Pac-rt

[kb3hlp]

Can anyone give me a quick rundown on the unit?

I understand the basics of it but how programmable is it? RSS? or suitecase/eprom or crystal?

Does one need the control unit to make it work?

I think it would be really cool to hook it up to my SyntorX and play radio at work.

Thanks in advance

Alex


Alex

[fireradio]

I too have been curious about how exactly the PAC-RT system works. Sounds like fun!

FireRadio

[Mike B]

I have replaced and updated the original posting because I recently completed a web page about PAC repeater units that does a better job of answering the questions above.

Here is the link:
http://www.open.org/~blenderm/syntorx/pac.html
________
Mike B
[email protected]

<font size=-1>[ This Message was edited by: Mike B on 2002-04-09 14:34 ]</font>

[CHEFA2001]

Mike, OR anyone else out there, Do any of you know details on the mode steering of the VRS,such as how well it works, options,etc..

thanks

[Mike B]

The VRS is a different animal than the PAC repeaters (the PAC units do not have mode steering and the VRS will only work with a few Systems 9000 radio models). The mode steering is programmed in the RSS. Here is some Syntor X 9000 VRS programming information:
http://www.open.org/~blenderm/syntorx/p ... ml#pgq_vrs

The VRS uses 4 MX365 chips as dedicated PL decoders. The RSS programs each chip with a different PL frequency for decoding only. When the chip decodes its programmed PL frequency it activates an input to the VRS microprocessor chip, so the VRS microprocessor knows when a valid PL has been received from the handheld radio. The VRS microprocessor can then tell the Syntor X 9000 or Spectra mobile radio through the Systems 9000 communications lines between the VRS and mobile radio. The RSS is programmed such that one of 4 valid detected PL tones can steer the mobile radio to a preprogrammed mode or to the current selected mode. You can RSS program the VRS to not use mode steering or to have up to 4 mode steering selections.

The mobile radio mode steering can be temporary (just for the duration of the VRS repeat) or you can set the mobile to latch onto the steered mode and remain there after the VRS repeat is done. You have to set this in the RSS.

After you get the VRS setup and programmed, you setup a handheld radio on the VRS simplex frequency that has up to 4 different selectable PL transmit tones (the normal way of doing this to program up to 4 channels with the same simplex frequency and different Tx PL tones). Then you select the correct PL tone on your handheld radio, transmit to the VRS and the mobile radio will steer to and repeat on the mode you programmed for that PL tone.

The Astro Spectra VRS-EP can steer with up to 8 different PL tones, but, I do not know exactly how they decode these PL tones.
________
MIke B
[email protected]

<font size=-1>[ This Message was edited by: Mike B on 2002-04-09 14:25 ]</font>

[deptchief14]

I need help on hooking a pac-rt up to my maratrac lowband i have already made the modifications but my control head does not work any help would be appreciated thanks

[tomskillman]

First of all, Mike, I love your website...has been a lot of help. But, I am wondering one thing. I noticed you state that the Pac-RT should be in a different band than the mobile. Is this a recommendation, or 100% necessary. I was looking into setting up a UHF-UHF system. I have a 110 watt UHF spectra with the A9 head.

[wa2zdy]

Desense and overload will be a problem if you use a PAC on the same band as your mobile radio. Yes, you can buy/build filters that should help, but you're not talking quick, cheap, and easy.

Good luck,

[HumHead]

Pyramid Communications (among others) makes filter sets for VHF-VHF in band repeaters.

If you check their web site, they have a downloadable "range calculator that shows the approximate desense effects with various radio / antenna / filter combinations in a VHF-VHF configuration.

http://www.pyramidcomm.com/BPNF.HTM

[xmo]

"the PAC units do not have mode steering "

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PAC units were available with channel steering.

This was an SP option on the H14TTY3110A units. The NLN4358A logic board is replaced by NLN4358A-SP7 and PLN1005 Steering logic with lockout is added. These will steer four channels.

Usually these are connected to radios that use rotary type channel selection, but we had one entire County Sheriff system that had these on SyntorX units with System 90 heads, scan, 32 modes, etc. Obviously you can only steer to four modes (which four is an interface set up & programming decision)

It takes a magic circuit board in the PAC cable junction box to 'gate' the PAC channel info to the radio at the right time.

Then there were the PAC-TR and PAC-TL units which can steer trunked radios up to 20 talkgroups. I've got catalog sheets on these but no service manuals, so I'm not sure what is inside them.