1) Does anyone know of a good source for PAC channel elements and Vibrasponder reeds?
2) What is the difference between the PAC (no suffix) and the PAC-PL or PAC-RT?
3) I'm currently experimenting with a SP PAC unit with a five frequency auxiliary low band
receiver board, but haven't been able to make heads or tails out of getting the board to
function. There is a jumper to select between F5 and audio out, and the board is currently
jumpered for F5, so there does not appear to be any audio out. Any ideas?
Thanks!
PAC rechanneling, etc.
Moderator: Queue Moderator
I got the PAC-RT and PAC-PL manuals out to see what the main difference was (sorry, I do not have any PAC manuals).
PAC-PL is simpler then PAC-RT, only requiring a PL or DPL signal from the portable radio to repeat through the mobile. There is no priority system.
PAC-RT has a single tone based priority signaling system. This is used when several mobile units using the same frequencies are near each other. It automatically sorts which mobile has priority and all the non-priority PAC-RTs remain quite. Imagine what a mess it would be if 2 or more high power mobiles next to each other were both transmitting together on the same frequency.
Because PAC-RT has this priority system, it needs to be able to listen for other mobile radios. So it has optional receiver boards called mobile detectors. The VHF PAC-RT can have an optional low band (30 to 50 MHz) or UHF mobile detector. The UHF PAC-RT can have an optional low band or VHF mobile detector. Here are some of the part numbers that might help you sort out what options you have in your unit:
http://www.open.org/~blenderm/syntorx/c ... tml#pac_rt
The low band and VHF mobile detectors can have up to 5 frequencies each. The UHF mobile detector can have up to 4 frequencies. An optional mobile detector board could be the source of the F5 jumper you are seeing. It appears the mobile detector receiver is only used internally inside the PAC-RT for priority resolution so you can not get it to repeat to the handheld from the mobile detector frequency (i.e. it will only repeat what the mobile radio it is hooked to hears).
The PAC-RT can also use PL for the portable frequency.
Some of the manual part numbers for the PAC-RT and PAC-PL are here:
http://www.open.org/~blenderm/syntorx/m ... ml#xaccman
Maybe someone else who has experience with these can fill in more details?
________
Mike B
http://www.open.org/~blenderm/syntorx/
PAC-PL is simpler then PAC-RT, only requiring a PL or DPL signal from the portable radio to repeat through the mobile. There is no priority system.
PAC-RT has a single tone based priority signaling system. This is used when several mobile units using the same frequencies are near each other. It automatically sorts which mobile has priority and all the non-priority PAC-RTs remain quite. Imagine what a mess it would be if 2 or more high power mobiles next to each other were both transmitting together on the same frequency.
Because PAC-RT has this priority system, it needs to be able to listen for other mobile radios. So it has optional receiver boards called mobile detectors. The VHF PAC-RT can have an optional low band (30 to 50 MHz) or UHF mobile detector. The UHF PAC-RT can have an optional low band or VHF mobile detector. Here are some of the part numbers that might help you sort out what options you have in your unit:
http://www.open.org/~blenderm/syntorx/c ... tml#pac_rt
The low band and VHF mobile detectors can have up to 5 frequencies each. The UHF mobile detector can have up to 4 frequencies. An optional mobile detector board could be the source of the F5 jumper you are seeing. It appears the mobile detector receiver is only used internally inside the PAC-RT for priority resolution so you can not get it to repeat to the handheld from the mobile detector frequency (i.e. it will only repeat what the mobile radio it is hooked to hears).
The PAC-RT can also use PL for the portable frequency.
Some of the manual part numbers for the PAC-RT and PAC-PL are here:
http://www.open.org/~blenderm/syntorx/m ... ml#xaccman
Maybe someone else who has experience with these can fill in more details?
________
Mike B
http://www.open.org/~blenderm/syntorx/
Thanks Mike!
A look at the parts link revealed that these are, in fact, PAC-RT units, with different case labeling.
The unit I'm most intrigued by playing with is a model# H13TTY3110ASP29. It's tagged as having originally been for the Michigan Dept. of Natural Resoursces. In addition to the 5F low band receiver board, it also has a small board (marked PLN8128A) mounted near the front of the unit, with leads going to the pads where the repeater sq and mobile pl pads would normally be. There are trimmer pots marked "port" and "PAC" on the board.
Also, I'm looking for information on the purpose / function of the F1-F4 pins on the connector. The schematic shows them going back to the aux. receiver board, but I can't discern to what end. Is it possible to do channel steering of the mobile radios with these units?
I'm still hoping for information on rechanneling these to a useable frequency, as well as a source for vibrasponder reeds.
Thanks!
<font size=-1>[ This Message was edited by: HumHead on 2002-02-23 14:12 ]</font>
A look at the parts link revealed that these are, in fact, PAC-RT units, with different case labeling.
The unit I'm most intrigued by playing with is a model# H13TTY3110ASP29. It's tagged as having originally been for the Michigan Dept. of Natural Resoursces. In addition to the 5F low band receiver board, it also has a small board (marked PLN8128A) mounted near the front of the unit, with leads going to the pads where the repeater sq and mobile pl pads would normally be. There are trimmer pots marked "port" and "PAC" on the board.
Also, I'm looking for information on the purpose / function of the F1-F4 pins on the connector. The schematic shows them going back to the aux. receiver board, but I can't discern to what end. Is it possible to do channel steering of the mobile radios with these units?
I'm still hoping for information on rechanneling these to a useable frequency, as well as a source for vibrasponder reeds.
Thanks!
<font size=-1>[ This Message was edited by: HumHead on 2002-02-23 14:12 ]</font>
Thanks Will.
I think I have a couple of MT500s buried around here somewhere. I'll see if I can dig them out and check the elements.
Drop me a private message if you want to unload a couple of vibrasponders in the 100.0 -162.2 PL range.
I'm finding that the current 225.6Hz tone is noticable in the transmitted audio.
Thanks!
I think I have a couple of MT500s buried around here somewhere. I'll see if I can dig them out and check the elements.
Drop me a private message if you want to unload a couple of vibrasponders in the 100.0 -162.2 PL range.
I'm finding that the current 225.6Hz tone is noticable in the transmitted audio.
Thanks!
Looking back at the manuals, they point out your channel selection can be wired to select when tied to the positive B+ voltage or to ground. CR314 and R340 for B+ switching OR CR315 for ground switching (the part numbers are from the "typical" example in the manual). The mobile detector receiver just goes to an on/off squelch detect gate, but, there is an audio test output point. Maybe you can do something special or different with this mobile detector "test point" audio? All the standard PAC-RT appears to care about is if the squelch on the mobile detector frequency has opened or not.
The frequency select lines go to individual mobile detector 1 transistor crystal oscillators that are each individually tuned. If the crystal is present in the mobile detector oscillator and one of the F1, F2, F3, F4 or F5 select line is activated then the oscillator attached to it will be active. All these oscillators are tied together and go to the same buffer amplifier input. The active one ultimately selects the mobile detector receive frequency.
I looked and can not find any information on the PLN8128A. This however is typical of Motorola SP units. Often exactly what they were supposed to do and exactly how they did it is a mystery you have to solve. In a standard factory PAC-RT setup the mobile detector receiver is only useful when you use the multiple PAC-RT priority resolution scheme. I think you will need the PAC-RT manuals to get much further with your project.
________
Mike B.
[email protected]
The frequency select lines go to individual mobile detector 1 transistor crystal oscillators that are each individually tuned. If the crystal is present in the mobile detector oscillator and one of the F1, F2, F3, F4 or F5 select line is activated then the oscillator attached to it will be active. All these oscillators are tied together and go to the same buffer amplifier input. The active one ultimately selects the mobile detector receive frequency.
I looked and can not find any information on the PLN8128A. This however is typical of Motorola SP units. Often exactly what they were supposed to do and exactly how they did it is a mystery you have to solve. In a standard factory PAC-RT setup the mobile detector receiver is only useful when you use the multiple PAC-RT priority resolution scheme. I think you will need the PAC-RT manuals to get much further with your project.
________
Mike B.
[email protected]
I am also looking for some PAC information. I have a pair of Motorola Mitreks, each with PAC-PL vehicular repeaters. I'm interested in getting the PAC-PLs re-crystaled for Ham band useage. I have everything I need to convert the Mireks, but know nothing about the PAC-PLs. I did discover that they are the DPL version. If I pull the PL board they will receive w/o the DPL, but not transmit. The DSC, or the digital PL, is 754 and will open for me when enabling this code on one of my newer Kenwood mobiles. I'd like to just find out how to bypass the DPL, or just use regular PL and get new crystals for the PAC-PL on the VHF ham band. Does the PAC-PL have seperate TX and RX crystals? I'd appreciate any info anyone might have! Thanks, Chuck KA0GFC