digital through a analog repeater

radioactive69 · Post by **radioactive69** » Sun May 01, 2005 11:51 am

I tried to run a digital signal through an analog repeater and was unable to decode the digital signal successfully.

Two Astro programed HT's on a carrier squelch repeater.

I probably don't know my digital but, why doesn't this work?

Doug.

Post by **batdude** » Sun May 01, 2005 12:46 pm

b/c the analog repeater is not capable of re-clocking the astro data during inbound receive recovery... and screws up the timing upon transmit.

you CAN repeat astro on an analog radio - it just takes some mods

doug

maxtrac300 · Post by **maxtrac300** » Sun May 01, 2005 1:40 pm

You can pass p25 through two back/back maxtracs, without reclocking. Basically the mods that batdude speaks of, pass the discriminator/flat audio (receiver) directly into the modulator of the transmitter. There is no emphasis or other audio filtering done.

In this configuration, FSK is possible. (Astro is 4-level FSK)

Make sure to limit the deviation of your transmitter to 2.83 KHz.

http://batboard.batlabs.com/viewtopic.php?t=13797

http://batboard.batlabs.com/viewtopic.php?t=15728

http://batboard.batlabs.com/viewtopic.php?t=31482

http://batboard.batlabs.com/viewtopic.php?t=42690

radioactive69 · Post by **radioactive69** » Sun May 01, 2005 9:23 pm

That was greatly informative. More data added to the brain.

Thank you for your help, Doug.

hamptonbeach · Post by **hamptonbeach** » Mon May 02, 2005 7:20 am

There was a lot of info in those threads, with some people saying they did it, but no one has said 'how' they did it - unless I missed it.

I have an MSR2000 repeater, but only 1 IMBE capable radio, so I can't tell if it works or not. Anyone have experiences with MSR2000?

radioactive69 · Post by **radioactive69** » Tue May 03, 2005 2:27 pm

What I have is a MSF5000 and two XTS HT's. I turned the MSF to COS and programed both HT's to Astro and gave it a try.

I read the articals but, as you said nothing specific to the MSF (for my needs). The station control board would be the starting place for any mod's. But, since the MSF is a digital process in part, that is where the timing would come in play (I assume). Also, the fact that Astro is a mode not able to be correctly repeated by an analog FM repeater.

Doug.

RESCUE161 · Post by **RESCUE161** » Tue May 03, 2005 10:20 pm

http://batboard.batlabs.com/viewtopic.php?t=45645