Kahuna

Kahuna

Moderatoring
I have an Apollo SL15/PMA 7000B that works perfectly fine. One problem, it sits low in the panel and I can not see what COM is selected when Im busy entertaining folks.
In the middle of a show Im swapping back and forth (com swap on stick) to deal with the team and air boss. I have screwed up more than once transmitting on the wrong com due to sunlight on the audio panel that washes out the lights.
What I need is for someone to wire up a jumper to a spare edge card finger so I can pull off of it and wire up a remote light up on my glare shield to show com 2 transmit is active.

PS Engineering will not help me even though its their unit.
Please PM me if your interested in this work.
PMA7000BFront.JPG
 
Have you considered re-purposing the remote com swap button? Why not connect it as a dedicated ptt? I have two ptt buttons on the stick, one for com1 and one for com2.

Paige
 
Another option would be to tap off the PTT lines and drive an led that shows which comm is active. Granted you would not know until you keyed the mic which comm you were on, but it may be better than a major mod to the IC (that may void ANY factory support from PSE in the future).
 
PaigeHoffart said:
Have you considered re-purposing the remote com swap button? Why not connect it as a dedicated ptt? I have two ptt buttons on the stick, one for com1 and one for com2.

Paige
Click to expand...

Hmmm. This is an interesting thought. I assumed that the key was not only putting the com in transmit, but also the audio panel routing voice to the proper com. 2 com switches would require direct key to ground for each radio but how would the radio get the voice from the proper mic? This seems to be defeating the audio panel functionality. Im sure there are other unintended consequences of this as welll.

Walt said:
Another option would be to tap off the PTT lines and drive an led that shows which comm is active. Granted you would not know until you keyed the mic which comm you were on, but it may be better than a major mod to the IC (that may void ANY factory support from PSE in the future).
Click to expand...

Yes this basically requires me to key first then hope its right. Would also put unnecessary clicks on the com to others if I relied on it.

I dont care about warranty or factory support.
 
Do you have a schematic/service manual available? Would be helpful to review that to see whats inside.
 
No Im afraid I only have the Installation manual. Ive had it apart and there are several unused fingers available, no tracks to them and exposed.
 
Without a schematic for finding how/where to pick off the signals it would be very risky or even impossible. I personally would not be comfortable attempting something like this on a "customers" unit without one. If I smoked it for you, I doubt you would be real happy with me :eek:
 
Remote Com indication

Dear Mike:

I would like to explain why our original answer to you was "no" and then tell you why we were potentially wrong by saying no.

First one (and probably does not apply to you) is that it is TSO'd, so we can't return to service a modified unit without the necessary FAA paper work.

Second, the amount of engineering time to design a circuit that we believe would be robust enough to be installed in an aircraft is not inexpensive. So "Would we make this modification for you if you do not need a certified part?" Maybe.

At minimum, it would be at least one man day to design and prototype the change. Then at least another day integrating it back into our production line as a "modified" unit for a complete retest of the system.

So, we probably should not have told you no, but should had given you a rough estimate to how much it would cost to make the change.

We should have put you in the position so you could have made that decision, and I'm sorry we didn't.

On the other hand, if we told you how much it would cost, you "might" have taken the position that PS Engineering is asking a rediculous amount of money to make such a simple change. We might have been profiled as price gougers.

The cost we would charge would reflect the amount of time it would take to make a design change, prototype the change, test the change, and then return the unit to service. Finally, the cost of pulling an engineer off a project is significant as well. The consequence of interrupting an engineer is "priceless" ;)

If the unit is in a certified aircraft, the answer would still be no. The added cost to make a change to our TSO would be prohibitive.

I have a question, I am assuming you have just two radios, in order to elminate the swap function from cycling through all three radios, if you configure Com 3 for Telephone mode, you then will only cycle through Com 1 and Com 2. Has the PMA7000B been configured for Tel mode?

Hope this helps.

Mark Scheuer
PS Engineering, Inc.

Kahuna said:
I have an Apollo SL15/PMA 7000B that works perfectly fine. One problem, it sits low in the panel and I can not see what COM is selected when Im busy entertaining folks.
In the middle of a show Im swapping back and forth (com swap on stick) to deal with the team and air boss. I have screwed up more than once transmitting on the wrong com due to sunlight on the audio panel that washes out the lights.
What I need is for someone to wire up a jumper to a spare edge card finger so I can pull off of it and wire up a remote light up on my glare shield to show com 2 transmit is active.

PS Engineering will not help me even though its their unit.
Please PM me if your interested in this work.
PMA7000BFront.JPG
Click to expand...
 
Mark, thanks for the response.
Yes it has been configured for tel mode and only swaps between com 1 & 2.
Im sure my requirements are unique. Yes its on an experimental.
If I could get some voltage on a finger on the edge card, I could wire that externally to a relay if is a low voltage light in the button on that circuit.
An external micro relay could do the work.
I want one small light on my glare shield indicating that one of the coms is on transmit, just like the button has. I need it for only one.
I have a similar light for smoke on. I need indication in my field of view for the environment I fly in. I just dont have the cycles to be looking down on the panel for these 2 items that I flop on and off a dozen times in a 15 min routine. I need to free up my 'bucket'/workload.
 
Surely, with all the smart guys and gals we have on VAF, we can come up with a solution. I see it as a safety thing.
Tom
 
Kahuna said:
I want one small light on my glare shield indicating that one of the coms is on transmit, just like the button has.
Click to expand...

I am no electrical wizard, but it seems like you (or whoever does the actual work) could just re-direct the power from the button to the external light.

You would loose the light on the button, but you would have the glare shield light instead.
 
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can you swap the pushbutton

If you can switch out the pushbotton on your stick with a toggle switch I have a solution for you.

I don't know of an on-off-on pushbutton. This would also work if one existed.
 
Caution

The LEDs as well as the pushbutton switchs are controlled by FPGAs with TTL control. I do not recommend bringing those signals out of the audio panel, these signals would have to be conditioned before meeting the outside world.

Mark
PS Engineering, Inc.

Mike S said:
I am no electrical wizard, but it seems like you (or whoever does the actual work) could just re-direct the power from the button to the external light.

You would loose the light on the button, but you would have the glare shield light instead.
Click to expand...
 
If you want to build a box with some relays:

1. Wire your flip-flop stick button to cause a latching relay to flip.
2. Wire that latching relay to control other relays, which will:
A. Connect your mike, PTT, and headphones alternately to the pilot inputs, or the copilot inputs, on the audio panel; and
B. drive indicator lights on the glare shield.
3. Put your audio panel into the multiplex mode, or whatever it is called (designed to let the copilot transmit on com 2 while the pilot transmits on com 1.)

Basically you are flipping yourself from pilot position to copilot position.

Edit: I see PS calls this "split mode", not multiplex.

Mark, what do you think?
 
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Kahuna said:
Hmmm. This is an interesting thought. I assumed that the key was not only putting the com in transmit, but also the audio panel routing voice to the proper com. 2 com switches would require direct key to ground for each radio but how would the radio get the voice from the proper mic? This seems to be defeating the audio panel functionality. Im sure there are other unintended consequences of this as welll.
Click to expand...

My audio system is a bit unique, I didn't use a commercial audio panel. You could however achieve the same effect with one relay. Your first PTT will work with the audio panel just as it does now. The second PTT will bypass it and connect the pilots mic directly to one of the radios.

12V 4PDT relays are easy to find. You can get sockets that make wiring with ring terminals easy. Route the pilot's mic wires through two poles, intercom to the NC contacts and radio to the NO contacts. Use one of the remaining poles for PTT. Radio PTT to the common, NC contact to the intercom PTT out, and ground the NO contact. Wire the Relay coil to the second PTT switch.

The downside is that if the relay fails, you could lose the ability to transmit. Solid state switching would have higher reliability, but the mechanical life of most of these relays is in excess of 20 million operations anyway.

There is also a possibility that you could run into issues with hearing your transmissions on the other radio; you could use the fourth contact to mute it if necessary.

Paige
 
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mscheuer said:
The LEDs as well as the pushbutton switchs are controlled by FPGAs with TTL control. I do not recommend bringing those signals out of the audio panel, these signals would have to be conditioned before meeting the outside world.
Click to expand...

Take the signal off the LED in the Com2 Xmit button, and send it to a one-transistor relay driver circuit. Make the 1-transistor relay circuit as small as possible to fit somewhere inside the audio panel case itself to protect it. Then send a relay-switched +12V out the back thru an unused or re-purposed rear connector pin

Here's some examples of both active-high and active-low switching circuits depending on how your FPGA drives the LEDs.
http://www.pcbheaven.com/wikipages/Transistor_Circuits/
 
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