TK790H Remote Head Dual Speaker

[crawler]

Hello,

Searched around and can't seem to find the answer I am looking for.

I have a TK790H and a KCH10 remote head with the internal speaker.

A jumper is installed on the 9 pin Molex connector across pins 3 & 6; the speaker on the KCH10 currently functions as intended.

I would like to add an external speaker in addition to the speaker on the KCH10... but am not sure which route to take or if it is even possible.

Ideally, both speakers would be hooked up and active at the same time, allowing incoming communication to be heard from inside or outside of the vehicle the radio is mounted in.

On the 9 pin Molex, can pins 3 & 6 be jumped while pins 2 & 6 are being used for an external speaker or is it one or the other?

On the 12 pin Molex, can pins 10 & 11 be used for an external speaker without disconnecting the KCH10 internal speaker?

In the programming software I have, I see an option to allocate a button for "speaker int/ext", which to my understanding would allow me to toggle the speaker output to pins 7 & 8 on the 9 pin Molex (?). This is listed as a PA output though... so am I correct in thinking that I will be unable to transmit out while using the external speaker in this mode?

Are there any other options that I am missing?

Thank you in advance

 

[mmckenna]

Leave the jumper in place (that will give you audio to the internal speaker).
Connect the second speaker to pins 7&8.
You can program a button for PA, which will make pins 7&8 act like an external PA speaker, or you can program a button for external speaker, which will give you received audio out the external speaker. That sounds like what you are looking for.

 

[ramal121]

To have both internal and external speakers on the KCH-10 at the same time would require some surgery in the head as Kenwood made it either/or by the internal cabling.

Using pins 7 & 8 on the brick 12 pin will give you PA (transmit disabled and mic audio to speaker) or External Speaker which will route radio receive to this port while disabling the primary speaker (control head). Depends on how a button is programmed.

If you want to use both speakers at the same time from the 12 pin molex, you would leave the 3-6 jumper in place and tap one speaker lead into it and the other speaker lead to pin 2.

Running 2 speakers off the radio puts more of a load on the audio amp. I will say though that I have done 2 of the KES-5 speakers (2 to3 ohm in parallel) without an amplifier failure yet but would not do more than that.

Radio shipped with the KCH-10 will have a dropping resistor in the speaker line to reduce the audio to the whimpy internal control head speaker. There is a jumper inside the radio to bypass this to supply the full 13 watt audio in case you have the external KES-5 speaker which will handle the higher output. If you need the higher audio and still use the control head internal speaker, well you've been warned. Best to use two external speakers that have the nut to handle 13 watts.

 

[crawler]

Thank you both so much for the info!

 

[crawler]

If you want to use both speakers at the same time from the 12 pin molex, you would leave the 3-6 jumper in place and tap one speaker lead into it and the other speaker lead to pin 2.

In this example did you mean the "9 pin" molex on the base of the radio?

Both speakers active at the same time without needing to utilize a button would be preferred, but if that is not ideal I'll go the other route.

Am I safe to run a KES-5 external speaker in parallel with the KCH-10 (3w/8ohm) speaker as you've described, or am I risking damaging something? (IE- Pins 3 & 6 jumped on the 9 pin molex to retain the KCH-10 speaker, and pins 2 & 6 out to the KES-5)

I confirmed the 0ohm limiting resistor (R628) is in place so the speaker in the control head has been safe. With this in place I suppose I wouldn't be using the KES-5 to it's fullest potential, but I'm not certain if volume will be an issue until I give it a try.

Thanks again! This forum is a wealth of knowledge.

 

[ramal121]

In this example did you mean the "9 pin" molex on the base of the radio?

Yes, my dyslexic mistake.

Am I safe to run a KES-5 external speaker in parallel with the KCH-10 (3w/8ohm) speaker as you've described, or am I risking damaging something? (IE- Pins 3 & 6 jumped on the 9 pin molex to retain the KCH-10 speaker, and pins 2 & 6 out to the KES-5)

If the limiting resistor is in place for lower audio then you should be just fine.