The Svetlana tube was the EL509 ... The old Svetlana web site
used to have a technical bulletin covering the conversion.
Will is correct ... Far Circuits still shows the PC Board set
or the conversion, including a tuned input board and new power
supply board. http://www.farcircuits.net/rfpa1.htm and scroll
to the bottom of the list. The EL509/6KG6A conversion tech
note is available here:
http://www.garant-funk.com/svetlana/technoteNO.32.html
W6TC who I believe is a member of this list is listed as one
of the authors of the tech note.
73,
... Joe, W4TV
> -----Original Message-----
> From: amps-bounces@contesting.com
> [mailto:amps-bounces@contesting.com] On Behalf Of Will Matney
> Sent: Monday, June 05, 2006 11:41 AM
> To: amps@contesting.com
> Subject: Re: [Amps] la-1000 what to convert to?
>
>
> Chuck,
>
> Why not convert it to run on four 6KG6A (EL-519) tubes?
> There's replacement boards available from FAR Circuits if I
> recall. To be honest though, they ran those four 6LQ6 tubes a
> little too hot at that anode voltage. A better voltage is at
> 900 Vdc. I guess they were thinking squeeze all you can get
> out of the four but the tube life isn't as good. A couple of
> 6KG6A's will do approximately 275 watts PEP so four should
> get you 550. I built several grid driven units using these
> and that's about what I could get without the anode cherrying
> up. That's something else to keep in mind also. A sweep tube
> does not act like a broadcasting tube where the anode can get
> red hot. A sweep tube will start to fail considerably after
> the anode starts to get red one time. Adjust the drive for
> full output from the amp with the bias backed off to about
> -100 Vdc. I used the bias as a hi/lo circuit varying it from
> about -100 to -150 Vdc with a variable supply. The EL-519
> tubes are about $15 to $20 eac
> h now I think.
>
> For any interested in building one of these that is grid
> drive, below if the following approximate circuit voltages I used;
>
> Anode voltage: +900 Vdc @ 1 amp
> Screen voltage: +450 Vdc (from center of plate voltage doubler)
> Control voltage: -100 to -150 Vdc (250 mA)
> Heater voltage: 6 Vac @ 2 amps each
>
> Best,
>
> Will
>
>
> *********** REPLY SEPARATOR ***********
>
> On 6/5/06 at 9:37 AM Partain, Chuck wrote:
>
> >I have a orig la-1000 amp supply laying about and figure for
> this winter,
> >that might be a good project to tear into.
> >Parts collection will start soon. I see a few folks have converted to
> >ceramic tubes, russian glass or whatnot.
> >anyone do any of these? and what might you suggest is best?
> >
> >on a REALLY good day I can see ~500w out of the 4 sweeps!!!
> >
> >1100v at 1 amp I THINK the transformer will do, I don't want
> to replace it
> >yet.
> >
> >
> >ka1mwp
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>
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