Here are my results pertaining to your Tuesday, March 26, 2019 transmissions. I was able to lock onto several slow scan images utilizing different frequencies ranging between good to very good image quality. The Narration broadcast session proved to have stronger audio and signal qualities too. All times and dates stated below are in UTC. Here are details of what I heard:

Sessions I - VII proved to be unsuccessful in providing any acceptable signals here at all.

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VIII. Pictures and Words
East 4.50 Mhz AM
March 27, 2019 0241:30 - 0245:30z UTC
Vertical antenna provided acceptable (S3) signal for SSTV locks.
SSTV Scottie 1 image captured at 0241:30z, link: https://imgur.com/HrvJhkl
SSTV Scottie 1 image captured at 0243:40z, link: https://imgur.com/8ZwYqr3
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IX. Spy Cameras from the Sky and a Mystery Box in the Woods
West 5.10 Mhz AM
March 27, 2019 0246 - 0252z UTC
Vertical antenna provided acceptable (S3-4) signal for SSTV locks.
SSTV Scottie 1 image captured at 0246z, link: https://imgur.com/qpBPleG
SSTV Scottie 1 image captured at 0248z, link: https://imgur.com/6GTxFqD
SSTV Scottie 1 image captured at 0250z, link: https://imgur.com/CdFpdlH

East 6.90 Mhz AM
March 27, 2019 0252 - 0256z UTC
Vertical antenna detected very strong (S9+10dB's) signals for both the female Narration and slow scan Scottie 1 image.
0252 - 0254z Narration audio recording link: https://drive.google.com/file/d/1u5xGLGAtRyBxhxDVq0OQnuGKNU5k2I47/view?…
SSTV Scottie 1 image captured at 0254z, link: https://imgur.com/4wJvfc8
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X. Not with a Bang but with a WSPR
3.20 Mhz AM
March 27, 2019 0258:12 - 0259:30z UTC
Vertical antenna detected a strong (S5-7) signal for the morse code transmission
0258:12 - 0259:30z audio link: https://drive.google.com/file/d/1S0qB_fcLjH6SGy5ahrIT7And71hzrQ3-/view?…
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Receiving equipment consisted of the following:
Icom 756Pro3 transceiver - digital noise processing was set at 40% reduction for the audio Narration but disabled for all SSTV; the bandwidth filter was set to 6.0 khz and the pre-amplifier was disabled (0 dB gain) during the test transmissions to minimize interference. The antenna system consisted of either (1) a 40-meter Carolina-Windom wire antenna or (2) a 5-band ground mounted vertical. The Carolina-Windom dipole is 60 feet long strung between 3 trees 40 feet high and oriented northeast by southwest. The vertical antenna utilizes 10 buried radials, two per band. The slow scan images were decoded using the SignaLink USB sound card in combination with the MMSSTV Ver. 1.13A interface.