>From the manual it says it uses a 4 meg crystal 

Thank You ,Ian Wells
Kerinvale Comaudio,
361 Camboon road, Biloela.4715
Ph 0749922449 Mb 0409159932 
Hm 0749922574 Fx 0749922767
www.kerinvalecomaudio.com.au
 
-------Original Message-------
 
From: Don Crutcher
Date: 3/03/2010 3:04:49 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Adapting ctcss decoders to maxon pm150
 
  
Hello Ian
 
IF your repeater is a UHF and the CTCSS decoder has a 5 MHz crystal
oscillator, it will mix with the transmitter and give a signal at the
receiver frequency 5 MHz lower (in Australia RX 433-435 TX 438-440 MHz)
This a is a common occurrence with UHF Philips FM-828's.
The fix is to use a tuneable CTCSS decoder and not use the one with a
crystal oscillator in it.
Been there and done that. Took years to find out why we had a whistle in the
receiver (heterodyne).
 
Regards
Don vk2zcz
 
----- Original Message ----- 
From: Ian Wells 
To: Repeater-Builder@yahoogroups.com 
Sent: Wednesday, March 03, 2010 2:48 PM
Subject: [Repeater-Builder] Adapting ctcss decoders to maxon pm150


  
Hi guys .I was looking at adapting a midian tds-1 to a maxon pm150 but we
end up with feedback problems when used in repeater .
Can anyone suggest ideas to give rf protection to the decoder chip .I came
up with shielded cable between the board and the chip 
And to install the chip in a metal case on near the radio .or mounting it as
close to the rf motherboard as possible but I don't think 
It will fit under the lid .The reason we would like to use the tds-1 is that
the radio has to unmute before it decodes
And I would like it to decode before the signal opens the mute .This
improves the speed the repeater opening up
On a valid signal .
Thank You ,Ian Wells
Kerinvale Comaudio,
361 Camboon road, Biloela.4715
Ph 0749922449 Mb 0409159932 
Hm 0749922574 Fx 0749922767
www.kerinvalecomaudio.com.au
 




 

<<faint_grain.jpg>>

Reply via email to