Shure 527b microphone to 4 pin cobra.

[SMILEX2692002]

399,

You're 100% correct. The black wire off the mic element should be swapped with the red wire on the PTT switch, and the black wire on the PTT switch should be swapped with the green wire on the PTT switch. In the end it should look like the drawing below.

Don't know what I was thinking when I made the first post at the time. Oops.


Thanks for the correction!


~Cheers~

Just wondering what black wire to use for the connection to the mic plug once this is done? The microphone has 2 black wires at the end that could be soldered to a 4 pin plug.

 

[SMILEX2692002]

Wired the microphone last night.
Tested on my TS-2000 last night and had excellent results. The FM audio quality is far above anything I have used before.
The SSB audio quality is also quite nice.

 

[Aegir]

I want to revive this old thread. I have a Shure 527B microphone. I'm trying to wire it to a 5 Pin plug for a Uniden Grant XL/Uniden Madison.

Unfortunately, I cannot get it to work. I get squeal upon transmit. I've tried the 4.7k ohm resistor on the audio line solution, and this only disables my transmit ability. Without the resistor, I get key plus feedback.

I've tried rewiring according to the drawing posted here, but I"m not quite sure it's correct. Squeal is still a problem.

I've contacted Shure, and followed the advice given. I've achieved the same result. Surely there must be someone out there using this microphone successfully with a 5 pin - or even a 4 pin?

Here's the response from Shure:



527B connected to Cobra radio

Response By Email (Michael P) (06/30/2016 03:19 PM)
Sorry, I do not have input on this. Cobra must be the source of the answer.
Inform Cobra that the 527B/577B can provide a dry contact closure; the closure is normally open when the mic signal is muted, and the closure is closed with the mic signal is active. Only Cobra knows how their radio will react.
If you wish to experiment, try Red wire to TX and Black wire to Common/Shield. This should work is the radio is normally in Rx mode.
Customer By Email (Bryne Last Name) (06/30/2016 03:03 PM)
Hi thanks for your response. TX is transmit, RX is receive & there's a key at the top
If the drawing.
RX and TX together upon PTT will cause the radio to squeal
I think.
I know these radios do not receive without a
Microphone plugged in. So, Receive needs to be "on"
When mic is plugged in, and "off" upon transmit.
Wouldn't this require a modification of the wiring to the switch itself?
Please advise - I'm hoping you might have some input on this.
Thanks for your help.
Bryne
N7BB

On Jun 30, 2016, at 11:15 AM, Shure Support <support@shure.com> wrote:

Response By Email (Michael P) (06/30/2016 01:15 PM)
For 527B/577B, the audio is the simple part:
Green wire to MODULATION pin
White wire to Common/Shield pin
Shield surrounding Green and White to Common/Shield pin
However, the RX and TX pins are ill-defined based on the drawing. So as a starting point:
Red wire to TX
Black wire to RX
When the 527B/577B mic button is depressed, the RX pin and the TX pin will be connected together. We hope this will put the radio in Transmit mode.
If not, please contact Cobra. The red wire and black wire are a simple dry contact closure.


I would appreciate any assistance from anyone who has wired this microphone to this transceiver correctly - even if it involves getting a different type of switch.

Thanks.

 

[Aegir]

Good Morning. I'm wondering if anyone can comment on how to wire a Shure 527 B to a 5 pin Uniden Grant? I still can't figure this out. I haven't worked on it in awhile. Previously someone posted a drawing, but I see the image isn't available for viewing any longer. Any help would be appreciated.

 

[nomadradio]

So, refresh my memory.

Is this a mike with a 4-wire cord?

If so, you have a very simple math problem Five is not equal to four.

The 5-pin Uniden-made 40-channel SSB radios have two separate ground pins.

This is to provide two separate ground circuits.

One for the mike audio.

Alone.

One for the transmit/receive switching circuits.

Only.

Back in the 70s Turner sold an "upgrade" kit for their desk mikes. It included additional switch contacts, insulators and longer screws to mount the now-taller stack of switch contacts and insulators.

This provided the additional switch circuits that permit you to provide two separate ground circuits inside the mike.

But the 527 presents an even bigger challenge.

Just found my copy of the instructions for this mike. See attached file.

It has no normally-closed contact for you to use as the receive side of the transmit-receive switching circuit.

The 527 mike works on radios that will RECEIVE WITHOUT THE MIKE PLUGGED IN.

And any radio that only receives with the mike plugged in just is not compatible.

73

 

[Aegir]

So, refresh my memory.

Is this a mike with a 4-wire cord?

If so, you have a very simple math problem Five is not equal to four.

The 5-pin Uniden-made 40-channel SSB radios have two separate ground pins.

This is to provide two separate ground circuits.

One for the mike audio.

Alone.

One for the transmit/receive switching circuits.

Only.

Back in the 70s Turner sold an "upgrade" kit for their desk mikes. It included additional switch contacts, insulators and longer screws to mount the now-taller stack of switch contacts and insulators.

This provided the additional switch circuits that permit you to provide two separate ground circuits inside the mike.

But the 527 presents an even bigger challenge.

Just found my copy of the instructions for this mike. See attached file.

It has no normally-closed contact for you to use as the receive side of the transmit-receive switching circuit.

The 527 mike works on radios that will RECEIVE WITHOUT THE MIKE PLUGGED IN.

And any radio that only receives with the mike plugged in just is not compatible.

73

Thank you for posting this.
The Grant LT is a 5 pin radio, btw.
I wonder if the other offerings from Shure would work instead? The schematics are a little different.
There's the 514B, the 577B, and the 596LB. The 596LB is 400 ohms - closest to matching the impedance of the Grant LT, I think. Since I'm no expert at schematics, care to take a look at the other two? There's also the Turner NC450D. Same issue on all of these?

 

[nomadradio]

Looks like the 450D and 596 mikes could work with a new cord. The cords that come with these mikes don't appear adaptable

The diagram shows a separate SPDT switch section that can be wired for the three keying wires in a 5-pin Uniden-made 40-channel SSB radio.

The switch in the 514 does not appear to have enough contacts to do the job.

73