[HBR] HBR Under Construction - info and pix

[Hopperdhh at aol.com]

I enjoyed looking at those pictures, too.  Great job.  I too  wondered about 
the connection of the beam deflection tube.  The one I put  in the BC-348 
years ago (I still have it) is connected as Walt described, and  has the self 
oscillating BFO.
 
You caused me to laugh at memories of  a power supply I used with my  first 
6146 rig.  I was about 19 years old then and in the Air  Force.  Talk about 
unsafe!  The power supply was built in a  wooden orange crate box and had old 
wall switches for the power and  stand-by switch functions.  Actually they were 
ceramic switches --  probably the safest part of the station.  It sat under the 
operating  table.  I had a 100 ohm resistor haywired in line to discharge the 
filter  caps to help keep from blasting the speaker when switching back to  
receive.  One time the resistor blew up and the 600  volt wire went flying 
loose back under there  somewhere!  At first I didn't know what happened, of 
course.  That was  a great rig.  I needed money, so I ran an ad in the Tampa 
Tribune  and a young novice came to look at it with his mother.  I don't remember if 
 I had improved the power supply by then or not.  I remember that the rig  
was only VFO.  So to sell it I asked for a couple of days to build a  crystal 
oscillator circuit into it.  (Novices had to use crystal control  back then.)  
They came back in a few days and bought it for, I think,  $30.  I felt a little 
guilty for asking so much for it.  This was in  1963.  Sure wish I still had 
it.  It had a built in modulator using a  pair of 6L6s, and an ARC-5 VFO that 
was so stable that when I broke in to a  local SSB QSO, one of them came back 
and asked where I got the new SSB  rig.  They didn't realize that I was on AM 
until one of them  tuned off frequency and heard the carrier.
 
I was receiving on a BC-453 with a crystal convertor as in Jan. 1960  CQ.  
That thing was so stable that you could literally slam it up and  down on the 
table without the note changing but a fraction of a cycle.  (We  had cycles back 
then.)  Every novice should have had that kind of stability  in a CW 
receiver.  Ah, but that's another story.... 
 
Sorry for the off topic reply.  Do not archive, etc., etc.
 
Dan K9WEK
 
 
In a message dated 4/17/2006 8:09:04 P.M. Eastern Daylight Time,  
dkelly42 at cox.net writes:


This  weekend I worked on a tube transmitter recently built. I rebuilt
the power  supply and mounted certain circuits and HV lines in a safer
manner. I  raised the plate voltage on the 6146 from 560 to 750VDC. I was
using the  400ct from an 800VCT transformer with a capacitive input
filter. Voltage  regulation was ok but the whole supply was not very
safely built. Also, I  was using dropping resistors to reduce the voltage
from 560vdc to 300vdc  for the plates of the 5763 buffer and 5763 driver.
Again, not very good  technique. Certainly not efficient with lots of
waste in the form of heat.