[MrFixr55]

Hi 462 Ron.

Other than the detector, TRF sets are actually easier to figure out than Superhets.

The 4 big issues with TRF sets of this vintage (assuming you have it powered right):

First issue, Yes, very few TRFs had calibrated scales. I have a 1027 Federal 10 "Orthosonic" (Wonder if Victor smelled trademark infringement here) The scale was calibrated but was calibrated in meters. Back in the day, people kept logs as to station callsigns, frequencies and what number on the scale that the station appeared on. the "1 dial" sets started to appear in earnest in 1925 - 1926. This is why you have 3 separate caps ganged by pulleys and belts. A-K did not have time to arrange for a 3 section single frame capacitor; neither did anyone else except possibly RCA and Philco (?).

Second is selectivity. The A-K 35 was introduced somewhere between1926 and 1927, By then, there were at least 3 clear channel stations in NYC, WEAF (Later WNBC, now WFAN) at 660KHZ, WOR (710KHZ) and WJZ (WABC) at 770KHZ The TRF set of this type with 3 tuned circuits had reasonable selectivity but not as good as a superhet. There should be a reasonable amount of RF Gain from this system . Note that the 1st RF stage in this set is not tuned. The RCA Radiola 16 (battery) and 17 (AC) were very similar to this set. However, the A-K 35 has separate bias connections for the 1st AF vs the AF Output, and has separate B+
BTW, make sure that the 1K Ohm wire-wound "grid resistors" on the 2nd RF and 3rd RF (first and second tuned circuits) are intact. They almost always are open. If open, bridge with a 1K resistor, but leave the windings there. These resistors were there to help prevent oscillations in these stages (These sets were not neutralized (Neutrodyne) sets.



Third, the detector (the reason for the experiments) is certainly not HiFi. in addition, a 200 is much more distorted than a 201A tube, but more sensitive. You can use either.

Finally, the available tubes did not have earth shattering power in the Audio Output stage. A 01A at 90V and -4.5V Bias but out less than 20 mW. a 112 in the same condition put out 30 mW A 71A could put out 700mW but at 180 Deg and -40V grid bias (C-)

f you are using an ARBE III, their table assumes 01A tubes in all sockets, and does not follow Atwater Kent instructions.

Make sure that you are set up per the following chart:
For 01A and 112A, for 90VB+, Bias (C-)should be -4.5V. For 135V B+, bias should be -9V.

For the 71A (UX171 or 171A), there must be much greater bias. Per the RCA Receiving Tube Manual RC10 (Ca 1930), for the '71A, for 90V B+, bias is -16.5V. For 135V B+, bias is -27V. For 180V B+, bias is -40V.

Connections to power cable are as follows:
Red- A+, B-
Black- A-, C+
Yellow- B+ for detector, usually 22.5V but also try 45V
White- B+ for all tubes except Output, should be 67V
Green / Yellow- C- for output stage, set per above table.
Brown- B+ for Output stage. Use above table.

If using a horn or magnetic speaker, polarity of the speaker wiring is important. I lik to use an 8" dynamic speaker with an output transformer primary impedance of about 2500Ohm. One from an AA5 works fine.

Make sure that you have a long, high antenna and no CFLs, LEDs computers, etc.

Attached below are links for instructions from the Atwater Kent website:

https://www.atwaterkentradio.com/ak_booklets.htm

Download both booklets, they should be useful and are interesting.

Hope this makes sense (I am hopped up on cold remedies!)

Best Regards,

John, MrFixdr55