SBE Mic M-100X to COBRA 29

[Robb]

I CANNOT FIND ANYTING ONLINE FOR THIS MIC.
ANYBODY KNOW?
Need wiring this mic to this radio.
THANX IN ADVANCE!

 

[Bionic Chicken]

If it is wired for a SBE then it should be plug and play. Direct fit.

 

[Robb]

Thanks for that reply BC.
This mic had no plug on it. I tried wiring it all kinds of ways - with no results. It has a 7v battery in it - and there is no marking for polarity on the mic for + and -. The grounding wire appears to use the same path as the battery. So - without the battery - there is no complete circuit.

I was hoping that someone else on this forum had a lot of experience with this mic. It is NOS, and it is a friend of mine's mic.

SO far - SOL on anything online and absoulutely no clue as to why it won't work so far. I'm beginning to wonder if the battery wasn't put in backwards and fried the transistors, as that can happen all too easy without any markings on the mic for polarity.

 

[WR0220]

The audio wire is usually the one that has the shield wrapped around it. Using a multimeter, attach one probe to the shield wire and touch the other probe to each of the remaining wires. When you touch a wire and get a reading on the meter, hold the probe on that wire and press the ptt switch. The reading should drop back to zero. This is your receive wire. The remaining wire is transmit. To verify this, hold the probe on the wire (no reading) and press the ptt switch. You should get a reading on the meter, and it should drop back to zero when you release the ptt switch. The battery powers the amplifier circuit, so you should still be able to determine the wiring configuration with/without a battery in the mic. Hope this helps...

 

[Bionic Chicken]

Thanks for that reply BC.
This mic had no plug on it. I tried wiring it all kinds of ways - with no results. It has a 7v battery in it - and there is no marking for polarity on the mic for + and -. The grounding wire appears to use the same path as the battery. So - without the battery - there is no complete circuit.

I was hoping that someone else on this forum had a lot of experience with this mic. It is NOS, and it is a friend of mine's mic.

SO far - SOL on anything online and absoulutely no clue as to why it won't work so far. I'm beginning to wonder if the battery wasn't put in backwards and fried the transistors, as that can happen all too easy without any markings on the mic for polarity.

Hmmm, usually the SBE desk mikes all had 9 volt batteries in them or at least the ones I have seen. White (or yellow) should be audio and wrapped with the shield, this will go to pin 2. The shield will go to pin 1. Either the black or red wire will go to pin 3 to key the radio. Pin 4 will be for receive. Hopefully this will get you going.

BC

 

[Robb]

This is the way I have it wired:
pin 1 - Shield
pin 2 - White
Pin 3 - Black
Pin 4 - Red
With this arrangement - using a Magnum OmegaForce as the test bed (same as Cobra wiring), when I key the mic I get audio in my talkback - but the radio will not key/TX.

BTW - the battery with the + twards the outside of the mic got the loudest modulation - so that should be right. I don't know why they didn't stamp this info somewhere on the mic - but they didn't...

Thanks for all of the help. Now, if I can get it to key up/TX - I'll be done.
So far - no dice.
I think I will pull hair out over this one,
Doesn't anybody use one of these; or had a similar situation?
It's only got four wires, and I've tried all of the combinations.
Do these mics require a relay?

Edit - When hooked up to the Cobra 29 with this wiring scheme and keying the mic, I get a loud buzz.
No audio when unkeyed. It isn't right yet. When I switched the red and black wires - same buzzing thing happens.
Stock Cobra 29 LTD wiring:
1- Shield
2- Audio
3- Transmit
4- Receive
When I opened up the mic, the red and black wires go directly to one side of the PTT switch.

 

[Bionic Chicken]

Take an ohmeter and find out which two wires show continuity with mike unkeyed. When you key the mike one of these wires should show continuity to another wire. The one that is common in both cases should go to pin 1. The one that common with the mike unkeyed will go to pin 4. The wire that makes it with the mike keyed goes to pin 3. The remaining wire goes to pin 2. It should work. If it doesn't something may be wrong with the mike.
Those are great mikes with good audio. I think you will enjoy it when you get it wired up.

BC

 

[Big Dummy 123]

Hi all, Robb I think it the same as a Hygain 611 take a look on cbtrick mic section, or close to it.I hope this helps Ben

 

[Drenalin]

SBE M 100X to a Cobra Radio

Hello all. I know that this thread is 2 years old, but I seem to have the same problem as Rob so here goe's.

The mic is Factory wired for a 4-pin midland radio so reverse 1 &2 and 3&4 for the pins to match up to a cobra radio but now the tricky part.

The switching inside the microphone is wired for relay switching. I unsoldered the black wire and moved it over to the right to the normally closed side of the PTT switch. I then soldered a wire from the point where the black wire was originally soldered and soldered the other end to the shield wiring, this shows on my T747 mic test center as green LED on for receive and when PTT is pushed, I get a red LED on for TX.

The problem Im havivg is when I plug in the mic I still get a squeal. Im wondering if someone can point me to a Schematic on this mic since cbtricks has no info on a schematic.

Thanks in advance.

 

[kb2crk]

I know this thread is old as dirt but it is the only thing that comes up on Google for the SBE M100X microphone. Does anyone know what Battery it takes? The mic does not say and all the paperwork in the box says is that its a penlight battery. I have this NOS microphone I am trying to get up and working on my Sidebander II.

 

[sonoma]

for its age I would think it takes one of the old 7 volt battery's

 

[kb2crk]

The paper work says a Penlight battery which would put it in the 1.5v range. The N cell looks to be about the right size but I don't want to run out and buy a bunch of different batteries just to try. I was hoping someone knew which one it took.

 

[R0B]

I CANNOT FIND ANYTING ONLINE FOR THIS MIC.
ANYBODY KNOW?
Need wiring this mic to this radio.
THANX IN ADVANCE!

found some stuff out.

It works fine on a 6 volt battery
the red wire is plus mic,
earth + black is mass, solder them together
blue is TX
White is RX
yellow not used in my case

ps,

And the audio is superb

Just seen you're silent key.... r.i.p this info is for anybody that can use it then