To all, ref. the GS-35B's efficiency: It is a medium MU triode, not a high
MU triode that folks are trying to compare to ! Willy K3VW
In a message dated 12/19/2009 9:21:18 P.M. Eastern Standard Time,
amps-request@contesting.com writes:
Send Amps mailing list submissions to
amps@contesting.com
To subscribe or unsubscribe via the World Wide Web, visit
http://lists.contesting.com/mailman/listinfo/amps
or, via email, send a message with subject or body 'help' to
amps-request@contesting.com
You can reach the person managing the list at
amps-owner@contesting.com
When replying, please edit your Subject line so it is more specific
than "Re: Contents of Amps digest..."
Today's Topics:
1. Re: [rfamplifiers] Question about GS-35b efficiency (kd4e)
2. Topics about Class A amplifier (Hsu)
3. Re: Alternative cooling strategies for SB-220? (Mike using AT&T)
4. Re: water cooling (Ron Youvan)
5. Re: Alternative cooling strategies for SB-220? (Dave White)
6. Dentron Needs Plate Choke (Wayne King)
7. Site translator (MIKE DURKIN)
8. Re: QSK switching time...etc. (Roy)
9. Re: Alternative cooling strategies for SB-220? (texasrf@aol.com)
----------------------------------------------------------------------
Message: 1
Date: Thu, 17 Dec 2009 23:24:01 -0500
From: kd4e <doc@kd4e.com>
Subject: Re: [Amps] [rfamplifiers] Question about GS-35b efficiency
To: rfamplifiers@yahoogroups.com
Cc: Amps reflector <amps@contesting.com>
Message-ID: <4B2B03E1.6070707@kd4e.com>
Content-Type: text/plain; charset=windows-1252; format=flowed
When I incorrectly imagined myself capable of building an
amp like this I discovered this site:
http://gs35b.com/gs35bvs8877.html
It contains an excellent charted and textually-described
explanation of the specs and practical applications of the
two - as well as a compare and contrast of the tubes.
Although the 8877 has higher "mu" it has a lower tolerance
for error.
I seem to also recall that tuned-circuit components that
work well with an 8877 may not function as efficiently with
s GS-35b due to different inductance and capacitance factors.
Of course I am the least-informed and experienced here ...
so please consider the link without my commentary and see
what the gathered wisdom here has to offer from their
hands-on experience!
73, doc KD4E
And, in case I forget, a blessed CHRIST-mas to all!
> I have a question about the plate efficiency of a GS-35b amplifier.
>
> I have built two of them for 160-10 meters, and while they worked ok, the
> efficiency was not as good as I expected. In both cases I ran them at 3
> kVDC and
> in order to get a full 1500 watts out, had to drive them to 1000 mA plate
> current. That equates to about 50% efficiency, which seemed a bit low.
>
> In both cases, I removed the GS-35b and replaced it with an 8877. With
> no other
> changes except bias diode and heater transformer, I was able to get 1500
> watts
> out with only 830 mA plate current, an efficiency of 60%. I swapped two
> different GS-35b's with the same result. Both were brand new tubes.
> Results were
> essentially the same on all bands, with a slight drop off on 15 and 10
> meters
> with all three tubes.
>
> With all of the different tubes, I set the bias for a ZSAC of about 200
mA.
>
> I have spoken to two European hams and one US ham and they have reported
> similar
> results.I wonder if the GS-35b might achieve higher efficiency at higher
> plate
> voltages?
>
> I would appreciate hearing from anyone who has made similar measurements.
>
> 73, Bill W6WRT
>
> __._,_.___
> Reply to sender <mailto:dezrat1242@yahoo.com?subject=Question about
> GS-35b efficiency > | Reply to group
> <mailto:rfamplifiers@yahoogroups.com?subject=Question about GS-35b
> efficiency >
> Messages in this topic
>
<http://groups.yahoo.com/group/rfamplifiers/message/7296;_ylc=X3oDMTM1aXM3NzB1BF9TAzk3MzU5NzE0BGdycElkAzExODA4NTA4BGdycHNwSWQDMTcwNTA2MzEwNwRtc2dJZAM
3Mjk2BHNlYwNmdHIEc2xrA3Z0cGMEc3RpbWUDMTI2MTEwOTYzMQR0cGNJZAM3Mjk2>
> (1)
> Recent Activity:
>
> * New Members
>
<http://groups.yahoo.com/group/rfamplifiers/members;_ylc=X3oDMTJnMjEzbjR1BF9TAzk3MzU5NzE0BGdycElkAzExODA4NTA4BGdycHNwSWQDMTcwNTA2MzEwNwRzZWMDdn
RsBHNsawN2bWJycwRzdGltZQMxMjYxMTA5NjMx?o=6>
> 2
> * New Files
>
<http://groups.yahoo.com/group/rfamplifiers/files;_ylc=X3oDMTJobXFzOGVpBF9TAzk3MzU5NzE0BGdycElkAzExODA4NTA4BGdycHNwSWQDMTcwNTA2MzEwNwRzZWMDdnRsBHNs
awN2ZmlsZXMEc3RpbWUDMTI2MTEwOTYzMQ-->
> 1
>
> Visit Your Group
>
<http://groups.yahoo.com/group/rfamplifiers;_ylc=X3oDMTJmMmxpamUwBF9TAzk3MzU5NzE0BGdycElkAzExODA4NTA4BGdycHNwSWQDMTcwNTA2MzEwNwRzZWMDdnRsBHNsawN2Z2hw
BHN0aW1lAzEyNjExMDk2MzE->
> Start a New Topic
>
<http://groups.yahoo.com/group/rfamplifiers/post;_ylc=X3oDMTJmNmtmYWpmBF9TAzk3MzU5NzE0BGdycElkAzExODA4NTA4BGdycHNwSWQDMTcwNTA2MzEwNwRzZWMDZnRyBHNsawN
udHBjBHN0aW1lAzEyNjExMDk2MzE->
>
> MARKETPLACE
>
> Going Green: Your Yahoo! Groups resource for green living
>
<http://us.ard.yahoo.com/SIG=14k7kq0im/M=493064.13814333.13821539.13298430/D=groups/S=1705063107:MKP1/Y=YAHOO/EXP=1261116832/L=/B=jHLcXEPDhEU-/J=1261
109632026697/K=m32OmkKBJ_PSEOyUPJfIiQ/A=5922843/R=0/SIG=11ckn2mo6/*http://ad
vision.webevents.yahoo.com/green/>
>
> ------------------------------------------------------------------------
>
> Going Green: Your Yahoo! Groups resource for green living
>
<http://us.ard.yahoo.com/SIG=14kv0ukqo/M=493064.13814537.13821737.10835568/D=groups/S=1705063107:MKP1/Y=YAHOO/EXP=1261116832/L=/B=jXLcXEPDhEU-/J=1261
109632026697/K=m32OmkKBJ_PSEOyUPJfIiQ/A=5922843/R=0/SIG=11ckn2mo6/*http://ad
vision.webevents.yahoo.com/green/>
>
> Yahoo! Groups
>
<http://groups.yahoo.com/;_ylc=X3oDMTJlczZ1a2JzBF9TAzk3MzU5NzE0BGdycElkAzExODA4NTA4BGdycHNwSWQDMTcwNTA2MzEwNwRzZWMDZnRyBHNsawNnZnAEc3RpbWUDMTI2MTEwOT
YzMQ-->
>
> Switch to: Text-Only
> <mailto:rfamplifiers-traditional@yahoogroups.com?subject=Change Delivery
> Format: Traditional>, Daily Digest
> <mailto:rfamplifiers-digest@yahoogroups.com?subject=Email Delivery:
> Digest> ? Unsubscribe
> <mailto:rfamplifiers-unsubscribe@yahoogroups.com?subject=Unsubscribe> ?
> Terms of Use <http://docs.yahoo.com/info/terms/>
> .
>
> __,_._,___
--
Thanks! & 73, doc, KD4E
FS/Swap/Wanted: http://kd4e.com/swapn.html
Free OS : http://www.PuppyLinux.com
Personal: http://kd4e.com
|_|___|_|
| | & | |
/\ {|
/ \ {|
/ \ {|
/ @ \ {|
| |~_|~~~~|
| -| | |
============\ # KD4E
Have an http://ultrafidian.com day!
------------------------------
Message: 2
Date: Sun, 20 Dec 2009 08:58:11 +0800
From: "Hsu" <hsu4qro@gmail.com>
Subject: [Amps] Topics about Class A amplifier
To: <ham_amplifiers@yahoogroups.com>
Cc: amps@contesting.com
Message-ID: <1BAAF40AA74948B38564474F47073A78@PC200912151238>
Content-Type: text/plain; charset="iso-8859-1"
a) Anyone have experience to modify his transceiver's final to Class A
mode as FT-1000MP MK V?
I think if we haven't good enough driver, the external Power amplifier
cann't be have good 3rd IMD
performance, especially for tetrode amplifier.
b)I'm planing to build an antenna muti-coupler for my 20 receivers.(
similar ROHDE/SCHWARTZ
NV-14T(http://bama.edebris.com/manuals/rohdeschwarz/nv14t/, MF-HF range)But
R/S's design seems unmodern. I want to know anyone knows about
hybrid-model or MMIC for this application?the antenna multi-couple only have
0db
power gain
, but with very good reverse isolation and very large dynamic range/3rd
IMD performance.
I find out some models, for example MHW591/592, but these model's gain are
too more(more than 35db). Any guys knows more information about the
appropriate Hybrid model/MMIC?
Thanks in advance!
73!Hsu
------------------------------
Message: 3
Date: Thu, 17 Dec 2009 15:48:47 -0600
From: "Mike using AT&T" <k9mk@flash.net>
Subject: Re: [Amps] Alternative cooling strategies for SB-220?
To: "'Carl'" <km1h@jeremy.mv.com>, "'Hardy Landskov'" <n7rt@cox.net>,
"'Colin Lamb'" <k7fm@teleport.com>, "'Roger'" <sub1@rogerhalstead.com>
Cc: amps@contesting.com
Message-ID: <007e01ca7f62$b73d4950$25b7dbf0$@net>
Content-Type: text/plain; charset="us-ascii"
The 70V uses a 3CV1500A7.
Instant on and water cooled, it does not get better than this...
Mike
K9MK
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
Behalf Of Carl
Sent: Thursday, December 17, 2009 2:29 PM
To: Hardy Landskov; Colin Lamb; Roger
Cc: amps@contesting.com
Subject: Re: [Amps] Alternative cooling strategies for SB-220?
That was the 1971 70V which used a modified 3CX1000A7. It was somewhat
troublesome and they soon added the 70A to the mix which used the regular
air cooled tube. A short time later the first of the 77 models came along.
Carl
KM1H
----- Original Message -----
From: "Hardy Landskov" <n7rt@cox.net>
To: "Colin Lamb" <k7fm@teleport.com>; "Roger" <sub1@rogerhalstead.com>;
"Carl" <km1h@jeremy.mv.com>
Cc: <amps@contesting.com>
Sent: Thursday, December 17, 2009 2:57 PM
Subject: Re: [Amps] Alternative cooling strategies for SB-220?
> There was an article in QST many years ago called "The Stanley Steamer"
> which described water cooled tubes. I believe ETO built an amp based on
a
> water cooled tube that Eimac made that had 1500 watts plate dissipation.
> The principle being it takes 539 calories of heat to convert 1 gram of
> water at 100 deg C to vapor if I remember my thermodynamics correctly.
> 73 Hardy N7RT
>
> ----- Original Message -----
> From: "Colin Lamb" <k7fm@teleport.com>
> To: "Roger" <sub1@rogerhalstead.com>; "Carl" <km1h@jeremy.mv.com>
> Cc: <amps@contesting.com>
> Sent: Thursday, December 17, 2009 11:58 AM
> Subject: Re: [Amps] Alternative cooling strategies for SB-220?
>
>
>> Water Cooling:
>>
>> Jo Jennings, W6EI, installed a converted water cooled 4CX250 in the
base
>> of his mobile whip. He converted. I think Eimac subsequently built
some
>> water cooled version based upon the results. There was a writeup in CQ
>> or QST in the fifties.
>>
>> 73, Colin K7FM
>> _______________________________________________
>> 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
------------------------------
Message: 4
Date: Sat, 19 Dec 2009 13:20:10 +0000
From: Ron Youvan <ka4inm@tampabay.rr.com>
Subject: Re: [Amps] water cooling
To: amps <amps@contesting.com>
Message-ID: <4B2CD30A.1010109@tampabay.rr.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> MSDC Klystrons ran around ten feet @ 32KV applied.
If they use Teflon tubing a foot might be sufficient. Different brands
are cooled differently so
it may depend on the arrangement.
--
Ron KA4INM - Of what you see in books, believe 75%. Of newspapers,
believe 50%.
And of TV news, believe 25% --
make that 5% if the anchorman wears a blazer.
------------------------------
Message: 5
Date: Thu, 17 Dec 2009 20:26:57 +0000
From: Dave White <mausoptik@btinternet.com>
Subject: Re: [Amps] Alternative cooling strategies for SB-220?
To: Hardy Landskov <n7rt@cox.net>, Colin Lamb <k7fm@teleport.com>,
Roger <sub1@rogerhalstead.com>, Carl <km1h@jeremy.mv.com>
Cc: amps@contesting.com
Message-ID: <20091217202705.A4EC01B607D5@dayton.contesting.com>
Content-Type: text/plain; charset="iso-8859-1"
If my memory serves me correctly the Stanley Steamer was actually a vapour
phase tube (a 3CV*** or 4CV*** as opposed to a 3CW*** etc) in a boiler
rather than a water cooled tube.
Eimac published this as an amateur service newsletter or similar. I do
have a copy somewhere if you'd like me to copy it. Actually I have all the
Eimac bulletins and keep meaning to scan them when I get some of that rare
resource called 'time'
Cheers
Dave G0OIL
-----Original Message-----
From: "Hardy Landskov" <n7rt@cox.net>
To: "Colin Lamb" <k7fm@teleport.com>; "Roger" <sub1@rogerhalstead.com>;
"Carl" <km1h@jeremy.mv.com>
Cc: amps@contesting.com
Sent: 17/12/2009 19:57
Subject: Re: [Amps] Alternative cooling strategies for SB-220?
There was an article in QST many years ago called "The Stanley Steamer"
which described water cooled tubes. I believe ETO built an amp based on a
water cooled tube that Eimac made that had 1500 watts plate dissipation.
The
principle being it takes 539 calories of heat to convert 1 gram of water
at
100 deg C to vapor if I remember my thermodynamics correctly.
73 Hardy N7RT
----- Original Message -----
From: "Colin Lamb" <k7fm@teleport.com>
To: "Roger" <sub1@rogerhalstead.com>; "Carl" <km1h@jeremy.mv.com>
Cc: <amps@contesting.com>
Sent: Thursday, December 17, 2009 11:58 AM
Subject: Re: [Amps] Alternative cooling strategies for SB-220?
[truncated by sender]
------------------------------
Message: 6
Date: Fri, 18 Dec 2009 05:15:07 -0500
From: "Wayne King" <n2wk@rochester.rr.com>
Subject: [Amps] Dentron Needs Plate Choke
To: <amps@contesting.com>
Message-ID: <001FDAF99B904691A1FDCA1EFDEFBDED@WAYNEKING>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
I need to replace the plate choke in my DTR-2000L. It's arching and
causing
an intermittent buzz on the air. Anyone have some old spare parts (plate
choke) from these amps or the MLA series laying around? If not what would
be
a suitable replacement and from who?
73, and Season's Greeting,
Wayne N2WK
------------------------------
Message: 7
Date: Sat, 19 Dec 2009 07:57:23 -0800
From: MIKE DURKIN <patriot121@msn.com>
Subject: [Amps] Site translator
To: amps fourm <amps@contesting.com>
Message-ID: <COL110-W154DBF396C04C031C84D2492840@phx.gbl>
Content-Type: text/plain; charset="iso-8859-1"
Any one know of a web page translator that translates the WHOLE page?? I
tried Googles trnslator and it only trnslated the first 20 lines or so... of
this page
http://www.cqham.ru/HiFi_Contester_EX8A.htm or an english version ....
Mike
KC7NOA
_________________________________________________________________
Your E-mail and More On-the-Go. Get Windows Live Hotmail Free.
http://clk.atdmt.com/GBL/go/171222985/direct/01/
------------------------------
Message: 8
Date: Sat, 19 Dec 2009 10:07:24 -0600
From: "Roy" <royanjoy@ncn.net>
Subject: Re: [Amps] QSK switching time...etc.
To: <amps@contesting.com>
Message-ID: <E5844B57ED6F4FFF835C686EBC4E018A@RoyPC>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=original
About,
"...When back biased a diode exhibits a varactor effect: it acts as a
capacitance, whose magnitude is inversely proportional with the applied
voltage. Even a few Pico farads in series with the receive path can have a
disastrous effect on the receiver. Sooo the receive path has to be back
biased by high voltage too!
This characteristic is exhibited even by the very highest quality PIN
diodes, like those manufactured by Chelton especially for the purpose. I
know: I used them when I was working, designing multikilowatt amplifiers
for
the army. (etc.)"
True only if you are using separates. With a transceiver, the rig is in
transmit mode during key downs. Receiver is disconnected then from the
PINs.
73, Roy K6XK
------------------------------
Message: 9
Date: Thu, 17 Dec 2009 16:26:53 EST
From: texasrf@aol.com
Subject: Re: [Amps] Alternative cooling strategies for SB-220?
To: mausoptik@btinternet.com, k7fm@teleport.com,
sub1@rogerhalstead.com, km1h@jeremy.mv.com
Cc: amps@contesting.com
Message-ID: <1925.66e48d64.385bfc1d@aol.com>
Content-Type: text/plain; charset="US-ASCII"
You can narrow it down to only 10 issues by referring to the yearly index
in the December issues in those days.
73,
Gerald K5GW
In a message dated 12/17/2009 2:17:39 P.M. Central Standard Time,
mausoptik@btinternet.com writes:
Colin, can you narrow it down a bit beyond 'the fifties'? I have most
QSTs
from that era but if you or anyone can narrow it below 120 issues.....
Cheers
Dave
-----Original Message-----
From: "Colin Lamb" <k7fm@teleport.com>
To: "Roger" <sub1@rogerhalstead.com>; "Carl" <km1h@jeremy.mv.com>
Cc: amps@contesting.com
Sent: 17/12/2009 18:58
Subject: Re: [Amps] Alternative cooling strategies for SB-220?
Water Cooling:
Jo Jennings, W6EI, installed a converted water cooled 4CX250 in the base
of his mobile whip. He converted. I think Eimac subsequently built some
water cooled version based upon the results. There was a writeup in CQ
or
QST in the fifties.
73, Colin K7FM
_______________________________________________
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
------------------------------
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
End of Amps Digest, Vol 84, Issue 63
************************************
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|