[1000mp] W2VJN Comments on Roofing Filter IF Adjustment

[Mike Schatzberg]

Hello Yaesu Fans:

Well, I guess this posting may remove the remaining doubt about what has
been posted here, over and over again.  This clearly verifies what I have
posted in the past, as well as many others, and provides the explanation for
the needed IF gain setting changes.

Clearly, Inrad will change its instructions.  With that much net gain, you
will indeed not need to have both mods in your radio.

The newer crystal filters are working incredibly well, far more efficiently
than the earliest units which were produced by Inrad.

This mod does it all.  Just add the NB mod, and the keyclick mod, and your
MP or Mark V will compete with the newest, and most expensive of the upper
end offerings from all manufacturers.

Thanks for the info Carl, this is the final piece of the roofing filter
story.

Regards and Happy DXing,

Mike Schatzberg
WB2AJI
----- Original Message ----- 
From: "Carl Kratzer" <k3rv at usa.net>
To: <1000mp at mailman.qth.net>
Sent: Tuesday, February 01, 2005 2:20 PM
Subject: [1000mp] W2VJN Comments on Roofing Filter IF Adjustment


See comments below.

------ Original Message ------
Received: Tue, 01 Feb 2005 12:26:53 PM EST
From: "International Radio" <inrad at rosenet.net>
To: "Carl Kratzer" <k3rv at usa.net>
Subject: Re: Roofing Filter IF Adjustment

Hi Carl,

When I wrote the instuctions the excess gain was from 0 to 2 dB.  This could
be compensated by a 9-1 reduction of 0 to 1 integer.  Now the filters are
coming through with less insertion loss and the excess gain is running from
3 to 5 dB.  In the normal range of 9-1 numbers, the gain variation is about
2 dB per integer, so reductions of 2 to 4 integers can be used to
compensate.  Note that this is not a critical adjustment at all.  It's more
cosmetic to get the S meter reading about the same as the sub rcvr.  When we
do another run of instructions, I'll note these variations.

You can post this to the list if you like.

George, W2VJN


----- Original Message ----- 
From: "Carl Kratzer" <k3rv at usa.net>
To: <inrad at rosenet.net>
Sent: Monday, January 31, 2005 2:55 PM
Subject: Roofing Filter IF Adjustment


Hi George:  thanks for the roofing filter which arrived last week.  I have
installed it in my Mark V Field and it works great.  There has been quite a
bit of chatter on the MP reflector concerning the readjustment of the IF
gain
(9-1 menu).  I noticed that earlier instructions with your kits said to keep
the setting unchanged (for new installation), but instructions with my unit
said to drop the setting by one integer.  However, some guys are saying the
setting should be reduced by 2 or 3 integers and a few of them are using
elaborate test equipment to "optimize" the setting.

I wonder if you could comment further.  Is there much gain variation between
one roofing filter and another, so that the best setting would change from
one
unit to another?  Or is one integer decrease, as recommended in your
instructions OK for all units?  Does it really even matter, hi.

Any further advice would be appreciated.  Best regards, Carl, K3RV.







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