[Milsurplus] Bathtubs redux

[wf2u at ws19ops.com]

Hello all and happy 2009,

About 2 weeks ago I asked for opinions regarding bathtub capacitor recapping.

Just relating my experience with recapping the bathtubs in the E.H.  
Scott RCH receiver I was working on.

The bathtubs didn't contain oil, just plain beeswax. Used a 100 W  
soldering iron to unsolder the lid, which popped off in seconds.  
Poured the melting besswax out, kept the wax impregnated paper spacers  
between the caps. Unsoldered the caps from the tabs (there are small  
through holes where the leads come out and soldered to the bottoms of  
the tabs). Opened the holes with solder sucker, put in the new 630V  
mylar film caps, soldered everything back together, sealed the lid  
again and the whole bathtub looks intact.
Reconnected the leads which connect the tubs to their appropriate tie points.
Each tub took approximately 15 minutes to do.
The receiver is now very much alive, and working  normally. I tweaked  
it according to the manual, but it wasn't very far off the optimum.
It's a hot receiver, very stable, good BFO injection (although I'm not  
using it for SSB, but sideband reception is excellent even with RF  
gain control alsmost to the max. Stability is above expectations.  
Audio quality is superb.
Since it has no filters or adjustable bandwidth in the IF chain - the  
receiver is a bit broad this way but usable - for crowded band  
conditions I'll use an external audio filter on CW. The receiver is  
going to be used with my Mackay Marine 167BY transmitter in the FT-102  
Liberty/Victory Ship radio console. According to the FT-102 manual and  
some radio room photos, the receivers used in these consoles are  
either the RMCA AR-8506B (mine needs recapping but works OK so far) or  
the E.H Scott SLR-F which is the same as the Navy RCH. So far looks  
like the Scott is the better performer.

Again, thanks for all the input on "retubbing"...

73, Meir WF2U
Landrum, SC



What's nice is that in the Scott RCH all the tubs are very accessible
and the screw heads are on the outside surface of the chassis.
Drilling small holes prior to heating up the caps of course makes
sense for draining the oil.
This will be a good rehearsal for doing the restoration of the
bathtubs in my ex-RCAF AR88LF which is another project waiting its
turn...

73, Meir WF2U
Landrum, SC