RE: [Repeater-Builder] Help with Motorola amp

2009-02-05 Thread Eric Lemmon 
It's not clear (literally) which component in the pictures is suspect.
However, the N1254A amplifier was never intended, nor is it suitable, for
repeater service.  It was designed as an accessory for the MX300
ConvertaCom, where its duty cycle was very low, and it was fed just 4 to 5
watts.  The fact that it lasted as long as it did is probably luck, and
possibly a testament to its good design.

The instruction manual for the N1254A amplifier is 6881013C30 which,
unfortunately, is NLA from Motorola.  There are a few of these amplifiers
and manuals listed on one of the auction sites.

73, Eric Lemmon WB6FLY
 

-Original Message-
From: Repeater-Builder@yahoogroups.com
[mailto:repeater-buil...@yahoogroups.com] On Behalf Of The Marlins
Sent: Thursday, February 05, 2009 9:31 AM
To: repeater-builder@yahoogroups.com
Subject: [Repeater-Builder] Help with Motorola amp

Hello group,
The Fessenden Club on Hatteras Island has a Motorola brick mobile type amp
on our Two Meter repeater.
We have had this thing for years.  we feed it about 7 watts and it
faithfully puts out about sixty into our Sinclair duplexer and up to a DB
224 at about 180 ft.  This amp has crashed and one of our fellow club
members is repairing it (AA3ID).But we cant find any information
about it anywhere.
HELP !   
 K4HAT down Cape Hatteras way.
 
Amp is a Motorola N1254A, VHF
Board is the main power amp board, 84E84361B01
Unknown component is either a diode or resistor.
 
Photos attached

Re: [Repeater-Builder] Help with Motorola amp

2009-02-05 Thread Chuck Kelsey 
A photo of the entire PA may help someone identify it better. Looks like a 
resistor. If it's one of the resistors I'm thinking of, it might be cheaper to 
replace the entire board because the final transistors may be blown. But, it 
can't be certain without more information. And I'm not that much of a Motorola 
guy.

Chuck
WB2EDV



  - Original Message - 
  From: The Marlins 
  To: repeater-builder@yahoogroups.com 
  Sent: Thursday, February 05, 2009 12:30 PM
  Subject: [Repeater-Builder] Help with Motorola amp


  Hello group,
  The Fessenden Club on Hatteras Island has a Motorola brick mobile type amp 
on our Two Meter repeater.
  We have had this thing for years.  we feed it about 7 watts and it faithfully 
puts out about sixty into our Sinclair duplexer and up to a DB 224 at about 180 
ft.  This amp has crashed and one of our fellow club members is repairing it 
(AA3ID).But we cant find any information about it anywhere.
  HELP !   
   K4HAT down Cape Hatteras way.

  Amp is a Motorola N1254A, VHF
  Board is the main power amp board, 84E84361B01
  Unknown component is either a diode or resistor.

  Photos attached