600 ohm 2 wire question

[FMROB]

Is there a way to isolate a two wire tone remote line from another, possibly using rectifier diodes in line?

My friend is in the middle of a project with a special console need. Due to buttonology and operational needs he needs to be able to connect two differnet tone remote adapters to two different consoles. Also needs to be able to operate one TRA or the other or both, but without backfeeding and causing the other to key. There is no practical way to configure the console button or TRA for special function tones that I can see, and at this point a mechanically operated PTT relay is not feasible to do switch the line on PTT.

Thx, Rob

[kb4mdz]

Wow, sounds quite unusual. Two consoles, 1 base station/repeater? Or 2 radios? Sounds very strange, and I'm having a hard time wrapping my head around the requirements. And if you can't add any extra functions to the consoles buttons, your friend may be really stuck.

And what are the two consoles in use?

[FMROB]

Two different radios, two different consoles (and radio adapters). There are two seperate buttons on each console for each of the radios (no issues), there is a need to simul-transmit on the two radios on a separate or third button, but there also needs to be the ability to transmit seperatly button for button, console to console. The console just cant be configured to do it, but I thought maybe with some one-way isolation of the TR lines and an additional console radio adapter he could do this by assigning a new button that will activate and additional tone remote wired in parallel but isolated from the original set of TRA and console radio modules. I just dont know if in-line diodes will work??

Thanks, Rob

[Bill_G]

Your friend needs to add LOTL or crossmute to everything on the line so they mute when one of the other units is keyed. ie: the LOTL or crossmute detects 2175 and mutes the local speaker. Consoles generally have crossmute built in. You have to program it (source - target). Remotes generally don't, and he'll have to McGuiver something with a 2175 detector. Diodes won't do anything except make it not work at all.

[d119]

Two different radios, two different consoles (and radio adapters). There are two seperate buttons on each console for each of the radios (no issues), there is a need to simul-transmit on the two radios on a separate or third button, but there also needs to be the ability to transmit seperatly button for button, console to console. The console just cant be configured to do it, but I thought maybe with some one-way isolation of the TR lines and an additional console radio adapter he could do this by assigning a new button that will activate and additional tone remote wired in parallel but isolated from the original set of TRA and console radio modules. I just dont know if in-line diodes will work??

Thanks, Rob

Rob,

What kind of console, please?

[FMROB]

BIll,
Cross mute will not work in this particular case, although crossmute is fully programmable It is a sheer limitation of the avtec programming. They are looking to keep the functionality of two different radios, two different "button modules" however want a simul-select TX button to PTT and transmit on both radios at once. This can not be programmed this way, so the only was around it is to make another button module labled simul TX (or whatever) and point it to another tone remote that is wired in parallel with the existing radios. Now the problem is the feed back on the line. For example, if you wanted to only tx on button 1 radio 1, now all the radio wired in will tx. So the thought was to just isolate the third simul select tone remote from the two radios.

Any thoughts?

[d119]

The Avtec console doesn't have a multiselect option where you can press a button, press the resources you want, hit Master TX and away you go???!?!?

[FMROB]

I forgot, yes it most certainly does. However, this particular customer wants a "one button" solution. I am as serious as a heart attack, apparantly a big issue. They just want to push the one button and talk on both radios at the same time, hence my buddies delema.

- Rob

[d119]

Well, I want a million dollars, but it just doesn't work that way.

Doesn't the thing allow preprogrammed Multiselect, and then allow you to have a Multiselect TX button?

In Centracom B&L, you hit Msel 1, hit select on the resources you want, hit Msel 1, and the thing will remember that until you undo it.

To transmit, you press APB 1 and it transmits on those multiselected resources.

Avtec doesn't do that?

[Bill_G]

Well, if it has multi-select, then problem solved. That's how it works. The dispatchers will just have to learn how to run the machine. Golly people. Touch MS, touch the radio modules, hit xmit. Touch MS again to break it down. I don't think Avtec will run a script from a button which is what they are asking for. There are limits to every machine.

[Bill_G]

Offer to mount big baton switches under the console that join the phone lines together through a balanced bridge in the back room. Drill holes through the desktop to mount lights to show current status. Get those big panel lights. Make sure you run lots of wire back and forth between the consoles. They don't have to connect to anything. Just look impressive. barrier strips. Don't forget those. nail every wire down under a screw terminal. Use lots of colors, and make sure to mix them up - blu to org, blk to wht, wht to wht, wht to grn, vio to blu.

[FMROB]

Ouch.. LOL. I know what you guys mean. This was a two hour phone call with the poor guy today. I went through this stuff in my head, but to no avail. Any on the quick electrical isolation that you can think of??

Thx, Rob

[Bill_G]

A dpdt relay would do it, but he needs some way to control the relay. A Radio Shack 1:1 audio xfrmr in series with one side of each phone line would couple them together without needing matching resistors. The NC side of the relay would short the coils out when he wanted to kill the bridge.

[FMROB]

my thoughts exactly Bill. He can get PTT out of the media workstation, but it is across the other side of the building apparently

[Bill_G]

He needs the Avtec aux i/o panel.

[FMROB]

LOL, they have five on that install. I dont think that you can program an aux i/o to operate in conjunction with a audio endpoint (outpost)? I will have to check, otherwise that would work.

[chris.a.terry]

BIll,
Cross mute will not work in this particular case, although crossmute is fully programmable It is a sheer limitation of the avtec programming. They are looking to keep the functionality of two different radios, two different "button modules" however want a simul-select TX button to PTT and transmit on both radios at once. This can not be programmed this way, so the only was around it is to make another button module labled simul TX (or whatever) and point it to another tone remote that is wired in parallel with the existing radios. Now the problem is the feed back on the line. For example, if you wanted to only tx on button 1 radio 1, now all the radio wired in will tx. So the thought was to just isolate the third simul select tone remote from the two radios.

Any thoughts?

When (or if) is the customer getting the new 2.1 upgrade?

[FMROB]

It is a brand new install. I would have to assume that it has the newest firmware. Why? Is there a software upgrade available.

[chris.a.terry]

It is a brand new install. I would have to assume that it has the newest firmware. Why? Is there a software upgrade available.

We received a software upgrade that gives an option to have an outpost control another outpost.
Make sure they are running 2.1, if not, call your rep and ask when it will be available for your customer.
Are they using any Kenwood radios?

[FMROB]

No kenwood in these neck of the woods. I will check out for him the f/w situation and that specific feature that you mentioned. Thanks, Rob