[ARC5] BC-946

[D C _Mac_ Macdonald]

BFD - all of ~1.09 dB more output! 
 
* * * * * * * * * * * 
* 73 - Mac, K2GKK/5 * 
* (Since 30 Nov 53) * 
* k2gkk hotmail com * 
* Oklahoma City, OK * 
* USAF & FAA (Ret.) * 
* * * * * * * * * * * 
 

 
> Date: Tue, 29 Apr 2014 13:21:04 -0700
> From: ianmwilson73 at gmail.com
> To: vk2bcu at operamail.com
> CC: arc5 at mailman.qth.net
> Subject: Re: [ARC5] BC-946
> 
> Possibly not the reason for the substitution, but the 6V6 has higher
> plate dissipation and can provide more audio power (4.5W with a
> plate load of 5k) compared to the 12A6 (3.5W / 7.5k) with 250V
> supplies.
> 
> (When I was looking for alternative tubes to use in a Paraset
> lookalike, I hoped the 12A6 was the answer - but you can squeeze
> quite a bit more RF power out of a crystal-controlled self-oscillating
> 6V6 than a 12A6).
> 
> 73, ian K3IMW
> 
> 
> 
> On Tue, Apr 29, 2014 at 11:00 AM, Leslie Smith <vk2bcu at operamail.com> wrote:
> 
> >   Hi Mike,
> >   You answer prompted me to check the three surplus conversion manuals.
> >   I found the article you mentioned in volume #1 - but the mods
> >   suggested there are not in the set I have.
> >
> >   Basically the BFO is removed and that stage re-wired to be used as an
> >   AF pre-amp.
> >   In my view, that's un-necessary.  By reducing the cathode resistor
> >   (from the 1.5k as wired) the 12A6 will supply good volume.
> >
> >   On the point of details in the article, a 6V6 (or similar) is used in
> >   place of the 12A6.
> >   Question:  What real advantage would the 6V6 give?  The 12A6 seems
> >   virtually the same.
> >   Both are beam tetrodes; the 12A6 is a neat 'toob" - and it's metal!
> >
> >   It may be that my questions are pointless.
> >   A fool can ask more questions in 5 minutes than a wise man can answer
> >   in a day.
> >
> >   73 de Les Smith
> >   vk2bcu at operamail.com