NOISEY MOTO MT2000 ON XMIT

[marcus]

Motorola SRN-1202D dated June 1997 but up-issued January 2000 recommends the method of soldering the shields together. This method works best in my experience, and beats the old conductive tape pads hands down. And you can do about ten radios with this method for every one radio that you remove and re-solder the shields on.

This is a quoted post from a Moto tech does anyone have and pics on what sheilds need to be soldered to try to aleviate the annoying xmit noises on my Moto mt2000.

Thanks
Marc
W2MLH

[Batwings21]

SRN - 1202D
APC - 355, 402, 432,466, 511
Date: June 1997 : Up Issued 1/00
Date Extension Only
Memo To: SRN Mailing List
Deadline: Dec. 31, 2001
From: Subscribers Product Groups/Plantation, FL
Subject: Transmit Microphonics on HT1000, JT1000, MTX838, MT2000 & MTS2000 UHF Radios
Symptoms:
A small percentage of HT1000, JT1000, MTX838, MT2000, & MTS2000 UHF radios may exhibit transmit microphonics, where
one of the following occurs:
1) Popping, crackling, or snapping noise at times making audio communication
unintelligible in the receiving radio.
2) Transmitting radio may be transmitting distorted DTMF tones.
Potential Problem Radios:
HT1000, JT1000, MTX838, MT2000 & MTS2000 UHF band radios manufactured between November of 1995 through May of
1997 Serial numbers denoted by: xxxAVWxxxx to xxxAXKxxxx
HT1000 model numbers: H01RDC..., H01SDC......N
JT1000 model numbers: H01RDH..., H01SDH.....N
MTX838 model numbers: H01RDC..., H01RDD..., & H01RDH.....N
MT2000 model numbers: H01RDx...., H01SDx......N
MTS2000 model numbers: H01RDx9PW1xN or H01SDx9PW1xN
Cause:
Some of the above radios may have been manufactured with inadequate / unequal internal grounds and shield flexibility.
Required Material:
REX4465A, material in this kit is listed below.
Part Number Description
1405307X07 Kapton Tape
2605891U03 Front Shield
NTN7087A Control Flex
7505922Z01 Thermal Pad
1185821A01 Copper Tape
SRN 1202D
7505393N33 Shock Pad
Corrective Action:
Remove any solder on the RF Printed Circuit ground tab by coil L11. Remove the kapton tape from the strip, part number
1405307X07 and trim it to size approximately .3"x.2". The tape on the strip is .5" x .25" before trimming. When placing
the tape on the printed circuit board make sure there is a sufficient amount to go over the tab to insulate it from the
projection of the front shield. See figure 1.
1.
Page 1 of 3
Remove all conductive pads that may have been placed on the RF board, part numbers 7505870Z01,
7505870Z02, or 7505870Z03. (These pads were added in some radios per SRN 1202.)
2. Solder shield ME1 to ME2. See figure 2. A minimum of three solder bridges should be used. The solder should bridge the gap
between the shields but not project above the top of the shields on the PCB. Solder shields ME6 and ME7 together in the same
manner. See figure 3.
3. Inspect the surface of the PA, U105, where it rests on the casting. See figure 4. This casting surface acts as a heat sink and may
be covered by thermal grease or a thermal pad which must be removed for inspection. The exposed PA surface must be flat with
no evidence of solder build up along the entire surface. The build up will look like bumps or blisters which may cause the board to
rock. Remove any build up with a sharp blade or similar tool. Do not leave burrs. (NOTE: DO NOT REMOVE THE PA TO
PERFORM THIS STEP.)
4. If the portable was shipped with thermal grease or a thermal pad replace with the thermal pad provided in the kit, part number
7505922Z01.
5. Replace the front shield with part number 2605891U03. A new control flex, part number NTN7087A, will have to be attached
to this shield. When attaching the new shield pay special attention that the shield tabs are properly engaged into the rear casting.
The lance of the tabs should be seated into the rear casting as deeply as possible. A small screwdriver should be used to ensure
proper seating. See figure 5.
6. HT1000 ONLY: Apply a piece of copper tape, part number 1185821A01, across the silver ground contact on the control flex
and main shield. Place a shock pad, part number 7505393N33, over the copper tape above the main shield to prevent contact with
the front cover.
Parts and $45 labor is authorized by warranty. Contact your local Motorola Authorized Service Representative to arrange for this
modification. Agency Approved product should follow the guidelines for repairs and service.
Reply With Quote

[marcus]

Motorola SRN-1202D yes i have read the SRN...But im looking for the quick fix by soldering the just the shields with out totally removing the sheild plate...

"quoted "January 2000 recommends the method of soldering the shields together. This method works best in my experience, and beats the old conductive tape pads hands down.

Which sheilds are to be soldered together?? wanna try this first before taking the HT apart and doing the Microphonics Mod...

Thanks Much
Marc
W2MLH

SRN - 1202D
APC - 355, 402, 432,466, 511
Date: June 1997 : Up Issued 1/00
Date Extension Only
Memo To: SRN Mailing List
Deadline: Dec. 31, 2001
From: Subscribers Product Groups/Plantation, FL
Subject: Transmit Microphonics on HT1000, JT1000, MTX838, MT2000 & MTS2000 UHF Radios
Symptoms:
A small percentage of HT1000, JT1000, MTX838, MT2000, & MTS2000 UHF radios may exhibit transmit microphonics, where
one of the following occurs:
1) Popping, crackling, or snapping noise at times making audio communication
unintelligible in the receiving radio.
2) Transmitting radio may be transmitting distorted DTMF tones.
Potential Problem Radios:
HT1000, JT1000, MTX838, MT2000 & MTS2000 UHF band radios manufactured between November of 1995 through May of
1997 Serial numbers denoted by: xxxAVWxxxx to xxxAXKxxxx
HT1000 model numbers: H01RDC..., H01SDC......N
JT1000 model numbers: H01RDH..., H01SDH.....N
MTX838 model numbers: H01RDC..., H01RDD..., & H01RDH.....N
MT2000 model numbers: H01RDx...., H01SDx......N
MTS2000 model numbers: H01RDx9PW1xN or H01SDx9PW1xN
Cause:
Some of the above radios may have been manufactured with inadequate / unequal internal grounds and shield flexibility.
Required Material:
REX4465A, material in this kit is listed below.
Part Number Description
1405307X07 Kapton Tape
2605891U03 Front Shield
NTN7087A Control Flex
7505922Z01 Thermal Pad
1185821A01 Copper Tape
SRN 1202D
7505393N33 Shock Pad
Corrective Action:
Remove any solder on the RF Printed Circuit ground tab by coil L11. Remove the kapton tape from the strip, part number
1405307X07 and trim it to size approximately .3"x.2". The tape on the strip is .5" x .25" before trimming. When placing
the tape on the printed circuit board make sure there is a sufficient amount to go over the tab to insulate it from the
projection of the front shield. See figure 1.
1.
Page 1 of 3
Remove all conductive pads that may have been placed on the RF board, part numbers 7505870Z01,
7505870Z02, or 7505870Z03. (These pads were added in some radios per SRN 1202.)
2. Solder shield ME1 to ME2. See figure 2. A minimum of three solder bridges should be used. The solder should bridge the gap
between the shields but not project above the top of the shields on the PCB. Solder shields ME6 and ME7 together in the same
manner. See figure 3.
3. Inspect the surface of the PA, U105, where it rests on the casting. See figure 4. This casting surface acts as a heat sink and may
be covered by thermal grease or a thermal pad which must be removed for inspection. The exposed PA surface must be flat with
no evidence of solder build up along the entire surface. The build up will look like bumps or blisters which may cause the board to
rock. Remove any build up with a sharp blade or similar tool. Do not leave burrs. (NOTE: DO NOT REMOVE THE PA TO
PERFORM THIS STEP.)
4. If the portable was shipped with thermal grease or a thermal pad replace with the thermal pad provided in the kit, part number
7505922Z01.
5. Replace the front shield with part number 2605891U03. A new control flex, part number NTN7087A, will have to be attached
to this shield. When attaching the new shield pay special attention that the shield tabs are properly engaged into the rear casting.
The lance of the tabs should be seated into the rear casting as deeply as possible. A small screwdriver should be used to ensure
proper seating. See figure 5.
6. HT1000 ONLY: Apply a piece of copper tape, part number 1185821A01, across the silver ground contact on the control flex
and main shield. Place a shock pad, part number 7505393N33, over the copper tape above the main shield to prevent contact with
the front cover.
Parts and $45 labor is authorized by warranty. Contact your local Motorola Authorized Service Representative to arrange for this
modification. Agency Approved product should follow the guidelines for repairs and service.
Reply With Quote

[marcus]

Thanks much for the SRN im aware of this but have read some posts stating that there is a work around ::

January 2000 recommends the method of soldering the shields together. This method works best in my experience, and beats the old conductive tape pads hands down. And you can do about ten radios with this method for every one radio that you remove and re-solder the shields on.
Looking for this info and what sheilds need to soldered together...member tony soprano whom is a Moto tech quoted this above but i cant contact him via PM....

Any help is appreciated...

Thanks
Marc
W2MLH

[com501]

Solder adjacent shields together, center and each end, evenly spaced. Any shield that you can fit a medium sized tip in between. I usually use a chisel tip that when manipulated will contact both shields at the same time, and flow some silver solder in there.

I do hundreds of State radios that way, they usually never come back for that reason ever again.

[Will]

I am working on Marc's radio. Most of the mods were already done per the SRN before he got it.

Will