[ARC5] [Milsurplus] Low B+: The Genius of A.R.C.

[Kludge]

-----Original Message-----
From: milsurplus-bounces at mailman.qth.net
[mailto:milsurplus-bounces at mailman.qth.net] On Behalf Of B Smith
> Some of us are missing the point about lower voltage operation.  You 
> can look at  tube characteristics curves all day long and reach the 
> same conclusion.

In any situation where theory (in this case, tube manuals) collides with the
real world, the real world invariably wins.  In this case, these receivers
are operating despite what the curves say, perhaps not to spec but well
enough to be useful.  But then, look at the TRF & regen receivers that are
being built that use three 9v batteries in series for B+ and were built with
equally low B+ from other battery combinations.  These tubes are also
operating at the skinny end of the performance curves yet there's no
argument they don't (and didn't) work and do so quite well.  This includes
the tetrodes & pentodes where screen voltage was used to control
regeneration.

If I follow Dave in running a full command Rx & Tx, I'll use the voltage
divider he suggested a year or two go in place of the modulator, wedge the
select and antenna relays closed and key the B+ as was originally done.
Power will come from a couple motorcycle batteries left over from another
project and a couple 45v B batteries I'm assembling for TRF & regen
receivers using stacked 9v batteries.  Yeah, I know, that's recklessly high
for B+ but what can I say.  I'm a wild and crazy sort of guy.  :-)

> It amazes  me  that you can take a 70 year old receiver, power it up 
> using lower voltages and it works immediately.

And, in a few cases, completely unaltered at full power.  

Best regards,
 
Michael, WH7HG ex-K3MXO, ex-KN3MXO, WPE3ARS, BL01xh ex-Mensa A&P PP BGI 
I am me.  I’m the only one who’s qualified.
http://www.nationalmssociety.org/chapters/NTH/index.aspx
http://wh7hg.blogspot.com/
http://kludges-other-blog.blogspot.com
Hiki Nô!