I can program the proper pins on the UHF Maxtrac to work with the RICK just fine, but the Maxtracs RSS will only let me program pin 9 on the Smartnet Maxtrac. I can't access the other pins to change them from NULL.
Is there a way around this?
help: can't program the 16 pin connecter on 800 MHz Maxtrac
Moderator: Queue Moderator
help: can't program the 16 pin connecter on 800 MHz Maxtrac
I'm trying to use an 800 MHz Smartnet Maxtrac and a UHF Maxtrac with a RICK to make a bidirectional cross band repeater.
I can program the proper pins on the UHF Maxtrac to work with the RICK just fine, but the Maxtracs RSS will only let me program pin 9 on the Smartnet Maxtrac. I can't access the other pins to change them from NULL.
Is there a way around this?
I can program the proper pins on the UHF Maxtrac to work with the RICK just fine, but the Maxtracs RSS will only let me program pin 9 on the Smartnet Maxtrac. I can't access the other pins to change them from NULL.
Is there a way around this?
I assume what you are trying to do is create a "linker" package that will allow interoperability between a trunking talkgroup and a conventional channel. Basically this would be like a cross band repeater and the RICK seems like the natural device to glue the two radios together.
What you need is a signal from the trunking radio that indicates it is receiving a talkgroup call so that it can tell the RICK to key the conventional radio, a sort of 'trunked COR'. Unfortunately, as you have discovered, the trunking RSS won't let you program any such a signal to the accessory connector.
There is a way to do this, but you will have to do some surgery on the radio's logic board. I have done this to Spectras and I will soon be doing it to a couple Maxtracs. The idea is that the radio unmutes its RX path and enables its audio PA when it is receiving a signal, We need to connect one of those logic signals to the outside world - and do it in a way that protects everything from damage.
If you're up to hardware hacking the logic board, I'll add some details after I get one of these working.
What you need is a signal from the trunking radio that indicates it is receiving a talkgroup call so that it can tell the RICK to key the conventional radio, a sort of 'trunked COR'. Unfortunately, as you have discovered, the trunking RSS won't let you program any such a signal to the accessory connector.
There is a way to do this, but you will have to do some surgery on the radio's logic board. I have done this to Spectras and I will soon be doing it to a couple Maxtracs. The idea is that the radio unmutes its RX path and enables its audio PA when it is receiving a signal, We need to connect one of those logic signals to the outside world - and do it in a way that protects everything from damage.
If you're up to hardware hacking the logic board, I'll add some details after I get one of these working.
Yes, that is exactly what I want to do, and I would be willing to modify the Maxtrac to do it.
You say you've also done this with a Spectra. I also have a 800 MHz Spectra lying around that I could use, if the Maxtrac modification proves to be significantly more difficult for some reason. All things being equal however, I guess I would prefer to use the Maxtrac.
Thanks in advance for supplying the mod instructions!
Tom
You say you've also done this with a Spectra. I also have a 800 MHz Spectra lying around that I could use, if the Maxtrac modification proves to be significantly more difficult for some reason. All things being equal however, I guess I would prefer to use the Maxtrac.
Thanks in advance for supplying the mod instructions!
Tom
When I did the Spectra mods I isolated the audio PA enable signal through a 10 K resistor and brought it out of the accessory connector. Then I put a buffer transistor inside the D-sub 15 connector so the whole thing was neat & tidy.
The Maxtrac has buffer transistors for the accessory port programmable outputs. Since it won't let you use them anyway - the idea is to use one of them. This will involve removing the resistor that goes between the existing logic signal and the base of the buffer trasnsistor, then connecting a new resistor from the base of that transistor to the audio enable logic signal, thus 'hardware programming' the I/O pin to do what we want.
Steve Ciarcia (circuit cellar) once wrote: "My favorite programming language is solder". I'm with him.
The Maxtrac has buffer transistors for the accessory port programmable outputs. Since it won't let you use them anyway - the idea is to use one of them. This will involve removing the resistor that goes between the existing logic signal and the base of the buffer trasnsistor, then connecting a new resistor from the base of that transistor to the audio enable logic signal, thus 'hardware programming' the I/O pin to do what we want.
Steve Ciarcia (circuit cellar) once wrote: "My favorite programming language is solder". I'm with him.
When I wanted to use a pair of MaxTrac/Radius rigs to make a repeater, I was stuck with a 5-pin acc jack, which left me very few options to get a signal out of the radio that would indicate a received signal.
In the audio circuit there's a line that comes from the microprocessor that unmutes the audio when a valid signal has been received. In this case, one with the proper PL/DPL tone. As I recall, the signal goes high and turns on a transistor in series with the audio chain. Audio prior to this point is always active, so you'd get noise with no signal or whatever a user was saying if he didn't have PL on his carrier.
I used an ordinary 2N2222 plus a 4.7k resistor to make a COR- signal come out of the radio. The emitter goes to ground, the collector goes to one of the two unused pins on the mike jack, and the resistor goes between the microprocessor's output pin (or signal) and the base of the transistor. Whenever the audio unsquelches, the transistor turns on and provides a very nice ground-active signal to my repeater control unit. With no input signal or the wrong PL, the radio remains squelched and the collector floats. I'm also using the headphone audio out of the mike jack as a receiver audio source. Similarly, the mike input and PTT lines complete the repeater connections. I can control the state of the hang-up line from my repeater controller, so for normal PL enabled, I ground this line. No RICK needed, no 16-pin acc jack, and a very simple mod to the radio brings a much-needed signal out to the rest of the world.
I doubt there's enough audio coming out of the mike jack to feed back into the transmit audio directly, but one can hook the COR- signal directly to the PTT line and have a fairly simple uni-directional repeater setup.
I made a similar connection, again through the remaining unused pin on the mike jack, to control transmit PL on/off, using one transistor and one resistor. However it only works on some of the logic boards, particularly those whose first op-amp (that generates the PL stepped waveform) has a feedback resistor present. My circuit shorts this out, effectively making the gain of this stage very small, and the PL disappears. Works very nice, quick, and simple.
Bob M.
In the audio circuit there's a line that comes from the microprocessor that unmutes the audio when a valid signal has been received. In this case, one with the proper PL/DPL tone. As I recall, the signal goes high and turns on a transistor in series with the audio chain. Audio prior to this point is always active, so you'd get noise with no signal or whatever a user was saying if he didn't have PL on his carrier.
I used an ordinary 2N2222 plus a 4.7k resistor to make a COR- signal come out of the radio. The emitter goes to ground, the collector goes to one of the two unused pins on the mike jack, and the resistor goes between the microprocessor's output pin (or signal) and the base of the transistor. Whenever the audio unsquelches, the transistor turns on and provides a very nice ground-active signal to my repeater control unit. With no input signal or the wrong PL, the radio remains squelched and the collector floats. I'm also using the headphone audio out of the mike jack as a receiver audio source. Similarly, the mike input and PTT lines complete the repeater connections. I can control the state of the hang-up line from my repeater controller, so for normal PL enabled, I ground this line. No RICK needed, no 16-pin acc jack, and a very simple mod to the radio brings a much-needed signal out to the rest of the world.
I doubt there's enough audio coming out of the mike jack to feed back into the transmit audio directly, but one can hook the COR- signal directly to the PTT line and have a fairly simple uni-directional repeater setup.
I made a similar connection, again through the remaining unused pin on the mike jack, to control transmit PL on/off, using one transistor and one resistor. However it only works on some of the logic boards, particularly those whose first op-amp (that generates the PL stepped waveform) has a feedback resistor present. My circuit shorts this out, effectively making the gain of this stage very small, and the PL disappears. Works very nice, quick, and simple.
Bob M.