Icom external speaker jack

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nmelfi

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I know this is a 3.5 mm jack but nowhere in the manual does it say if it is a stereo or mono jack. I would like to try my logitech THX speakers on it before I put out $160 for a sounds sweet speaker. Any input? Thanks in advance, Nick
 

jim202

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I know this is a 3.5 mm jack but nowhere in the manual does it say if it is a stereo or mono jack. I would like to try my logitech THX speakers on it before I put out $160 for a sounds sweet speaker. Any input? Thanks in advance, Nick
Why would it make any difference if it is a stereo or mono jack? If you plug in a stereo jack and it's mono, you get sound only out of one speaker. The Icom will only deliver one channel of audio no matter how you look at it.
 

nmelfi

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Why would it make any difference if it is a stereo or mono jack? If you plug in a stereo jack and it's mono, you get sound only out of one speaker. The Icom will only deliver one channel of audio no matter how you look at it.
It called nervous about shorting something out. A stereo jack has two connection points, where a mono jack has one. Just trying to make sure i won't hurt the reciever by plugging a stereo jack into it.
 

OCO

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The part in your hand is the plug, you plug it into the jack...Stereo plug into a mono jack is alright, but a mono plug into a stereo jack will short the ring (middle band) to ground, which will short one of the stereo channels to ground (The HP1 is an example of stereo jacks on the headphone and line out). Your ICOM is probably mono (check the manual) and it should be safe plugging a stereo plug into it. (you may get only one of the pair of speakers working depending on how the jack ring contact is shaped).
 

nmelfi

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Thank you that was what I was looking for. The manual does not state mono or stereo, but as long as a stereo plug is backwards compatible I should be fine. Thanks again for the help.
 

Comint

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Most Icom scanners have a Stereo Jack, however they have Mono audio output, as the Ring is used for Programming and Cloning purposes. Don't know about the R75.

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Comint
 

Nap

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Generally it is safe to plug a stereo jack into a mono connector. Usually you will hear the signal only in one speaker though. You still have to check the headphones impedance so it's not too low. It can happen that for a certain position of the jack it makes contact to both speakers (and you hear the signal with both ears), at this moment the speakers are connected in parallel so their total impedance is the nominal one dived by 2. Rule: if the mono output specification says something like "Minimum 8 Ohms", observe that your stereo headphones are specified at least at double that impedance (i.e. they are 16 Ohms or more). So for that particular position of the jack you're still not overloading the amp.

Plugging a mono connector into a stereo output should be avoided as it will connect together the outputs of two distinct audio amplifiers. Not good.
 

kruser

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Plugging a mono connector into a stereo output should be avoided as it will connect together the outputs of two distinct audio amplifiers. Not good.
Some of the Icoms used a TRS (3 conductor jack) even though they only deliver a single mono signal. If you plug a mono plug into those, the ring and sleeve will short the audio out signal to ground and you will hear nothing or super low volume. The jacks are wired with the single audio signal on both the tip and ring terminals. I forget which Icom I found like this but I think it was the R7000, R71 or maybe the R9000. Those are the only older Icoms I have and one of them was setup like that.

I've never hurt a radio yet by shorting the audio output but of course I start with open squelch and no volume so I can bring it up slowly if I'm unsure of the jack type and wiring. If I do not hear noise right away, I assume it is shorted and I'll grab an adapter to test with. I suppose you may harm the audio output device if you left it in a shorted condition with the volume turned up for any length of time greater than a few seconds or so.

I assume the OP is referring to the IC-R75 from his signature line info. The OP did not specify the actual model.
According to the service manual, the R75 has a standard Mono 1/8th inch external speaker jack so a stereo or mono plug will work but using stereo speakers will only produce an output on one channel unless you use a mono plug to stereo jack adapter.
The R75 also has a 1/4 inch jack on the front panel that is a stereo type setup to drive two speakers in a stereo headset. It is volume limited by resistors though but would work fine with amplified computer speakers.
I've never used the front panel jack on mine.
 
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