REPEATER / VOTER QUESTION
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roadhawg00
- Posts: 5
- Joined: Wed Feb 19, 2003 1:52 pm
REPEATER / VOTER QUESTION
Our agency has a new repeater system that involves a voter for a receiver on a second site. We are on a vhf radio system, but transmit to the voter site by uhf low power link. We have mountains in our area and have trouble getting signals back during a local incident(mobile command). I know that our uhf radios are set to provide a constant tone to lock in the voter to the other receiver. My question is this, can we place that card and radio on a freq and use a vhf uhf mobile repeater in vehicle to transmit to that 3rd card as a new site using a omni antenna at the voter site and tie that mobile repeater into the voter system and do we have to do a constant tone or can we just transmit by repeater to the uhf voter radio? Before it comes up yes we have extra assigned freqs. for the new links, we got those to expand.
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psapengineer
- Posts: 175
- Joined: Thu Oct 07, 2004 10:00 am
Depends
It kind of depends:
If you're using an older Motorola Spectra-Tac voter the answer is no. The older voters require the status tone to operate.
If you're using a newer JPS-SNV-12 voter the answer is you can accomplish your desired goal given the right configuration and dip switch settings. The SNV-12 will allow a mix of status tone triggered cards and VOX triggered cards. Status Tone, Vox and other trigger/squelch methods are set using the dip switches on the given card.
As a comment, it is likely that the overall VOX triggered configuration will have a much longer setup time than the existing configuration. So, those accessing the system through the "mobile command path" will need to push to talk, and then talk; or, the first syllables will likely be clipped.
Good Luck, Bob
If you're using an older Motorola Spectra-Tac voter the answer is no. The older voters require the status tone to operate.
If you're using a newer JPS-SNV-12 voter the answer is you can accomplish your desired goal given the right configuration and dip switch settings. The SNV-12 will allow a mix of status tone triggered cards and VOX triggered cards. Status Tone, Vox and other trigger/squelch methods are set using the dip switches on the given card.
As a comment, it is likely that the overall VOX triggered configuration will have a much longer setup time than the existing configuration. So, those accessing the system through the "mobile command path" will need to push to talk, and then talk; or, the first syllables will likely be clipped.
Good Luck, Bob
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roadhawg00
- Posts: 5
- Joined: Wed Feb 19, 2003 1:52 pm
Thanks, we were going to buy some mobile repeaters to help with these problems and wondered if we should attempt the uhf path or just set up a vhf only one. We have the spectra tac it was installed just last year, i guess we should have looked into the jps. I assume that you would have to buy a signal generator to use the vhf uhf setup? Can you get them for a mobile repeater that would allow the mobile use? We are like some others who are running out of room on our portables for new freqs. thanks for the 411.
A mobile satellite voting receiver - an interesting concept.
There are several ways you could make that work with Motorola Spectra-TAC. Your problem is with the Motorola design that uses a continuous status tone. It is the same problem faced by hams who want to use surplus Spectra-TAC without needing 24x7 full time links [frowned on in amateur service]
You can find some guidance on the repeater-builder.com web pages.
The first alternative is to have the central UHF receiver insert the status tone [i.e. it is a Spectra-TAC receiver]. Your mobile unit will cross-band repeat on scene VHF traffic up to the central site via the UHF frequency. This can work well but suffers from problems with audio holes. When the VHF signal drops out of the cross-band repeater there is a finite time when it drops out that the central receiver sees 'quiet'. Until it reinserts status tone the comparator can vote that 'quiet' and produce an audio hole.
A second method would be to put the status tone insertion at the vehicular repeater. In this case everything will work fine. The problem is that the vehicular repeater needs to be keyed continuously. That may not be a problem for the duration of an 'event' - assuming the unit has a low power continuous capable transmitter.
The real problem comes at the end of an event when you shut down the vehicular transmitter. The system will lock and vote dead quiet from the lack of the status tone. This will last for the duration of the Spectra-TAC line failure timer. That may be an issue you can live with. You can warn the users that the channel will be out of service for 60 seconds or so when you shut down the link.
Another concept is to disable the Spectra-TAC status tone decoder on that one receiver port [SQM card] and use manual level setting to replace the AGC function of the status tone. The signal present/absent function is then driven by COR from the link. This can also work well but can still have the same audio hole issue.
The most satisfactory method is also the most complex and involves inserting the status tone at both the remote [vehicular] receiver and at the central UHF receiver. The vehicular repeater is then set for a long drop out delay - 10 seconds or more. If your dispatch is wireline connected, I would make that drop out be a minute or longer. That way the remote receiver status tone controls the signal present function for normal traffic and when the channel is idle, the cross-band repeater drops out at which point the central [local] status tone takes its place and precludes the lock up line fail issue.
There are several ways you could make that work with Motorola Spectra-TAC. Your problem is with the Motorola design that uses a continuous status tone. It is the same problem faced by hams who want to use surplus Spectra-TAC without needing 24x7 full time links [frowned on in amateur service]
You can find some guidance on the repeater-builder.com web pages.
The first alternative is to have the central UHF receiver insert the status tone [i.e. it is a Spectra-TAC receiver]. Your mobile unit will cross-band repeat on scene VHF traffic up to the central site via the UHF frequency. This can work well but suffers from problems with audio holes. When the VHF signal drops out of the cross-band repeater there is a finite time when it drops out that the central receiver sees 'quiet'. Until it reinserts status tone the comparator can vote that 'quiet' and produce an audio hole.
A second method would be to put the status tone insertion at the vehicular repeater. In this case everything will work fine. The problem is that the vehicular repeater needs to be keyed continuously. That may not be a problem for the duration of an 'event' - assuming the unit has a low power continuous capable transmitter.
The real problem comes at the end of an event when you shut down the vehicular transmitter. The system will lock and vote dead quiet from the lack of the status tone. This will last for the duration of the Spectra-TAC line failure timer. That may be an issue you can live with. You can warn the users that the channel will be out of service for 60 seconds or so when you shut down the link.
Another concept is to disable the Spectra-TAC status tone decoder on that one receiver port [SQM card] and use manual level setting to replace the AGC function of the status tone. The signal present/absent function is then driven by COR from the link. This can also work well but can still have the same audio hole issue.
The most satisfactory method is also the most complex and involves inserting the status tone at both the remote [vehicular] receiver and at the central UHF receiver. The vehicular repeater is then set for a long drop out delay - 10 seconds or more. If your dispatch is wireline connected, I would make that drop out be a minute or longer. That way the remote receiver status tone controls the signal present function for normal traffic and when the channel is idle, the cross-band repeater drops out at which point the central [local] status tone takes its place and precludes the lock up line fail issue.
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ASTROMODAT
- Posts: 1825
- Joined: Tue Nov 05, 2002 12:32 am
I assume you are using a DIU3000 with your Quantar. If you really want that thing to play, you can hang a controller (such as the SCOM 7K) off the DIU3000, and the controller can output EIA tone remote control tones, which will allow it to do anything you want---literally. This will give you literally an unlimited amount of flexibility, which is even more powerful than the SAM.
larry
larry