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
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Amps mailing list
>>>>> Amps@contesting.com
>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>
>>>>
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>>>
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