How to disassemble Shure SM58 with wireless UT2 transmitter.

[David Farber]

I have an intermittent Shure wireless UT2 mic/transmitter. The user said
that tapping on the mic when it wasn't working would restore its operation
but now even that doesn't help. I would like to have look inside but I don't
see a simple way of opening it. I removed the windscreen and there is a
label that says, "Caution do not attempt to open or turn. Warranty will be
voided." I wanted to know if turning the microphone will damage the wiring
going to it or if that warning is just telling you to, "Keep out!."

I found some disassembly instructions here that did not mention anything
about "turning" the mic as dangerous.
https://shure.custhelp.com/app/answers/detail/a_id/3447/~/disassembly-of-a-handheld-transmitter%3A-t-series-and-others

Thanks for your reply.
--
David Farber
Los Osos, CA

[Phil Allison]

** The head screws off easily and holds the mic capsule, normally an SM58.

The main electronics are trapped under a large C-clip:

http://i.ebayimg.com/00/s/MTU0OFgxNjAw/z/EMkAAOSwUuFWxVdj/$_1.JPG

The instructions you cited seem accurate but may well be not needed.

COS you have NOT said if just the audio cuts out or the RF carrier stops.

You do have the receiver, don't you ?

More info please.



.... Phil

[David Farber]

Hi Phil,

I have the UT4 receiver. The green power l.e.d. illumintates on both the mic
and the receiver but neither of the antenna receiver lights (A or B)
illuminate. The mute switch on the mic seems a little wonky. There is a lot
resistance (physical) moving it to the mute position and almost no
resistance moving it back to the "on" position. Does enabling the mute
switch turn off the RF?

[Phil Allison]

David Farber wrote:

> I have an intermittent Shure wireless UT2 mic/transmitter. The user said
> that tapping on the mic when it wasn't working would restore its operation
> but now even that doesn't help. I would like to have look inside but I don't
> see a simple way of opening it. I removed the windscreen and there is a
> label that says, "Caution do not attempt to open or turn. Warranty will be
> voided." I wanted to know if turning the microphone will damage the wiring
> going to it or if that warning is just telling you to, "Keep out!."
>

** Hang on a mo - you are trying to take apart the Cartridge Assembly - right ?

1. Put the wind shield back on.

2. Run the transmitter and see if it outputs a carrier.

3. If 2 is OK, connect an audio signal ( via a cap) to the "AUD IN" terminal on the transmitter and see if you can hear it coming out the receiver.

4. If 4 is OK, the capsule is the problem.

5. There is an SMD board that is a pre-amp for the SM58 capsule - removing it is tricky but IIRC the capsule is attached to it.

Shure consider it to be non repairable, but you may as well have a go if it is the problem. In your case it might be a bad solder joint on the 58 capsule itself.


.... Phil

[Phil Allison]

David Farber wrote:

> Phil Allison wrote:
>
> > You do have the receiver, don't you ?
> >
> > More info please.
>
>

> I have the UT4 receiver. The green power l.e.d. illumintates on both the mic
> and the receiver but neither of the antenna receiver lights (A or B)
> illuminate.
>

** So no RF OR maybe the frequency is off.

Do you have a frequency counter that works at UHF ?

If so, use that to see if there is a carrier and at what frequency - just hold the mic right next to a short antenna plugged into the input.

> The mute switch on the mic seems a little wonky. There is a lot
> resistance (physical) moving it to the mute position and almost no
> resistance moving it back to the "on" position. Does enabling the mute
> switch turn off the RF?
>

** No, it just mutes the audio.

Last one of these beasts I saw had a problem with the frequency synthesiser
inside the mic handle. It was outputting a carrier frequency the receiver did not work on. Off by only 100kHz from one of the available ones, but that was enough - plus the buttons on the mic did nothing to change that frequency.

The local Shure agents supplied a new mic at trade price to my customer, cos that had no way to fix it either.


.... Phil

[David Farber]

I have a frequency counter... a Heathkit I built around 1982 I believe its
upper range is 30MHz. I was thinking if I could open up the transmitter,
maybe there was some minor physical damaged caused by some rough handling
around the mute switch area. Getting back to the disassembly question, can I
just unscrew the mic capsule? I don't want to force it but if it's ok to
safely remove it that way, then I'd like to get to the internal circuitry.

Just to make sure you understand which mic/transmitter I have, you can see a
picture of it here.
http://www.shure.com/user-guides/us_pro_ut_wireless_en_ug.pdf
on page 6, Figure 5.. I do not see any "AUD IN" on the transmitter.

Thanks for your reply.
.--

[Phil Allison]

David Farber wrote:

>
> >
> > ** So no RF OR maybe the frequency is off.
> >
> > Do you have a frequency counter that works at UHF ?
> >
> > If so, use that to see if there is a carrier and at what frequency -
> > just hold the mic right next to a short antenna plugged into the
> > input.
> >
> >
> >
> >> The mute switch on the mic seems a little wonky. There is a lot
> >> resistance (physical) moving it to the mute position and almost no
> >> resistance moving it back to the "on" position. Does enabling the
> >> mute switch turn off the RF?
> >>
> >
> > ** No, it just mutes the audio.
> >
> > Last one of these beasts I saw had a problem with the frequency
> > synthesiser
> > inside the mic handle. It was outputting a carrier frequency the
> > receiver did not work on. Off by only 100kHz from one of the
> > available ones, but that was enough - plus the buttons on the mic did
> > nothing to change that frequency.
> >
> > The local Shure agents supplied a new mic at trade price to my
> > customer, cos that had no way to fix it either.
> >
> >

> I have a frequency counter... a Heathkit I built around 1982 I believe its
> upper range is 30MHz.
>

** No use at all.

> I was thinking if I could open up the transmitter,
> maybe there was some minor physical damaged caused by some rough handling
> around the mute switch area.

** The mute switch doe not stop RF.

> Getting back to the disassembly question, can I
> just unscrew the mic capsule? I don't want to force it but if it's ok to
> safely remove it that way, then I'd like to get to the internal circuitry.
>

** The head should unscrew easily, then the C-clip as previously stated.

Be CAREFULL, the buttons that operate the switches are FRAGILE.

BTW:

Do you know the mic's frequency ??

The handbook gives tables for code letters and actual frequencies.

Do you have a radio scanner that covers the UHF band ??

You MUST have a counter or a radio scanner or you cannot service radio mics.



.... Phil

[David Farber]

I do have a scanner. It's a Bearcat BC125AT. It will receive analog only. I
do no plan on making a habit out of servicing radio mics but this is for a
charity.

There is a label near the battery that says, 623.350 MHz FM. According to my
scanner's user manual the upper limit of the UHF band is 512 MHz. I'm
guessing that's not going to work.

Thanks for your reply.
--

[Phil Allison]

David Farber wrote:

>
> >
> > ** The mute switch doe not stop RF.
> >
> >> Getting back to the disassembly question, can I
> >> just unscrew the mic capsule? I don't want to force it but if it's
> >> ok to safely remove it that way, then I'd like to get to the
> >> internal circuitry.
> >>
> >
> > ** The head should unscrew easily, then the C-clip as previously
> > stated.
> >
> > Be CAREFULL, the buttons that operate the switches are FRAGILE.
> >
> > BTW:
> >
> > Do you know the mic's frequency ??
> >
> > The handbook gives tables for code letters and actual frequencies.
> >
> > Do you have a radio scanner that covers the UHF band ??
> >
> > You MUST have a counter or a radio scanner or you cannot service
> > radio mics.
> >
>

> I do have a scanner. It's a Bearcat BC125AT. It will receive analog only.
>

** Radio mics a nearly all wide FM.

>
> There is a label near the battery that says, 623.350 MHz FM. According to my
> scanner's user manual the upper limit of the UHF band is 512 MHz. I'm
> guessing that's not going to work.
>

** Correct.

I have a frequency counter ( built from a kit) that operates to 950MHz and a radio scanner ( AR 1000XLT ) that goes to 1.3 GHz. Both were acquired with radio mics in mind.

I used to have a nice RF Generator made by Wavetek - but that went totally belly up long ago.

http://2.bp.blogspot.com/-qVmROlXBCT8/T4idLzUwcOI/AAAAAAAACro/2IIxhSM9PW4/s1600/wavetek%2B3000-200.jpg

I know it only went to 520MHZ, but you can cause & use harmonics.



.... Phil

[Jeff Liebermann]

On Wed, 1 Mar 2017 19:26:59 -0800, "David Farber"
<farberbe...@aol.com> wrote:
(...)

"How to take apart a UHF U2 Shure wireless Microphone"
<https://www.youtube.com/watch?v=UFcDXRhNEhQ> (1:28)

--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[David Farber]

Jeff Liebermann wrote:
> On Wed, 1 Mar 2017 19:26:59 -0800, "David Farber"
> <farberbe...@aol.com> wrote:
> (...)
>
> "How to take apart a UHF U2 Shure wireless Microphone"
> <https://www.youtube.com/watch?v=UFcDXRhNEhQ> (1:28)

Hi Jeff,

That microphone is not at all physically similar to the one that I am
servicing. I told the user it wasn't worth fixing. You can buy a new one,
though not a Shure model, for under
$100.

[mako...@yahoo.com]

623 is UHF TV channel 39 in the USA.

If you have an analog UHF TV set for off the air mode (not cable) and tune it to Channel 39, you should see some change in the snow when you turn the mic on and off. I doubt it will demod the audio but you should see some effect of the mic onto the snow. That will tell you if it is putting out RF or not.
m

[Phil Allison]

David Farber wrote:

>
>
> That microphone is not at all physically similar to the one that I am
> servicing.
>

** It should be very similar.

Are you SURE it is a Shure mic ??

The Chinese have been making copies of Shure mics and radio mics.

> I told the user it wasn't worth fixing. You can buy a new one,
> though not a Shure model, for under $100.

** Fine, if all you want is a piece of garbage.


.... Phil

[David Farber]

Am I SURE it's a Shure mic?? Excellent question. It says Shure and it's
spelled correctly. The thing that doesn't make sense to me is that when you
unscrew the top cover, the microphone remains in place and there doesn't
seem to be an easy way to remove the microphone capsule from the rest of the
unit. I had to force off the bottom part of the mic handle to get to the
circuit board. Inside I found that the tab that extends from the mute switch
was broken. (I know you said the switches are delicate but I could not find
any other way of opening the case and even before I opened the case it
appeared the mute switch wasn't working properly.) I did not find any
physical damage to the board. When I tried to reinstall the circuit board
into the handle, it took a lot of pushing. Is there an easy way to determine
if this is a knockoff?

[David Farber]

I do have an old Sony set which I still watch every day. I'll give it a try
tomorrow and let you know what happens.

[Phil Allison]

David Farber wrote:
> Phil Allison wrote:
> > David Farber wrote:
> >
> >>
> >>
> >> That microphone is not at all physically similar to the one that I am
> >> servicing.
> >>
> >
> > ** It should be very similar.
> >
> > Are you SURE it is a Shure mic ??
> >
> > The Chinese have been making copies of Shure mics and radio mics.
> >
> >> I told the user it wasn't worth fixing. You can buy a new one,
> >> though not a Shure model, for under $100.
> >
> > ** Fine, if all you want is a piece of garbage.
> >
> >
>

> Am I SURE it's a Shure mic?? Excellent question.
>

** Pun fully intended.

> It says Shure and it's spelled correctly.

** Very comforting.

> The thing that doesn't make sense to me is that when you
> unscrew the top cover, the microphone remains in place and there doesn't
> seem to be an easy way to remove the microphone capsule from the rest of the
> unit. I had to force off the bottom part of the mic handle to get to the
> circuit board. Inside I found that the tab that extends from the mute switch
> was broken. (I know you said the switches are delicate but I could not find
> any other way of opening the case and even before I opened the case it
> appeared the mute switch wasn't working properly.) I did not find any
> physical damage to the board. When I tried to reinstall the circuit board
> into the handle, it took a lot of pushing. Is there an easy way to determine
> if this is a knockoff?
>

** I was sent a Shure fake model a couple of years ago, the Chinese had copied the handbook, the brochure, the plastic case in every detail - except the electronics.

The Rx had two antennas, but only one was connected to anything inside.

The capsule was nothing like an SM58 and the performance was bloody awful.

The BIGGEST clue was that it was purchased from Honk Kong for an absurdly low price. AFAIK, genuine Shure product is never sold that way.

There are a bunch of Chinese SM58 knock-offs too, some worse than others, none worth buying - mainly cos none of them last for decades the way the famous mic is famous for.



.... Phil

[David Farber]

I reset my TV to over-the-air reception, tuned it to 39 and then turned on
the mic. I could not see any change in the snow pattern.