Ok so i went out and got a Command Plus...... So i now know that i have to have tone remotes as i do not have the E&M Module.. (At least i dont think i do)
I just want the thing to make a radio transmit. I have 3 radios all that must be accessable to the dispatcher but i will soon have more.. making the desk pretty cluttered. being a non profit org my funds are non existant after i repaired a few radios this year.
Ok to the point
Seeing as i want to just control the transmit funtion.. (Monitor would be great too) Recieving and stripping some simple tones that make a relay close cant be too hard to do but i cannot seem to find a schematic on it..
Recieve seems pretty simple as i just hook the speaker leads to the correct terminals..
If anyone has any ideas i would greatly appriciate it!
Is it possible to build a simple Tone Remote?
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john.elkin
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Re: Is it possible to build a simple Tone Remote?
Let me make sure I understand what you want: do you want to build a simple tone remote decoder - that is, a device which will detect the tones and act upon them, right?
You might look into using a simple LM567 tone decoder PLL chip. Use one to detect the activation tone, one to detect the action tone, and one to detect the guard tone. That will give you a TTL compatible output when the tones are present. You should be able to then use some very simple logic to check sequencing (i.e. insure the main tone comes first, then the action tone, then the guard tone).
You might look into using a simple LM567 tone decoder PLL chip. Use one to detect the activation tone, one to detect the action tone, and one to detect the guard tone. That will give you a TTL compatible output when the tones are present. You should be able to then use some very simple logic to check sequencing (i.e. insure the main tone comes first, then the action tone, then the guard tone).
This is my opinion, not Aeroflex's.
I WILL NOT give you proprietary information. I make too much money to jeopardize my job.
I AM NOT the Service department: You want official info, manuals, service info, parts, calibration, etc., contact Aeroflex directly, please.
I WILL NOT give you proprietary information. I make too much money to jeopardize my job.
I AM NOT the Service department: You want official info, manuals, service info, parts, calibration, etc., contact Aeroflex directly, please.
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psapengineer
- Posts: 175
- Joined: Thu Oct 07, 2004 10:00 am
Re: Is it possible to build a simple Tone Remote?
Have you considered buying something off of e-bay and modifying it? Regards, Bob
Re: Is it possible to build a simple Tone Remote?
I think that once you have detected the action/keytone you probably want to create a notch filter to remove it before transmission.
On the whole, unless electronics design is a big hobby for you, I think that the ebay idea is the best.
Tone detection is fairly easy with some of the chipsets.
Tone removal (notch filter) is a bit harder\
Tone detection in the presence of (possibly loud) voice with a good false off rate is hard.
NB. False on shouldn't be too much of a problem because you can easily tweak the tone level threshold until you are happy that you hardly ever key up inadvertently.
False off is much harder because the tone level threshold is set for False on and there could be loud voice drowning your keytone.
On the whole, unless electronics design is a big hobby for you, I think that the ebay idea is the best.
Tone detection is fairly easy with some of the chipsets.
Tone removal (notch filter) is a bit harder\
Tone detection in the presence of (possibly loud) voice with a good false off rate is hard.
NB. False on shouldn't be too much of a problem because you can easily tweak the tone level threshold until you are happy that you hardly ever key up inadvertently.
False off is much harder because the tone level threshold is set for False on and there could be loud voice drowning your keytone.
Re: Is it possible to build a simple Tone Remote?
I'm using a TNA200 tied into a Comtegra to a CDM1250 here at home and it works well.
You can usually find a TNA200 for sub-$100 if you look at the right times on eBay.
You can usually find a TNA200 for sub-$100 if you look at the right times on eBay.
Re: Is it possible to build a simple Tone Remote?
My two bits worth:
The device you need is generically known as a "Tone Remote Adapter" There have been many companies that produced these over the years.
Unless you have much time and no money, I would purchase a commercial product. CPI comes to mind.
The "Guard Tone" is -30dbm below the test tone, so you will need filtering to ensure other frequencies do not false, or desensitize the decoder, as well as you will need to filter the 2175 tone, or it will get very irritating to the mobile users.
If you really have too much time, I would find some Guard Tone Decoder cards from a Micor base, and make the modifications to wire it into your cludge. Option the card for "Guard Tone Keying" You will also need some sort of matching transformer, If you don't have a DC adapter, you could also use a Micor line driver card. I think that it is easier to modify an existing circuit card, rather than spending the time and money designing, and locating the components for your own circuit.
The device you need is generically known as a "Tone Remote Adapter" There have been many companies that produced these over the years.
Unless you have much time and no money, I would purchase a commercial product. CPI comes to mind.
The "Guard Tone" is -30dbm below the test tone, so you will need filtering to ensure other frequencies do not false, or desensitize the decoder, as well as you will need to filter the 2175 tone, or it will get very irritating to the mobile users.
If you really have too much time, I would find some Guard Tone Decoder cards from a Micor base, and make the modifications to wire it into your cludge. Option the card for "Guard Tone Keying" You will also need some sort of matching transformer, If you don't have a DC adapter, you could also use a Micor line driver card. I think that it is easier to modify an existing circuit card, rather than spending the time and money designing, and locating the components for your own circuit.
Aloha, Bernie