Alek,
The heater for the average sweep tube (6LQ6) consumes
about 16 watts of power. Yes, you can run an out board
transformer, or an inboard additional transformer in a few
different types of circuits.
1. You can remove the 6.3 volt paralleled leads from the tube
sockets. Add a 24 volt ~2 amp transformer secondary in
series with the 6.3. The primary wired parallel with the other
xmfrs primary, the proper leads connected "in phase" to the
117 vac for an approx 31 vac secondary, just what you need.
2. If an amplifier has 12.6 volt heaters, you can secondary
series another 18 volt transformer to obtain the ~31 volts.
3. Series up the four 31 volt heaters (`124 volts) and you'd be able
to run a filament transformer in reverse off the original amp
windings. Not realistic since you require a 12 amp xmfr for this
"trick".
cheers
skipp
####
From: Alek Petkovic <vk6apk@eon.net.au>
ps: I ended up with 8 x 31LZ6's at $14.00 each so I think I got a
reasonable deal.
They are supposed to be like the LQ6's.
At 10:48 PM 16-05-00 -0700, you wrote:
>Hi Alek,
>Marv is right, my spec sheet for that tube (RCA Brand) states the warmup
>as 11 seconds min. Typical
>of sweep tubes. Be sure to go over to my http://sonic.ucdavis.edu
>server and down load my Dentron
>Cathode current cutoff mod for the Dentron. Save your tubes. There
are
>two Dentron Download available
>on the site, one is a copy of an old Ham Radio Mag article, the second
is
>my work up with the circuit
>diagram.
>cheers
>skipp
>
> > On Mon, 01 May 2000 17:54:45 +0800 Alek Petkovic
><vk6apk@eon.net.au>writes:
> >G'day from "Down Under.
> >I've just ordered 2 sets of 4 x 31LQ6 tubes for my little Dentron
>GLA-1000
> >amp. These will replace the tired 6LQ6 tubes presently in the unit.
> >The tube swap will of course necessitate an extra transformer to run
the
> >heaters of the new tubes.
> >
> >Does anybody on the reflector have an idea of the current drawn by the
> >heaters in these tubes?
> >... so I figure on around 2A total for the four tubes in parallel.
> >I have a transformer rated at 100VA which I hope will do the job with
a
> >generous safety margin.
> >Am I correct in the above assumption?
>
>:Hi Alek,
>:Yes, that's the way it works -- should be right around 500 mA per
>:tube. The 31's also have a "controlled" warm-up time which was a
>:requirement for their original application in series filament string
>:style TV's.
>:73, Marv WC6W 310 649 3111
>
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