[ARC5] Added 6F6 audio stage.

[Geoff]

I was referring to ARC-5's along with that shortcoming. My own choice was 
headphones but when my parents or ham friends wanted to also listen the 
volume was too low for weak signals. If I had that CQ issue Id likely have 
added a 6F6/6V6 on the back.

If you want an audio preamp stage the triode connected 42/6F6 in the early 
Super Pros will light a fire (-;.


----- Original Message ----- 
From: "mac" <w7qho at aol.com>
To: "Geoff" <geoffrey at jeremy.mv.com>
Cc: "Ken Gordon" <kgordon2006 at frontier.com>; <Arc5 at mailman.qth.net>
Sent: Friday, October 19, 2012 8:16 PM
Subject: Re: [ARC5] Added 6F6 audio stage.


>A 12A6 has plenty of capacity to drive a speaker.  The audio gain 
>shortfall complaint with command set receivers and others such as the 
>BC-348 voiced by (some) hams is due to the absence of an intermediate 
>audio amplifier between the 2nd detector and the audio output stage as 
>found in most standard superhet designs of the era. Usually a triode  stage 
>but not always (high gain pentode in the AR-88 for ex).  The  extra gain 
>was not needed in most aircraft sets where headphones were  the norm.  This 
>subject comes up about once a year on these forums.
>
> On Oct 19, 2012, at 4:03 PM, Geoff wrote:
>
>> Maybe he wanted enough audio to drive an old 12" console speaker.
>> I drove a small 5x7 auto speaker with the 12A6 in the 50's and it  wasnt 
>> very
>> loud.
>>
>> Has anyone measured the distortion of a stocker?
>>
>>
>> ----- Original Message -----
>> From: "Kenneth G. Gordon" <kgordon2006 at frontier.com>
>> To: <Arc5 at mailman.qth.net>
>> Sent: Friday, October 19, 2012 2:35 PM
>> Subject: [ARC5] Added 6F6 audio stage.
>>
>>
>>> Someone here mentioned that he owns an ARC-5 receiver which has an 
>>> added
>>> 6F6 audio
>>> stage on the "back porch", and a 6J5 where the 12A6 is supposed to  be.
>>>
>>> Undoubtedly, that comes from an article entitled "New Life for the 
>>> Q5er"
>>> by Douglas R.
>>> Jordan printed in QST for February 1951 beginning on page 37.
>>>
>>> All the mods detailed in that article could be applied to any of the
>>> models, not just the BC-
>>> 453.
>>>
>>> All I can say is, "Whew!", and "Crap-ola". :-(
>>>
>>> That article might be a help for the owner to "un-hack" or "reverse- 
>>> hack"
>>> his receiver.
>>>
>>> Maybe...
>>>
>>> One thing I found rather interesting about the article is that the 
>>> author
>>> used a hacksaw to
>>> remove the dynamotor mounts, when all that is really required is a 
>>> small
>>> pipe-wrench to
>>> simply unscrew them.
>>>
>>> Gee...whatever happened to the KISS principle?
>>>
>>> Ken W7EKB
>>> ______________________________________________________________
>>> ARC5 mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/arc5
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:ARC5 at mailman.qth.net
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>>
>>>
>>> -----
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 10.0.1427 / Virus Database: 2441/5341 - Release Date:  10/19/12
>>>
>>
>> ______________________________________________________________
>> ARC5 mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/arc5
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:ARC5 at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1427 / Virus Database: 2441/5341 - Release Date: 10/19/12
>