In the PSU area, the RA117 differs from the RA17 and 17L in that the ubiquitous GZ34
rectifier has been replaced with a semiconductor bridge, the mains cord is hard-
The two EF91 audio pentodes have been replaced with a 12AT7 double-
It should also be noted that the RA117 (followed by the 117A and 117E) was NOT a replacement to the RA17L. It came about in response to a specific requirement and was manufactured alongside the RA17L.
As can be seen, some of the PSU/Audio components had been previously replaced. However the only one which I retained was the 0.47uF capacitor across the negative bias line. In the RA117, the 165R resistor is replaced with a 120R one.
PSU/Audio compartment before and after
September 2012 … I finally have an RA117 !
This had sat in my radio room awaiting refurbishment for several months … other more
pressing projects having precedence. When I picked it up I was forewarned that it
was faulty. Fortunately it was complete, so getting it working was as far as I was
concerned, just a matter of carrying out a full refurbishment. The main tuning bezel
is attached by way of three screws and there is a small scuff in the bottom left
corner of the front panel where the primer coat is visible. Behind the front panel,
the chassis bore the usual signs of ageing and the warning label shielding the RX-
Curious as to exactly what the fault was, I ‘fired’ it up as soon as I got it home.
Just to be safe, I ran the volts up slowly via a variac. I didn’t want any ‘loud’
surprises! It actually worked! Granted, it was very deaf though. But it was indeed
a good start. When it came time to start the ‘refurb’ proper, I removed all the under-