[GE] RE: Re: RE GE CMVP

Thu, 11 Apr 2002 15:19:59 -0400

Original Message:
-----------------
From: Thomas Staley Jr. [email protected]

>In summary:
>The MVP's also use an ICOM but there a different type then the MASRII's.

The ICOMs are the same...BUT the standard xtal elements for the MVP
is different...the ICOM is OPTIONAL for the MVP....and require an
extra board. The 2C ICOM is 2ppm, the 5C ICOM is 5ppm, the standard
xtal elements for the MVP are also 5ppm....which is why you almost never
see the 5C ICOM used in a MVP....

>One 5ppm part and one 2ppm fits all MVPs, regardless of band and low/high >side injection.

Not entirely true...the 2C ICOM will fit the MVP with the optional board.
the standard xtal elements are 5ppm only...they DO fit all MVPs.

>I have some 1 channel and some 4 channel radios but all of them take ICOMs.

No, they take the standard elements...the ICOMs require the optional
board and are marked 2C or 5C...in your case you have the STANDARD
elements, NOT ICOMs...you are confusing the terms...

>The temperature range is what I think my trunk will be in Michigan during >winter thorough summer.
>The 5ppm ICOM are an open type.

It is not called an ICOM..it is an element...

>It receives it temp comp from the radio (exciter).  I believe it only kicks >in below a certain temp and above a certain=
 temp, otherwise there is no temp >comp.

True......

>No special board required.

True...except for multi freq operation...

>In full duplex, I need to wire 3.9 volts to the Rx ICOM to keep it from >being pulled off freq.  I assume this is do to =
the temp comp line on the >exciter trying to comp the Tx.

Yes....wire 3.9v to the rcvr temp comp line (after cutting it off from
the exciter...) this keeps the rcvr xtal on freq when the PA heats up..
ONLY if you BYPASS the MVP PA and run an external map, you dont need to do it.

>The 2ppm ICOM is a closed can.
> It contains its own temp comp and ignores the exciter temp comp?

The 2C ICOM (and the 5C ICOMs) are the same as the Mastr IIs...they
are closed and have their own internal comp ckt (the EC ICOMs are
externally comped by the 5Cs only..the 2C does NOT have an outside
connection to its comp line)

>It can or can not send its temp comp to a 5ppm?

TRUE

>It originally was meant for Tx only but can be also placed in the Rx??

Yes they can...if you modify the optional 2C board to work with the rcvr
LO OR hardwire the 2C to the rcvr LO board.

>Is there a board required for this. My Rx will except and open type now, I >don't know about the closed type.

Yes there IS a board required OR you have to handwire it..

ICOM IS only used to describe the MSTR II elements...the MVP can USE
the MII ICOM optionally...the MVP normally uses OPEN xtal elements..
do not call them ICOMs..

Chris
WB5ITT

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