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Re: [Amps] fl2100b

To: <>, <>
Subject: Re: [Amps] fl2100b
From: Kees - pa7two <>
Date: Tue, 20 Mar 2007 20:54:05 +0000
List-post: <>
Hi Carl, 
Look at the pics at the website of PA0FRI, the Dutch AMP guru. Go to the 'QRO' 
page, then select 'FL2100' for the photos. All is explained on that page. Have 
fun!Vy 73, de Kees > Date: Sun, 18 Mar 2007 10:12:14 -0500> From:> To:> Subject: Re: [Amps] fl2100b> 
> Kees: In reference to your comments on the FL2100B, your comment no. 5 > says 
"a thick copper cable" !! How thick?? 1/8 , ? 1/4 ? More > ?less?.also the part 
about a "y"shape ?? I'm not sure what you mean by a > "y" shape!! Can you 
explain that a bit.? (which end, ? or both? )> I have done most of the other 
checks and such.!! I have also seen > this copper wire thing in reference to 
SB200's also, including a picture > of one but the picture wasn'd very good and 
I couldn't quite see how it > was done.!!> It's been quite some time , as you 
can see from the date of my previous > messages and I'm still working on this 
amp as I get the time. I'd > appreciate any further comments you might have on 
the above questions.!!!!> Have a good day , my friend.!!!!> carl / kz5ca> > 
Kees - pa7two wrote:> > Carl, > >> > I have been dealing with FL2100B's in the 
past. I'l tell you my recommendations:> >> > Do the following mods in ANY case 
before troubleshooting this amp.> >> > 1 - Meassure the ceramic caps (HF 
compartment) in the amp. Most of them you will find in bad state, well under 
the stamped CAP value. 9 out 10 times at least -25% capacitance I meassured. 
Replace with Yaesu originals (I still have some of these if you need) or 
equivalent models capable of at least 3kV and lots of current. > > 2 - The 
blocking CAP between anode coil and antiparasite L&Rs is in most cases the 
culprit of many problems. In EVERY amp I found this CAP to be defect! Heat of 
the tubes and a whole lot of current & RF attacks this CAP and after 25 years 
this CAP says bye bye. Replace with 1000pf/3kV Russian type ceramic CAP. Cheap 
and these are VERY good quality ceramic CAPs.> > 3 - Put a fuse in the anode 
line. Use a fuse with rating 630ma type: Fast. Every time a oscillation occure, 
this fuse will blow and not your tubes. Shunt the fuse with some HV caps 10 - 
22nf.> > 4 - Replace the tubes wit a new matched pair, nowadays a matched pair 
high quality tubes Chinese make er cheap and performs really well. Look on ebay 
for a K5 (USA station, he uses his allsign in this ebay name as well) he sells 
100% OK Chinese tubes and cheap too. 69 dollar for a set of tubes or so.> > 5 - 
The earth pins on the tube socket needs to be contacted to the earth connection 
on the PLATE capacitor. Reason is that the negative current flow has to go thru 
all the bolted compartments. These amps are at least 25 years old and thus 
corrosion took place. Connecting the earth pin of the tubes to the earth point 
of the PLATE cap ensures a good path. Use a THICK copper cable for this 
purpose. In a Y shape.> > 6 - Protect the meters on the frontpanel with two 
diodes crossed. If any shootover occures, at least your meters are still OK. 
Use at least 5 amp diodes, high voltage.> > 7 - Screen resistors are in 50% of 
the amps I had to deal with not anymore 33ohm. Replace these old 33 ohm 
resistors with 3 x 100 ohm /2 watt resistors, >>carbon composite type<<!! Put 
them in parallel use, = 33 ohm!> > 8 - The resistors in the anti parasite L&R 
construction. They have to be 22 ohm in value. In 50% of the amps I had to deal 
with these resistors were or burned out or open. A common classical case for 
not surpressing the oscillations! Use 22-50 ohm, at least 2 watt, place them 
OUTSIDE the coil. Again, only carbon composite resistors, ensure that there are 
no metal caps on the end of the resistors!> > 9 - A good resource for how to 
deal with these kinda issues, go the the wesite of EIMAC and download "Caring 
and Feeding" book in electronical form free of charge, an excellent tube book.> 
>> > Sorry for my spelling misstakes, but wanted to help you quickly and have 
no spelling check on this PC.> >> > Let me know the progress you made after 
performing these modifications. I hope this helps?> >> > With kind regards,> >> 
> Kees - pa7two - m5wto.> >> >> > LetYourFingersTalk! > >> > AmateurRadio : 
PA7TWO - M5TWO U.K.S.M.G. # 1244> >> > 50MHz = The *M*A*G*I*C* band!> >> > 
Morse Code — One of the romance languages.> >> > (C)continues (W)ave, the 
oldest DiGiTaL mode used by Radio Amateurs.> >> > > >>> "Give a guy more tubes 
and they'll just wind up the juice" <<> >>> > >> > >From 'This Book Will Save 
Your Life' by A.M. Homes:> > And the cop taking the report is saying to 
Richard, "I just want to get this right. You were driving behind them and the 
car started talking to you?"> > "SOS, SOS," Richard says, "in Morse code."> > 
"And what's that, Morse code? Is that something I should know?"> > "Yes," 
Richard says.> > Cop: "Some kind of high-tech Internet talk?"> >> >> >> > 
----------------------------------------> > > >> Date: Thu, 19 Oct 2006 
17:12:39 -0400> >> From:> >> To:> 
>> Subject: [Amps] fl2100b> >>> >> Just when I thought I Knew it all (don't all 
we know0 I ran into > >> an amp which has decided to defy me !! I have found 
that on 15 and 10 > >> mtrs. it has decided to say, hey, I'll oscillate if I 
want too.!! I > >> Thought I knew all the answers, but as usual, there are a 
few left > >> unanswered.!!> >> Any answers would be appreciated.!!!> >> any 
thoughts will be appreciated.!!> >> carl / kz5ca> >>> >> 
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