[AMPS] Re: Filament Xfmr.

[Radiodan W7RF]

Indeed, my HENRY 2K serial number ONE has the original 3-400Z tubes in it
from 1963 and still puts out about 1200 watts (about what it did new). Many
HENRY 3K or 3K-A (pair 3-500Z) owners routinely get 2000 watts out and have
no life expectancy (tube anyway!) problems.

One the other hand, I've known guys who can't get more than a year out of
tubes! I think Rich told us of a fellow in Texas(?) who went through a
record SEVEN 8877 tubes!


73, Dan Magro W7RF, (President WARC 1999, member SCDXC, SCCC)
Manufacturers Rep & Distributor for HENRY RF Power Amplifiers.
RF Applications Power Measuring equipment, See the VFD!
www.radiodan.com <http://www.radiodan.com>     RFpower@radiodan.com
<mailto:RFpower@radiodan.com> A trip to our web site is worth the click!




> -----Original Message-----
> From: owner-amps@contesting.com [mailto:owner-amps@contesting.com]On
> Behalf Of Pat Barthelow
> Sent: Thursday, October 07, 1999 12:57 PM
> To: Alek Petkovic
> Cc: amps@contesting.com
> Subject: Re: [AMPS] Re: Filament Xfmr.
>
>
>
>
>
> I just thought a pair of 3-500Zs, properly used, even at full legal
> output, could also deliver a lifetime of service.  My L-4B's 3-500s have
> been delivering since 1965....in recent years, even in Contest Mode.
> I think the number of  on/ off cycles has a big effect in tube life times.
> I know of a TL-922A in the MARS service which delivered it's full rated CW
> power in Key Down 100% service, 24 hrs/day for 10 years...  I have to say,
> I was really suprised at that......
>
>  73, DX, de
> Pat, AA6EG/N6IJ;
> aa6eg@hh.tmx.com;n6ij@hotmail.com
> 599 DX Drive, Marina CA 93933
> See us on the web: www.polkinghorn.org/n6ij
> "The Contest Station from the Government"
>
> On Mon, 4 Oct 1999, Alek Petkovic wrote:
>
> > Hi Pat,
> > The answer to your question is Economics.
> >
> > Running legal power with 4 tubes rather than 2, means you would probably
> > never need to buy replacement tubes. 4 tubes should give a lifetime of
> > service under those conditions.
> >
> > 73 de Alek.
> > VK6APK
> >
> >
> > At 07:02 PM 10/03/1999 -0700, Pat wrote:
> > >
> > >Hi Larry,
> > >
> > >Why would you want 4 x 3-500Zs?  Two will do max legal power nicely...
> > >
> > >73, DX, de
> > >Pat, AA6EG/N6IJ;
> > >aa6eg@hh.tmx.com;n6ij@hotmail.com
> > >599 DX Drive, Marina CA 93933
> > >See us on the web: www.polkinghorn.org/n6ij
> > >"The Contest Station from the Government"
> > >
> > >On Sun, 3 Oct 1999, Larry Molitor wrote:
> > >
> > >>
> > >> At 11:39 AM 10/3/99 -0500, you wrote:
> > >> >
> > >> >About:
> > >> >
> > >> >"I am building an amp with four 3-500Z using low bands only (160 and
> > >> >80m).
> > >> >I do have two filament transformers, 5V/80A w/o a center tap on the
> > >> >secondary coil. The other one contains four coils with
> 5V/25A ea. coil
> > >> >also
> > >> >w/o any center taps on the secondary side."  (Etc.)
> > >> >
> > >> >How about connecting a small "audio" or "power supply"
> choke from each
> > >> >side of the secondary to "eventual" ground? Calculate the inductance
> > >> >value of them so that they will only allow a negligible (AC) current
> > >> >flow to ground while maintaining a balanced condition for
> all voltages
> > >> >involved in the circuits. I think reasonable sized, cheap
> chokes may be
> > >> >possible but must have low DC resistances. Maybe from junk box.
> > >> >
> > >> >73,    Roy         K6XK
> > >>
> > >> I use a small filament transformer with a secondary center
> tap. Connect the
> > >> secondary across the big transformer secondary. Leave the
> primary open. Use
> > >> the small transformer secondary center tap for your cathode return.
> > >>
> > >>
> > >>
> > >> 73,
> > >>
> > >> Larry - W7IUV
> > >> w7iuv@arrl.net
> > >> http://www.axtek.com/w7iuv
> > >> Amp pix at http://207.108.137.61
> > >>
> > >>
> > >>
> > >> --
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> > >
> > >
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> >
>
>
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>


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