Dear Kevan, 

In this email, I describe the results from 4 different experiments done on the detector modules. 

First experiment: 
I took 3 "perfect" (Board 026, 024, 039), 4 "good" (Board 013, 019, 012, 018), 3
"weak" (Board 031, 028, 034) and 2 "bad" (Board 003, 021) detector modules and
removed their coils, if they had coils on them. These boards were given the
designation of "perfect", "good", "bad" and "weak" with the -48 dBm SCT signal
from the signal generator. I added attenuators to the signal generator and
connected it to the "perfect" and "good" boards to see when they became "weak"
and removed attenuators from the signal generator to the "bad" boards to view
when they could be classified as "weak". 

In the "perfect" boards:

024 went from "perfect" to "good" when adding a 3 dB attenuator, then went from
"good" to "weak" when adding another 3 dB attenuator.

026 went from "perfect" to "good" when adding a 3 dB attenuator, then went from
"good" to "weak" when adding another attenuator at 2 dB.

039 went from "perfect" to "good" when adding a 3 dB attenuator, then went from
"good" to weak" when adding another attenuator at 4 dB.

In the "good" boards"

013 went from "good" to 'weak" when adding a 3 dB attenuator.

019 went from "good" to "weak" when adding a 1 dB attenuator.

018 went from "good" to "weak" when adding a 3 dB attenuator.

There were 3 boards that were "weak" which were all weak at -48 dBm and
rechecked at -48 dBm. In the "bad" boards:

003 was "bad" at -48 dBm, but became "weak" at -43 dBm.

021 was "bad" at -48 dBm, but became "weak" at -46 dBm. 

Second experiment: 

I took board 024, which had been designated as "perfect" and noted that it had
gone from "perfect" to "good" at -51 dBm. R1, R2, R3 were removed and then
replaced with 1 dB attenuators. The board was "bad" at -46 dBm and became "good"
at -45 dBm. I could not observe a point in which the board was designated as
"weak". R1, R2, R3 were replaced with 2 dB attenuators. The boards went from
"perfect" designation to "good" at -53 dBM. The boards went from "good" to
"weak" at -55 dBm. R1, R2, R3 were replaced with 0 dB attenuators. The boards
went from "perfect" to "good" at -38 dBm. The boards went from "good" to "weak"
at -39 dBm. R1, R2, R3 was replaced with 3 dB attenuators (replaced the old 3 dB
the board originally had). The board went from "perfect" to "good" at -52 dBm.
The board went from "good" to "weak" at -55 dBm. 

Third experiment: 

Then I replaced R3 on 2 boards designated as "weak" (031, 034) and on 2 boards
designated as "good" (019, 013). The 3 dB attenuator at R3 was replaced with a 0
dB attenuator. At -48 dBm, the "weak" boards went from "weak" to "bad" and the
"good" boards went from "good" to "weak". Then R3 was replaced with a 1 dB
attenuator. At -48 dBm, the "weak" boards were "bad", board 019 (a "good" board)
stayed "good" and board 013 (a "good" board) was "weak". Then R3 was replaced
with a 2 dB attenuator. At -48 dBm, the "weak" boards remained "weak" and the
"good" boards remained "good". 

Fourth experiment: 

The last experiment regarding the attenuators that was done was to take 4 boards
that were labeled "perfect" and replaced one of the attenuators on each board
with 0 dB. On board 026, R1 was changed from 3 dB to 0 dB. On board 024, R2 was
changed from 3 dB to 0 dB. On board 039, R3 was changed from 3 dB to 0 dB. On
board 022, R4 was changed from 3 dB to 0 dB.

For board 026: The board changed from "perfect" to "good" at -54 dBm. The board
changed from "good" to "weak" at -56 dBm. The board changed from "weak" to "bad"
at -58 dBm.

For board 024: The board changed from "perfect" to "good" at -52 dBm. The board
changed from "good" to "weak" at -54 dBm. The board changed from "weak" to "bad"
at -60 dBm.

For board 039: The board changed from "perfect" to "good" at -47 dBm. The board
changed from "good" to "weak" at -51 dBm. The board changed from "weak" to "bad"
at -58 dBm.

For board 022: The board changed from "perfect" to "good" at -50 dBm. The board
changed from "good" to "weak" at -51 dBm. The board changed from "weak" to "bad"
at -53 dBm. 

Let me know if there are any further tests you would like done with the attenuators on the detector modules. 

Best, Becca