Mic Testing

[long night]

Hi to all. I have a mic tester that works well. The mics I test show to be working correctly or not. Testing one mic in the proper jack, the rx light shows green and the tx light shows red as they should, but no modulation when talking. Could this condition be caused by a white audio wire that has come unsoldered in the mic plug?

Thanks for your help.

 

[999]

What mic?

 

[long night]

What mic?

No brand name on mic.

 

[KneeBiter]

Or could be a bad element

 

[Handy Andy]

Unsoldered?

Possibly.

Dynamic? Opened element or wire - certainly will go dead - won't show ohmic indication on any meter either...

Or,

Radio can require an Electret (low-power supplied to mic by radio) element and if you happen to plug in a dynamic, if the power supply is too great - and the ohmic of the element is too small - can open it (Element) that way too.

Seen some Mic elements "frozen" in the socket of the coil to magnet core - not sure from what - but knowing how "From my lips to your ear" moments are - someone may have given them a piece of their mind - by using said handset - physically...

 

[Dopple]

Use a multimeter (resistance/ohms) to verify that you have continuity between the mic element and the plug. If not, then check between the PTT and the plug, and the PTT and the mic element. As mentioned above, if it's an electret condenser mic element, they do require voltage to operate, your mic tester should have a switch to turn that voltage on and off. Mine is an older one, and the switch is labeled "grey" or "black" mic button. Grey is powered, electret, and black is non-powered, dynamic.

The elements are obvious when you see them, the dynamic ones look like a speaker, and the electret ones look like a small aluminum cylinder.

 

[guitar_199]

You mention the RX is green and TX is red..... but when you key it... do the lights switch? That would indicate that HALF of the switch is working properly. Typically one half of the switch handles RX/TX switching. The OTHER half commonly opens up the mic line in RX or connects it to the connector pin on TX. Some microphones go to the trouble to short the connector pin to ground in RX so it is not floating.
So the audio wire could be unsoldered from the pin or the switch, the mic element could be bad or unsoldered from the switch, or the switch contact(s) could be bad.

Just some ideas.

 

[Handy Andy]

To answer your question more specific...

The Red/Green switch - were speculating here - on the type of Mic Checker you're using or designed by yourself - there are two ways or two things - depending upon your view - that are happening

You plug the Mic cord into the jack, and key the Mic, it light is hooked up to the (speculation again) Pins 3, 4 and 1 - with 1 being Common - and Pin 2 being "audio" - again speculation - but if the DPDT switch of an unknown mic is wired correctly - or not, there may be enough conduction from the Dynamic element - to show toggling and is working.

How? By the Elements' ohmic result, and if Pin 2 - being Audio - is connected to an amplifier...but also must have its other half (the return wire) connected to either Pin 3, 4 or Pin 1 - so its circuit needs to be completed too - in order to HEAR the element and if it works or not.

Am I following you so far?

So if you are using the Mic checker, and you have no audio - again may show Red Green and that switching seems to work - is it really correct? You have no audio - but Element may show good - How? Because Pin 2 may be hooked up - but you're grounding the elements return to the wrong pin - it is possible to use Pin 4 in such a checker - unless it looks at KEYWAY - being that Pins 1 and 4 are possibly reversed.

We have recently been seeing several "knock off" brand radios that use the Cybernet chassis - with mic plugs and jacks seemingly wired the wrong way - as in Pin 1 and Pin 4 as well as Pins 2 and 3 - mirror images of each other and reversed in this fashion.

So since this thread is about "checking mic" I though I'd better bring this up so you can be aware of the differences in mirroring that some plug to jack "mistakes" that can be made - can occur and will throw you for a loop if you're not looking for it.