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Re: Drake 2880 mod (XTAL)




A couple of people have asked, the part number of the crystal is 540288
It is not in the HC49US package.  It looks to me like it is the  HC45U.
When I ordered, she tried to steer me to the HC49US, I finally just
said Give me what everyone else is getting.  It sounds like at least
two other people on this list are getting the 540288.

The crystals took about two weeks to arrive.

I don't think it is proven that it wouldn't have fit if I stood it
upright and shortened the leads.  I just wanted to give the heads up
that there may be a problem.  Will the next person try to "dry fit"
the thing in the full upright position and tell us if that works?
If not then I suggest leaving enough leg so the crystal can lay over
at 90 degrees.  What I did is clearly undesireable.  It is binding
on the cover, trying to short to the chip cap, and most likely flexing
the board.  The output freq went up about 2.5KHz when I put the cover
on.  Could that be from flexing the board?

Since I have the public fourm, Let me say thank you to Mark, and
also to JN1GKZ , G0MRF, and G6ZRU who published such excellent 
documentation on how to do the mods.

N8NPA Brian

> 
> Hmmmm,
> 
> How many days did it take to get the crystal?  I've had
> mine ordered for over 2 weeks.  I specified that the xtal
> be the short sized one, so hope it is.
> 
> The last one I did a couple of years ago I used the tall
> crystal and bent it over 90 degrees and it worked okay.
> Could here it chirping away at 8.8125 in my HF receiver,
> so it must have been happy.
> 
> de Bill, N4DH
> 
> At 20:25 2/10/01 -0600, Brian Mitton wrote:
> >Hi all,
> >
> >I got home late last night to find a box from ICM frozen to my porch,
> >so I had to come in tonight and mod up my new Drake.  It looks like
> >the surgery was successful, but I have one thing I really want to share.
> >The ICM crystal looked taller than the one it replaced, so I compounded
> >the situation by putting it on with a bit of room to bend it over.
> >I had to bend it about 30 degrees to get the lid on.  It really didn't
> >like to be touching the lid, so I put kapton tape over the top.
> >As I was tighting the lid I came to a point where the output would
> >jump almost 100 KHz (KC).  I noticed that the crystal case was touching
> >one of the chip caps, so with some tweezers I snuck a bit of kapton
> >tape down there as well.  It all seems to be working, but I am curious
> >if anyone else has tried putting in an ICM crystal, and if you have
> >had problems.
> >
> >My other observation, and this is probably a newbie question, is that
> >the hardest problem I had was getting that F connector un-soldered.
> >I worked on it with alot of solderwick and what I thought was patience,
> >but when I turned the nut-shaped-thing a piece of trace went with the
> >center conducter!  All the instructions start with the board out on the
> >bench ;)
> >
> >So I re-crystaled it.  Took out the red coils and green caps.
> >Put 18pf caps on either side of the green coil (all I have is 18 and 27)
> >Used clippings from the crystal leads to extend the bandpass filter.
> >Tweeked in the LO as best I could, and zipped it all up.  All in one
> >setting (two cans of coke).  It was really not that bad.
> >
> >Do I need more amplification or am I ready to move on to the antenna?
> >
> >73 de N8NPA Brian
> >
> >----
> >Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> >To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
> 
> 

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