[Amps] Amps Digest, Vol 44, Issue 75
Edwin Karl
edk0kl at centurytel.net
Tue Aug 22 12:45:35 EDT 2006
Regarding the selection of amplifiers, I have comments (everybody has an
opinion ...etc)
One of my considerations for an amplifier is the cost of replacement tubes.
As mentioned here, unlikely that in my lifetime, or what's left of it, I
would have to replace tubes because they wear out, but it's important for
me to sleep well.
There are many new amps in the 3 kilo buck range, some with delicate high
priced jugs. The 3-500Z is cheap enough, $250 or so for a pair get within
fractions of a db of full bore and they are rugged. No waiting for turn on,
watch for the grid to go positive and smoke your investment, etc.
Just plain old solid technology that gets you there.
Used amps are often orphans, so pay attention to parts replacement. Like
plate transformers, filter caps, etc. Most everything else in an amp is out
of
the Mouser catalog or RF Parts. If Peter Dahl transformers are used, you
always can
get replacement parts directly from them.
Do you want 160 meters? That can separate some of the used stuff for you.
i.e.
Heath SB-220 and most amps of that vintage don't cover 160.
For me, I own an Amp Supply LK-500ZB that has been updated and has QSK
(break-in)
is break-in important? I also have an Amp Supply LK-500ZC that also has been
modified
for my lifestyle, with no breakin. (Having been a broadcaster, I like
spares.)
If I had the funds and was so minded, I would choose EMTRON from Australia.
Many
FB amps, rugged construction, good performance, but not within my pocket
book. I'm
basically a low budget guy.
So I hope you find what your looking for and get lots of enjoyment. But as I
found out
you probably have to upgrade baluns, tuners, etc for the higher power.
ed K0KL
-----Original Message-----
From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com]On
Behalf Of amps-request at contesting.com
Sent: Tuesday, August 22, 2006 2:10 AM
To: amps at contesting.com
Subject: Amps Digest, Vol 44, Issue 75
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Today's Topics:
1. Henry 2K-3 (StephenTetorka at cs.com)
2. State of the Amp (Martin AA6E)
3. Re: State of the Amp (Ed Swynar)
4. Re: State of the Amp (Martin AA6E)
5. Source for AWG 16 tinned wire or small quantity of silver
plating solution? (Christopher J Galbraith)
6. Re: State of the Amp (Bill Turner)
7. Passive Grid Resistor Source? (Jennings)
8. Re: Passive Grid Resistor Source? (gdaught6 at stanford.edu)
9. Re: Passive Grid Resistor Source? (Will Matney)
10. 3CX3000A7 amp for sale (Carsten Esch)
----------------------------------------------------------------------
Message: 1
Date: Mon, 21 Aug 2006 15:26:30 EDT
From: StephenTetorka at cs.com
Subject: [Amps] Henry 2K-3
To: amps at contesting.com
Message-ID: <516.5e991f6.321b62e6 at cs.com>
Content-Type: text/plain; charset="US-ASCII"
Hi all:
I might be able to obtain this unit.
As I'm not able to use it, might anyone be interested in its purchase?
I'm in New Jersey..and good in QRZ.com.
Willing to deliver it 'wherever' as I have the time...and depending upon gas
cost.
Thanks alot,
Steve
WA2TAK
------------------------------
Message: 2
Date: Mon, 21 Aug 2006 19:40:55 -0400
From: Martin AA6E <aa6e at ewing.homedns.org>
Subject: [Amps] State of the Amp
To: amps at contesting.com
Message-ID: <44EA4487.4000707 at ewing.homedns.org>
Content-Type: text/plain; charset=ISO-8859-1
-----BEGIN PGP SIGNED MESSAGE-----
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Hello Amp people,
After nearly 50 years of hamming at the 100 W level, I have lately got
interested in making bigger zaps, dimming house lights, offending the
neighbors, etc.
So I've been surveying the HF amp marketplace. Funny, the rate of
technical progress seems to have been pretty slow over the last 30
years. My impression is that the "sweet spot" (price, performance,
versatility, etc.) is still the dual 3-500Z GG design. For a new amp, I
might choose the Ten-Tec Centurion -- it matches my Orion. Of course
there are competitors, too. Darwinian forces seem to have eliminated
other designs that are based on tubes that are no longer made.
If you need the last dB or two to get continuous 1.5 kW out, you can
spend $1K more. And if you want digital controls, even more. (More
stuff to break and go obsolete!)
But the XYL helpfully provided a sanity check, and so I'm really looking
for a used amp. That seems all the more reasonable because the vintage
amps aren't so different from current models. I'm looking at the Henry
2K-xx, for instance -- pushing 30 years old. The main thing it doesn't
have that I'd want is QSK switching, but I might be able to add that.
The big pedestal design is a plus for me. The PS isn't shoe-horned into
the RF box.
Anyway, my question for you is - has anyone written a recent survey of
the HF amp options along the lines of my notes above? I.e., to help
orient the newbie amp user to the range of options and choices that are
out there in the current market?
73, Martin AA6E
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------------------------------
Message: 3
Date: Mon, 21 Aug 2006 20:06:09 -0500
From: "Ed Swynar" <gswynar at durham.net>
Subject: Re: [Amps] State of the Amp
To: <amps at contesting.com>
Message-ID: <000f01c6c587$2b00d710$8a305a45 at CompaqS5000>
Content-Type: text/plain; charset="iso-8859-1"
Hi Martin,
How about HOMEBREWING a linear amplifier to YOUR specifications...?
It's really not all that insurmountable a task (heck, I've built three here
myself --- others have surpassed that number!). Best of all, there's a lot
of FUN waiting for you in the design, mods, accumulation of parts, lay-out,
assembly, etc. You may even discover that actual OPERATION is SECONDARY to
the whole process...!
Just a thought, anyway...and why those pricey 3-500Z tubes? Why not
something vintage/classic (and CHEAP!) like a 4-1000A, or four 813's...?
~73!~ Eddy VE3CUI - VE3XZ
----- Original Message -----
From: "Martin AA6E" <aa6e at ewing.homedns.org>
To: <amps at contesting.com>
Sent: Monday, August 21, 2006 6:40 PM
Subject: [Amps] State of the Amp
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Hello Amp people,
>
> After nearly 50 years of hamming at the 100 W level, I have lately got
> interested in making bigger zaps, dimming house lights, offending the
> neighbors, etc.
>
> So I've been surveying the HF amp marketplace. Funny, the rate of
> technical progress seems to have been pretty slow over the last 30
> years. My impression is that the "sweet spot" (price, performance,
> versatility, etc.) is still the dual 3-500Z GG design. For a new amp, I
> might choose the Ten-Tec Centurion -- it matches my Orion. Of course
> there are competitors, too. Darwinian forces seem to have eliminated
> other designs that are based on tubes that are no longer made.
>
> If you need the last dB or two to get continuous 1.5 kW out, you can
> spend $1K more. And if you want digital controls, even more. (More
> stuff to break and go obsolete!)
>
> But the XYL helpfully provided a sanity check, and so I'm really looking
> for a used amp. That seems all the more reasonable because the vintage
> amps aren't so different from current models. I'm looking at the Henry
> 2K-xx, for instance -- pushing 30 years old. The main thing it doesn't
> have that I'd want is QSK switching, but I might be able to add that.
> The big pedestal design is a plus for me. The PS isn't shoe-horned into
> the RF box.
>
> Anyway, my question for you is - has anyone written a recent survey of
> the HF amp options along the lines of my notes above? I.e., to help
> orient the newbie amp user to the range of options and choices that are
> out there in the current market?
>
> 73, Martin AA6E
>
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.5 (GNU/Linux)
> Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org
>
> iD8DBQFE6kSH5E7geDpEeTsRAs8NAJ0T6gdyR4bw3lpNXm0EFAfO5gstVACg7EEA
> RGVfN7GAs6e+jDTPuqMRYqQ=
> =igpX
> -----END PGP SIGNATURE-----
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
------------------------------
Message: 4
Date: Mon, 21 Aug 2006 20:32:55 -0400
From: Martin AA6E <aa6e at ewing.homedns.org>
Subject: Re: [Amps] State of the Amp
To: amps at contesting.com
Message-ID: <44EA50B7.5010603 at ewing.homedns.org>
Content-Type: text/plain; charset=ISO-8859-1
-----BEGIN PGP SIGNED MESSAGE-----
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Eddy,
Home brew is certainly an option, but it's not the quickest way to get
something on the air. It's not cheap if you value your time, but it's
great if you enjoy the process. I'm tempted.
Thanks for the note.
73 Martin AA6E
Ed Swynar wrote:
> Hi Martin,
>
> How about HOMEBREWING a linear amplifier to YOUR specifications...?
>
> It's really not all that insurmountable a task (heck, I've built three
here
> myself --- others have surpassed that number!). Best of all, there's a lot
> of FUN waiting for you in the design, mods, accumulation of parts,
lay-out,
> assembly, etc. You may even discover that actual OPERATION is SECONDARY to
> the whole process...!
>
> Just a thought, anyway...and why those pricey 3-500Z tubes? Why not
> something vintage/classic (and CHEAP!) like a 4-1000A, or four 813's...?
>
> ~73!~ Eddy VE3CUI - VE3XZ
>
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------------------------------
Message: 5
Date: Mon, 21 Aug 2006 17:47:24 -0700
From: "Christopher J Galbraith" <cgalbrai at umich.edu>
Subject: [Amps] Source for AWG 16 tinned wire or small quantity of
silver plating solution?
To: <amps at contesting.com>
Message-ID: <000001c6c584$914ac830$3b0fa8c0 at mems8>
Content-Type: text/plain; charset="us-ascii"
Hi gang,
Does anyone know of a source for AWG 16 tinned or silver-plated wire? I
just need a couple of feet for making a pair of plate leads/suppressor
inductors.
Alternatively, can someone point me to a supplier of some type of silver
plating solution in small quantities (I have some bare copper AWG 16 wire on
hand)? I've looked at Coolamp for silver plating, but the 4 oz at $50 is a
little overkill for what I need right now.
Thanks and 73, Chris KA8WFC
------------------------------
Message: 6
Date: Mon, 21 Aug 2006 19:09:18 -0700
From: Bill Turner <dezrat at copper.net>
Subject: Re: [Amps] State of the Amp
To: amps at contesting.com
Message-ID: <mcpke21a10ftughp4hjefalmijuk6ucibk at 4ax.com>
Content-Type: text/plain; charset=us-ascii
ORIGINAL MESSAGE:
On Mon, 21 Aug 2006 19:40:55 -0400, Martin AA6E
<aa6e at ewing.homedns.org> wrote:
>My impression is that the "sweet spot" (price, performance,
>versatility, etc.) is still the dual 3-500Z GG design.
------------ REPLY SEPARATOR ------------
True for the factory-built amps only because they have not discovered
the GS-35b Russian triode. It costs less than one 3-500Z, has five
times the plate dissipation and requires no socket. Having no long
leads to internal elements, it should be easier to tame parasitics in
most designs. Less than 100 watts will drive it to 1.5 KW output in
grounded grid and it's rated for full power way up in the UHF region.
Homebrewers on the other hand, have indeed discovered it.
--
Bill, W6WRT
------------------------------
Message: 7
Date: Tue, 22 Aug 2006 14:12:19 +1200
From: Jennings <leejen at paradise.net.nz>
Subject: [Amps] Passive Grid Resistor Source?
To: Amps Newsgroup <amps at contesting.com>
Message-ID: <000c01c6c590$65c26900$0900a8c0 at nanook>
Content-Type: text/plain; charset="Windows-1252"
I am thinking of a passive grid driven configuration for a GU74B/Tetrode
Board amp. I could parallel a bunch of 2W carbon resistors to make up 50
ohms at 100 watts, but the physical size worries me. Has anyone got an "off
the shelf" solution and source of supply or suggestions?
Lee ZL2AL
------------------------------
Message: 8
Date: Mon, 21 Aug 2006 21:31:11 -0700
From: gdaught6 at stanford.edu
Subject: Re: [Amps] Passive Grid Resistor Source?
To: amps at contesting.com
Message-ID: <44EA261F.1578.EFB472 at gdaught6.stanford.edu>
Content-Type: text/plain; charset=US-ASCII
On 22 Aug 2006 at 14:12, Jennings wrote:
> I am thinking of a passive grid driven configuration for a GU74B/Tetrode
Board amp. I could parallel a bunch of 2W carbon resistors to make up 50
ohms at 100 watts, but the physical size worries me. Has anyone got an "off
the shelf" solution and source of supply or suggestions?
Lee, you might try to locate some TO-220 sized power resistors made
by Caddock. They mount on a heatsink, but they are compact and have
low intrinsic inductance. A couple of 100 ohm 50 watt units could be
put in parallel, or two 25 ohm units in series. I've used these
resistors successfully in my 4cx1600b amp. (See "Sunnyvale/St.
Petersburg Kilowatt Plus in the ARRL handbook, 1999-2004.)
73,
George T. Daughters, K6GT
------------------------------
Message: 9
Date: Mon, 21 Aug 2006 22:38:56 -0400
From: "Will Matney" <craxd1 at verizon.net>
Subject: Re: [Amps] Passive Grid Resistor Source?
To: "Jennings" <leejen at paradise.net.nz>, amps at contesting.com
Message-ID: <200608212238560510.052AC1E9 at outgoing.verizon.net>
Content-Type: text/plain; charset=us-ascii
Lee,
Check this website out. Are you wondering about the resistor for the tetrode
board
or for an attenuator? The website doesn't have any info on Ians board but
has a good bit
of other info about a grid driven amp. Look at the planar type resistors the
builder used
for the attenuator network. They're high wattage types.
http://www.xs4all.nl/~pa0fri/Lineairs/Frinear1500/FRI1500eng.htm
Best,
Will
*********** REPLY SEPARATOR ***********
On 8/22/06 at 2:12 PM Jennings wrote:
>I am thinking of a passive grid driven configuration for a GU74B/Tetrode
>Board amp. I could parallel a bunch of 2W carbon resistors to make up 50
>ohms at 100 watts, but the physical size worries me. Has anyone got an
>"off the shelf" solution and source of supply or suggestions?
>
>Lee ZL2AL
>
>_______________________________________________
>Amps mailing list
>Amps at contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
------------------------------
Message: 10
Date: Tue, 22 Aug 2006 09:04:28 +0200
From: "Carsten Esch" <carsten.esch at appello.de>
Subject: [Amps] 3CX3000A7 amp for sale
To: <amps at contesting.com>
Message-ID: <000f01c6c5b9$36683b20$14b2a8c0 at carsten>
Content-Type: text/plain; charset="us-ascii"
Hi,
Still too much unused amps here so I would like to sell:
Commercial made 3CX3000A7 amp, will run on 3 phase 380V made by Creative
Electronics INC. Los Angeles, CA. Will work from 1.8 - 30MHz, includes BIRD
LINE Section with 5kW slug, looks and works like new. You can see a picture
here: <http://www.appello.de/ce2500.jpg> http://www.appello.de/ce2500.jpg.
Asking EUR 5.300,-
I can professionally crate the amps and ship world-wide at your cost.
Thanks for your interest!
Carsten, DL6LAU
------------------------------
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