30 Jun
2011
30 Jun
'11
6:50 p.m.
Thanks to the literally dozens of folks who emailed with ideas and suggestions. Never did
really figure out what was wrong, but Amplitec has kindly exchanged the amp for a
different one that is working great (knock on wood), just in time for the upcoming week of
good EME conditions.
After all this, sure hope to make at least a few 6m EME contacts at my moonset from here
in Slovakia.
73, Bill NZ5N/OM3BD
JN88mf
--- On Sat, 6/25/11, Bill Dzurilla <billdz.geo(a)yahoo.com> wrote:
_______________________________________________________
> > To post to this group, send email to moon-net(a)googlegroups.com
> > For more options, visit this group at
> > http://groups.google.com/group/moon-net?hl=en
> >
>
From: Bill Dzurilla <billdz.geo(a)yahoo.com>
Subject: Re: [Moon-net GG] Re: GS35b amp input problem - still not solved
To: moon-net(a)mailman.pe1itr.com, Outposter30(a)shaw.ca
Cc: moon-net(a)googlegroups.com
Date: Saturday, June 25, 2011, 12:32 PM
Not sure if this group allows email
attachments, but here's the schematic of the antenna relay
and PTT unit of the amp. If the attachment does not go
through, please email me for a copy.
73, Bill
--- On Fri, 6/24/11, Bill Dzurilla <billdz.geo(a)yahoo.com>
wrote:
From: Bill Dzurilla <billdz.geo(a)yahoo.com>
Subject: Re: [Moon-net GG] Re: GS35b amp input problem
- still not solved
To: moon-net(a)mailman.pe1itr.com,
Outposter30(a)shaw.ca
Cc: moon-net(a)googlegroups.com
Date: Friday, June 24, 2011, 7:23 PM
I do have a schematic, I'll try to
find a way to scan it and upload. The amp has a
built
in sequencer. The PTT jack is connected to a 1k
resistor, which attaches to the base of a
transistor.
The transistor's collector is grounded and
the emitter
goes
to the switching relays.
--- On Fri, 6/24/11, Jordan <outposter30(a)shaw.ca>
wrote:
> From: Jordan <outposter30(a)shaw.ca>
> Subject: Re: [Moon-net GG] Re: GS35b amp input
problem
- still not solved
switches
To: billdz.geo(a)yahoo.com,
moon-net(a)mailman.pe1itr.com
> Cc: moon-net(a)googlegroups.com
> Date: Friday, June 24, 2011, 6:49 PM
> Get the controlled relay as close to
> the amp PTT port as possible, and be sure it > directly to Amp ground on keying.
>
> Is there a schematic of your isolation cktry, and
amp
> keying ckt...?
>
> 73...Jordan VE6ZT
>
>
> ----- Original Message ----- From: "Bill
Dzurilla"
<billdz.geo(a)yahoo.com>
> To: <moon-net(a)mailman.pe1itr.com>
> Cc: <moon-net(a)googlegroups.com>
> Sent: Friday, June 24, 2011 4:35 PM
> Subject: [Moon-net GG] Re: GS35b amp input
problem -
still
> not solved
>
>
> Thanks to all who replied to my prior posts about
my
6
> meter PTT problem. Unfortunately, the problem has
not
been
> solved, and hopes are growing dimmer.
>
> Today my friend came back with his TS-480, this
time
with a
> PTT cable (last time we had to use a shorted RCA
plug
to
had
turn on the amp). With his PTT cable attached
between
> the TS-480 and the amp, we had the same problem I with
> my FT-847, low output and a high pitched noise
from
the
> vicinity of the GS-35b tube. Extensive efforts
to
find
> the cause and fear produced no real clues.
>
> To recap, here's what we know, what has been
tried,
and
> what can't be tried:
>
> * If the amp is keyed with a shorted RCA plug, we
get
full
> power and no noise with both the FT-847 and the
> TS-480. This is true even if the shorting cable
is
> unshielded.
>
> * If the amp is keyed with a PTT cable running
from
the
> transceiver to the amp, we get noise and low
power,
with
> both the FT-847 and the TS-480.
>
> * We tried bypass capacitors on the PTT cables,
no
> improvement.
>
> * We tried coiling the PTT cables, no
improvement.
>
> * We would have liked to have tried adding
ferrite to
the
> PTT lines but could not find any and are unlikely
to
find
> any.
>
> * We tried isolating the amp from the transceiver
with
2
> different amp keyer isolators, one with a reed
relay
and the
> other with a transistor circuit. Neither
helped. We
> tried using both of the isolators in
cascade, but
that
did
> not help either.
>
> * We do not have access to a spectrum analyzer or
an
> oscilloscope.
>
> * The SWR between the transceiver and the amp
measures
> low,
> > both with the FT-847 and the TS-480. The SWR
> between > amp
output and the antenna also is low.
>
> * The amp is brand new and under warranty. The
amp
> may or may be not responsible for the
problem, we
just
do
the
not know. The builder is willing to check
everything
> out and attempt to solve the problem, if I return amp to
> his shop in Hungary. That's not a very
attractive
> option, as it is about a 4 hour drive each
way to
his
shop
> from here in Slovakia.
>
> Anyone have any further ideas?
>
> 73, Bill NZ5N/OM3BD
>
> --- On Mon, 6/20/11, Bill Dzurilla <billdz.geo(a)yahoo.com>
> wrote:
>
> > From: Bill Dzurilla <billdz.geo(a)yahoo.com>
> > Subject: Re: GS35b amp input problem
> > To: moon-net(a)mailman.pe1itr.com
> > Cc: moon-net(a)googlegroups.com
> > Date: Monday, June 20, 2011, 6:59 PM
> > Thanks to the many folks who replied
> > to my question. Many of the replies had
great
> > suggestions, but only one person --
Lance
W7GJ --
hit
> on
> > what appears to be my problem. Lance
suggested
the
> > problem might be in the PTT line. It seemed
> improbable
> > that this could be the issue, but when I
replaced
the
> PTT
> > line from my FT-847 to the amp with a
shorted
RCA
> plug, sure
> > enough the noise was gone and the output was
up
to a
> > kilowatt.
> >
> > We used the same shorted plug when we ran
the
test
> with the
> > TS-480, so it's very possible the same
problem
would
> occur
> > had a PTT line been connected to the
TS-480.
> >
> > I have a homebrew PTT isolator, the device
that
> connects
> > the rig's PTT line to a relay, and when PTT
is
engaged
> the
> > relay closes and triggers the amp, and I
thought
for
> sure
> > this would solve my problem, but it did
not.
Even
> with
> > the isolator in line, I get the noise and
the
low
> output.
> >
> > Any thoughts? Where do I go from here?
> >
> > 73, Bill
> >
> > --- On Mon, 6/20/11, Bill Dzurilla <billdz.geo(a)yahoo.com>
> > wrote:
> >
> > > From: Bill Dzurilla <billdz.geo(a)yahoo.com>
> > > Subject: GS35b amp input problem
> > > To: moon-net(a)mailman.pe1itr.com,
> > "Alex Artieda" <hb9dri(a)emeham.com>
> > > Cc: moon-net(a)googlegroups.com
> > > Date: Monday, June 20, 2011, 10:45 AM
> > > Hi,
> > >
> > > I bought a new Amplitec 160-6m kilowatt
amp
with
160-10
a
> GS-35b
> > tube, details of the amp at
www.amplitec.hu.
> Driven
> > by
> > > my FT847, the amp works great on meters.
> > > However, on 6 meters there is a
strange
issue. I
> > was
> > > only getting 600w out, the tube lit up
much
> brighter
> > than on
> > > other bands, and there was a
high-pitched
noise,
> like
> > a
> > > squeal or whistle, coming from the area
of
the
> > GS-35b.
> > >
> > > My friend came today with his radio and
a 6
> meter
> > antenna.
> > > First we tried his antenna with the
amp. No
> success,
> > still
> > > 600 watts and the high pitch noise.
> > >
> > > Then we replaced my FT847 transceiver
with
his
> > Kenwood
> > > TS480. Success! No noise, 1100 watts
output.
But
> why?
> > Both
> > > radios have exactly the same output,
100
watts,
> we
> > used the
> > > same power supply, and we used the
same
coax
> > jumpers.
> > > Also, when we tested the amp at the
home of
the
> > Amplitec
> > > owner, he used an FT847 and there was
over
1000w
> out
> > with no
> > > noise.
> > >
> > > So, it appears that the problem is
somehow
> related to
> > my
> > > FT847. Any thoughts on what might be
wrong
or a
> > > possible fix? Need to get this working
in
time
_______________________________________________________
for
the
> good EME conditions starting June 30.
>
> 73, Bill NZ5N/OM3BD
>
>
-- To post
to this group, send email to moon-net(a)googlegroups.com
For more options, visit this group at
http://groups.google.com/group/moon-net?hl=en
--
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