[ARC5] BC-AN-229 Follies, part 5 - the 229 receives again!

[Ben Hall]

Afternoon all,

After building an interface box with the AUTO/MAN switch and dual RF/AF 
gain pot...and checking my repair work three times...I steeled myself 
and applied power to the BC-AN-229.

First 12 VDC to the filaments.  All tubes glowing, just under 1 amp 
current draw.  So I switched on the regulated B+ power supply and at 
about 100 VDC input...I heard noise from the amplified speaker I'm using 
to test it.  B+ draw was about 20 mA.

So I hooked it up to the URM-25D.  It hears the URM-25D just fine and 
seems to have reasonable sensitivity.  :)

So I hooked it up to the PA0RDT mini-whip and switched it onto the LF 
range.  (this is dual coil set)  Holy crap I about blasted myself out of 
the room.  I was sitting right on top of NDB "HUA" when I switched it 
onto LF.  Tuning around LF, I heard the usual WAAS stations (the normal 
three or four I can hear) plus about a half dozen NDB's.

In one of my last mails...I shared details of a Navy RU coil set that at 
one time was modified for, best I could tell, BC-xx-229 use.  The low 
range covers AM BC, so I popped it in.  It works!  Spent a few minutes 
listening to the Army/Navy game.

Interestingly...this was still at 100 VDC input.  The dynamotor 
originally supplied 375 VDC to the system, which is dropped via two 
resistors in the -229 junction box.  My junction box has those two 
resistors, so at 100 VDC input, I'm really not supplying anywhere near 
dynamotor-level voltages.  I know Dave has done some work in the past 
using receivers at reduced B+...the -229 seems to be a good candidate 
for reduced B+ use.

So...I'm a pretty happy camper.  Later this evening I'll see if I can 
hear anything on HF.  The two coil sets I've got, including the 
converter RU-coil above, cover 2500 to 4700 kHz which is pretty dead 
right now.

thanks much and 73,
ben, kd5byb