[Amps] Sell or trade a 3CX1200Z7 tube

Tue Nov 16 15:45:50 PST 2010

Will sell or trade for a used 8877, Eimac, full output, tube. Willy  k3VW

In a message dated 11/16/2010 3:01:48 P.M. Eastern Standard Time,  
amps-request at contesting.com writes:

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Today's Topics:

1. Re: Attenuator  needed (Vic K2VCO)
2. 3CX1000A7 (Jim Malone)
3. Re: 3CX1000A7 (Carl)
4. Re: Attenuator needed (Jim  Brown)

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Message:  1
Date: Mon, 15 Nov 2010 17:00:30 -0800
From: Vic K2VCO  <vic at rakefet.com>
Subject: Re: [Amps] Attenuator needed
To:  amps at contesting.com
Message-ID:  <4CE1D7AE.8000907 at rakefet.com>
Content-Type: text/plain;  charset=ISO-8859-1; format=flowed

The attenuator is inside the amp, so  it doesn't affect anything when the 
amp is bypassed. 
One nice feature when  using a solid-state driver is that a 6 db attenuator 
guarantees that 
the  swr to the exciter won't exceed 1.5:1. Of course it's only practical 
with an  amp that 
has extra gain, like a grid-driven one.

On 11/15/2010 1:50  PM, Jim Brown wrote:
> On 11/15/2010 12:38 PM, Vic K2VCO  wrote:
>> I made a 6 db attenuator for the input of my grid-driven  amplifier in 
order to bring the
>> drive requirement up a bit and to  provide a better SWR for the exciter 
during tuning.
>
> Another  downside to using an attenuator between the rig and the amp is
> that  unless you provide bypass switching,  it's still inline when you
>  want to operate without the amp.
>
> W8JI has noted the importance  of using the attenuator with some more
> primitive rigs that create a  full power spike when set for less than
> their max output power.   This is not an issue with the K3, and I don't
> think with the MP series  either, but Tom did specifically mention a
> couple of the 100W $1000  160-440 wonders as having this problem. :)
>
> 73, Jim  K9YC
>
>
>  _______________________________________________
> Amps mailing  list
> Amps at contesting.com
>  http://lists.contesting.com/mailman/listinfo/amps

-- 
Vic,  K2VCO
Fresno  CA
http://www.qsl.net/k2vco/

------------------------------

Message:  2
Date: Mon, 15 Nov 2010 21:25:03 -0500
From: Jim Malone  <wa3lbi at me.com>
Subject: [Amps] 3CX1000A7
To:  "amps at contesting.com" <amps at contesting.com>
Message-ID:  <920C8CC7-871D-469F-B850-12212DF58A8C at me.com>
Content-Type:  text/plain; charset=us-ascii

Hello everyone,

I am rebuilding a  very old HB amplifier on 2meters that incorporated a 
3CX1000 tube. The  filament gets the tube warm so i am hopeful the device is 
good.  

Looking for another tube in any condition and or a source of them.  

Thanks!

Jim WA3LBI

Sent from my  iPad

------------------------------

Message: 3
Date: Mon,  15 Nov 2010 21:52:14 -0500
From: "Carl"  <km1h at jeremy.mv.com>
Subject: Re: [Amps] 3CX1000A7
To: "Jim  Malone" <wa3lbi at me.com>,    <amps at contesting.com>
Message-ID:  <01ab01cb8539$482426f0$6501a8c0 at DAVES>
Content-Type: text/plain;  format=flowed; charset="iso-8859-1";
reply-type=original

Ive been using that tube in my 2M amp for over 25  years and it sill puts 
out 
over 1500W and it was used when I got it. The  Westinghouse branded spare 
(made by Eimac??) gets tossed in once a year  for a couple of days.

They come up on the market very seldom and often  very expensive as the 
primary user was 1000W VHF translator service on  mountain tops in the 
boonies which are long obsolete.

It is also  the lowest power Eimac rebuildable tube and its a shame that it 
didnt  continue as a regular base socketed tube such as the wimpy 8877. A  
3CX1000A7 socket often sells for more than the  tube.

Carl
KM1H

----- Original Message -----  
From: "Jim Malone" <wa3lbi at me.com>
To:  <amps at contesting.com>
Sent: Monday, November 15, 2010 9:25  PM
Subject: [Amps] 3CX1000A7

> Hello  everyone,
>
> I am rebuilding a very old HB amplifier on 2meters  that incorporated a 
> 3CX1000 tube. The filament gets the tube warm so  i am hopeful the device 
> is good.
>
> Looking for another  tube in any condition and or a source of them.
>
>  Thanks!
>
> Jim WA3LBI
>
>
>
>
>  Sent from my iPad
>  _______________________________________________
> Amps mailing  list
> Amps at contesting.com
>  http://lists.contesting.com/mailman/listinfo/amps  

------------------------------

Message: 4
Date: Tue,  16 Nov 2010 10:47:21 -0800
From: Jim Brown  <jim at audiosystemsgroup.com>
Subject: Re: [Amps] Attenuator  needed
To: amps at contesting.com
Message-ID:  <4CE2D1B9.1040302 at audiosystemsgroup.com>
Content-Type: text/plain;  charset=UTF-8; format=flowed

On 11/16/2010 2:05 AM, Uwe Egen  wrote:
> I made some measurements at different transceivers putting out  spikes at 
first rf out in cw and ssb.
> Today the article is only in  German. But diagrams speak for themselves - 
10 pages.
> Our local radio  website:
>  http://www.ov-n15.de/joomla/images/zoom/DL9NC/pz_32.pdf
> PZ stands for  "Problem Zone between TRX and PA".
> I checked about 20 transceivers.  Showing 4 as examples. BTW MP series 
did make some spikes.

Very  interesting, Uwe. Many thanks for the great work.  It would be nice  
to have English text.  Sadly, like most Americans, I have no  German.

73, Jim  K9YC

------------------------------

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End  of Amps Digest, Vol 95, Issue  38
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