deskmic for motorola consol help

[911-EMT]

hi i have a c200 consol and the newer mc2000 consol we used it with HMN3000A deskmic and it worked jus fine but its now discontinued so the replacement part is RMN5068A and it dos not work with the consols have anyone had any experience with the new deskmics

[Batwings21]

What problem are you having? These new mics we have used require a mod to the remote to get any audio out of the mic.

[911-EMT]

Ok so what is the mod and is it on the remote or on the mic

[Batwings21]

We have changed dip switches in the mic to get hot mic with no paddle pressing, and making both paddles ptt. Then there are some chip resistors in the audio path that need there value changed, but I don't have the info handy, I will dig it up later if I make it back to my shop.

[911-EMT]

thanks

[911-EMT]

ok i called moto and expand them the issue that i have a old motorola c200 and a newer mc2000 and the new mic is not working with any of the two consoles, so the tech. tolled me that for the motorola c200 i should call gai tronics and for the motorola mc2000 i should call cml, now after all nice excuses gai tronics and cml have nice products but with no support and all they offered me is a mic plus a audio acc. box and all they can do is hope it will work and cant guarantee me that it will and yes its $375 for the package lol. (it’s a true story) Now lets get series our deskmic is bad and need to be replaced so have anyone still in stock brand new of the old type of deskmic moto model# hmn3000a or we will need to look for of brand consoles or is their any suggestions in between.

[Batwings21]

This info is credited to a genius I work with, here are his mod instructions...

MODIFICATIONS TO MC2000 AND MC2500 DESKTOP REMOTES TO ALLOW USE OF RMN5068 DESK MICROPHONES

The RMN5068 microphone will not have any audio when used with the MC2000 and MC2500 remotes because the DC bias and load resistors in the remote's microphone input circuit are too low in value to provide the proper voltage and load impedance to the microphone's built in preamplifier. These resistors must be changed as follows:

1. On the top circuit board, remove resistors R101, R102, R103, and R104.

2. Place a 560 ohm resistor at location R101.

3. Place an 820 ohm resistor at location R103.

4. Leave locations R102 and R104 empty.

These resistors are surface mount parts.

To enable the RMN5068 microphone to be live even the paddles are not pressed (as for footswitch operation) and to make both paddles transmit push to talk, remove the bottom cover of the microphone and set DIP switches 1 and 8 to off and switches 2 through 7 to on.


MJK 7/25/08


Hope this helps you. We have notified CML, but as of yet have not talked to anyone who seems to care.

[911-EMT]

Thanks batwings21 for the info and your wellness to help and showing that you care, i will tri it an i hope it will work for the older c200 as well as the mc2000 thanks again

[911-EMT]

ok thanks to motorola their is no manual released for the rmn5068a so i will have to ask how do i take off the back cover the top part where it says motorola i have a hard time to get it apart its it a clip i have to open or is it a screw under the motorola label

[Batwings21]

Sorry for the mistake, but the resistor mod is for the mc2000 and mc2500. The dip switch part at the bottom is for the mic, just remove the 5 screws on the bottom for that.

[arlojanis]

What is the function of each dip switch in the mic?

How do you seperate the front and rear covers on the mic?

[Batwings21]

I have only taken the bottom cover off to get at the dip switches. Sorry I do not have the function of all dip switches, one of our techs called motorola and they told him what switches to set, we haven't seen a schematic yet either.

[zetron]

I know this thread is old , but updated info is important for anyone searching archived data on mc2000 & desk mic problems.

I found this while searching the net:




The main problem with the new RMN5068A Desk microphone that replaced the HMN3000 is that it works with the Motorola mobiles but doesn't work with dispatch solutions such as the MC series desksets and the Commandstar lite console all of which are manufactured by CML. What we discovered is the mic DC voltage supplied by the mobiles is around 5 to 7 volts. The mic dc that the CML products supplies is almost 12 volts. The HMN3000 tolerated the higher voltage without affecting the mike audio. The new
RMN5068A can't tolerate that higher voltage and causes the mic amplifier circuit to go into distortion.

We have modified the new mic by bridging a 680 ohm resistor across mic high to mic low in the mic. The resistor drops the mic DC voltage allowing the RMN5068A to work with the CML products with great success. We presently have about 20 RMN5068a working on MC series desksets. This modification is not from Motorola so it is not sanctioned by them but works every time.


As some additional information on this microphone, you will notice that there is a multi position switch located inside the mic to
allow the mic to be configured for different radios. (Monitor before transmit, separate grounds for PTT and mic low, etc.) You will find this info in no manual. If you call the System Support Center they will read you the functions of the various switch positions but they can not fax or email any documentation. I have included the switch functions in this email so you don't have to go through the same problem.

New Motorola Desk Microphone
RMN5068 replaces HMN3000B




Internal Switch S-5

S5-1 Off Microphone hot all the time
On Microphone switched w/ PTT

S5-2 Off PTT doesn't change state of Monitor
On PTT changes state of Monitor

S5-3 Off PTT and Monitor Buttons Function
Separately
On PTT and Monitor Buttons both act as PTT

S5-4 Off Must Monitor before PTT
On Monitor has no effect on PTT

S5-5 Off PTT Ground and Audio Ground are separate
On PTT Ground and Audio Ground are common

S5-6 and S5-7 work in conjunction For Monitor Polarity

S5-6 Off On
Monitor Low Monitor
High
S5-7 On Off

S5-8 On Microphone AGC on
Off Microphone Level adjusted by pot
accessed
Through hole in rear of
microphone only

[N5DQ]

I have connected a foot switch to accessory connector pin 3 and pin 7 on the M1225. PTT works but there is no transmit audio using the RMN5068A desk mic. I see from the posts that the dip switch controls the audio path.
S5-1 Off Microphone hot all the time
On Microphone switched w/ PTT

However neither switch position provides transmit audio when the foot PTT is used. The mic works fine as a conventional desk mic.

Any thoughts or solutions?

Thanks.