The problem with 6146's and the reason they weren't used in place of sweep
tubes, is the internal connection between the cathode and suppressor grid-
makes driving the grid a necessity, and therefore the sweep tube amps were
simpler and cheaper.
Tim N6DRA
----- Original Message -----
From: <amps-request@contesting.com>
To: <amps@contesting.com>
Sent: Wednesday, August 10, 2005 12:00 PM
Subject: Amps Digest, Vol 32, Issue 53
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> Today's Topics:
>
> 1. Re: TV sweep tubes and 6146s (R.Measures)
> 2. Re: 2 X 3-500Z's and Plate Voltage Choice (R.Measures)
> 3. Re: TV sweep tubes and 6146s (Karl-Arne Markstr?m)
> 4. Re: TV sweep tubes and 6146s (va3pl @ cuic.ca)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 10 Aug 2005 07:42:29 -0700
> From: R.Measures <r@somis.org>
> Subject: Re: [Amps] TV sweep tubes and 6146s
> To: "Dr. William J. Schmidt, II" <bill@wjschmidt.com>
> Cc: amps@contesting.com
> Message-ID: <4413c0171b9be95cfd87114bbac83d8e@somis.org>
> Content-Type: text/plain; charset=US-ASCII; format=flowed
>
>
> On Aug 10, 2005, at 7:03 AM, Dr. William J. Schmidt, II wrote:
>
> > Ah yes! good choice!, but there is an absolute price constraint as
> > well; 8171's are not in the same basic price class as the
> > aforementioned tubes...
>
> Good point, but, on occasion, a big stick is not without amusing uses.
> >
> > Sincerely,
> >
> > Dr. William J. Schmidt, II K9HZ
> > Trustee of the North American QRO - Central Division Club - K9ZC
> >
> > Email: bill@wjschmidt.com
> > WebPage: www.wjschmidt.com
> >
> > "If computers get too powerful, we can organize them into a committee;
> > that will do them in." -- Bradley's Bromide
> >
> >
> > ----- Original Message ----- From: "R. Measures" <r@somis.org>
> > To: "Dr. William J. Schmidt, II" <bill@wjschmidt.com>
> > Cc: <amps@contesting.com>
> > Sent: Wednesday, August 10, 2005 8:47 AM
> > Subject: Re: [Amps] TV sweep tubes and 6146s
> >
> >
> >>
> >> On Aug 10, 2005, at 6:16 AM, Dr. William J. Schmidt, II wrote:
> >>
> >>> I would think that using surplus tubes in the same basic price class
> >>> (813's,
> >>> 572B's, or 811A's), you would get a much higher "watt per dollar"
> >>> return.
> >>
> >> The best watts per dollar tube is seemingly the 8171. They go for c.
> >> $200 on eBay. That figures out to c. 12-cents per watt, including
> >> shipping.
> >>>
> >>> Sincerely,
> >>>
> >>> Dr. William J. Schmidt, II K9HZ
> >>> Trustee of the North American QRO - Central Division Club - K9ZC
> >>>
> >>> Email: bill@wjschmidt.com
> >>> WebPage: www.wjschmidt.com
> >>>
> >>> "If computers get too powerful, we can organize them into a
> >>> committee; that
> >>> will do them in." -- Bradley's Bromide
> >>>
> >>>
> >>> ----- Original Message -----
> >>> From: "Tom Bowman" <wa3rey@comcast.net>
> >>> To: <amps@contesting.com>
> >>> Sent: Wednesday, August 10, 2005 5:54 AM
> >>> Subject: [Amps] TV sweep tubes and 6146s
> >>>
> >>>
> >>>> What is the reason amplifiers never seem to be designed using four
> >>>> 6146s instead of TV sweep tubes like for example, four 6KD6s?
> >>>> I must be missing something obvious here.
> >>>>
> >>>> I'm asking because I'm thinking of building a 400W or so PEP
> >>>> amplifier
> >>>> for 75 and 40 meters.
> >>>>
> >>>> Keeping cost really low is one of my goals here and I have several
> >>>> good
> >>>> 6146s in the junk box.
> >>>>
> >>>>
> >>>> 73,
> >>>>
> >>>> Tom, WA3REY
> >>>> _______________________________________________
> >>>> Amps mailing list
> >>>> Amps@contesting.com
> >>>> http://lists.contesting.com/mailman/listinfo/amps
> >>>>
> >>>
> >>> _______________________________________________
> >>> Amps mailing list
> >>> Amps@contesting.com
> >>> http://lists.contesting.com/mailman/listinfo/amps
> >>>
> >>>
> >>
> >> Richard L. Measures, AG6K, 805.386.3734. www.somis.org
> >
> >
> >
>
> Richard L. Measures, AG6K, 805.386.3734. www.somis.org
>
>
>
> ------------------------------
>
> Message: 2
> Date: Wed, 10 Aug 2005 07:48:02 -0700
> From: R.Measures <r@somis.org>
> Subject: Re: [Amps] 2 X 3-500Z's and Plate Voltage Choice
> To: "Phil Clements" <philc@texascellnet.com>
> Cc: 'Amps' <amps@contesting.com>, 'Joe Isabella' <n3ji@yahoo.com>
> Message-ID: <8ed9ec7a20582d782b205e4e55bc8838@somis.org>
> Content-Type: text/plain; charset=US-ASCII; format=flowed
>
>
> On Aug 10, 2005, at 7:08 AM, Phil Clements wrote:
>
> > What is needed is the anode current required for these big claims of
> > QRO on
> > the 500Z. This will give us an idea of how many tubes you are going
> > through,
> > and how often!
>
> Good point, Phil. The linear-region peak emission for a 3-400Z or
> 3-500Z is around 1250 mA. However, operating above this level is
> likely to cause more rotten splatter than ruined cathodes.
> >
> > (((73)))
> > Phil, K5PC
> >
> >
> >> -----Original Message-----
> >> From: amps-bounces@contesting.com
> >> [mailto:amps-bounces@contesting.com] On
> >> Behalf Of Joe Isabella
> >> Sent: Tuesday, August 09, 2005 10:46 AM
> >> To: Amps
> >> Subject: Re: [Amps] 2 X 3-500Z's and Plate Voltage Choice
> >>
> >> Steve,
> >> That's what my Henry runs (4kV SSB/3kV CW, no load). Under load, it
> >> drops
> >> to something like 2800 & 3700.
> >>
> >> And I've seen over 2k with just over 100W input. I now have a rig
> >> that
> >> will drive it with 150W, but I have yet to try it. I can send you
> >> some
> >> pics of the amp's HV meter & RF Applications VFD power meter, if you
> >> like.
> >> I have no doubts that the tube is good for 1kW each (ask Ameritron
> >> about
> >> their AL-80B).
> >>
> >> Joe, N3JI
> >>
> >> sccook1@cox.net wrote:
> >> Morning all,
> >>
> >> Was thinking about upgrading my Henry 2K-4 to a 4A configuration with
> >> the
> >> CW/SSB switch. Was also thinking about puting in a transformer with
> >> two
> >> secondary voltages. I have seen amps running a pair of 3-500Zs with
> >> all
> >> kind of plate voltage schemes -- some running CW plate voltage as low
> >> as
> >> 2100 V no-load and as high as 4KV for SSB no-load.
> >>
> >> What would be a suitable voltage to shoot for for CW and SSB?
> >> 3000/4000?
> >> Less / More?
> >>
> >> Your thoughts?
> >>
> >> Steve (WG7K)
> >>
> >> _______________________________________________
> >> Amps mailing list
> >> Amps@contesting.com
> >> http://lists.contesting.com/mailman/listinfo/amps
> >>
> >>
> >> ---------------------------------
> >> Start your day with Yahoo! - make it your home page
> >> _______________________________________________
> >> Amps mailing list
> >> Amps@contesting.com
> >> http://lists.contesting.com/mailman/listinfo/amps
> >
> >
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
> >
>
> Richard L. Measures, AG6K, 805.386.3734. www.somis.org
>
>
>
> ------------------------------
>
> Message: 3
> Date: Wed, 10 Aug 2005 17:43:23 +0200
> From: Karl-Arne Markstr?m <sm0aom@telia.com>
> Subject: Re: [Amps] TV sweep tubes and 6146s
> To: <amps@contesting.com>
> Message-ID: <00ef01c59dc2$3dd34780$bc01a8c0@speedbox>
> Content-Type: text/plain; charset=iso-8859-1
>
> I would tend to agree with Peter.
>
> The surplus 813 is probably one of the available tubes with best W/$,
> but a factor may be the cost of the HV power supply.
>
> This is one of the problems with most inexpensive power tubes,
> they either require a fairly high HV potential or forced cooling.
>
> I recall what probably was the most inexpensive PA I ever made; a 2 x 813
single-band amp for 80m
> [used in 1979 as an IPA (!) ]. Total cost: 200 SEK (approx. 50 USD today)
, of which the ex-microwave oven power transformer (95 SEK + carriage) took
half.
>
> If a prospective builder already has the HV power supply, it might be a
better choice to select tubes
> after the voltages available instead of the other way around.
>
> Finally a question to the list;
>
> A TMC PAL-500 amplifier + PS recently followed me home.
> Are there any chances of finding scanned schematics somewhere among the
distinguished membership?
>
> 73/
> Karl-Arne
> SM0AOM
>
> ----- Original Message -----
> From: "Peter Chadwick" <g3rzp@g3rzp.wanadoo.co.uk>
> To: <amps@contesting.com>
> Sent: Wednesday, August 10, 2005 4:40 PM
> Subject: Re: [Amps] TV sweep tubes and 6146s
>
>
> > For 400 watts, I think you might get it with 4 6146Bs, with 1400 on the
plates. You would need lots of cooling, no speech processing, a pulser for
tuning, a big box of spares and no SSTV or RTTY.
> > There's a big difference between what you may be able to do, and what is
worth doing. In terms of watts/ $, surplus tubes like 813 etc are probably
the best. I've seen 4CX250B pulls as low as $8 each, so despite needing a
blower, they could be the way to go - a pair of them should give 400 watts
out.
> > As Karl Arne said, the peak cathode current capability of the 6146 isn't
as great as a sweep tube, so you need a lot more plate volts.
> > Asking around can get you things even cheaper - over the years, I've
been given a pair of good 4CX1000 tubes and a brand new socket and chimney
for them, and a spare breech block base, and a pair of vacuum
variables..........
> > 73
> >
> > Peter SM/G3RZP/P
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > ========================================
> > Message Received: Aug 10 2005, 12:52 PM
> > From: "Peter Chadwick"
> > To: craxd1@verizon.net, amps@contesting.com
> > Cc:
> > Subject: Re: [Amps] TV sweep tubes and 6146s
> >
> > Back when I had almost limitless supplies of 6146Bs, I ran a pair at
1200 volts on the plates. They lasted well, provided you didn't run steady
carrier, and gave about 180watts PEP out with 3rd order IMD at about -28dB
relative to PEP. They were rated in plate modulated Class C servicve at
600volts on the plates, so had the potential to hit up to around 2400 volts
or so peak. This suggests that pushing them much beyond about 1400 or so
would probably be dodgy. However, at that , you copuld maybe get 400 watts
or so. On the other hand, some of the transmitters we did with 3 6146Bs and
about 800 on thenplates would hit 200 watts PEP out at -27dB rel PEP third
order: others would only hit 100 watts at the same IMD. Of course, there
were variations in the driver IMD to consider, too.
> >
> > Incidentally, I'm not sure I completely agree with all K9STH's comments
on 6146Bs. Tx's that I've designed have got down production lines in enough
quantities to have used over 10,000 6146Bs in their construction, so I
figure I can claim some experience.
> >
> > 73
> >
> > Petere SM/G3RZP/P
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
> >
> > --
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> > Version: 7.0.338 / Virus Database: 267.10.5/67 - Release Date:
2005-08-09
> >
> >
>
>
> --
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>
>
> ------------------------------
>
> Message: 4
> Date: Wed, 10 Aug 2005 11:53:41 -0400
> From: "va3pl @ cuic.ca" <va3pl@cuic.ca>
> Subject: Re: [Amps] TV sweep tubes and 6146s
> To: <amps@contesting.com>
> Message-ID: <008901c59dc3$af1500e0$3e3c0282@orenda.com>
> Content-Type: text/plain; charset="iso-8859-1"
>
>
> ----- Original Message -----
> From: "Karl-Arne Markstr?m" <sm0aom@telia.com>
> To: <amps@contesting.com>
> Sent: Wednesday, August 10, 2005 11:43 AM
> Subject: Re: [Amps] TV sweep tubes and 6146s
>
>
> > [used in 1979 as an IPA (!) ]. Total cost: 200 SEK (approx. 50 USD
today)
> , of which the ex-microwave oven power transformer (95 SEK + carriage)
took
> half.
> >
>
> Is anybody building small amp using microwave oven power transformer?
> How those transformer are made and what kind of winding they have?
>
> Andy - VA3PL
>
>
>
>
>
> ------------------------------
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> End of Amps Digest, Vol 32, Issue 53
> ************************************
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