NX-700 - External Speaker Only?

[03msc]

Connected an external speaker to the speaker jack on the back of the 700 but I still get audio out of the front speaker of the radio, as well.

Is there a 'switch' in the software to tell it to not output via the built-in speaker when an external is attached? I looked but did not see anything. 7160 and 7180 work properly (connect a speaker and the internal speaker is bypassed, as it should be) but the 700 seems to want to continue to output from the front speaker, as well.

 

[mmckenna]

It's supposed to disconnect the internal speaker when you plug in an external speaker. I suspect there's either an issue with the external speaker jack, or if it's a used radio, someone monkeyed with it.

One way around it is to use the external speaker output on the KAP2 cable. When you install that, you'll remove a connector from CN705 that has a jumper on it. That jumper will normally loop the audio amplifier output to the external speaker jack.

 

[03msc]

It's supposed to disconnect the internal speaker when you plug in an external speaker. I suspect there's either an issue with the external speaker jack, or if it's a used radio, someone monkeyed with it.

One way around it is to use the external speaker output on the KAP2 cable. When you install that, you'll remove a connector from CN705 that has a jumper on it. That jumper will normally loop the audio amplifier output to the external speaker jack.

Thanks. I thought it was odd behavior so I'm glad to know they didn't make it this way on purpose. I may open it up sometime and see if I see anything that looks changed. Maybe it's a simple jumper someone added?

 

[n0fwg]

Thanks. I thought it was odd behavior so I'm glad to know they didn't make it this way on purpose. I may open it up sometime and see if I see anything that looks changed. Maybe it's a simple jumper someone added?

Does your NX-700 have a pigtail with a 6 pin molex socket on the back coming out above the speaker jack? If so then it has a KAP-2 board that may need a header type jumper moved on the board

 

[mmckenna]

Does your NX-700 have a pigtail with a 6 pin molex socket on the back coming out above the speaker jack? If so then it has a KAP-2 board that may need a header type jumper moved on the board

CN705, where KAP2 connects, is between the audio amp and the external speaker jack. If it wasn't set right, or the factory jumper was not installed, no audio would get to the 1/8" external speaker jack or the built in speaker.

The 1/8" external speaker jack has a bypass position that is supposed to disconnect the internal speaker when an external speaker is plugged in. I suspect that either someone has modified it, or it's damaged.

 

[n0fwg]

Sorry I miss read the original post, got mislead by the followup. Sounds like someone has modified the radio, maybe a solder jumper across the switch part of the 1/8" jack

 

[03msc]

Will check it. Seems I do remember the guy who I bought it from said he used it in his truck (he contracted for railroad work) and had a speaker in the back of his truck on a toggle switch so that he could listen to railroad radio traffic when working outside the truck. This would make sense that it may have been modded to run both. I had forgotten that, though, until the jumper was mentioned.

 

[KK6ZTE]

Railroad radios had a different firmware and had an "external speaker" button that would toggle inside/outside like the newer NX5000s do. The speaker bypass on the 1/8" jack is software configurable on the newer radios, unlike the older radios. The option isn't available in regular KPG so the button (Square) would have a "blank" Key Assignment.

 

[03msc]

Railroad radios had a different firmware and had an "external speaker" button that would toggle inside/outside like the newer NX5000s do. The speaker bypass on the 1/8" jack is software configurable on the newer radios, unlike the older radios. The option isn't available in regular KPG so the button (Square) would have a "blank" Key Assignment.

Yeah, I looked all through the software and I do not find an option for it...

 

[03msc]

OK, well, over a month later and I finally had a chance to take a look inside this 700. I don't see anything that just jumps out at me as changed. What are my options here? Is this something that the RR firmware (or software?) would need to be utilized to change and then it'd be good or is it stuck this way forever or what? I suppose it's not a huge deal but it does sound a bit odd when connected to an external speaker as there is a very small but still audible delay between the two speakers. I've attached a shot of the inside. Anybody see anything that's incorrect?

 

[n0fwg]

The green wire is a aftermarket modification. It appears to be routed from CN705 (the white plug next to the speaker jack) to the front panel connector speaker pins effectivly bypassing the speaker jack switch.

Unplugging CN705 will disable both speakers, cutting or removing the green wire should make it normal.

Jerry

 

[03msc]

The green wire is a aftermarket modification. It appears to be routed from CN705 (the white plug next to the speaker jack) to the front panel connector speaker pins effectivly bypassing the speaker jack switch.

Unplugging CN705 will disable both speakers, cutting or removing the green wire should make it normal.

Jerry

I guess I thought that was the jumper that mmckenna was talking about as supposed to be there. So...if I snip it then I should be good? I know, as you said, if it's unplugged from CN705 then there's no audio...

 

[mmckenna]

I guess I thought that was the jumper that mmckenna was talking about as supposed to be there. So...if I snip it then I should be good? I know, as you said, if it's unplugged from CN705 then there's no audio...

From the factory, the plug on CN705 would have a wire jumpering pin 2 and 3. Pin 2 is the speaker output, pin 3 is speaker input.
For some reason, someone ran the green wire from Pin 2 to the control head cable cable plug. On the control head, there's several pins that feed the speaker.

Not sure why, makes me wonder if there's a damaged trace on the board they were bypassing.

 

[03msc]

I'm not at home right now but I think the small jumper between 2 and 3 is still there. So...remove the green wire or...?

 

[n0fwg]

I suspect someone wanted to have both the external speaker jack and the internal active at the same time.

To jump the jack, you need to take the board out of the chassis, that is time consuming and a pain So they came up with a easier way

Leave the white jumper from CN 705 pins 2-3 remove the green

 

[mmckenna]

Yeah, cut it in the middle and tape off the two ends and make sure it does what you want.
I agree with n0fwg, sounds like they were trying to keep them both working.

 

[03msc]

Thank you all - I appreciate your help and patience. I'll test it later and report back.

 

[KK6ZTE]

If you need one of those jumpers, I'm about to install a couple horn alert kits so I can send you a removed jumper.

 

[03msc]

If you need one of those jumpers, I'm about to install a couple horn alert kits so I can send you a removed jumper.

Thanks. Best I can tell, I think 2 and 3 are still 'jumped' and it was just tapped with the green line (see pic). I got home later tonight than I thought I would so I didn't get to do anything else with it but I'm thinking if I snip the green then it will solve my problem. (?) If that's the case then I should be good but I'll keep you in mind for sure.

 

[03msc]

UPDATE:

Snipping the green jumper that had been added fixed the issue, as expected. Thanks, everyone, for the help and patience. One of my first times to dig into something like that (as simple as it was) so I wanted to make sure I wasn't doing something that would cause other issues.