June 24, 1988

HW-24						Bulletin No:

Twin-Bander Mobile Transceiver			HW-24-1



		Increasing Coverage of Receiver



The following modification increases the frequency coverage of the

receiver section only.  The coverage will incease as follows:



		         From		          To		



	VHF:	144-147.995 MHz		130-169.995 MHz

	UHF:	438-449.995 MHz		360-489.995 MHz



Procedure



During this procedure, you'll reset the Tranceiver.  This will erase the

data stored in memory.  If you want to save the data, turn the

Transceiver on and write down the contents of each memory location before

beginning.



-- Disconnect the power plug from the Transceiver.



-- Refer to Pictorial 1 and remove the mounting stand.

   ////Pictorial shows removal of the [5] bottom plate screws////



-- Remove the five screws that secure the bottom plate.



-- Refer to Pictorial 2 and position the bottom plate as shown.

    ////Pictorial shows bottom plate laid beside the xcvr and to the left

of it - speaker 

        remains connected.////



--  To increase the 144 MHz band coverage, refer to Inset #1 and cut the

lead of 

     diode QD22.  Position the leads so they won't accidentally touch

each other.

     ////Insert just shows the QD22 & QD24 Lead to be cut.////



--  To increase the 450 MHz band coverage, refer to Inset #1 and cut the

lead of 

     diode QD24.



--  Apply power to the Transceiver and turn it on.



CAUTION - The next step resets the Ransceiver and clears all memory

locations.  Have you written down the contents of the memory locations

that you want to save?  This is your last chance.



--  Refer to Inset #2 of Pictorial 2 and briefly short together the two

terminals as     shown.  The current display will disappear and the

display frequencies will be     reset to 146.000 MHz and 446.000 MHz.

    ////Inset #2 shows the two terminals to be shorted. They are at the

center of the 

        bottom of the xcvr, to the right of the QD22/24 diodes and

multi-wire         connector.////



--  Turn off the Transceiver and disconnect the power.



--  Reinstall the bottom plate and wire mounting stand.



The modification of the Transceiver is completed.

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			October 27, 1989



HW-24							Bulletin No:

Twin-Bander Mobile Tranceiver				HW-24-2



		              Lithium Battery Source



Heath Parts Replacement does not stock the lithium battery for this unit.

 A source for the lithium battery is:



	DIGI-KEY

	701 Brook Avenue South

	Thief River Falls, MN 56701



	Battery type CR2032

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