federal systems.     

  Standard gain is 8 db
    
  For +$25, you can order it with ~4 dB gain and steeper skirts on the filter  
or
  ~11 dB gain and gentler slope on the filter skirts.

  For extreeme  interference,  one  usage of the preselector has been to place 
a coax stub notch filter between the antenna and the preselector.  I have done  
~3MHz spacing of the notches of the comb for a marine radio BASE application 
using ~ 35?? feet of LMR 400 for my stub.   One of the notches was placed 
directly onto the frequency of collocated marine base station  giving us an 
extra 22dB of suppression at that frequency.    Using excessive length of coax 
resulting in a comb allows the overallbandwidth to repeak steeply and with 
minimal loss  between the notches of the comb.     A single notch approach (not 
a comb) when placed close to your desired carrier will often have unacceptable 
insertional loss at your desired frequency.    The comb notch filter is just 
extra coax and minimizes the insertion loss close to the notch. .  The calcs 
for length  are not too difficult.   

  Warmest Regards
  Frank Neuperger
  Simrex Corporation
  VE3FNZ
      

  ----- Original Message ----- 
  From: Steven M Hodell 
  To: Repeater-Builder@yahoogroups.com 
  Cc: sa...@simrex.com 
  Sent: Thursday, July 29, 2010 2:34 PM
  Subject: Re: [Repeater-Builder] Fw: TKR750 -Preamp


    

  Another very good choice for this application is the GLB Preselector / Preamp 
from Simrex Corp.

  I have several of these deployed on 144 /  220 / 440 Amateur repeaters and 
they all perform very well. They can be tuned to maximize gain or selectivity 
per your requirements and their support is outstanding.

  http://www.simrex.com/site/products/special.htm

  PRESELECTOR PREAMPLIFER
    a.. Low cost solution to interference, intermodulation and desensitization 
problems. 
    b.. Helical Resonator Design.

    c.. Preselector Specifications (pdf 63k) 
    d.. Preselector Example Diagram (pdf 10k)


    ----- Original Message ----- 
    From: Ken Arck 
    To: Repeater-Builder@yahoogroups.com 
    Sent: Thursday, July 29, 2010 2:15 PM
    Subject: Re: [Repeater-Builder] Fw: TKR750 -Preamp


      
    At 10:30 AM 7/29/2010, Doug Hutchison wrote:
    >
    >
    >Where does one obtain these and at what cost?

    http://www.anglelinear.com

    Chip Angle is arguably one of the top 10 RF guys in the world

    Ken
    ----------------------------------------------------------
    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!"




  

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