About 30 mils per triode max key down. If your grid current shunt is ok, the
tubes may be soft.
73,
Mike
W2AJI
-----Original Message-----
From: jsternmd <jsternmd@earthlink.net>
Sent: Monday, December 31, 2007 11:26 AM
To: amps@contesting.com
Subject: [Amps] Alpha 87A Tubes 3CX800A7 and the 3CX P 800A7
What would typical grid current be for an Alpha 87A running 1500w on 20
or 40m? My 87A gets up to 105 ma (Yellow LED) at times (into a very low
SWR antenna or dummy load). Is this normal? WOuld the 3CPX800A run
1500w at a lower grid current?
73 de K1JOS (Jerry)
CCA #11906
CRA #1777
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]
On Behalf Of amps-request@contesting.com
Sent: Monday, December 31, 2007 8:37 AM
To: amps@contesting.com
Subject: Amps Digest, Vol 60, Issue 45
Send Amps mailing list submissions to
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When replying, please edit your Subject line so it is more specific than
"Re: Contents of Amps digest..."
Today's Topics:
1. Re: Alpha 87A Tubes (Gary Smith)
2. Alpha 87A Tubes 3CX800A7 and the 3CX P 800A7 ? (DC)
3. Re: Alpha 87A Tubes 3CX800A7 and the 3CX P 800A7 ? (jeremy-ca)
4. Re: Alpha 87A Tubes 3CX800A7 and the 3CX P 800A7 ? (Paul Hewitt)
5. Re: [TenTec] Corsair II & Titan 425 (Gary Smith)
6. Re: [TenTec] Corsair II & Titan 425 (Gary Smith)
7. Re: [TenTec] Corsair II & Titan 425 (Gary Smith)
8. Looking for David Kechkaylo (TS711A@aol.com)
9. 2x813 or 2x3-500zg ? (Mike Bondarev)
10. Re: 2x813 or 2x3-500zg ? (Roger)
11. Re: 2x813 or 2x3-500zg ? (jeremy-ca)
----------------------------------------------------------------------
Message: 1
Date: Sun, 30 Dec 2007 14:08:56 -0800
From: "Gary Smith" <wa6fgi@sbcglobal.net>
Subject: Re: [Amps] Alpha 87A Tubes
To: "Larry P. Greenberg" <wa9mag@ameritech.net>,
<amps@contesting.com>
Message-ID: <007e01c84b30$997c1b20$4001a8c0@garys>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
3CX800A7's are standard (from the factory) in my/their Ameritron
AL-800H. Never had a minute's problem with them. Runs "legal" all bands
easily, but I
do pay attention to the grid current.
There is a tube the 3CX P 800A7, only diff is they are rated for pulse
service.
My .02 on this thread,
73's,
Gary...wa6fgi
------ Original Message -----
From: "Larry P. Greenberg" <wa9mag@ameritech.net>
To: <amps@contesting.com>
Sent: Saturday, December 29, 2007 10:31 AM
Subject: [Amps] Alpha 87A Tubes
>I copied the following from the Alpha website.
>
> The Alpha 87A, 89 and 86 were designed to use the YC-238 tube which
> is
> an Eimac 3CX800A7 that has been screened for low grid current.
Replacing
> one or both of the tubes in your amplifier with a regular 3CX800 or
with a
> 3CPX800 could lead to unintended problems and consequences which again
we
> are not able to cover under warranty.
>
> I don't find YC-238 tubes on the Eimac website. While I understand
> that
> we may not want to use non Eimac tubes in our amplifiers, I don't
> understand why replacements cannot be non-matched Eimac 3CX800A7 tubes
> that can be purchased from known wholesale dealers or reputable
hamfest
> dealers. I would like to keep spare finals on the shelf but $1,500 a
pair
> is really steep.
>
> Has anybody used regular 3CX800A7's in their amplifier? Is the YC-238
> nomenclature an Eimac name or an Alpha name? Does anybody have a
> specification sheet that they can send me?
>
> Larry, WA9MAG
> _______________________________________________
> Amps mailing list
> Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
------------------------------
Message: 2
Date: Sun, 30 Dec 2007 17:41:08 -0500
From: "DC" <daclark56@hotmail.com>
Subject: [Amps] Alpha 87A Tubes 3CX800A7 and the 3CX P 800A7 ?
To: <amps@contesting.com>
Message-ID: <BLU126-DAV13D200DCC88E663CA32FB9BE570@phx.gbl>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Is the 3CX P 800A7 interchangable with the 3CX800A7?
------------------------------
Message: 3
Date: Sun, 30 Dec 2007 19:20:12 -0500
From: "jeremy-ca" <km1h@jeremy.mv.com>
Subject: Re: [Amps] Alpha 87A Tubes 3CX800A7 and the 3CX P 800A7 ?
To: "DC" <daclark56@hotmail.com>, <amps@contesting.com>
Message-ID: <014101c84b42$eaaa8e70$6500a8c0@KITTYMA123>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
All varieties can be considered the same tube for ham use.
Also any Eimac tube beginning with a Y is automatically 40-100% more
expensive than its regular production brethren.
Carl
KM1H
----- Original Message -----
From: "DC" <daclark56@hotmail.com>
To: <amps@contesting.com>
Sent: Sunday, December 30, 2007 5:41 PM
Subject: [Amps] Alpha 87A Tubes 3CX800A7 and the 3CX P 800A7 ?
> Is the 3CX P 800A7 interchangable with the 3CX800A7?
>
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
>
------------------------------
Message: 4
Date: Sun, 30 Dec 2007 16:44:53 -0800
From: "Paul Hewitt" <wd7s@earthlink.net>
Subject: Re: [Amps] Alpha 87A Tubes 3CX800A7 and the 3CX P 800A7 ?
To: "DC" <daclark56@hotmail.com>, <amps@contesting.com>
Message-ID: <002801c84b46$5d0e95d0$9539f604@qroproductions>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
Yes and no. The CPX version is rated for a higher plate voltage than
the CX
version with the Eimac tube. The CPX tube has a taller ceramic
insulating
portion at the base. The Svetlana CPX and CX versions had the same
ceramic
height and both will take the higher plate voltage.
73, Paul
PAUL HEWITT
WD7S PRODUCTIONS
QRO HOMEBREW COMPONENTS
http://home.earthlink.net/~wd7s
----- Original Message -----
From: "DC" <daclark56@hotmail.com>
To: <amps@contesting.com>
Sent: Sunday, December 30, 2007 2:41 PM
Subject: [Amps] Alpha 87A Tubes 3CX800A7 and the 3CX P 800A7 ?
> Is the 3CX P 800A7 interchangable with the 3CX800A7?
>
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
>
------------------------------
Message: 5
Date: Sun, 30 Dec 2007 20:51:28 -0500
From: "Gary Smith" <Gary@doctorgary.net>
Subject: Re: [Amps] [TenTec] Corsair II & Titan 425
To: Amps@contesting.com
Message-ID: <477804D0.5692.12D1044@Gary.doctorgary.net>
Content-Type: text/plain; charset=US-ASCII
Hi Carl,
I've tried that and the amp keys but it does not seem to key the
Corsair. I can see where there's a slight dip in voltage and a show
of some grid current to the 425 when I key but the key out from the
425 into the key in of the corsair does not trigger the corsair.
If I run the key in to the corsair via the same RCA jack, the corsair
transmits just fine.
So key the amp? yes but the amp key the corsair? No.
Ideas?
Thanks!
Gary
> No. QSK and Ext T/R are very different. The corsair never had the
> TXOut and TXEn lines on it, which are required for a QSK amp. What
> you are supposed to do is connect Ext T/R to the amplifier keying
> line. This will not give you QSK but it will work with the amp that
> way.
>
> Another completely different approach is to connect your keyer output
> directly to where TXOut would have been connected to the amp. Then
> connect the output keying line of the amp to key the corsair. This
> will give you QSK and guarantee that the amp keys before the corsair
> transmits.
>
> Carl Moreschi N4PY
> 121 Little Bell Drive
> Bell Mountain
> Hays, NC 28635
> ----- Original Message -----
> From: "Gary Smith" <Gary@doctorgary.net>
> To: <tentec@contesting.com>
> Sent: Sunday, December 30, 2007 7:37 PM
> Subject: [TenTec] Corsair II & Titan 425
>
>
> > Am sending the Omni V to TenTec for allignment. Not sure of the best
> > way to connect my back up rig (Corsair II) to the amp for QSK.
> >
> > With the Omni V I connected the TX out & TX en to their counterparts
> > on the 425. I see no TX out or TX en on the Corsair but there exists
> > QSK and EXT T/R connectors on the Corsair. Are these the same
> > function but different names? I do want to use QSK.
> >
> > Thanks,
> >
> > Gary
> > KA1J
> > _______________________________________________
> > TenTec mailing list
> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
>
>
------------------------------
Message: 6
Date: Sun, 30 Dec 2007 21:01:52 -0500
From: "Gary Smith" <Gary@doctorgary.net>
Subject: Re: [Amps] [TenTec] Corsair II & Titan 425
To: Amps@contesting.com
Message-ID: <47780740.29591.13692D6@Gary.doctorgary.net>
Content-Type: text/plain; charset=US-ASCII
Carl, somehow related to the keyer & the 425...
If I run a straight key into the 425 as you suggested, it works fine
and the amp & Corsair both fire.
By the keyer alone it triggers the 425 but the 425 does not trigger
the Corsair.
Interesting.
Gary
> Hi Carl,
>
> I've tried that and the amp keys but it does not seem to key the
> Corsair. I can see where there's a slight dip in voltage and a show of
> some grid current to the 425 when I key but the key out from the 425
> into the key in of the corsair does not trigger the corsair.
>
> If I run the key in to the corsair via the same RCA jack, the corsair
> transmits just fine.
>
> So key the amp? yes but the amp key the corsair? No.
>
> Ideas?
>
> Thanks!
>
> Gary
>
> > No. QSK and Ext T/R are very different. The corsair never had the
>
> > TXOut and TXEn lines on it, which are required for a QSK amp. What
>
> > you are supposed to do is connect Ext T/R to the amplifier keying
> > line. This will not give you QSK but it will work with the amp
> that
> > way.
> >
> > Another completely different approach is to connect your keyer
> output
> > directly to where TXOut would have been connected to the amp. Then
>
> > connect the output keying line of the amp to key the corsair. This
>
> > will give you QSK and guarantee that the amp keys before the
> corsair
> > transmits.
> >
> > Carl Moreschi N4PY
> > 121 Little Bell Drive
> > Bell Mountain
> > Hays, NC 28635
> > ----- Original Message -----
> > From: "Gary Smith" <Gary@doctorgary.net>
> > To: <tentec@contesting.com>
> > Sent: Sunday, December 30, 2007 7:37 PM
> > Subject: [TenTec] Corsair II & Titan 425
> >
> >
> > > Am sending the Omni V to TenTec for allignment. Not sure of the
> best
> > > way to connect my back up rig (Corsair II) to the amp for QSK.
> > >
> > > With the Omni V I connected the TX out & TX en to their
> counterparts
> > > on the 425. I see no TX out or TX en on the Corsair but there
> exists
> > > QSK and EXT T/R connectors on the Corsair. Are these the same
> > > function but different names? I do want to use QSK.
> > >
> > > Thanks,
> > >
> > > Gary
> > > KA1J
> > > _______________________________________________
> > > TenTec mailing list
> > > TenTec@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/tentec
> >
> >
>
>
------------------------------
Message: 7
Date: Sun, 30 Dec 2007 21:11:51 -0500
From: "Gary Smith" <Gary@doctorgary.net>
Subject: Re: [Amps] [TenTec] Corsair II & Titan 425
To: Amps@contesting.com
Message-ID: <47780997.4618.13FB825@Gary.doctorgary.net>
Content-Type: text/plain; charset=US-ASCII
Ah rats,
Cross post. Sorry
Gary
KA1J
------------------------------
Message: 8
Date: Mon, 31 Dec 2007 01:07:47 EST
From: TS711A@aol.com
Subject: [Amps] Looking for David Kechkaylo
To: Amps@contesting.com
Message-ID: <d01.205cf240.34a9e133@aol.com>
Content-Type: text/plain; charset="US-ASCII"
Hello, does anyone have an email for David Kechkaylo? He worked at
Heathkit
at one time and has lots of good info. I only find old posts from him
online.
Thanks !!
**************************************See AOL's top rated recipes
(http://food.aol.com/top-rated-recipes?NCID=aoltop00030000000004)
------------------------------
Message: 9
Date: Mon, 31 Dec 2007 10:42:34 +0300
From: Mike Bondarev <mikebond@mosfirm.ru>
Subject: [Amps] 2x813 or 2x3-500zg ?
To: Amps@contesting.com
Message-ID: <1494475189.20071231104234@mosfirm.ru>
Content-Type: text/plain; charset=us-ascii
Hello to everybody! Happy New Year 2008!
In the coming year I would like to build an amplifier for "everyday
use". For the contesting I already made the amplifier with GU-84B and
GM3SEK's tetrode boards and it work fantastic! The second amp I would
like to make with glass tubes. What you guys can recommend me? I was
thinking about two 813 in grounded grid configurations but now I'm
thinking why not the pair of 3-500zg from RF-parts? I newer used 3-500zg
before so I can't compare it to 813. I understand the difference in
pricing but I also know it's easy to buy matched set of 3-500zg but it's
just impossible to find matched pair of 813.
Regards, Mike RL3BM
------------------------------
Message: 10
Date: Mon, 31 Dec 2007 03:32:29 -0500
From: "Roger" <sub1@rogerhalstead.com>
Subject: Re: [Amps] 2x813 or 2x3-500zg ?
To: <Amps@contesting.com>
Message-ID: <000401c84b87$aea7cd80$6600a8c0@shop32>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
My personal opinions:
The 813 is a nice tube and I have built amps using them. However the
3-500Z is a current tube, in production, and not outlandishly
priced.
As far as as a matched pair, I've never worried about that with 3-500s
unless they are way off and I've not found any that were. The 3-500s
are
not a higain tube, but if you have an honest 100 watts and enough plate
voltage they'll run the legal limit.
Roger (K8RI)
> Hello to everybody! Happy New Year 2008!
> In the coming year I would like to build an amplifier for "everyday
> use". For the contesting I already made the amplifier with GU-84B and
> GM3SEK's tetrode boards and it work fantastic! The second amp I would
> like to make with glass tubes. What you guys can recommend me? I was
> thinking about two 813 in grounded grid configurations but now I'm
> thinking why not the pair of 3-500zg from RF-parts? I newer used
> 3-500zg before so I can't compare it to 813. I understand the
> difference in pricing but I also know it's easy to buy matched set of
> 3-500zg but it's just impossible to find matched pair of 813.
>
> Regards, Mike RL3BM
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
------------------------------
Message: 11
Date: Mon, 31 Dec 2007 08:36:44 -0500
From: "jeremy-ca" <km1h@jeremy.mv.com>
Subject: Re: [Amps] 2x813 or 2x3-500zg ?
To: "Mike Bondarev" <mikebond@mosfirm.ru>, <Amps@contesting.com>
Message-ID: <002501c84bb2$313e7da0$6500a8c0@KITTYMA123>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
The 813 is almost a 70 year old design yet it is still one of the best
tubes
ever made.
Brand new US military surplus ones are on Ebay on a regular basis and at
very low prices. No matching is required. I recently bought 4 813's and
sockets off Ebay for around $80 for all. These are for an AM amplifier.
In GG service the 813 IMD is in the -33dB range according to published
info
making it a very clean performer.
My regular SSB/CW HF amp uses 3-500Z's and they are also an excellent
tube.
Carl
KM1H
----- Original Message -----
From: "Mike Bondarev" <mikebond@mosfirm.ru>
To: <Amps@contesting.com>
Sent: Monday, December 31, 2007 2:42 AM
Subject: [Amps] 2x813 or 2x3-500zg ?
> Hello to everybody! Happy New Year 2008!
> In the coming year I would like to build an amplifier for "everyday
> use". For the contesting I already made the amplifier with GU-84B and
> GM3SEK's tetrode boards and it work fantastic! The second amp I would
> like to make with glass tubes. What you guys can recommend me? I was
> thinking about two 813 in grounded grid configurations but now I'm
> thinking why not the pair of 3-500zg from RF-parts? I newer used
> 3-500zg before so I can't compare it to 813. I understand the
> difference in pricing but I also know it's easy to buy matched set of
> 3-500zg but it's just impossible to find matched pair of 813.
>
> Regards, Mike RL3BM
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
>
------------------------------
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End of Amps Digest, Vol 60, Issue 45
************************************
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