[Amps] FL-2100F/B

Tue Oct 28 09:41:29 EST 2003

Simply that a casual 'glance over' doesn't reveal any problem. Mine didn't
fall apart till I remomoved it, revealing a big burn on the inside.

Vy 73 de OZ1PIF, Peter

**********  OZ1PIF **************
email: oz1pif(no-spam-filler)@get2net.dk
http://hjem.get2net.dk/oz1pif
Ph. +45 4619 3239
Snailmail:
Peter Frenning
Ternevej 23
DK-4130 Viby Sj.
Denmark
***********************************
----- Original Message -----
From: "R_Davis" <WD8JJA at arrl.net>
To: "H & W Electronics" <info at handwelectronics.com>;
<Fox_Tango at mailman.qth.net>; <amps at contesting.com>
Sent: Tuesday, October 28, 2003 3:37 AM
Subject: Re: [Amps] FL-2100F/B

> Another question, Peter,
> What do you mean by "carefully" checking the caps?
>
> Rick, WD8JJA.
>
> ----- Original Message -----
> From: "R_Davis" <WD8JJA at arrl.net>
> To: "H & W Electronics" <info at handwelectronics.com>;
> <Fox_Tango at mailman.qth.net>; <amps at contesting.com>
> Sent: Monday, October 27, 2003 8:51 PM
> Subject: Re: [Amps] FL-2100F/B
>
>
> > Very interesting, Peter,
> >
> >  Actually, the question was proposed by "H & W Electronics" on another
> > reflector; I have a 2100B with the similar symptoms, while he asked
about
> > the 2100F.
> >
> > The 2100B schematic calls for a 220pF on each grid. If only one went
bad,
> > wouldn't I see a different response by using only one tube and switching
> it
> > from one socket to the other?
> > What do you think about the disc/electrolytic combination between the
> > bias-set resistor and the RF choke? This may be just a filter for the
> ripple
> > on the half-wave rectified bias, but they are common to both tubes. so
if
> > one was leaking, wouldn't it pull both grids down by the same amount?  I
> > can't read my schematic very well, but it looks like they are a 0.01 uF
> disc
> > to ground in parallel with a 2 uF/25V electrolytic to ground (although
the
> > parts list calls it a 2.2uF/50V - more likely).
> >
> > The 2100F is laid out a little different, with a 10uF on the
> relay/grid/bias
> > board.
> >
> > All comments appreciated.
> >
> > Rick, WD8JJA.
> >
> >
> > ----- Original Message -----
> > From: "Peter Frenning, OZ1PIF" <oz1pif at get2net.dk>
> > To: "R_Davis" <WD8JJA at arrl.net>; "H & W Electronics"
> > <info at handwelectronics.com>; <Fox_Tango at mailman.qth.net>;
> > <amps at contesting.com>
> > Sent: Monday, October 27, 2003 3:32 AM
> > Subject: Re: [Amps] FL-2100F
> >
> >
> > > Hi Rick,
> > >
> > > Check very carefully the two caps tying the grids to ground, I believe
> > they
> > > are C8-9 220pF in your version.
> > > I had exactly the same symptoms in my FL2000B, with a set of new
> bottles,
> > > and not until I took it completely apart for conversion to a QB4/1100,
> did
> > I
> > > find that one of these caps had blown - split completely open, but
> > invisible
> > > from the outside!
> > >
> > > Vy 73 de OZ1PIF, Peter
> > >
> > > **********  OZ1PIF **************
> > > email: oz1pif(no-spam-filler)@get2net.dk
> > > http://hjem.get2net.dk/oz1pif
> > > Ph. +45 4619 3239
> > > Snailmail:
> > > Peter Frenning
> > > Ternevej 23
> > > DK-4130 Viby Sj.
> > > Denmark
> > > ***********************************
> > > ----- Original Message -----
> > > From: "R_Davis" <WD8JJA at arrl.net>
> > > To: "H & W Electronics" <info at handwelectronics.com>;
> > > <Fox_Tango at mailman.qth.net>; <amps at contesting.com>
> > > Sent: Monday, October 27, 2003 4:15 AM
> > > Subject: [Amps] FL-2100F
> > >
> > >
> > > > Copy to AMPS reflector.
> > > >
> > > > H & W Electronics <info at handwelectronics.com>:
> > > >
> > > > Did you get a satisfactory answer to this, yet?
> > > >
> > > > I have an FL-2100B with similar symptoms.
> > > > I used to have normal (~.090) bias, was able to drive it to >
500mils,
> > and
> > > > it put out 700 - 800 watts peak normally (more if I crowded it).
Now
> I
> > > get
> > > > only about 60 mA bias, can only drive it to 250-300 mA, and get 300
> > watts
> > > > out, at best.  Also, driving it real hard, the LOAD control stays at
> or
> > > near
> > > > 0.
> > > > Those are my symptoms.
> > > >
> > > > Possible related causes: One time, I accidentally was tuning into
the
> > > > internal dummy load of my Dentron MT-3000A which is rated for 200
> watts
> > > and
> > > > is protected by an internal fuse. I popped the fuse, but quit as
soon
> as
> > I
> > > > saw the SWR skyrocket.
> > > > On another occasion, and I cannot remember if it was before or
after,
> I
> > > > heard a "TINK" from the amp.
> > > > Neither time did I notice these symptoms immediately, but it has
only
> > been
> > > a
> > > > few months since the blown fuse and the "TINK".
> > > >
> > > > Is the concensus that the tubes are now soft?  Funny thing, I
checked
> it
> > > > with one tube at a time, and with either tube in either socket, I
can
> > > drive
> > > > it to over 200 mA, maybe even 250 with my FT-101E.  But I can't get
> 500
> > mA
> > > > with both tubes in. HV still looks good @ 2400V, dropping to around
> 2200
> > > > under load.  ALC action looks normal, but at only about 300 watts
out.
> I
> > > > haven't cut the ALC line yet to see if it is holding it back.  I
don't
> > > think
> > > > it is since I.C. on the exciter looks normal.
> > > >
> > > > Any suggestions before I by a new set of bottles??
> > > >
> > > > Rick, WD8JJA.
> > > > ----- Original Message -----
> > > > From: "H & W Electronics" <info at handwelectronics.com>
> > > > To: <Fox_Tango at mailman.qth.net>
> > > > Sent: Monday, October 20, 2003 11:29 PM
> > > > Subject: [Fox_Tango] FL-2100F
> > > >
> > > >
> > > > > Hi All!
> > > > >    Anyone ever had low reading on the bias current? This one does
> only
> > > > > .06 while spec is .09. What gives?
> > > > >
> > > > > Now, more than ever, QSL.NET is in urgent need of your financial
> > > support.
> > > > >
> > > > > Please help QSL.NET by sending a donation now.
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