OK Ian
Hope that helps.
Regards
Don
----- Original Message -----
From: Ian Wells
To: Repeater-Builder@yahoogroups.com
Sent: Wednesday, March 03, 2010 4:29 PM
Subject: Re: [Repeater-Builder] Adapting ctcss decoders to maxon pm150
Thanks don that would explain the trouble I had a couple years ago and
we setup the radios to decode on their own .that works ok but it is slow
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 4:21:09 PM
To: Repeater-Builder@yahoogroups.com
Subject: Re: [Repeater-Builder] Adapting ctcss decoders to maxon pm150
Hello again Ian
I've also tried a decoder with a 4 MHz crystal and it still heterodyned.
Get a tunable decoder and your troubles will be solved.
What I found was if I turned up the TX CTCSS encode, the decoder
activated and held up the receiver which held up the transmitter etc.
We also had a ~ 1KHz whistle, probably the receive signals or TX were
off frequency by that much.
Peter VK2ZTV also has had the same problem with FM-828's
Regards
Don vk2zcz
----- Original Message -----
From: Ian Wells
To: Repeater-Builder@yahoogroups.com
Sent: Wednesday, March 03, 2010 3:12 PM
Subject: Re: [Repeater-Builder] Adapting ctcss decoders to maxon pm150
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
