I did not find the 1136A at Channel Master's website, so I cannot compare it with the Winegard 7698. I think it helps that the VHF section of the 7698 is designed precisely and exclusively for channels 7-13 - the design not being compromised to include also channels 2-6.
I have observed a similar phenomenon with WBTW (their tower being 111.5 miles northeast of me). Before the June 12, 2009 transition, I could view their 1 million-watt non-directional DT signal on channel 56 (725 MHz) no more than maybe twice per month, on average. It was transmitted from a very short distance below their channel 13 spot - VHF-13 transmitting from the top of the 2,000-ft tower. Since June 12, 2009, I can watch their 11pm news via their non-directional 31,600-watt channel 13 signal (213 MHz) most nights (thick clouds or strong winds preclude it). It seems clear to me that my far greater incidence of reception of the channel 13 signal is due to its wavelength being 3.4 times longer than that of the channel 56 signal - overcoming the fact that the channel 56 signal was 31.65 times stronger!
The same observation can be made at radio-locator.com, comparing the coverage of non-directional WLW-AM of Cincinnati (700 kHz) with the daytime coverage of non-directional WCKY (1530 KHz). They are both 50kw, but WLW's coverage area is quite larger, its wavelength being 2.2 times longer. And, before the 7698 I had a Winegard 7084. There, the VHF section is designed for channels 2-13. More often than I ever received WBTW-DT on channel 56 I would receive WCES-DT channel 6 (85 MHz). Their tower is west of Augusta, Georgia, 129 miles from me, approximately 1,350 ft tall, and their non-directional signal is 7,900 watts. Obviously, wavelength made that reception possible, WCES's being 2.5 times longer than that of WBTW-13, and 8.5 times longer than that of WBTW-56.
All of that said, it remains a fact that some report that they got long-distance reception consistently on WIS-DT 41 but are not getting it for WIS-DT 10. Go figure!