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Re: [Amps] 8874?

To: Adrian Rees <rees.a@btconnect.com>
Subject: Re: [Amps] 8874?
From: Roger <sub1@rogerhalstead.com>
Date: Wed, 01 Jul 2009 15:06:51 -0400
List-post: <amps@contesting.com">mailto:amps@contesting.com>

Adrian Rees wrote:
> Erm, the MLA2500 uses the 8875 not the 8873. Sorry for being a pedant !
>   
Thanks for the correction.  My mind did a transposition there. <:-))  
When I woke this afternoon I was wondering if I'd gotten that straight 
and the first e-mail I saw answered my question.
The 8873 was the conduction cooled version of the tube.  All 3 are just 
physical variations on the cooling for the same tube. 

Heath made a nice little amp that used a pair of the 8873s. The whole 
back of it was a heatsink.  I finally set up a muffin fan to blow on it 
because the darn thing got so hot.  After that I could put my hand on 
the heat sink even after and hour of running CW or SSB at tilt.   I 
think it was rated at 1200 PEP or carrier on CW.  It certainly wasn't 
CCS <:-))

73


Roger (K8RI)
>  
> I have never seen a Dentron DTR-2000 and am curious to see the circuit 
> diagram. I must admit I do like Dentron amps, even though they all seem to 
> suffer from dodgy power supplies (still rebuilding my MLA2500B's supply !)
>  
> Best wishes
>  
> Adrian MW1LCR 
>
> ________________________________
>
> From: amps-bounces@contesting.com on behalf of Roger
> Sent: Wed 01/07/2009 09:21
> To: Charles Harpole
> Cc: amps@contesting.com; herzog@frontiernet.net
> Subject: Re: [Amps] 8874?
>
>
>
>
>
> Charles Harpole wrote:
>   
>> about 20 yrs ago, I bought a Dentron DTR-2000 for $800.
>>
>>
>>  
>>     
> The DTR-2000 used a single 8877/3CX1500A7 which is much larger
> physically than the 8874. I was getting 8877s at the time for $305 (at a
> discount)and had a number of them (when the DTR2000 first came out) I
> liked the amp, but the voltage regulation was poor and IIRC a bit on the
> low side.  I had one of the low voltage caps explode. It was loud enough
> to make my ears ring. It blew the can right off, which hit the top of
> the cabinet. The can looked like a 38 wad cutter that had hit something
> really hard.
>
> The MLA2500 used the 8873 (Aluminum anode and transverse cooling) I
> believe while the 8874/3CX400 is used in the old alpha 76 and 78 series.
> Back then it was much less expensive.Now days you can get 3CX800s for
> less although new 8874s and 3CX800s from Eimac are quite pricey.
>
> 73
>
> Roger (K8RI)
>   
>> I figured I bought the tube (which is what a new one
>>
>>
>>
>> went for then) and got the amp for free.  It drives
>>
>>
>>
>> so easily and puts out POWER.... great tube.
>>
>>
>>
>> Anyone know how many (less than 500???)
>>
>>
>>
>> DTR-2000 were made????   73
>>
>>
>>
>> Charles Harpole k4vud@hotmail.com
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>  
>>     
>>> From: hsu4qro@gmail.com
>>> To: herzog@frontiernet.net; amps@contesting.com
>>> Date: Tue, 30 Jun 2009 12:18:02 +0800
>>> Subject: Re: [Amps] NCL2000
>>>
>>> That is natural, My friend pick up a Heny Tempo 2001, the cost only $250, 
>>> he ask me to find a pair inexpensive brand new NOS EIMAC 3CX8874A, a guy 
>>> who in this list ask $400/ea.Could you help him
>>> to find inexpensve pair?
>>> 73!Hsu
>>> ----- Original Message -----
>>> From: "Herzog" <herzog@frontiernet.net>
>>> To: "Ham-amps" <amps@contesting.com>
>>> Sent: Tuesday, June 30, 2009 8:16 AM
>>> Subject: [Amps] NCL2000
>>>
>>>
>>>    
>>>       
>>>> RE: Hi,
>>>> I have some brand new NOS RCA 8122 for sale,I ask $350/ea or tell me
>>>> what's your best offer.
>>>> And another guy wanting parts of no description.
>>>>
>>>> Herzog, from Different world! Prices, I Had my NCL2000 up for sale,
>>>> asking $600; and no takers for 2 years. And it included 4 spares 811
>>>> tubes, plus the ones inside a perfect operating Ampflier
>>>> I finally just gave to antique collectors!! See if the AWA wants to
>>>> sell. (Antique Wireless Association.)
>>>> _______________________________________________
>>>> Amps mailing list
>>>> Amps@contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>      
>>>>         
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>>>    
>>>       
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>>  
>>     
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>   
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