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[AMPS] RE: [Alpha models: 91B vs. 89

To: <amps@contesting.com>
Subject: [AMPS] RE: [Alpha models: 91B vs. 89
From: morel.grunberg@telrad.co.il (Morel Grunberg)
Date: Tue, 6 May 1997 11:31:00 +0300

>Jeff,
>
>If you have another kilobuck to spend , don't think twice.
>If you don't have , find it. There are no advantages on 91B
>over 89A. If you want superior reliability, quality and performance,
>go for american made parts only.  
> 
>
>                Alpha 91B               Alpha 89
> 
>>Tubes (2)       Svetlana 4CX800A        Eimac 3CX800A7
>
>There is a big difference between the two brands.
>
>>T/R             Vacuum relay            PIN diode 
>
>PIN switching is quieter and faster and I heard that they solved
>the first series problems.
>
>>Transformer     3.5kVA Unisil-H         ? kVA Hipersil
>
>Go for US-made hypersil.
>
>>Input           Tuned input not req'd   Tuned Input
>
>Tuned input is expensive but is a "must" not only for purists.
>
>>Parts Source    Bulgaria, Russia, USA   USA
>
>No comments. 
>
>What about the spectral purity ? They cannot be compared.
>  
>>3) The 91B is reportedly louder in operation (ignoring for the moment
>    the sound of the vacuum relay. I presume that this is the noise
>    of teh blower and (possibly) transformer hum. How significant is
>    the difference?
> 
>If you like SSB contests with processor and vox , it makes a big difference
>
>
>>5) Is the auxilliary fan a good idea for someone who will be making
>    contest use of one of these models? How much noise does it add?
> 
>This is a good ideea for contesting.
>
>
>73 de Morel, 4X1AD
>    
>
>

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