[MrFixr55]

Hi RG, 
It's Deja Vu all over again.  I thought that I posted a reply to you, but I can't find it, so here goes again.  Forgive me if you already saw my post, but I am adding some new info, so it maty be worthwhile to read this post.

The set uses the "01" or "01A" triode for all positions except for the detector which should be a "00" or "00A". The difference is that the following:
00 and 01 tubes had 5V 1A bright tungsten filaments.  00A and 01A have 5V 1/4A dim thoriated tungsten filaments.

RCA tubes were referred to UV201s if the pins were short and the base was the "navy" base, or UX201s if they had the long pins for plug in sockets  However, UX 201s will fit the same sockets used for UV201s.  Cunningham tubes are referred to as C301, C300 C301A or C300A.  However, both RCA and Cunningham tubes were built by RCA- actually, built by GE or Westinghouse and are the same, no matter if they were RCA branded or Cunningham branded.  (RCA held the patents and provided worldwide radiotelephone service, radio equipment sales and service, and managed broadcasting through the NBC Radio Networks.  GE and Westinghouse manufactured the receivers, transmitters and tubes.  RCA themselves did not have manufacturing facilities until they bought GE's Harrison Tube Works and the Victor Talking Machine company.) 

The "Grid Leak" triode detector with or without regeneration was the common detector used in radios from about 1920 to about 1929 when the "Biased" triode detector became popular.  Diode detectors did not become popular until about 1933 and the introduction of the 55, 75, 2B7, 6Q7 dual diode-triode detector / 1st AF amp tube. 

Attached are links to the 1932 and 1940 versions of the RCA Receiving Tube Manuals from World Radio History website.  There are great descriptions of these tubes and the circuits involved:

SplitPDF

RCA-Receiving-Tube-Manual-1940-RC-14-OCR.pdf

Unfortunately, I cannot find any diagram for the FADA 175-A.  The one from the Nostalgia Air collection of Rider's service documents shows an entirely different 8 tube AC-DC set ca late 1930s.

Here is a video of the repair of a 175A
Repair of FADA 175A 1924 RADIO

Here is the Rider schematic of the FADA 140 which I own, and the FADA 170A and 192 series radios.

The 160 and 175A Schematics do not show the detector's grid leak condenser and resistor, but the 192 schematic does.  Schematics here:

FADA 160A 170A 192.pdf Size: 350.5 KB  Downloads: 125

Hope this helps.

The 00 and 00A were "soft" tubes to which a small amount of gas (usually argon, I believe) was added to the tube.  This made it a poor amplifier, but made it a rather sensitive "Grid Leak" detector.  )11s and 01As were referred as "hard" tubes, evacuated to a very high vacuum while the components were inductively heated, then a "getter" was flashed.  The getter is a coating inside the tube meant to react with any O2 left in the tube.

Good 00s or 00As are not too easy to find.  Theoretically, a 01A or a 112A should work as a detector.  However, use 45V as the detector plate voltage if using a 01A or 112A as a detector.  If you have a good 00A, then the plate voltage of 00 or 00A tubes is 22V.