Batboard

I have a base quantar with a co located centracom console. We have a secondary dispatch center (different location) with one of the those fancy IP consoles with one of the IP to tone boxes located in the same room as the quantar. My question is can I run in parralel the tone line level tone remotes.

In this case one being the centra com BIN and the 600 ohm IP tone box of the console? I am going to change the impedance of the line too low, or will it not pose a problem.

It is noteworthy to mention that the consoles will not be used at the same time, it is an either or suituation, if one is not manned the other one is.

Thanks, again - Rob

Leave the BIM at 600 ohms, and move the jumper in the other device to high impedance to keep your high freq rolloff from sounding mushy. Set your levels outta/intta and you should be golden.

Bill,

I dont know that the IP "Play toy" has an impedance setting. I am not that versed in the BIM so I dont really want to pay with the.

Do you think that there will be an issue if I cant change the impedance of the IP box.

Thx, Rob

Eeeeh ... it might sound mushy. Might sound okay. Both will definitely drop levels because of the double termination. You'll have to bump them up 6db or so. If you aren't trying to encode/decode high freq tones or data, you can get away with it. You can get a 4W to 2W hybrid bridge, or make one, or series some resistors on each line to get your impedance correct. What's the make/model of the ip device?

BIll,

It is an Avtech Outpost IP radio box, I have the schematic buried in the car for it. It is basically the "back end" for the avetec console (what the CEB was). One outpost will allow 4 wire control of two radios. When using ICOM radios, it attaches directly to te radio without the need for a tone remote. The outpost provides all of the signal processing for the console system.

In theory the console is nice, but is largely a playtoy in my estimation. Not public safety grade, but would work well for a municipality, electric or gas, etc.

I can push the line levels around some, the ouptost allows for adjustment the way a tone remote does. I can also try to strike a balance with the quantar and low band base radio as well.

BTW I generally set up the incoming RX audio into the console for -10db, and about -15 or -20 for the TX audio. Does that sound about right for the TX. How do you equate about 2.5 (12.5) kc of audio to DB measurement.

- Thx Rob

Interesting. I have a customer that just purchased an Avtech. Should be interesting to set up.

I like -10db to represent 2/3 system deviation with 1k tone for both tx and rx if at all possible. Nice easy number to remember. There is no direct correlation between line level and deviation unless you establish one. A good exciter tends to be linear until it hits it's limiter and stops increasing. Where that point of non-linearity begins is a function of the transmitter design. If you set your dev and line input correctly, -10db should give you 1.6khz dev on a 12.5kc channel, and 3.3khz dev on a 25kc channel. Halving it (-16db) should give you .8khz and 1.6khz dev respectively. Doubling (-4db) should go into limiting and not exceed full system deviation. But, some transmitters are more musical than compliant. They will go beyond the rated deviation, but still sound very natural in the receiver. If that is the case, then you should do all your adjustments to represent full deviation. Again, -10db is a nice, easy number to remember, but it is you who sets the relationship between line level and deviation.

Bill,

It is pretty easy. Like I said, It is a nice "bells and whistle" product with lots of options and is very easily expandable. It can work through the internet (although for PS that might be dicey) and will work well through a privat intranet or over microwave. The Scout IP/Radio box is intuitive and they keep upgrading it. The entire console operations are in the Outpost. All the front end equipment is simply the graphical and human interface, including the audio amps for the speakers.

BUT

it is no centracom or zetron, as I see it. If you PM your e-mail address I can scan the scout manual for you so you can prime yourself on the cable making aspect of it. There is alot of programing involved in the console software, so hopefully the avtech dealer is well versed. Also, thanks for the post above, it makes sense now.


- Thx, Rob