[Johnson] 866 & 3B28 replacement

[Rodger]

David is correct in that the voltage drop is so low for MV/gaseous 
rectifiers that you don't need to worry about the very minor voltage 
increase and since this is a choke input configuration you won't have 
excessive startup surge current from charging a large filter bank.  My 
only additional suggestion is to disconnect and insulate the 5 volt 
leads to the 866 sockets since these are not needed with the SS 
rectifiers and this will remove one failure risk for the LV 
transformer.  I just unsolder and insulate them so that the transmitter 
can easily be returned to original condition.

Rodger WQ9E

David C. Hallam wrote:
> Chris,
>
> You are correct.  The 1N2637 is the replacement for 866 or 3B28.  Actually
> there will be very little increase of the HV with the replacement.
> Rectifiers like the 866 or 3B28 do not have the internal resistance of a
> vacuum rectifier, i.e., a 5R4, and they do not induce the voltage drop.
> Just take the old rectifier out and put the 1N2637 in.
>
> David
> KC2JD/4
>
>   
>> -----Original Message-----
>> From: johnson-bounces at mailman.qth.net
>> [mailto:johnson-bounces at mailman.qth.net]On Behalf Of Chris
>> Sent: Monday, April 21, 2008 9:38 AM
>> To: Johnson List serv
>> Subject: [Johnson] 866 & 3B28 replacement
>>
>>
>> Hello to the group
>>
>>  Can someone tell me what the solid state Plug in is for the 866 & 3B28
>> tubes?
>> Is it the 1N2637??? Thanks Chris
>>
>> P.S
>> If I replace the 3B28 in my Valiant with the Solid State replacement do I
>> have to do any thing to make them work correctly? I was thinking that it
>> would Increase the HV
>>
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>>
>>     
>
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