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[Amps] bandswitch repaired (photos)...now plate choke

To: AMPS@contesting.com
Subject: [Amps] bandswitch repaired (photos)...now plate choke
From: Kevin Normoyle <knormoyle@comcast.net>
Date: Wed, 09 Mar 2005 02:38:01 -0800
List-post: <mailto:amps@contesting.com>
Gary S. had asked for internal photos of a fl2100b he was repairing, so 
I uploaded some to msn.
(I was taking snaps to remember where everything goes)
http://groups.msn.com/yaesurotatorphotos/yaesufl2100b.msnw

Just going to reference some bandswitch shots here.

I was dreading the bandswitch repair, but once you accept the idea
that you have to take the whole thing out to do a good job, then
it's not too bad.

Tools used: variable speed drill with sharp bit, dremel tool (thin 
cutting wheel),
brass 2-56x3/8 pan head machine screws and nuts (cut off excess length
when done). Center punch was useful brace. (put right-sized one in rivet 
hole on other side while
drilling to provide steady back pressure against drilll)

There was a prior set of repairs that was pretty bad. Copper tape bent 
around
the ceramic wafer. See right side, middle wafer
http://groups.msn.com/yaesurotatorphotos/yaesufl2100b.msnw?action=ShowPhoto&PhotoID=31

(it's a yaesu FL2100-B not a rotator...url was created for something 
else originally)

Same photo you can see the 10 meter blown switch position. Lower right. 
You can also
see where the metal strip to the tank was blown before and repaired with 
a soldered
on wire instead of strip.

One thing that was interesting to me. Each position on the wafer has 4 
wipes.
Two on top and two on bottom. When I examined the ones that weren't 
blown, not
all wipes were making contact. I replaced any that seemed iffy . Was 
thinking that
any time you have smaller number of wipes working, you're stressing things.

Got replacement contacts from these wafers:
http://groups.msn.com/yaesurotatorphotos/yaesufl2100b.msnw?action=ShowPhoto&PhotoID=48

Close ups of blown contacts (two top middle)
http://groups.msn.com/yaesurotatorphotos/yaesufl2100b.msnw?action=ShowPhoto&PhotoID=50
http://groups.msn.com/yaesurotatorphotos/yaesufl2100b.msnw?action=ShowPhoto&PhotoID=51

After repair
http://groups.msn.com/yaesurotatorphotos/yaesufl2100b.msnw?action=ShowPhoto&PhotoID=52
http://groups.msn.com/yaesurotatorphotos/yaesufl2100b.msnw?action=ShowPhoto&PhotoID=53

Next:  I know I should rewind this burnt plate choke.
http://groups.msn.com/yaesurotatorphotos/yaesufl2100b.msnw?action=ShowPhoto&PhotoID=37

I measured about 64 turns/inch? That would make it 27 awg wire? As 
anyone rewound
a FL2100B choke? is it 27 awg or ???

Should I just mark the form and wind exactly as there already. (gaps and 
all).
I have a dip meter to check resonances afterwards.

I see some people saying that the gaps in the choke coil doesn't help 
change resonances,

But then some people said that having the burning in specific places in 
the coil, would likely
point to specific resonances (vhf or in-band hf). Looking at the burn 
patterns in the photo,
it would seem like the gaps did have an effect?

Thanks,
-Kevin


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