Yep, nice tube.was used in the original Alpha 70...You are blessed to have
some, because they are VERY hard to come by indeed..!!
I wish I had a couple, but not for what they bring now days..
W6RD
----- Original Message -----
From: "jeremy-ca" <km1h@jeremy.mv.com>
To: "Chuck & Vicki Tifft" <cftifft@sbcglobal.net>; <sub1@rogerhalstead.com>
Cc: "Amps Reflector" <amps@contesting.com>
Sent: Tuesday, May 20, 2008 5:35 PM
Subject: Re: [Amps] New Amps at Dayton
>I would hope that the Russians or Chinese have a less complicated socket.
>It doesnt take much to work fine at HF.
>
> A rather scarce tube is the 3CX1000A7. It basically has the filament and
> grid ratings of a 3-1000Z and the anode of an 8877 and uses the same style
> socket as the 4CX1000A. Originally built for VHF TV translator use.
> Instant on and bullet proof. I use them in 2M and 222 MHz homebrew amps
> and easily get 1500W+ .
>
> If the Chinese offered that tube and an economical socket it would solve a
> lot of problems.
>
> Carl
> KM1H
>
>
>
> ----- Original Message -----
> From: "Chuck & Vicki Tifft" <cftifft@sbcglobal.net>
> To: <sub1@rogerhalstead.com>
> Cc: "Amps Reflector" <amps@contesting.com>
> Sent: Tuesday, May 20, 2008 7:39 PM
> Subject: Re: [Amps] New Amps at Dayton
>
>
>> No, I don't think so. I homebrewed one about 30 yars ago.Back then free
>> pulls were easy to come by from one of the other local high VHF
>> channels.(we
>> were low VHF and didn't use them) Was a great amp/tube, but it needed
>> lots
>> of protection to keep it safe and about 1500 to 1600 watts was all you
>> dared
>> squeeze out of it. I soon decided the the warm up time and complexity
>> wasn't
>> worth it, so I tore it down. I spent lots of hours building it up, but it
>> didn't take long to rip it apart. My only regret was I didn't take any
>> pictures of it before demolition.. Done right the bias and screen
>> supplies
>> need to be regulated and the screen supply interlocked to the HV..There
>> certainly were then and are now better ways to go. I can't see why
>> anybody
>> would go that way now. The sockets and bypass rings weren't cheap then,
>> can
>> only imagine about now.
>> Chuck
>> W6RD
>> ----- Original Message -----
>> From: "Bob Maser" <bmaser@tampabay.rr.com>
>> To: "Roger (K8RI)" <sub1@rogerhalstead.com>; "Amps" <amps@contesting.com>
>> Sent: Tuesday, May 20, 2008 4:13 PM
>> Subject: Re: [Amps] New Amps at Dayton
>>
>>
>>> The same socket is used for the 4CX1000A and the 4CX1500B(p/n SK800B).
>>> The
>>> 4CX1500A uses a different socket(SK831). Increasing the screen voltage
>>> does
>>> wonders for output. That is how owners of the 30S1 were able to improve
>>> performance.
>>>
>>> Bob
>>> ----- Original Message -----
>>> From: "Roger (K8RI)" <sub1@rogerhalstead.com>
>>> To: "Amps" <amps@contesting.com>
>>> Sent: Tuesday, May 20, 2008 6:03 PM
>>> Subject: Re: [Amps] New Amps at Dayton
>>>
>>>
>>>> Bob Maser wrote:
>>>>> The new Alpha amp that runs a pair of 4CX1000A's is the 8410. This
>>>>> amp
>>>>> uses
>>>>> a 3.6KVA plate transformer.
>>>>>
>>>>
>>>> The same 4CX-1000A used in the 30-S1? The one with zero grid
>>>> dissipation?
>>>> That's the tube I've always said I'd never use in anything because it's
>>>> so fragile or have I missed something?
>>>>> Also at Dayton Emtron introduced their new DX2B which also uses the
>>>>> 4CX1000A. They are in the process of introducing the DX3B which will
>>>>> run
>>>>> a
>>>>> pair of the same tube. Looks like all the manufacturers of amps are
>>>>> scrambling to replace the Russian tubes. The 4CX1000A can be replaced
>>>>> by
>>>>> the 4CX1500B, which has higher plate dissipation(remember the 30S-1
>>>>> mod
>>>>> with
>>>>> the high screen voltage?).
>>>>>
>>>> Isn't that quite a project? IIRC the 4CX-1000 uses a bayonet socket
>>>> while the 4CX-1500 uses a more conventional socket.
>>>>
>>>> If the Chinese are building lots of tubes are't they building the 3CX
>>>> and 4CX 800's?
>>>> Maybe I should consider rebuilding my 2002A, but it doesn't have a
>>>> heavy
>>>> enough PS for the 4CX1500 let alone the screen supply. <:-))
>>>>
>>>> 73
>>>>
>>>> Roger (K8RI)
>>>>> Bob W6TR
>>>>> ----- Original Message -----
>>>>> From: "Dennis W0JX" <w0jx@yahoo.com>
>>>>> To: "Amplifiers" <amps@contesting.com>
>>>>> Sent: Tuesday, May 20, 2008 9:42 AM
>>>>> Subject: Re: [Amps] New Amps at Dayton
>>>>>
>>>>>
>>>>>
>>>>>> The only thing that I saw at Dayton worth noting is a change in the
>>>>>> current Alpha 8100.
>>>>>>
>>>>>> The finals have been replaced with TWO 4CX1000A's instead of the
>>>>>> 4CX800A7's and the amp has been relabeled either an Alpha 8200 0r
>>>>>> 8400
>>>>>> (sorry I tossed the literature and can't remember the exact number).
>>>>>>
>>>>>> Anyway, this should be considered a warning to any amp owner who has
>>>>>> an
>>>>>> Alpha 91, 99 or 8100, QRO 2500, or ACOM 1000 and 2000A. Alpha said
>>>>>> the
>>>>>> supply of GU-74B's is drying up quickly and they made the switch to
>>>>>> ensure
>>>>>> availability.
>>>>>>
>>>>>> Incidentally, the 4CX1000A's used are NOT Eimac but made by Penta in
>>>>>> China.
>>>>>>
>>>>>> 73, Dennis W0JX/8
>>>>>>
>>>>>>
>>>>>> _______________________________________________
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>>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>>
>>>>>
>>>>> _______________________________________________
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>>>>>
>>>>>
>>>>
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