Andrew VK3BFA wrote:
Needs a little cleaning up. Note the careful placement of the grid coil
at right angles to the final and with the Masonite panel between for
good shielding.
ERK! - looks like a 6146 PA, rather than an 807. And, congrats at the
attempt
I thought the "Masonite shielding" would suffice for a smiley.
That was my first attempt at a wooden chassis and it became obvious why
metal is better and I abandoned it a few weeks ago.
It started out xtal controlled but then I got the bug to add a VFO which
is the crap on the left. The 807 turned into an 866 so I substituted
the 6146 till I got another 807. The missing meter was a hamfest
special that bounced so much it was useless and then crapped out completely.
It is now all neatly mounted on a home made aluminum chassis and
unfortunately looks a lot better than it works.
I will take a for real pic tomorrow. That one was just too good not to
share.
And whats with the 3 big wire wound resistors? - screen supply to the
PA - what a potential source of stray coupling. A 1 watt resistor is
usually sufficient, you wont need the string of 10 watt ones....
One of the plans I was working for called for 25W. Seems like a
misprint because it does not even get warm. The 10K in the VR150 leg
gets hotter than hell and probably should be 25W. I burned my finger
just checking it.
And the anode tuning is about 100 yards from the tube! - can you get
it any closer?
If you look closely, you can see the 807 socket between the 6146 and the
cap. The 6146 is where the other 6ag7 is supposed to be.
And keep going - its worth the effort -
It's been a challenge. I made a simpler version of this as a kid and am
sort of re-living my childhood. It's like a Mr Wizzard Science project
for me.
I am now plagued with real test equipment and can't play "ignorance is
bliss".
js
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