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Removing the reflector from the cs4 will likely reduce its gain to around 6dbd(8.15dbi)
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No, the maximum theoretical difference is 3 dB. In actual practice, it might be a bit more or a bit less.
Note that the term dBi is only used when comparing the gain of any antenna to an idealized isotropic antenna. When comparing the difference in gain between two or more specific antennas or before and after antenna comparisons, the term dB is used since it's a simple ratio.
When comparing the "specs" from various antenna companies, it is important to note or be aware of the difference in how the specifications, either in dBi (generally as a result of computational modelling) or dBd (which is the generally used term when the values are from antenna range comparisons where a simple calibrated dipole serves as the reference), are used. Either term is correct as long as it's quantified. Conversion from dBd to dBi involve adding or subtracting 2.15 if going the opposite direction. Of course, there are a few antenna makers out there that simply state the dimensionless term dB" for antenna gain so you have know way of knowing which term should apply. If you want to see some real mathematical and marketing gymnastics, you ought to see the hard-to-find data sheet for the Winegard FV-HD30, the last of their "new" models for which they published a data sheet!
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and you would be inviting the co- channel interference.
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Absolutely a concern. ATSC requires about a 35 dB difference in co-channel signal strength in order to resolve the stronger signal. If both channels are strong enough that the required differential is not achieved, then reception for both will fail. The CBS stations out of New York city and Hartford both operate on UHF channel 33 and are calculated to be of nearly identical signal power. If you go "reflector-less" and the actual signals correspond to the TVF simulation, you will get neither station's primary broadcast. Note that WCBS does operate a UHF translator halfway up Long Island, so there is a second chance for that station.
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Will the DB4e pick up signal off the back?
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The technical data sheet for that model is on our website, look under the "Documents" tab on the DB4e's product page for our computed results. Reception off the back is reduced intentionally to provide addition directivity towards the front.
The following graphs were done by our design engineer as part of project to see of the horizontal spacing could be reduced so that it's overall physical size could be made smaller and thus be attractive to more retail sales partners.
The black trace is the one that is the current spacing in both plots. For the purpose of this illustration, ignore the other traces.
With Reflectors
No Reflectors
