[Amps] FW: Autot>>Orr book here<<

[Sam Carpenter]

 In PDF Format


http://www.pmillett.com/tubebooks/technical_books_online.htm



-----Original Message-----
From: Sam Carpenter [mailto:sam at owenscommunication.com] 
Sent: Thursday, October 07, 2010 3:44 PM
To: 'audioguy at charter.net'
Subject: RE: [Amps] Autot>>Orr book here<<

If you wanted to read the Orr book it is in PDF format at this site:

http://www.pmillett.com/tubebooks/technical_books_online.htm



-----Original Message-----
From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
Behalf Of Jim Barber
Sent: Thursday, October 07, 2010 3:35 PM
Cc: amps at contesting.com
Subject: Re: [Amps] Autotuner for Amp Input

That works, thanks.

Playing with the models shows that designs between 25 and 70 ohms 
cathode impedance meet the 13pf/meter criteria using a pi-net input with 
a Q of 4. Above 70 ohms not so much.

If I ever find a copy of Orr's 23rd edition at a reasonable price I'll 
pick it up. I see quotes from it zip past here every now and then.

73,
Jim N7CXI


On 10/7/2010 11:58 AM, Gary Schafer wrote:
> Bill Orr recommends around 13pf per meter for the capacitance at the
cathode
> of a GG amplifier.
>
> 73
> Gary  K4FMX
>
>> -----Original Message-----
>> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
>> Behalf Of Jim Barber
>> Sent: Thursday, October 07, 2010 1:23 PM
>> Cc: amps at contesting.com
>> Subject: Re: [Amps] Autotuner for Amp Input
>>
>> This has no doubt been covered here before, but is there a "shotgun"
>> equation or rule of thumb for this? (minimum Q for adequate flywheel
>> effect)
>>
>> In the past I've started with a pi input network with a Q of 4, (based
>> on an approximation of the tube operating parameters) but primarily
>> because that's about the highest I could use and get reasonable input
>> VSWR bandwidth on amateur bands. I'd like to accomodate "flywheel
>> effect", but haven't been able to find any reference so far beyond
>> cut-and-try.
>>
>> I can see where using an autotuner (L network) would be a crapshoot,
>> since Q isn't part of the matching criteria and (generally speaking) the
>> algorithms basically cycle through the relay combos until a match is
>> found.
>>
>> So... With regard to my current YC156 project, I could summarize by
>> asking if with an assumed input impedance of around 25 ohms, (mostly
>> resistive) would a pi-net with a Q of 4 be an adequate flywheel?
>>
>> BTW&  OT:
>> I ended up ordering (2) guaranteed YC156 pulls from Tom, WA8WZG. Thanks
>> to all that offered the suggestion(s).
>>
>> Thanks,
>> Jim N7CXI
>>
>>
>> On 10/7/2010 10:55 AM, Bill, W6WRT wrote:
>>> ORIGINAL MESSAGE:
>>>
>>> On Thu, 7 Oct 2010 07:40:50 -0700 (PDT), Lee Buller<k0wa at swbell.net>
>>> wrote:
>>>
>>>>
>>>> Have any of you used the method?  Seems to have worked for the author
>> of the
>>>> article in the Handbook.
>>>
>>> REPLY:
>>>
>>> The LDG autotuner does provide a good impedance match, but the only
>>> question is whether it provides sufficient Q to provide the "flywheel"
>>> effect needed for SSB operation. If you are going to be operating only
>>> CW, RTTY or FM, whatever Q it has is probably enough.
>>>
>>> I wish I had a more definitive answer.
>>>
>>> 73, Bill W6WRT
>>> _______________________________________________
>>> Amps mailing list
>>> Amps at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
>>>
>> _______________________________________________
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>
>
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