Beats me. I've never been on 6, not since 1961 anyway. A lot of builders
install a filament choke on a 8877 amp, example my Henry 4K Ultra, which
runs a single 8877, had a filament choke. I'm not sure about an Alpha 77.
I have always been told that in the HF region running a 8877, you don't need
one in the filament circuit but a 2.5uH choke is required in the cathode to
bias line. Bill Orr shows this in his 21st edition (1978)Radio Handbook on
page 22.41. If you don't already have some of Bill's old handbooks start
looking for one if you're serious about amp building.
Bob W6TR
----- Original Message -----
From: "Roger" <sub1@rogerhalstead.com>
To: "Bob Maser" <bmaser@tampabay.rr.com>; "Rick Stealey"
<rstealey@hotmail.com>; <amps@contesting.com>
Sent: Thursday, November 15, 2007 5:41 PM
Subject: Re: [Amps] 8877 Filament choke
>
>
>
>> With an indirectly heated cathode you don't need a filament choke, in the
>> HF
>> region.
>
> What about when running one on 6-meters?
>
> Roger (K8RI)
>
>>
>> Bob W6TR
>> ----- Original Message -----
>> From: "Rick Stealey" <rstealey@hotmail.com>
>> To: <amps@contesting.com>
>> Sent: Thursday, November 15, 2007 9:26 AM
>> Subject: [Amps] 8877 Filament choke
>>
>>
>>>
>>> Info in the ARRL handbook seems to indicate that it might be better to
>>> not
>>> use a filament choke on an 8877 amplifier, that it might cause more
>>> problems than it solves.
>>> I wonder what you guys who have homebrewed 8877s think?
>>>
>>> Rick K2XT
>>>
>>>
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