Midnight,
Why not have a look at the FAA AIM, it's all on the web, and convince yourself that what I am about to say is correct.
Except for the 30nm transponder veil centred on the airports justifying Class B airspace, there is no transponder requirement for ANY VFR in E, below 10,000 ft.
There are some variations to this for active TSRA ---- but this is Homeland Security stuff, not generally permanent, and not FAA, whose general "rule" is above.
The ADS-B NPRM makes more or less the same provisions.
Tootle pip!!