Using that original filament xfmr on an 8877 will raise the voltage so
you will have to add a resistor to drop it.
Carl
KM1H
----- Original Message -----
From: "Roger" <sub1@rogerhalstead.com>
Cc: <amps@contesting.com>
Sent: Wednesday, January 21, 2009 8:26 PM
Subject: Re: [Amps] 3-500zs to 8877
>
>
> Bob Maser wrote:
>> Not only is the 3-500Z a more robust tube than the 8877, the 8877
>> requires a
>> 3 minute warm-up, the circuit for that would be an added complexity.
>
> A bit, but it's just a time delay to prevent keying up before the warm
> up
>
> 73
>
> Roger (K8RI)
>> I
>> agree with Hsu that the 3CX1200D7 would be a better swap, being
>> instant on
>> and using the same socket, and probably not replacement of the
>> blower. You
>> would have to change the filament supply but that is easy. I swapped
>> the
>> 8877 in my 4K Ultra for the D7 and I haven't regretted it once.
>>
>> Bob W6TR
>> ----- Original Message -----
>> From: "DAVE WHITE" <mausoptik@btinternet.com>
>> To: "Donald Fox" <taurusshoguy@yahoo.com>; "Robert Morris"
>> <robrk@nidhog.net>
>> Cc: <amps@contesting.com>
>> Sent: Wednesday, January 21, 2009 3:48 PM
>> Subject: Re: [Amps] 3-500zs to 8877
>>
>>
>>
>>> I'd echo this sentiment. You've got a good, tried and tested amp
>>> with
>>> robust tubes. Why spend the time and money (and run barefoot whilst
>>> you're
>>> working on it) simply for a lower drive requirement? I may get
>>> shouted
>>> down for saying this, but personally I think the 8877 is a more
>>> fragile
>>> tube than the Good Ol' 3-500.
>>>
>>> Start a new amp as you collect the parts from junksales and
>>> fleamarkets. I
>>> think that few people out these know what this stuff is these days
>>> so it
>>> seems to command lower prices than it once did. Recently at Dayton I
>>> had
>>> quite a few 1x2 and 2x1 extra class licensees come up to me and ask
>>> me
>>> "what those things are". They were vacuum variable capacitors!
>>>
>>> cheers
>>>
>>> Dave G0OIL
>>>
>>> --- On Wed, 21/1/09, Robert Morris <robrk@nidhog.net> wrote:
>>> From: Robert Morris <robrk@nidhog.net>
>>> Subject: Re: [Amps] 3-500zs to 8877
>>> To: "Donald Fox" <taurusshoguy@yahoo.com>
>>> Cc: amps@contesting.com
>>> Date: Wednesday, 21 January, 2009, 3:36 PM
>>>
>>> Donald Fox wrote:
>>>
>>>> Gentlemen:
>>>>
>>>> Just submitting a quick poll to see what the feeling is about
>>>> making
>>>> the
>>>>
>>> swap from a pair of 3-500s to the almighty 8877.
>>>
>>>> The donor is my very good condx Henry 2K Classic X which I do not
>>>> want
>>>>
>>> to butcher. I am aware that the Henry consoles were oem equipped
>>> with the
>>> 8877
>>> and other tubes.
>>>
>>>> My goal is not for more power, but to enjoy the lower drive
>>>> requirement
>>>>
>>> of the 8877 for my IC746.
>>>
>>>> I know that the filament xformer and socket would need to change
>>>> as
>>>> well
>>>>
>>> as reworking the airflow for cooling.
>>>
>>>> So, can the change be done without major mods to the input/output
>>>>
>>> networks??
>>>
>>>> If not, then I will drop the idea and enjoy it as is. Changing to
>>>>
>>> another amplifier is not in the budget, and since I have a soft spot
>>> for
>>> the
>>> 80's model Henry consoles, this one is bound to be around as long as
>>> I can
>>> afford it.
>>>
>>>> Thanks for your comments pro or con in advance.
>>>>
>>>> Don N8ECH
>>>>
>>>>
>>>> _______________________________________________
>>>> Amps mailing list
>>>> Amps@contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>
>>>>
>>> I'm of the "if it works, don't fix it crowd". No matter how
>>> good you are, you
>>> still messed with it. If you have the money for an 8877, start a
>>> project
>>> to
>>> build a complete amp, even single band to start.
>>>
>>> --
>>> This message has been scanned for viruses and
>>> dangerous content by MailScanner, and is
>>> believed to be clean.
>>>
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>>>
>>
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>>
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