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FT-1000MP 455 kHz 500 Hz CW filter full scale glitch

To: <yaesu@contesting.com>
Subject: FT-1000MP 455 kHz 500 Hz CW filter full scale glitch
From: aa4nu@raider.raider.net (Billy W. Cox)
Date: Thu, 01 Aug 1996 14:22:05 -0700
Robert A. Wilson wrote:
> 
> There are at least two Yaesu reflectors.  Which one should we use?
> Let's continue this discussion on the one that generates the most
> response.
> 
> Has anyone else noticed this behavior on an FT-1000MP?  Whenever
> I switch to the 455 kHz 500 Hz CW filter, the S-meter briefly pegs to
> full scale while the receiver goes "dead" for about twice as long as
> it goes dead when switching to other filters (why it has to go dead at
> all is another mystery).
> 
> I tried AGC in both AUTO and FAST, but it does not seem to make any
> difference in the "dead time" you get when switching filters.  I
> disabled the "confirmation beep," but it still goes dead.  FT-1000Ds
> also go dead when you switch filters.  They go dead just long enough
> to miss a dot or truncate a dash (about 50ms I guess).  I have never
> observed this behavior on other radios.
> 
> I tried an experiment with two FT-1000MPs.  Both radios had all filter
> options installed, including the subreceiver filter.  Radio A had the
> "full scale glitch," but Radio B did not.  I exchanged the 455 kHz 500
> Hz filters between the two radios.  This made BOTH radios show the
> full scale glitch.  Can anyone offer an explanation for this?
> 
> Could the orientation of the filters make a difference?  They are
> symmetrical; they can be installed in two orientations.  The
> installation instructions don't say anything about orientation being
> important as long as you get all 4 pins properly seated in each
> connector.  The pre-installed 455 kHz SSB filter was "upside down"
> compared to the photograph in the manual, so I did the same.
> 
> The 500 Hz 455 kHz filter is the only one that shows this glitch.
> Switching to any other filter in any other combination never makes the
> S-meter jump to full scale.
> 
> 73,
> Bob, N6TV

Hi Bob, 

I checked TWO MPs and they both acted the same way ... And they both have
ALL the filters installed exactly the same ... both have all slots full.

I looked at the schematic, and decided that the INPUT/OUTPUT were NOT the 
same ... and loaded them in so that the 'labels' all read the same ... In
fact I think I pulled the "stock" ones out and flipped them over also ...
seems like I was trying to follow the "picture' on the PC board ???

You could try putting the 500 in the 250 slot, and see if the 'flicker'
follows ?  Is there anything in the 8.2 slots ?

The SUB-RCVR also 'flickers' it's S-mtr, but not full scale, when the 500
for the sub-rcvr is kicked in ...

The other 'positions' do cause flicker, but the 500 hz does seems worst ...

Trying to recall if my IC-765 had a similar 'delay', but I have do not remember.

Let's see what other on here say also ... OK folks ... hit the buttons and tell 
!

73 Bill AA4NU   aa4nu@raider.raider.net


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