[lr172]

I will have one panel mounted Comm wired into my PM3000 Intercom. I want an easy way to connect my portable comm into the system for comm failure situations.

My plan was to bridge the connection between the Radio and Intercom (both Mic and Spk). I would take the bridged wires to panel mounted 3.5mm jacks for connection to my portable. I would keep these jacks isolated from the panel and use shielded cable The jacks would normally be empty. When I need the portable Comm, I would turn off the panel mounted comm before turning on the portable comm.

Is there any reason that this installation would cause any problems such as noise?

Thanks for your assistance with this.

Larry

 

[BobTurner]

I would recommend against your plan:
1. Depending on what is inside the com, it may look like a short circuit to the portable. e.g., the mike and/or audio signals may flow into the com instead of the intercom and/or the portable. You can get around this by using jacks that have a switch feature built in, but then you have another potential failure point for the main com.
2. This is not useable if you have a complete power failure, because the intercom won't work. (unless it has a 'fail-safe' provision)

Why not just get headset adaptors (3.5 mm to standard) and plug your headset directly into the portable?

In most cases reception will be okay but transmission range limited. To fix that you need an external antenna you can plug into.

 

[lr172]

I would recommend against your plan:
1. Depending on what is inside the com, it may look like a short circuit to the portable. e.g., the mike and/or audio signals may flow into the com instead of the intercom and/or the portable. You can get around this by using jacks that have a switch feature built in, but then you have another potential failure point for the main com.
2. This is not useable if you have a complete power failure, because the intercom won't work. (unless it has a 'fail-safe' provision)

Why not just get headset adaptors (3.5 mm to standard) and plug your headset directly into the portable?

In most cases reception will be okay but transmission range limited. To fix that you need an external antenna you can plug into.

Thanks for the input here. I liked the idea of having the intercom and PTT on the stick if I lost the primary COMM. It was my understanding that the PM3000 would provide a direct bridge from the headset to the radio in the event of it's failure or power loss. I may have misunderstood this. The radio is an SL-30. Maybe if the Garmin guys see this they can address how that radio would behave in this application. I suppose I can wire in a DPDT switch to avoid any issues. I think you mentioned once before that I can bridge the ground connection to both sources to avoid a 3PDT switch.

I plan to leave a male/female BNC connection with a loop of cable under the panel so that I have access to an external antenna for the portable in the event the SL-30 bites the dust or I lose power.

Building some cables adapters shouldn't be too hard.

Larry

 

[BobTurner]

Not sure how many portables will take an external PTT input, you'll probably need to use the switch on the radio.

 

[lr172]

Not sure how many portables will take an external PTT input, you'll probably need to use the switch on the radio.

I have one of the old Sporty's radio. The manual seems to indicate that it will take an external PTT and the Mike input jack looks to have two prongs (Tin and Ring) giving me confidence that it will take the PTT input. I won't be able to confirm until I get it wired up.

Larry

 

[bruggers]

External Push to Talk for Icom IC-A24

Yes, Icom IC-A24 Headset Adapter does have push to talk adapter included.

KenB