[ARC5] R1155: Getting to Work

[David Stinson]

First:  Thank you everyone for your kind help and 
information on the R1155 resurrection.
I continue to be grateful for our community. Awesome.

This radio is in good, original condition with no hacks.  
The wires- often "rotten" in these radios- are in excellent
 shape.  It is a better representative of its type than 
one which has been heavily reworked.
Coil Box cover off:
https://goo.gl/photos/eW8i989mbkpQ1Sqc7

Goals for this repair:
To enjoy the challenge and "puzzle" of reviving the radio
in a minimally-destructive way, thus preserving its history.
To repair it in such a manner that the radio has a good
chance to be preserved by a responsible owner 
after I am gone.
To acheve these goals, the radio must play.  It need not
play with 100% of its original specifications, but it must
be capable of basic performance over extended listening
periods.  After a long look at it, I think this radio a 
strong candidate for the "Lowered B+" solution.
Experience has show that capacitors that leak terribly
at 250VDC may function acceptably at 45 or 90 VDC.
Grid resistors that have wandered from 1 Meg to 
3 Megs may still provide acceptable function at
a lower overall voltage.

After a first cleaning (deep cleaning later), leached 
DeOxit into the toggle switches and pots.  Lubricated
the mechanical shafts and bearings and DeOxit-ed the
Fuction and Band switch wafers.  Gave all the tubes
a little "wiggle" in their sockets.  Lit-up the Filament buss
and confirmed all tubes lit.  (Was the Lancaster a 
6-Volt aircraft?).  Let it "cook" with no B+
for an hour and noted no current spikes or other 
problems.

An important test with any receiver like this- apply
a low voltage to the B+ buss without filament voltage
and slowly increase while monitoring the current draw, 
looking for shorts or large leakages.  Noted currents 
at 60, 80 and 100 Volts.  Little current draw with 
no filament voltage, so no shorts.  Lit the filaments,
put a Heathkit signal tracer on the PHONES connection,
said a little prayer and applied 45 Volts to the B buss.
The radio was on Band 3 (3-7.5 MC) and there was the
familiar "BFO-On" noise floor, but no signals.  Found that 
there is a disconnect between the ANT connection and 
the RF Amp.  Connected the antenna directly to C59
(grid input coil for Band 3)  and the radio took a breath
and played.  However, Bands 1 and 2 had no LO operation
at 45 Volts, so popped it up to 80 Volts.  The radio came 
alive then.   Had to crank down the signal tracer.
https://goo.gl/photos/h8Fy7EFo56YjHMZ39

B-buss current at 80V was about 15 mills.
After playing it at 80 V. for about 20 minutes,
slowly brought the set up to 200 V for a short test,
while watching the current.  
At 200V, it pulls about 30 mills.  Did not leave 
it there long.  Risky taking it there in the first place,
but I just had to see that eye tube glow.
https://goo.gl/photos/xMS937JEgfpEUFmM8

There's still plenty to do.  Need to find that antenna
connection issue.  Work over the grounds.  
Test all the tubes.  Refurb the Type 35 dial drive.
Determine the "right" B+ buss level for long-term 
operation and preservation.  Complete alignment.
And a deep cleaning.  
Then to find the loop and meter (wishful thinking).

We're on our way.
GL OM ES 73 DE Dave AB5S